ALOE-PAPAYA-NEEM MONOGRAPH PART-II

PAPAYA
Introduction:
Papaya or Papaw (Carica Papaya) is a tropical fruit-bearing tree widely spread throughout the world in countries like India, Pakistan, Ceylon, Hawaii, South and Central America. Papaya is a tropical plant that grows in warm to dry- moist zones and in some forest areas too.
Top Ten Countries
(% of world production)
1. Brazil (25%) 6. Ethiopia (4%)
2.Nigeria(13%)
7. Congo (4%)
3. India (12%) 8. Peru (3%)
4. Mexico (12%) 9. China (3%)
5.Indonesia(9%)
10. Colombia (2%)

It requires an annual precipitation anywhere between 64 to 429 cm, and annual temperatures to be in the range of 16 to 27 C. The soil has to possess a pH in between 4.2 and 8.0. Papaya do not tolerate any frost and should be maintained at all times above 18 C, necessarily if fruit is aimed from the plant. It does not grow under shade, waterlogging or strong winds and if damage occurred to the plant; it recuperates slowly from serious leaf/branch injury to normal reachable height. Rich soil condition with pH 6-7 is preferred. Papaya grows best in warm zones below 500ft. elevation on slopy soils that are not affected by waterlogging. Evenly distributed rainfall at the location in the range of 102-152 cm would ensure a good crop.

Description: Commonly referred to as a "tree", the plant is light, tall, unbranched, growing at the rate of 6 to 10 ft (1.8-3 m) the first year and reaching 20 or even 30 ft (6-9 m) height later, with a hollow green or deep-purple stem becoming 12 to 16 in (30-40 cm) or more, thick at the base and roughened by leaf scars. The leaves emerge directly from the upper part of the stem in a spiral on nearly horizontal petioles 1 to 3 1/2 ft (30-105 cm) long, hollow, succulent, green or more or less dark purple. The blade deeply divided into 5 to 9 main segments, each irregularly subdivided, varies from 1 to 2 ft (30-60 cm) in width and has prominent yellowish ribs and veins. The life of a leaf is 4 to 6 months. Both the stem and leaves contain copious white milky latex.

The 5-petalled flowers are fleshy, waxy and slightly fragrant. Some plants bear only short-stalked pistillate (female) flowers, waxy and ivory-white, or hermaprodite (perfect) flowers (having female and male organs), ivory-white with bright-yellow anthers and borne on short stalks. Other plants may bear only staminate (male) flowers, clustered on panicles to 5 or 6 ft (1.5-1.8 m) long. There may even be monoecious plants having both male and female flowers. Some plants at certain seasons produce short-stalked male flowers, at other times perfect flowers. This change of sex may occur temporarily during high temperatures in midsummer. Some "all-male" plants occasionally bear, at the tip of the spray, small flowers with perfect pistils and these produce abnormally slender fruits. Male or hermaphrodite plants may change completely to female plants after being beheaded.
Pollination
If a papaya plant is inadequately pollinated, it will bear a light crop of fruits lacking uniformity in size and shape. Therefore, hand-pollination is advisable in commercial plantations that are not entirely bisexual.
Bags are tied over bisexual blossoms for several days to assure that they are self-pollinated. The progeny of self-pollinated bisexual flowers are 67% bisexual, the rest being female.
To cross-pollinate, one or 2 stamens from a bisexual flower are placed on the pistil of a female flower about to open and a bag is tied over the flower for a few days. Most of such cross-pollinated blooms may set fruit. Resulting seeds will produce 1/2 female and 1/2 bisexual plants.
By another method, all but the apical female flower bud are removed from a stalk and the apical bud is bagged 1-2 days before opening. At full opening, the stigma is dusted with pollen from a selected male bloom and the bag quickly resealed and it remains so for 7 days.
Plants from female flowers crossed with male flowers are 50-50 male and female. Bisexual flowers pollinated by males give rise to 1/3 female, 1/3 bisexual and 1/3 male plants.
Generally, the fruit is melon-like, oval to nearly round, somewhat pyriform, or elongated club-shaped, 6 to 20 in (15-50 cm) long and 4 to 8 in (10-20 cm) thick, weighing up to 20 lbs (9 kg). Semi-wild (naturalized) plants bear miniature fruits 1 to 6 in (2.5-15 cm) long. The skin is waxy and thin but fairly tough. When the fruit is green and hard it is rich in white latex. As it ripens, it becomes lighter in color or deep-yellow externally and the thick wall of succulent flesh becomes aromatic, yellow, orange or various shades of salmon or red. It is then juicy, sweetish and somewhat like a cantaloupe in flavor and in some types quite musky. Attached lightly to the inner wall by soft, white, fibrous tissue, are usually numerous small, black, ovoid, corrugated, peppery seeds about 3/16 in (5 mm) long, each coated with a transparent, gelatinous aril.
Fruits from bisexual plants are usually cylindrical or pyriform with small seed cavity and thick wall of firm flesh which stands handling and shipping well. In contrast, fruits from female flowers are nearly round or oval and thin-walled. In some areas, bisexual types are in greatest demand. In South Africa, round or oval Papayas are preferred.
(Morton, J, 1987, Fruits of warm climates--- from: National Tropical Botanical Garden.)

Fruit Varieties:
If the papaya grower is looking for any profitable variety for fruit-yield, it is only the ‘solo’ type that yields plenty of fruit; these species were first introduced into Hawaii from Barbados in 1911 as the best variety of ripe sweet fruit for servings in meals. ‘Solo’ type produces only female flowers that finally render round shallow furrowed fruits as well as pear-shaped bisexual fruits in equal quantities. When the fruits are fully ripe, the thin skin is orange in colour and the flesh is soft, sweet and each one weighs between 0.5 to 1.0 kg. The peel of fruit is rather thin and the latex that comes out from the raw as well as ripe fruit and the tree is minimal.

