Plant , tropical, protein

Because composition and nutritional properties of the major food legumes and oilseeds have been reported in numerous technical journals and books (listed above), the section devoted to composition and chemistry highlights lesser-known but potentially important sources of plant protein that have not received the same attention. Some of these food crops have been cultivated for many years so that they are not "new" sources. Such crops as winged bean, sweet potato, tropical seeds, fruits and leaves, yams and cucurbits are potential sources of protein in areas where they are grown. These are discussed in greater detail in the remaining five chapters. 

Table I. Protein and Free Amino Acid Compositions of Leaves from Tropical and Subtropical Plants [Adapted from Hall et al. (7 )]...

Cow pea and urd bean, two common legumes are only slightly lower. An excellent review by H. D. Tindall of the leguminosae plants indicates most of their seeds have high protein contents, are directly consumable, and they are easily grown in tropical and subtropical climates (30). 

Table V. Weights and Protein Contents of Leaves from Four Tropical Plants [from Nagy et al. (4 )]...

The design of safe sweeteners is very important for people who are afiected by diabetes, hyperlipemia, caries and other diseases that are linked to sugar consumption. Sweet proteins, which are found in several tropical plants, are many times (100-100,000) sweeter than sucrose on a molar basis. Only a few sweet proteins are known miraculin, monellin, thaumatin, curculin, mabinlin. 

Pentadin is a sweet protein extracted from the plant, Pentadiplandra brazzeana Baillon, a shrub found in tropical forests of a few African... 

Witherup KM, Ransom RW, Graham AC, Bernard AM, Salvatore MJ, Lumma WC, Anderson PS, Pitzenberger SM, Varga SL (1995) Martinelline and martinellic acid, novel G-protein linked receptor antagonists from the tropical plant Martinella iquitosensis (Bignoniaceae). J Am Chem Soc 117 6682-6685... 

A number of plants and some trees contain a white, milky liquid that is released when the stem or bark is cut. The liquid is called a latex from the Latin meaning liquid. Common sources include dandelions, milkweed, goldenrod, and potted rubber plants. Rubber trees, from which substantial quantities of latex can be harvested, grow in some tropical areas of the world. A major constituent of this latex is a homopolymer of isoprene (2-methyl-1,3-butadiene), called polyisoprene. Polyisoprene, as well as a number of other elastomers, has a carbon-carbon double bond in every repeat unit. The properties of polyisoprene are the result of the presence of these double bonds. Just as stereochemistry plays a critical role in both proteins and polysaccharides, we will see its importance here. 

Some substances have the ability to modify our perception of taste qualities. Two such compounds are gymnemagenin, which is able to suppress the ability to taste sweetness, and the protein from miracle fruit, which changes the perception of sour to sweet. Both compounds are obtained from tropical plants. 

---