Papaya: A Nutritious Tropical Fruit   
  Published in: Food Product Design, Oct. 12, 2011
By Kasi Sundaresan, Ph. D., Contributing Editor 

         Papaya is a fruit from the group of yellow and orange fruits
gaining immense popularity in the United States. This tropical fruit
was reputedly called "The Fruit of the Angels" by Christopher
Columbus.  Originally from southern Mexico, Central America and
northern South  America, the fruit is now cultivated throughout the
tropical world and  in the warmest parts of the subtropics. Papaya
fruit is commonly  consumed fresh, but it is also cooked or used in
salads, preserves,  sauces, dressings, juices, nectars, smoothies and
pies.  

         Papaya cultivation 

         Papaya belongs to the family Caricaceae, which includes  four
genera and about 20 species native to the growing region. The  papaya
tree is a rapid-growing perennial that looks like a small palm  tree,
with a single slender, cylindrical trunk with a crown of leaves.  The
tree attains an average height of 10 to 13 feet. It is propagated
from seeds. Because of open pollination, it is difficult to obtain a
pure cultivar for papaya. Papaya trees develop to their full size in
less than a year and are ready to bear fruit at any time during the
year.  

         Among the numerous varieties of papaya are important commercial
varieties such as 'Red Lady', 'Maradol',
‘Waimanalo' and different  ‘Solo' types. Two
kinds of papayas are commonly grown; red papaya has  sweet, red (or
orange) flesh, and yellow papaya has yellow flesh.  The
large-fruited, red-fleshed 'Maradol', 'Sunrise', and
'Caribbean Red'  papayas often sold in U.S. markets are
commonly grown in Mexico and  Belize. Weather conditions, such as
cold temperatures, lack of water  (drought), high, constant winds, or
shade, will reduce papaya growth and production. Papaya plants grow
best in areas where temperatures remain  warm to hot (70 to 90°
F; 21 to 32° C). Papaya trees are not tolerant of freezing
temperatures and are damaged or killed below 31° F (-0.6° C).
Papaya trees are susceptible to wind damage and will not establish or
grow well in continuously windy areas. The fruit is commonly
spherical  to cylindrical in form. Attached along the walls of the
large inner  cavity of the fruit are numerous small, round, wrinkled
black seeds The  juicy flesh is deep yellow, orange, red or salmon,
and its flavor  profile strongly resembles a muskmelon. Deliciously
sweet with musky  undertones and a soft, butterlike consistency, it
is greatly enjoyed in  tropical countries. The soluble-solids level
of the mature fruits is  typically 11.5% or higher, 

         Of nutritional note 

         Puréed papaya is a good source of beta carotene and iron for
lactating mothers, according to a study in the Journal of Nutrition
(2001; 131:1,497-1,502.). Papaya is an excellent source of ascorbic
acid (about 60 mg to 100 mg per 100 grams pulp), a good source of
provitamin A, some B complex vitamins and many phytochemicals having
antioxidant properties. During the the papaya's development,
ascorbic  acid increases gradually until the fruit reaches maturity.
The change in outer color is an indicator of ripeness, and this
change is considered  mainly due to increase in carotene content and
decrease in chlorophyll.  Carotenoid contents differ between yellow-
and red-fleshed papaya. The  red-fleshed papaya has 64 % of the total
carotenoids as lycopene.  

         Papaya has many applications in processed-food products and is
available in a variety of forms, including purée, concentrate,
powder,  and dried or canned slices or chunks. Papaya purée is
the major  semiprocessed product that finds use in juices, nectars,
fruit  cocktails, jams and jellies. A number of low-moisture
products, such as  fruit leather, toffees, chunks, rolls and slices,
have also been  prepared from papaya purée. Besides its
well-known use in food  applications, the papaya has many traditional
medicinal uses. Shamans in the Amazon used the seeds to cure
parasites, which commonly affect  native people.  

         Most villages plant papaya in their medicinal gardens to make use
of this treatment. It also is used in medicines to treat arthritis
and  asthma. An extract from the fruit was also used to treat ulcers
and  reduce swelling after surgery. Papain is also applied topically
(in  countries where it grows) for the treatment of cuts, rashes,
stings and  burns. Women in some Asian countries have long used green
papaya as a  folk remedy for contraception and abortion. Enslaved
women in the West  Indies were noted for consuming papaya to prevent
pregnancies and thus  preventing their children from being born into
slavery.  

         Due to its unique flavor, papaya is a popular ingredient in fruit
juices, nectars and squashes in various parts of the world. Papaya
pairs well with fruits like mango and guava in fruit-juice
formulations. 

         Enzymatic magic 

         The latex of the papaya plant and its green fruits contain two
proteolytic enzymes, papain and chymopapain. Chymopapain is more
abundant in the fruit, but papain is twice as potent in usage.
Papain, a cysteine proteinase, also has a vast number of commercial
uses. Papain  is extracted and purifies to make digestive-enzyme
dietary supplements,  and is also used as an ingredient in some
chewing gums.  

         One of the best-known uses of papain is as a meat tenderizer,
especially for home or foodservice use. The enzyme can be applied to
the surface, but is best as part of a marinade. The result depends on
the  time and temperature of the application. Papain-treated meat
should  never be cooked "rare," but should be cooked sufficiently to
inactivate  the enzyme, requiring a temperature as high as 170
to185°F to completely inactivate it.  

         Papain has many other practical applications. It is used to
clarify beer, treat wool and silk before dyeing, to de-hair hides
before tanning, and also serves as an adjunct in rubber
manufacturing. It is  used in making toothpaste, and cosmetic
products.  

         Papaya is a delicious and nutritious fruit, and is of  considerable
economic importance in many tropical countries and export  markets in
temperate countries.  

         Kasi Sundaresan, Ph. D, is manager of research, development  and
quality for iTi Tropicals. For more information visit
ititropicals.com.