Important plant varieties under cultivation in India
Pusa varieties Coimbatore varieties Bengalore varieties; Pantnagar varieties Other varieties
Pusa delicious Co2 Coorg honey Pant 1 Ranchi
Pusa majesty Co3 Pink flesh Washington,
Pusa giant Co4 Honey dew
Pusa dwarf Co5 Taiwan varieties like golden queen, No 815 and others.
Pusa nanha Co6
(Source: Crop Information by indiaagronet).
Cultivars:
Active breeding programs in a number of countries have produced cultivars that match local preferences for fruit size, shape, flesh color, flavor, and other characteristics. 'Hortus Gold' and 'Honey Gold' are gold-yellow skinned; yellow fleshed cultivars popular in South Africa; they are twice the size of 'Solo' types known in Hawaii, but smaller than most papaya grown in tropical America. Cultivars grown in Central America are larger, often cylindrical in shape, denoted as 'Cartagena', 'Cedro', and 'Santa Cruz Giant'. Larger fruits are also preferred in India (e.g., 'Coorg Honey Dew'). In Australia, 'Improved Petersen', 'Guinea Gold', and 'Sunnybank' are major cultivars of intermediate size and yellow flesh color.
Indian names of the tree: Papaya is known by the following vernacular names in India.
Boppayi pandu in Telugu.
Pappali in Tamil; Pharangi in Kannada; Popai in Marati; Omakai in Malayalam;
Pepe in Bengali
Paw-Paw in USA; Papayer and also ‘figuier des Iles’ (French); Papayo or papayero or melon zapote or lechosa (Spanish); Mamao (in Brazil).
The tree(in India):The parts of the tree that find varied application in India are: the leaves, the trunk, the fruit both ripe and raw. A large number of food preparations are made out of the flesh of the fruit. The trunk and leaves in addition to raw fruit yield a copious quantity of a proteolytic enzyme, namely papain, that is used to tenderise meats. The tree is valued for all these produce.
The fruit is cultivated in over 17,000 hectares throughout Indian States. The trees grow on most types of soil in tropical regions and require minimum irrigation. Its maximum height is around 25 feet with a trunk diameter about 10 inches and maintains copious latex. The tree has a central hollow herbaceous stem that rises tall and possess no branches. The long hollow petioles attaching the central stem bear palm-like leaves at the stem apex near the top of the tree. When flowers start coming they attach to the leaf at the axils. As the tree grows the older leaves change their colour and fall down. The papaya flowers usually smell aromatic.. The female flowers solitary or cymose in axils with 4-5 free yellow petals(1-2inches long), 5 stigmas on ovary bear the fruits; these are oblong to globose/pyriform shaped, 12-15 inches long, and the flesh of thickness 1-2 inches, slightly orange coloured, sweet smelling and containing innumerable round black/brown seeds (of ¼” diameter about 8000 in number/kg of fruit flesh). The seeds are naturally covered with a gelatinous membrane and are useful for future farming.
The leaves: The trunk of papaya tree is the place where deeply lobed leaves and fruits find their place directly without the intervention of branches. The leaves also contain latex material that is the real source for the proteolytic enzyme, papain. Crushed leaves wrapped around tough meat will tenderize it overnight. The leaf also functions as a vermifuge and as a primitive soap substitute in laundry. Dried leaves are smoked to relieve asthma or as a tobacco substitute. Packages of dried, pulverized leaves are sold by "health food" stores for making tea, despite the fact that the leaf decoction was used as a purgative for horses in Ghana and in the Ivory Coast; it is a treatment for genito-urinary ailments. The dried leaf infusion is taken for stomach troubles in Ghana and it is said to be a purgative; it may even cause abortion. Papaya leaves contain the bitter alkaloids, namely, carpaine and pseudocarpaine, which act on the heart and respiration like digitalis, but are destroyed by heat. In addition, two major D1-piperideine alkaloids, dehydrocarpaine I and II, that are more potent than carpaine, were discovered by the University of Hawaii in 1979.
.The leaves are used in dressing the wounds too.
The fruit: Large, oval to round berries; sometimes called pepo-like berries, as they resemble melons by having a central seed cavity. Fruits are borne axillary on the main stem, usually singly but sometimes in small clusters. Fruits weigh from 0.5 up to 20 lbs, and are green until ripe, turning yellow or red-orange. Fruits from female flowers are more round in shape and thin-skinned, whereas fruits arising from bisexual flowers are the typical pyriform/oval shape with thicker skin. Flesh is yellow-orange to salmon at maturity, the edible portion surrounding the large, central seed cavity in the center. Hundreds of small black seeds (3/16 inch) "looking like capers crossed with beluga caviar" ( James A. Duke) are lightly attached to the flesh in the central cavity, each surrounded by a transparent, gelatinous aril (like a cantaloupe). Fruit production occurs year-round since flowering is continuous; individual fruits mature in 5-9 months, depending on cultivar and temperature. Plants begin bearing in 6-12 months.

Papaya fruit is a wholesome delicious fruit that is available in all seasons of the year. It is abundantly grown, cheap priced and nutritive. The rich people consume the fruit as a breakfast serving and the common man consumes it as post-lunch/dinner dish. The fruit is rich in beta-carotene and provides low calories; therefore its consumption is benificial to obess persons (WH Foods, AH.Enmngr et.al, Fotin &Frcoi,Rebecca).
.



Dietary value, per 100 gram/ edible portion of ripe fruit.
Water (%) 88

Calories
43

Protein (%) 0.6

Fat (%)
0.1

Carbohydrates (%) 10

Crude Fiber (%) 0.1


% of US RDA*
Vitamin A 48

Thiamin, B1 3.6

Riboflavin, B2
8.1

Niacin 2.2

Vitamin C 80

Calcium 2.4

Phosphorus
1.6

Iron 3.0

Sodium
---

Potassium ---
* Percent of recommended daily allowance set by FDA, (assuming a 154 lb male adult), is 2700 calories per day.
Volatiles from Fruit
106 volatile compounds were identified in 1977 using GC/MS techniques. The compound thought to have the odour that most closely resembled that of papayas was linalool - 68%. Benzyl isothiocyanate - 13% contributes a pungent off-odour and is present as a major component.
Chemistry of constituents:
Sugars:
After a lot of controversy on the method of estimation of sucrose etc. in presence of an invertase enzyme that interferes in the experiment it has been established that sucrose (48.3%,), glucose (29.8%) and fructose (21.9%) stands correct.. The total carbohydrate content has been found to be around 10 g per 100 g of edible portion.
Acids:
The acid content of papayas is very low and the pH is generally between 5.5 - 5.9 and comes from almost equal amounts of citric and malic acid.
Pigments:
The difference between yellow and red-fleshed papayas was first described in 1964 and the total carotenoid content was reported to be 3.7 mg/100 g and 4.2mg/100g respectively.

Percent composition of carotenoid pigments
pigment yellow red
beta-carotene 4.8 4.8
zeta-carotene 24.8 5.9
cryptoxanthin
and monoepoxide 15.6 4.4
cryptoxanthin 38.9 19.2
lycopene 0.0 63.5
unresolved 15.9 2.2


Papaya fruit exhibits diverse morphology. a large, rounded type from the Yucatan; a cylindrical type from Costa Rica; a small ‘Caribbean Sunrise' fruit, one of several cultivars related to ‘Solo', typical of Hawaii.
The first major cultivar of international importance was the small, pear-shaped 'Solo', which was introduced to Hawaii from Barbados in 1911. The name derives from the relatively small size of the fruit - at 0.5-1.5 lbs, it can be eaten by one person, as opposed to the watermelon-sized types grown in Central America and elsewhere. It has been used as a parent in breeding newer cultivars such as 'Kapoho solo', 'Waimanalo', 'Higgins', and 'Wilder' varieties. The transgenic cultivars 'Sunup' (red flesh) and 'Rainbow' (yellow flesh) have resistance to papaya ringspot virus, and were derived from 'Solo' parent lines. 'Solo' types are the most abundant cultivars imported to the USA.
Important varieties under cultivation in India/cultivation practices
Pusa varieties:
Pusa delicious
Pusa majesty.
Pusa jiant
Pusa dwarf
Pusa nanha
Coimbatore varieties:
Co2
Co3
Co5
Co4
Co5
Co6
C. Bengalore varieties:
Coorg honey
Pink flesh
D. Pantnagar varieties:
Pant 1
Other varieties: Ranchi, Washington, Honey dew, Taiwan varieties like, golden queen, No 815 and others.

Propagation: Commercially the papaya is propagated by seeds. The tissue culture technique is limited to research laboratories only. The seeds loose viability in a short period and therefore the seeds should not be stored for more than a season. The seedlings in polybags are prepared. Due care is taken to avoid dumping off of the newly germinated and young seedlings. The seedlings become ready for transplanting within 6-8 weeks.
Planting and season: Planting is done during the flowering seasons:
Spring season ( February – March)
Monsoon season (June-July)
Autumn season (October-November)
Heavy rains, hot air, frost, etc are considered while selecting the season for planting in a particular area. The pits of 30x30 x 30” are prepared in already selected and the prepared field at the distance of 2.5 to 3 meters distance. The pits are filled with well- decomposed NPK mixtures. Care is taken not to disturb the roots while transplanting the seedlings.
Intercultivation: Interculturing is mainly done to remove the weeds during the early period of growth, weeding and hoeing in between rows also favour better aeration to root zone. Sometimes pre-emerging weed killers like Basalin are used. Secondly, roughing is done to remove extra plants, weak plants and affected plants. After ensuring one plant per pit, earthing up is done 30 cm in radius around the plants.
Special horticultural practices: Planting of 3 to 4 seedling in one pit and then removing extra plants and keeping one plant per pit while doing so 10 per cent male plants are kept in female plant population to have pollination and to improve the fruit set.
Irrigation: For better growth, production and quality, the optimum soil moisture is maintained by irrigating the crop judiciously. Irrigation interval will depends on season, crop growth and soil type. In no case, water should be allowed to stagnate causing root and stem rot. Drip system of irrigation is beneficial and the actual quantity of water to be given per plant per day should be worked out critically.
Nutrition: The papaya is a very feeder type and requires the application of chemical, organic and biofertilisers. The dose of NPK @ 500 kg each per ha, along with 20-25 tonnes of FYM, 50 to 100 kg of ormichemi mirco-nutrients and ultrazyme sea weed extract granules 25 kg is found for a crop of about 50 tonnes within 18-20 months. Additional 60% of this dose is again applied for the second flush.
Plant protection: The papaya is susceptible for virus disease, which are spread through insect vector. The rouging of is strictly followed to avoid further spread of the disease, in addition the insecticidal sprays are taken against aphids, white flies and other sucking pests. Powdery mildews, downy mildew and stem rot. Providing wind breaks, well drained conditions to soil avoiding planting papaya after papaya and following a suitable crop rotation keeping the field clean and weed-free are some of the measures which will help to keep the papaya crop in good healthy condition
Harvesting, packing, post harvest handling: Usually the fruits are harvested when they are full size, light green with a tinge of yellow at epical end. When the latex ceases to be milky and become watery the fruits are considered suitable for harvesting. First picking may start at 14/15 months after planting. Three to five picking for one season are often taken fetching about 30-35 tonnes per hectare. Suitable grading must be done before packing. Since the fruits are easily perishable, care should be taken to wrap the individual fruit in paper and finally packed in crates (India: Crop information by indiaagronet).

Cultivation practices:
Papaya is grown from seeds. Dry seeds may be stored in air-tight or refrigerated containers over a period of one year. Sowing of seeds in coldframes or boxes can be effected during January ; or in the open during March of the year. Fresh seeds will often germinate in 2 to 3 weeks and this process can be enhanced by removing the outer seed coat (sarcotesta) before drying. When two or three leaves come out of the plant the seedlings are to be transplanted in 5-7.5cm spacing apart in the seedbeds. Later they can be shifted to permanent pits in the fields when they bear sufficient trunk and leaves. In this manner one can rear 1750 trees in a hectare of land. Good rainfall and soil condition are to be ensured for each plant/cluster of transplanted, and this will ensure a rapid growth of plant. Mulch assists in preserving moisture and shading of the soil in summer months, at the same time preventing unnecessary weeds in the field. Even the burning of humus in the soil occurs thereby reasonable growth for the plant is ensured. Appropriate manuring of the soil is welcome.
When plants are 7—10m tall, maintaining a planting distance of about 5-7ft apart, the discarding process for most male plants(non fruit-yielding type) has to commence; and this is done by selecting 3 vigorous seedlings per hole and removing the rest. When first flowering buds start coming in 5-7 months after planting, the female ones can easily be distinguished and they only be retained mostly, allowing them to grow at reasonable distance; the male plants in the field are allowed to persist in the ratio of 1 to every 25 female plants (Chia,CL and Tripton,TV et.al).
Papaya plant bears fruit throughout the year. The period for a papaya plant from bloom to maturity is 5-8 months; that is to say, if seeds are sown during May month they shall yield fruit by next January. The normal life of a tree is two years but some wild varieties live beyond. In commercial production, the fields are either replanted or abandoned after three years. The yield of the fruit is highest in the first year, and in subsequent years its production lowers. The fruits usually ripen on the tree itself with yellowing spots all over; but for rapid marketting purposes, such fruits can be carefully picked up using cotton gloves, placed in picking trays and thereafter subjected to ripening at temperatures between 21-26.5 C.
Maturity:
Papayas develop their highest eating quality when the skin is 80% yellow in color. However, for shipping papayas are harvested when the first hint of yellow coloration appears.
Harvest
Fruits are hand harvested carefully to avoid scratching the skin, which would release latex and stain the skin. On taller plants, harvesters use poles or hydraulic lifts to reach fruit. Harvest is a continuous process once plants reach 6-12 months of age, and constitutes 40% of the total labor cost of producing papayas.
Post-harvest Handling
To reduce post-harvest fruit rot, papayas are commonly heat treated at 110-120°F, then rinsed in cool water. Fungicides also may be used, generally in the wax applied during packing. Radiation treatments such as "Sure Beam" are used to sterilize fruit fly eggs and larva in fruit intended for export. Fruit are packed into single-layer boxes (10-15 lbs), often with tissue or foam padding to avoid bruising. Fruits can be cured at 85F and 100% humidity for better color expression prior to shipping.
Storage
Below 50°F, papayas experience chilling injury. Various protocol have been developed for controlled atmosphere storage (1-4% O2, 55°F) and hypobaric storage to increase fruit shelf life by several days, but they are not commercially practiced. Papayas are extremely perishable; shelf life at room temperature ranges from 3 to 8 days, depending on storage atmosphere.
Papaya may be stored for periods from 7-21 days if kept at 7 C and relative humidity of 85-90% without damage to the skin and structure. It cannot be subjected to chilling. Both ‘fruit-harvesting’ through ripening and ‘latex dripping’ to harvest the natural product, papain, can be achieved on the same papaya fruit at different stages. Ripened fruits must be treated on the surface to kill any larve or eggs of flies that might have surrounded it.
Crop yields: The papaya tree yields 30-150 fruits under normal circumstances every year and each one weighing a minimum of one kilogram. A minimum marketable yield of 34,000 kg/ha is considered noteworthy. In literature, several authors record yields upto 100 metric tons/ha/year with 1750 fruit-bearing trees. The variety of papaya grown was ‘Honey Dew’ ; during the first year of harvest it was 100 mtons/ha on most fertile soils and in the second year the yield was 85mtons and subsequent year(3rd year) it stood at 75mtons. The yield of ‘papain’, the enzyme isolated from latex is also reckonable. The yield of papain during five years life of a tree is on average 70—130kg/ha. It is usually equated as 5kg fresh latex = 1kg crude papain. In addition, there have been reports coming in on the development of ‘renewable energy resources’ such as ethanol being produced from papaya fruit through fermentation processes. Some scientists consider that even the ‘latex’ may provide itself as a hydrocarbon source namely the‘biofuel’.. Since ‘Papaya’ tree provides the harvest of both the edible delicious fruit and the industrial product papain together , it is an ‘economic crop’ (James A.Duke).
Crop pests and control:
The papaya fruit-fly (Toxotrypana curvicauda) is a serious pest in some areas, so that bagging fruit while still quite small is the only means for protecting it. This most important insect pest in Florida, punctures the rind of fruit to lay eggs. Use of bags is only feasible in small plantings; in commercial plantings, selection of another area at least 2 miles from old plantations or wild stands usually gives protection for a few years. Papaya whitefly (Trialeurodes variabilis), hornworms and corn earworms (Heliothis zea) may also be pests. In Florida, the papaya webworm Romalopalpia dalera, produces webs around the fruits and stems therein (Malo and Campbell, s.d.). Soil used for seedbeds should be absolutely free from nematodes that cause root knot. Nematodes isolated from papaya include: Butlerius singularis, Criconemella curvata, Helicotylenchus concavus, H. dihystera, H. erythrinae, H. cavenessi, H. microcephalus, H. pseudorobustus, Remicycliophora penetrans, Hoplolaimus pararobustus, H. seinhorsti, Meloidogyne arenaria, M. incognita,, M. i. acrita, M. javanica, M. thamesi,, Peltamigratus nigeriensis, Pratylenchus coffeae, P. zeae, Rotylenchlus reniformis, Scutellonema clathricaudatum, Tylenchorhynchus annulatus, Xiphinema insigne, X. americanum. Fungi reported on papaya include: Alternaria tenuis, A. tenuissima, Armillaria mellea, Ascochyta caricae, Aspremisporium caricae, Asterina caricarum, Botrydiplodia caricae, B. papayae, B. theobromae, Cephaleuros mycoidea, C. virescens, Cercospora caricae, C. mamanois, C. papayae, Choanephora americana, C. cucurbitarium, Cicinnobolus cesatii, Cladosporium herbarum, C. sphaerospermum, Colletotrichum capsici, C. caricae, C. gloesporioides, C. papayae, Corticium solani, Corynespora cassicola, Curvularia carica-papayae, Dendryphiella interseminata, Didymella sp., Diplodia cacaoicola, R. papayae, Erysiphe cichoracearum, Fuligo cinerea, Fusarium bulbigenum, F. equiseti, F. lateritium, F. scirpi, F. solani, F. stilboides, Gloeosporium papayae, Glomerella cingulata, Guignardia caricae, Helminth rium papayae, Leveillula taurica, Macrophoma sp., Macrophomina phaseoli, Macrosporium commune, Mycosphaerella caricae, Myrothecium roridum, Nectria haematococca, Oidium caricae, O. indicum, Ovulariopsis papayae, Penicillium digitata, Periconia byssoides, P. pycnospora, Phaeoseptoria papayae, Phomopsis papayae, Phyllosticta papayina, P. caricae-papayae, P. sulata, Phymatotrichum omnivorum, Phytophthora cactorum, P. cinnamomi, P. palmivora, P. parasitica, Pucciniopsis caricae, Pythium aphanidermatum, P. butleri, P. complectans, P. debaryanum, P. gracile, P. indicum, P. irregulare, P. muriotylum, P. oligandrum, P. rostratum, P. spinosum, P. splendens, P. ultimum, P. vexans, Rhizoctonia solani, Rhizopus nigricans, R. stolonifer, Sclerotium rolfsii, Sphaceloma papayae, Sphaerostilbe repens, Stachybotrys kampalensis, Stilbella proliferans, Vermicularia dematium. Bacillus papayae and Pseudomonas carica-papayae also attack papaya. Viruses isolated from papaya include: Bunchy-top, Cucumber mosaic, Ringspot, Waialua virus, Yellow crinkle and Leaf-curl (Ag. Handbook 165, Reed, 1976). Papaya mosaic is spread by aphid, Myzus persicae.
(source: James A. Duke, Handbook of Energy Crops,1983.)
DISEASES
Anthracnose and chocolate spot, Colletotrichum gloeosporioides (fruits, petioles)
Phytophthora, Phytophthora palmivora (fruit, stem, roots)
Powdery mildew, Oidium caricae (leaves)
Black spot, Cercospora papayae (fruit)
Damping off, Pythium, Phytophthora, Rhizoctonia (seedlings)
Wet rot, Phomopsis sp. (fruit)
Dry rot, Mycosphaerella sp. (fruit)
Watery fruit rot, Rhizopus stolonifer
Stem-end rot, , Mycosphaerella Botryodiplodia theobromae sp., Rhizopus stolonifer, Phomopsis sp. (mature fruit)
Papaya ring spot virus (formerly referred to as papaya mosaic)
Reniform nematodes, Rotylenchulus reniformis
Root-knot nematodes, Meloidogyne spp.

INSECTS
Stevens leafhopper, Empoasca stevensi
Mediterranean fruit fly, Ceratitis capitata
Melon fly, Bactrocera cucurbitae
Oriental fruit fly, B. dorsalis

MITES
Broad mite, Polyphagotarsonemus latus (seedlings, young plants, lower surface of young leaves)
Red and black flat mite, Brevipalpus phoenicis (fruit)
Tuckerellid mites, Tuckerella ornata, T. pavoniformis (trunks of old plants)
Carmine spider mite, Tetranychus cinnabarinus (lower surface of mature leaves)
Citrus red mite, Panonychus citri (upper surface of mature leaves)
Texas citrus mite, Eutetranychus banksi (upper surface of mature leaves)
(source: Chia CL & Tripton TV et.al, Papaya-General crop information)

Genetically modified papaya
Amongst the most destructive pests that affect the papaya, the papaya ringspot potyvirus (PRSV), which is rapidly transmitted by a number of aphid species, severely damages the plants by causing the most serious virus disease of papaya worldwide. In fact, this was observed during the year 1943 at Oahu, Hawaii, when the plantations virtually were wiped out for a consecutive period of 5-7 years. Even relocating the plantation sites to another favourable area, eg.Puna-Hawaii did not help. Since papaya was the most economic crop of Hawaii, and is also fetching foreign exchange to the country through exports to nearby USA and Canada, the State could not remain silent over the problem; therefore, by the year 1980, research studies were diverted towards the development of PRSV resistant papaya and its ‘acceptance evaluation’, at the Hawaii university and the Cornell university as well. A Transgenic Genetically Modified papaya was evolved by the year 1996 (Cornell Science News- September release).
The new concept of 'pathogen-derived resistance', of a plant where it was proposed that transforming plants with a pathogen's gene would result in the new type of transgenic plant being resistant to the virus afflicting the original plant under study. In other words, a gene from the pathogen was being used to fight against the pathogen itself.
Certain viral genes encoding capsid proteins were transferred to the papaya genome. These viral capsid proteins facilitate an "immune response" from the papaya plant. These new, genetically modified papaya plants are no longer susceptible to infection, allowing farmers to cultivate the fruit even when the virus is widespread in the areas.
The first virus resistant papayas were commercially produced in Hawaii in the year 1999 for export. Transgenic papayas now cover about one thousand hectares, or three quarters of the total Hawaiian papaya crop. Studies have shown that the Genetically Modified papayas are acceptable in USA and Canada, whereas European Union countries have still got their reservations. Asian countries conducted similar studies with the locally persistent pathogenic virus affecting their papaya plantations and evolved the requisite virus- resistant varieties. Thus, we have in the ‘world papaya-producing countries’ today, a variety of GM papaya plants that are virus- resistant and as good as the original ‘non-pest-affected’ types, produced through biotechnology (see references under ‘papaya’).
Papaya in Foods:
(Carica papaya plant data- Microsoft Internet explorer extracts)
Ripe papayas are most commonly eaten fresh as a breakfast food. It is merely peeled, de-seeded, cut in wedges and served with a half or quarter of lime or lemon. Sometimes a few seeds are left attached for those who enjoy their peppery flavor but not many such pieces to be eaten. The flesh is often cubed or shaped into balls and served in fruit salad or fruit cup. Firm-ripe Papaya may be seasoned and baked for consumption as a vegetable. Ripe flesh is commonly made into sauce for shortcake or ice cream sundaes, or is added to ice cream just before freezing or is cooked in pie, pickled, or preserved as marmalade or jam. Papaya and Pineapple cubes, covered with sugar sirup, may be quick-frozen for later serving as dessert. Half-ripe fruits are sliced and crystallized as a sweetmeat. Ripe dehydrated papaya pieces form a good ingredient in dry fruits.
Papaya juice / nectar may be prepared from peeled or unpeeled fruit and are sold fresh in bottles or canned. In Hawaii, Papayas are reduced to puree with sucrose added to retard gelling and the puree is frozen for later use locally or in mainland USA in fruit juice blending or for making jam.
Unripe Papaya is never eaten raw because of its latex content that may cause allergies in some people. Even for use in salads, it must first be peeled first, de-seeded, and boiled until tender, and then chilled. Green Papaya is frequently boiled and served as a vegetable. Cubed green Papaya is cooked in a mixed vegetable soup. Green Papaya is commonly canned in sugar syrup in Puerto Rico for local consumption and for export.
Young leaves are cooked and eaten like spinach in the East Indies. Mature leaves are bitter and must be boiled with water to eliminate much of the bitterness.
Sprays of male flowers are sold in Asian and Indonesian markets and in New Guinea for boiling with several changes of water to remove bitterness and then eating as a vegetable. In Indonesia, the flowers are sometimes ‘candied’. Young stems are cooked and served in Africa. Older stems, after peeling, are grated, the bitter juice squeezed out, and the mash mixed with sugar and salt.
The Papaya is regarded as a fair source of iron and calcium, as well as vitamins A, B and an excellent source of vitamin C (ascorbic acid).
(Extract from: Morton, J. 1987. Fruits of Warm Climates.)

medicinal uses:
Studies at the University of Nigeria revealed that extracts of ripe and unripe Papaya fruits and of the seeds are active against gram-positive bacteria. Strong doses are effective against gram-negative bacteria. The substance has protein-like properties. The fresh crushed seeds yield the aglycone of glucotropaeolin benzyl isothiocyanate (BITC) which is bacteriostatic, bactericidal and fungicidal. A single effective dose is 4-5 g seeds (25-30 mg BITC).
It was reported that in a London hospital in 1977, a post-operative infection in a kidney-transplant patient was cured by strips of Papaya which were laid on the wound and left for 48 hours, after all modern medications had failed.
In tropical folk medicine, the fresh latex is smeared on boils, warts and freckles and given as a vermifuge. In India, it is applied on the uterus as an irritant to cause abortion. The unripe fruit is sometimes hazardously ingested to achieve abortion. Seeds, too, may bring abortion. They are often taken as an emmenagogue and given as a vermifuge. The root is ground to a paste with salt, diluted with water and given as an enema to induce abortion. A root decoction is claimed to expel roundworms. Roots are also used to make salt.
Crushed leaves wrapped around tough meat will tenderize it overnight. The leaf also functions as a vermifuge and as a primitive soap substitute in laundry. Dried leaves have been smoked to relieve asthma or as a tobacco substitute. Packages of dried, pulverized leaves are sold by "health food" stores for making tea, despite the fact that the leaf decoction is administered as a purgative for horses in Ghana, and in the Ivory Coast it is a treatment for genito-urinary ailments. The dried leaf infusion is taken for stomach troubles in Ghana; and it is said to be a purgative, and may cause abortion too.
(Extract from: Morton, J. 1987. Fruits of Warm Climates.)
Indigenous Practices: The lanced fruits of Papaya may be allowed to ripen and can be eaten locally, or they can be employed for making dried Papaya "leather" or powdered Papaya, or may be utilized as a source of pectin.
Because of its papain content, a piece of green Papaya can be rubbed on a portion of tough meat to tenderize it. Sometimes a chunk of green Papaya is cooked with meat for the same purpose.
One of the best known uses of papain is in commercial products marketed as meat tenderizers, especially for home use. Papain-treated meat should never be eaten "rare" but should be cooked sufficiently to inactivate the enzyme.
Papain has many other practical applications. It is used to clarify beer, also to treat wool and silk before dyeing, to de-hair hides before tanning, and it serves as an adjunct in rubber manufacturing. It is applied on tuna liver before extraction of the oil which is thereby made richer in vitamins A and D.
Papain is often incorporated into toothpastes, cosmetics and detergents, as well as pharmaceutical preparations to aid digestion.
Papaya Allergy: Mention has already been made of skin irritation in Papaya harvesters because of the action of fresh Papaya latex, and of the possible hazard of consuming undercooked meat tenderized with papain. It must be added that the pollen of Papaya flowers has induced severe respiratory reactions in sensitive individuals. Thereafter, such people react to contact with any part of the plant and to eating ripe Papaya even, or any food containing Papaya, or meat tenderized with papain.
Scientific Research: Papaya leaves contain the bitter alkaloids, carpaine and pseudocarpaine, which act on the heart and respiration like digitalis, but are destroyed by heat. In addition, two previously undiscovered major D1-piperideine alkaloids, dehydrocarpaine I and II, which are more potent than carpaine, were reported from the University of Hawaii in 1979.

Collaborating chemists in Italy and Somalia identified 18 amino acids in Papaya seeds, principally, in descending order of abundance, glutamic acid, arginine, proline, and aspartic acid in the endosperm and proline, tyrosine, lysine, aspartic acid, and glutamic acid in the sarcotesta.

The latex of the Papaya plant and its green fruits contains two proteolytic enzymes, papain and chymopapain. The latter is most abundant but papain is twice as potent. In 1933, Sri Lanka is the leading commercial source of papain but it has been surpassed by East Africa where large-scale production began recently. Papain has been employed to treat ulcers, dissolve membranes in diphtheria, and reduce swelling, fever and adhesions after surgery.
With considerable risk, it has been applied on meat impacted in the gullet.
Chymopapain is sometimes injected in cases of slipped spinal discs or pinched nerves. Precautions should be taken because some individuals are allergic to papain in any form and even to meat tenderized with papain.
(Extract from: Morton, J. 1987. Fruits of Warm Climates.)”

Papain production:
Crude papain in flakes or powder, crude papain white brown,spray dried crude papain, are the three types of papain extracted from raw-mature papaya fruits. About 8-10 g of final produce can be obtained from a well- developed fruit weighing about 2 kg. Tapping may be done 2 to 3 times preferably during cool hours. The fruits after de-latexing can be used as a table fruit or for preparing fruity or jams etc.
The latex of the Papaya plant and its green fruits contains two proteolytic enzymes, papain and chymopapain. Papain is a sulfhydryl protease from Carica papaya latex. A second protease, chymopapain, and a lysozyme have also been isolated from the same source.
Characteristics of Papain from Carica Papaya:
Molecular weight: 23,000 (Dreuth et al. 1968).
Composition: Papain is a single peptide chain of 211 residues folded into two parts that form a cleft (Dreuth et al. 1968). A three-dimensional structure has been indicated by Wolthers et al. (1970). The molecule has one free SH group which is functional (Smith et al. 1975; Shipton et al. 1975). According to Alecio et al. (1974) there are seven subsites each capable of accommodating a single amino acid residue of a peptide substrate (Glick and Brubacker 1974). Papain structural information is well-documented in literature.
Papain and other enzymes
$$$$ Several enzymes have been found in papayas of which papain is of commercial importance. About 60% of the enzyme is used as a meat tenderiser in USA; and it is a beer stabilising agent as well.
Papain is recovered by making scratches (tappings) in the unripe fruit.. 6 tappings over 15 days has been recommended for optimum recovery of the enzyme. The scratches are made 0.2 cm deep at 1.25 cm apart and are best done on days 1,3,6,9,12 and 16. The yield is of the order of 180 lb per acre. The latex is either hyper-allergenic or an irritant and so it is necessary to wear gloves. The scratches should not be made with a metallic knife although collection into aluminum trays is found to be an approved procedure. Processing by 95% alcohol followed by acetone allows complete precipitation and dehydration.The 212 amino acid sequence has been determined (Robert J.Lancashire, Dept.of chem., University of West Indies, Kingston, Jamaica, “Papaya-Paw Paw, Internet paper).

The Papaya latex is obtained by making incisions on the surface of the green fruits early in the morning and repeating every 4 or 5 days until the latex ceases to flow. The tool is of bone, glass, sharp-edged bamboo or stainless steel (knife or raxor blade). Ordinary steel stains the latex. Tappers hold a coconut shell, clay cup, or glass, porcelain or enamel pan beneath the fruit to catch the latex, or a container like an "inverted umbrella" is clamped around the stem. The latex coagulates quickly and, for best results, is spread on fabric and oven-dried at a low temperature, then ground to powder and packed in tins. Sun-drying tends to discolor the product. One must tap 1,500 average-size fruits to gain 1 1/2 lbs (.68 kg) of papain

Papain standards:
(Information from NRDC Technology—Papain from Papaya)
Papain is the crude latex extracted from papaya. It contains protolytic (protein digesting) enzyme and other possible components. Papain (IP) is widely used in pharmaceutical industries for the preparations of protein hydrolysates, lacto- peptones, etc. in the food industry for clarifying juices, beer etc, in textile industry for degumming and in leather industry for tanning. Papain concentrate is an odourless and colourless substance used in pharmaceuticals and food industries where products of higher purity without odour are required.
The commercial grade papain is the crude dried latex extracted from papaya. But due to its offensive odour, characteristic taste and low solubility in water its use is limited to certain food and pharmaceutical formulation. The technology being offered has been developed by Central Food Technological Research Institute, Mysore, India, produces better quality product.

The Process:
PAPAIN (IP) - Papaya latex is mixed with potassium metabisulphate, sieved to remove extraneous materials and then blended with activated zeocarb cation exchange resin. The mixture is then centrifuged to separate out the resin from the liquefied latex. The latex is again mixed with activated anion exchange resin, blended and centrifuged. The liquefied latex is spread in trays and dried in vacuum shelf drier, and mixed with potassium metabi sulphate, ground and diluted with lactose to get IP grade papain.

PAPAIN CONCENTRATE- Papaya latex is mixed with potassium metabisulphate and distilled/ demineralised water, stirred thoroughly and stored in cold room for settling. The supernatant liquid is siphoned off, filtered and the clear filtrate is mixed with denatured spirit and allowed to settle in cold room. The supernatant liquid is decanted from the slurry, and the slurry is filtered. The filtered cake washed with rectified spirit and dried first with compressed air and then in vacuum dryer. The dried material is mixed with potassium metabisulphite, ground to desired particle size and diluted with lactose.



Papain Enzyme Specification
(adapted from SSS Biotic.com)







































Commercial Papaya food products:

Papaya Enzyme Chewable Lozenges: Papaya Enzyme Lozenges have a refreshing taste and are excellent after meals. These tablets are made from whole, unripe, spray-dried papaya powder, and contain 40 mg papaya per lozenge. Other enzymes are added to supplement the preparation. This tablet is also useful as a mint breath freshener.
‘NOW’ Papaya Enzymes combines natural papaya enzymes with Mint and Chlorophyll. This product is good as a digestive aid, and should help with flatulence and bad breath as well. Since poor digestion can contribute to bad breath, Papaya Enzymes and Chlorophyll may help by supporting healthy digestion. This product is a vegetarian product. Stearic Acid and Magnesium Stearate are natural excipients derived from palm oil.
‘NOW’ Super Enzymes contains a broad array of digestive enzymes designed to assist the body in the digestion of different types of foods (product to be used only if contra indications are not noticed).
Suggested Use: As a dietary supplement, 2 lozenges in mouth can be chewed following meals or as needed.
Other Ingredients: sorbitol, mannitol, stearic acid, magnesium stearate, silica, peppermint powder, peppermint oil, sodium copper chlorophyllin.
Supplement Facts
Serving Size 2 lozenges
Servings Per Container 90
Amount Per Serving %DV

Calories 5
Total Carbohydrate 1.5 g <1%
Sugars 1.5 g *
Papain (2,000 USP) 100 mg *
Papaya fruit powder 80 mg *
Bromelain (2,300 GDU) 20 mg *
Protease (5,000 USP) 20 mg *
Lipase (2,000 USP) 10 mg *
Cellulase (500 AC units) 5 mg *
Alpha-amylase (30,000 USP) 2 mg *
Percent Daily Values are based on 2,000 calorie diet.
* Daily Value not established.

Papaya granules (Dry)
Dried Mature green Paw Paw (Papaya) fruit (Carica Papaya), in granulated form, unlike ripe Paw Paw (Papaya) fruit, is very high in Papain enzymes, carbohydrates and fats irrespective of an acid or alkaline environment. It is a source of Vitamin A, C, B complex and E, as well as minerals and a complex consisting of several nutrients and enzymes.

Dried Mature Green Papaya Fruit is beneficial especially for the elderly and those with a weak digestive system and is needed with today's high consumption of fast foods lacking in live enzymes.

One to two teaspoonsful may be sprinkled over foods, blended with fruit, vegetable juice or smoothies or soaked in a little fluid and chewed with meals. To retain valuable live enzymes, this is not to be heated or cooked further. It can be sprinkled over raw meat and left to marinate for 30 minutes to tenderise.


Appendix- 1
Role of amino acids present in papaya products – highlighted by Rochway Pty.Ltd, Australia.
PAPAYA 35:
RICH IN PAPAIN;
CONTAINS A COMPLEX VARIETY OF ENZYMES WHICH ASSIST IN BREAKING DOWN and DIGESTING PROTEINS, CARBOHYDRATES and FATS
THE IMPORTANCE OF AMINO ACIDS - Present in Papaya 50 Extract.

[The formulation of Papaya 35 and Rochway Super Strength Papaya Extract has been adjusted to be very similar to Papaya 50]

TRYPTOPHAN (Essential Amino Acid) 3mg/100gr - A natural relaxant, helps alleviate insomnia by inducing normal sleep; reduces anxiety and depression; helps in the treatment of migraine headaches; helps the immune system; helps reduce the risk of artery and heart spasms; works with Lysine in reducing cholesterol levels.

LYSINE (Essential Amino Acid) 11mg/100gr - ensures the adequate absorption of calcium; helps form collagen (which makes up bone cartilage & connective tissues); aids in the production of antibodies, hormones & enzymes. Recent studies have shown that lysine may be effective against herpes by improving the balance of nutrients that reduce viral growth. A deficiency may result in tiredness, inability to concentrate, irritability, bloodshot eyes, retarded growth, hair loss, anaemia and reproductive problems.
METHIONINE (Essential Amino Acid) 3mg/100gr - is a principal supplier of sulfur which prevents disorders of the hair, skin and nails; helps lower cholesterol levels by increasing the liver's production of lecithin; reduces liver fat and protects the kidneys; a natural chelating agent for heavy metals; regulates the formation of ammonia and creates ammonia-free urine which reduces bladder irritation; influences hair follicles and promotes hair growth.
PHENYLALAINE (Essential Amino Acid) 5mg/100gr - signals between nerve cells and the brain; keeps one awake and alert; reduces hunger pains; functions as an antidepressant and helps improve memory. Used by the brain to produce Norepinephrine, a chemical that transmits.
THREONINE (Essential Amino Acid) 9mg/100gr - is an important constituent of collagen, Elastin, and enamel protein; helps preventing fat build-up in the liver; helps the digestive and intestinal tracts function more smoothly; assists metabolism and assimilation.
VALINE (Essential Amino Acid) 9mg/100gr - promotes mental vigour, muscle coordination and calm emotions.
LEUCINE & ISOLEUCINE (Essential Amino Acid) 21gr/100gr - They provide ingredients for the manufacturing of other essential biochemical components in the body, some of which are utilized for the production of energy, stimulants to the upper brain and helping persons to be more alert.
ARGININE (Non-Essential Amino Acid) 8mg/100gr - Studies have shown that is has improved immune responses to bacteria, viruses and tumour cells; promotes wound healing and regeneration of the liver; causes the release of growth hormones; considered crucial for optimal muscle growth and tissue repair.
TYROSINE (Non-Essential Amino Acid) 5mg/100gr - transmits nerve impulses to the brain; helps overcome depression; improves memory; increases mental alertness; promotes the healthy functioning of the thyroid, adrenal and pituitary glands.
GLYCINE (Non-Essential Amino Acid) 11mg/100gr - helps trigger the release of oxygen to the energy requiring cell-making process; important in the manufacturing of hormones responsible for a strong immune system.
GLUTAMIC ACID (Non-Essential Amino Acid) 24mg/100gr - considered to be nature's "Brain food" by improving mental capacities; helps speed the healing of ulcers; gives a "lift" from fatigue; helps control alcoholism, schizophrenia and the craving for sugar.
ASPARTIC ACID (Non-Essential Amino Acid) 31mg/100gr - aids in the expulsion of harmful ammonia from the body. When ammonia enters the circulatory system it acts as a highly toxic substance which can be harmful to the central nervous system. Recent studies have shown that Aspartic Acid may increase resistance to fatigue and increase endurance.
HISTIDINE (Non-Essential Amino Acid) - is found abundantly in hemoglobin; has been used in the treatment of rheumatoid arthritis, allergic diseases, ulcers and anaemia. A deficiency can cause poor hearing.
PROLINE (Non-Essential Amino Acid) 27mg/100gr - is extremely important for the proper functioning of joints and tendons; also helps maintain and strengthen heart muscles.
ALANINE (Non-Essential Amino Acid) 16mg/100gr - is an important source of energy for muscle tissue, the brain and central nervous system; strengthens the immune system by producing antibodies; helps in the metabolism of sugars and organic acids.

Papaya is one of the richest sources of antioxidants and is upto twenty times more powerful than Vitamin E. The nutritinal value of Fermented Papaya Extract lies in Potassium, Magnesium, Iron, Zinc, Beta-carotene, Thiamin, Riboflavin, Niacin, Vitamin C and Vitamin A.
In the composition are also Arginine, Lysine, Hystidine, Phenylalanine, Tyrosine, Leucine, Isolucine, Methionine, Valine, Glycine, Preline, Gluthamic Acid, Serine, Treonine, Aspartic Acid and Triptophane and Alanine.Through the fermentation process, beneficial lactic acids are created which act as natural preservatives and help maintain a healthy intestinal tract.

Extracts from Dr. John Whitman Ray “Patients Guide to Body Electronics” 1994:
The mature green Papaya contains several vital Enzymes, Minerals and Vitamins. It contains more Vitamin A than carrots, more vitamin C than oranges, abundant Vitamin B factors and Vitamin E.
It also contains a complex of Enzymes that help breakdown and digest proteins, carbohydrates and fats. Papain found abundantly in the green mature Papaya (Paw Paw) is one of the most powerful plant Proteolytic enzymes, is a catalytic agent that will act in Protein digestion in an acid, alkaline or neutral medium.
“Our Living Food Products“are: RICH IN LIVE ENZYMES, FERMENTED (Pre-digested - easy to absorb) 100% ORGANIC INGREDIENTS, NATURALLY PRESERVED (Free of chemicals, pesticides, colourings, etc.)
Papaya 35 - 500ml - A Green tea fermented papaya product based on fermented liquid concentrate of mature green Paw Paw (Papaya) fruit, seeds and leaves. rich in live enzymes and anti-oxidants.
.Dried Mature Green Paw Paw (Papaya) Fruit (Carica Papaya), in granulated form, unlike ripe Paw Paw fruit, is very high in Papain enzymes which are known to digest proteins, carbohydrates and fats irrespective of an acid or alkaline environment.
.
PAPAYA PRODUCTS
Papaya & Dandelion
Papaya & Red Clover
PAPAYA CONCENTRATES
Papaya 35 Concentrate
Papaya & Guava Blend
Papaya 50 & fermented papaya products Concentrate
PAPAYA FACE PACK-Skin health
An organic face pack based on papaya which is powerful in cleansing action has been produced from making the fruit pulp and storing in refrigerator. A small quantity, eg. ¾ table spoonful pulp is applied on face, and allowed to remain for 15-20 minutes. Thereafter it is washed away with fresh water; this application leaves glowing and smooth skin.
DRIED PRODUCTS
Dried Paw Paw (Papaya) Leaf
Dried Paw Paw (Papaya) Fruit (Granules)
© Rochway Pty. Ltd. (ABN: 11 096 673 353), 2000 - 2006

Appendix -2 Papaya- Salient Information
The following is an extract from the paper produced in internet (whfoods.org-paper info to be used only for education purposes) by George Matelian Foundation under the title, “The world’s healthiest foods” -papaya, which deals with the papaya based foods and the health benefits caused to people.
Papaya
Deliciously sweet with musky undertones and a soft, butter-like consistency, it is no wonder the papaya was reputably called the "fruit of the angels" by Christopher Columbus. Once considered quite exotic, they can now be found in markets throughout the year. Although there is a slight seasonal peak in early summer and fall, papaya trees produce fruit year round.
Papayas are spherical or pear-shaped fruits that can be as long as 20 inches. The ones commonly found in the market usually average about 7 inches and weigh about one pound. Their flesh is a rich orange color with either yellow or pink hues. Inside the inner cavity of the fruit are black, round seeds encased in a gelatinous-like substance. Papaya's seeds are edible, although their peppery flavor is somewhat bitter. The fruit, as well as the other parts of the papaya tree, contain papain, an enzyme that helps digest proteins. This enzyme is especially concentrated in the fruit when it is unripe. Papain is extracted to make digestive enzyme, dietary supplements and is also used as an ingredient in some chewing gums.

Health Benefits
Papayas offer not only the luscious taste and sunlit color of the tropics, but are rich sources of antioxidant nutrients such as carotenes, vitamin C and flavonoids; the B vitamins, folate and pantothenic acid; and the minerals, potassium and magnesium; and fiber. Together, these nutrients promote the health of the cardiovascular system and also provide protection against colon cancer. In addition, papaya contains the digestive enzyme, papain, which is used like bromelain, a similar enzyme found in pineapple, to treat sports injuries, other causes of trauma, and allergies.
Protection against Heart Disease
Papaya is very helpful for the prevention of atherosclerosis and diabetic heart disease. Papayas are an excellent source of vitamin C as well as a good source of vitamin E and beta-carotene, three very powerful antioxidants. These nutrients help prevent the oxidation of cholesterol. Only when cholesterol becomes oxidized is it able to stick to and build up in blood vessel walls, forming dangerous plaques that can eventually cause heart attacks or strokes. One way in which dietary vitamin E and vitamin C may exert this effect is through their suggested association with a compound called paraoxonase, an enzyme that inhibits LDL cholesterol and HDL cholesterol oxidation.
Papayas are also a good source of fiber, which has been shown to lower high cholesterol levels. The folic acid found in papayas is needed for the conversion of homocysteine into benign amino acids such as cysteine or methionine. If unconverted, homocysteine can directly damage blood vessel walls and, if levels get too high, is considered a significant risk factor for a heart attack or stroke.
Cancer Protection
The nutrients in papaya have also been shown to be helpful in the prevention of colon cancer. Papaya's fiber is able to bind to cancer-causing toxins in the colon and keep them away from the healthy colon cells. In addition, papaya's folate, vitamin C, beta-carotene, and vitamin E have each been associated with a reduced risk of colon cancer.
These nutrients provide synergistic protection for colon cells from free radical damage to their DNA. Increasing intake of these nutrients by enjoying papaya is an especially good idea for individuals at risk of colon cancer.
Anti-Inflammatory Effects
Papaya contains several unique protein-digesting enzymes including papain and chymopapain. These enzymes have been shown to help lower inflammation and to improve healing for wounds from burns. In addition, the antioxidant nutrients found in papaya, including vitamin C, vitamin E and beta-carotene, are also very good at reducing inflammation. This may explain why people with diseases that are worsened by inflammation, such as asthma, osteoarthritis, and rheumatoid arthritis, find that the severity of their condition is reduced when they get more of these nutrients.
Immune Support
The fiber found in papayas also help with the symptoms of those suffering from irritable bowel syndrome. In addition, vitamin C and vitamin A, that is made in the body from the beta-carotene of papaya, are both needed for the proper function of a healthy immune system. Papaya is therefore be a healthy fruit choice for preventing such illnesses as recurrent ear infections, colds and flu.
Protection against Macular Degeneration
Data reported in a study published in the June 2004 issue of the Archives of Opthamology indicate that eating 3 or more servings of fruit per day may lower the risk of age-related macular degeneration (ARMD), the primary cause of vision loss in older adults, by 36%, compared to persons who consume less than 1.5 servings of fruit daily.
In this study, which involved 77,562 women and 40,866 men, researchers evaluated the effect of study participants' consumption of fruits; vegetables; the antioxidant vitamins A, C, and E; and carotenoids on the development of early ARMD or neovascular ARM, a more severe form of the illness associated with vision loss. Food intake information was collected periodically for up to 18 years for women and 12 years for men. While, surprisingly, intakes of vegetables, antioxidant vitamins and carotenoids were not strongly related to incidence of either form of ARM, fruit intake was definitely protective against the severe form of this vision-destroying disease. Three servings of fruit may sound like a lot to eat each day, but papaya can help one reach this goal. Slices of fresh papaya added to morning cereal, lunch time yogurt or green salads is a full supplement. Papaya cut in half and blended with cottage cheese, crab, shrimp or tuna salad is a good dish. For an elegant meal, slices of fresh papaya are placed over any broiled fish.
Protection against Rheumatoid Arthritis
While one July 2004 study suggests that high doses of supplemental vitamin C makes osteoarthritis, a type of degenerative arthritis that occurs with aging, worse in guinea pigs, another indicates that vitamin C-rich foods, such as papaya, provide humans with protection against inflammatory polyarthritis, a form of rheumatoid arthritis involving two or more joints.
The findings, presented in the Annals of the Rheumatic Diseases were drawn from a study of more than 20,000 subjects who kept diet diaries and were arthritis-free when the study began, and focused on 73 subjects who developed inflammatory polyarthritis and 146 similar subjects who remained arthritis-free during follow-up between 1993 and 2001. Subjects who consumed the lowest amounts of vitamin C-rich foods were more than three times more likely to develop arthritis than those who consumed the highest amounts.
Protection against Emphysema
Research conducted at Kansas State University concluded that consumption of papaya, a rich source of vitamin A restores good health for cigarette smokers or persons subjected to passive smoking.
While studying the relationship between vitamin A, lung inflammation, and emphysema, Richard Baybutt, associate professor of nutrition at Kansas State, made a surprising discovery: a common carcinogen in cigarette smoke, namely benzo(a)pyrene, induces vitamin A deficiency.
Baybutt's earlier research had shown that rats fed a’ vitamin A-deficient’ diet developed emphysema. His latest animal studies indicate that not only does the benzo(a)pyrene in cigarette smoke cause vitamin A deficiency, but that a diet rich in vitamin A can help counter this effect, thus greatly reducing emphysema.
In his initial research, Baybutt took just weaned male rats and divided them into two groups, one of which was exposed to cigarette smoke, and the other to air. In the rats exposed to cigarette smoke, levels of vitamin A dropped significantly in direct correlation with their development of emphysema. In the second study, both groups of rats were exposed to cigarette smoke, but one group was given a diet rich in vitamin A. Among those rats receiving the vitamin A-rich foods, emphysema was effectively reduced.
The implications are that those who start smoking at an early age are more likely to become vitamin A deficient and develop complications associated with cancer and emphysema. And if they have a poor diet, they have to protect themselves by making sure that at least one of the World's Healthiest Foods that are rich in vitamin A, such as papaya, be eaten daily as part of the healthy way of eating. (October, 21, 2004)

How to Select and Store:
Only red coloured soft papayas are to be chosen for same-day consumption. Papayas that are partially yellow should be left at room temperature where they will ripen in a few days..Ripe papayas should be stored in the refrigerator and consumed within one or two days, in order to enjoy their maximum flavor.
How to Enjoy:
Papayas can be used many different ways. They can be eaten as is, added to a fruit salad or to a host of different recipes.
One of the easiest (and most delightful) ways to eat papaya is to eat it just like a melon. After washing the fruit, it is cut lengthwise, the seeds removed and then eaten it with a spoon. For a little extra zest, one can squeeze lemon or lime juice on top.
While most people discard the big black seeds, they are actually edible and have a delightful peppery flavor. They can be chewed whole or blended into a creamy salad dressing, giving it a peppery flavor.
A Few Quick Serving Ideas:
Diced papaya, cilantro, jalapeno peppers and ginger together on mixing make a unique salsa that goes great with shrimp, scallops and halibut.
Papaya with fresh lime juice sprinkled is enjoyed as it is.
Small papaya lengthwise sliced and filled with fruit salad is a delicious dish.
In a blender, papaya, strawberries and yogurt combined form a cold soup treat.

Safety:
Papaya is not a commonly allergenic food, is not known to contain measurable amounts of goitrogens, oxalates, or purines, and is also not included in the Environmental Working Group's 2003 report "Shopper's Guide to Pesticides in Produce" as one of the 12 foods most frequently containing pesticide residues.