Bean, winged

KiMURA T, NAKATA s, HARADA Y, YOSHIDA A (1986) Effect of ingested winged bean lectin on gastrointestinal function in the rat. JNutr Sci Vitaminol (Tokyo). 32 101-10. 

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. 

Winged Bean as a Source of Protein Recent Advances... 

Protein quality studies evaluating various edible portions of the winged bean plant and the results of recent International Field Trials are reviewed. Research efforts have been focused upon the mature seed (protein content 20.7-45.9% in 240 accessions), which is occasionally eaten in parts of Indonesia and Papua, New Guinea. Autoclaved seed meal and wet heat treated seed meal provided a corrected PER value of 1.76 and 1.72 respectively, in comparison to casein control of 2.50. 

Of the 190 accessions evaluated after one year s growth in Florida, 38 showed tuber formation. Tender leaves are incorporated in the food preparations in the South Asian region. Leaf protein concentrate (crude protein 51.9%) prepared from leaves yielded a PER value of 2.2 in comparison to 2.7 for corn-soy control. International Winged Bean Trials conducted in 19 countries recommend 5 varieties as having the best yield potential under varying environmental conditions. 

The actively investigated areas and the locations where winged bean studies have been conducted are shown in Table I. Since 1975, on a conservative estimate, approximately 150 research reports covering areas such as microstructure of winged bean protein, nu-... 

Previously published reviews (59-61) have analyzed in detail the emergence of winged bean as a legume of significant potential. This paper summarizes recent reports on protein quality evaluation of the edible portions of this legume. 

Nutrition research on winged bean has mainly focused upon the tough, mature seed, which is rich in protein and oil. The seeds are occasionally consumed in Indonesia and Papua NewGuinea (59, 60). A survey of 240 winged bean accessions from 16 countries showed that the protein and oil contents range between 20.7-45.9% and 7.2-21.5% respectively (13). Studies on the evaluation of seed flour as an alternative feed source for livestock has only recently begun. The two most commonly used plant protein sources in broiler (chicken) diets to date have been soybean and peanut cake (62). 

The effect of replacing soybean meal with winged bean meal at 0,... 

Two studies (44,63) had shown that growth performance and nitrogen retention efficiency of chicks were severely reduced by the inclusion of raw full fat winged bean seeds at rates of up to 400g/kg in semi-purified diets. Heat treatment of winged beans prior to dietary incorporation results 1n reversal of the growth depression and increases the efficiency of food utilization. 

These investigations show the potential value of full fat winged bean as a broiler feed. However, further studies that define conditions for destruction of anti-nutrients which cause reduced growth performance should be performed. 

Tubers Tubers are quite commonly consumed by villagers in Burma. Other tropical countries also report sporadic use of winged bean tubers (59). However, in comparison to the available data on the nutrient, anti-nutrient composition and the protein quality of the seed flour, published data on the nutritional value of winged bean tuber is somewhat limited. The few reported studies dealing with a larger number of varieties grown in different locations (25,67-71) show that tubers are mainly composed of protein and carbohydrates. 

According to Masefield (7 ) the winged bean nodulated well wherever the crop has been grown, irrespective of whether the seed was inoculated or not. The mean protein contents (dry wt. basis + S.D.) of inoculated and uninoculated tubers of six strains originating from Sri Lanka, Nigeria, Indonesia, Papua, New Guinea and Thailand are reported as 20.0(+3.7) and 17.3(+6.2), respectively... 

Comparison of PER studies on heat-processed winged bean seeds in rats (fed at 10% protein level)... 

Chemical composition of winged bean tubers grown in different countries... 

Haulm (stem) The possibility of using winged bean haulm as a potential raw material for single cell protein production in the tropics has been investigated by Zomer et al. (78). Semi-sol id fermentation of haulm, using various fungi, yielded a product containing 20% true protein, a 30% increase over the native material. The fermentation also increased the sulfur amino acid content by 1.5 to 6 fold. 

After the First International Winged Bean Symposium held at Los Banos, Philippines in 1978, the first international winged bean trials were launched. According to the report of Khan (79), who served as the coordinator of the trials, the aims of the trials were to ... 

Presently, the expansion of winged bean production and commercial development is inhibited by the lack of dwarf morphological variants and ecological uncertainties (80). A preliminary note on the development of bush type mutant in India has appeared (81), though scientific details have not been reported yet. 

Winged bean varieties with greatest yield potential... 

In conclusion, winged bean is a legume crop with great potential but a combined research effort by agronomists, plant breeders, physiologists and nutritionists is needed to eliminate the obstacles which stand in the way of its realization. Large scale nutritional benefit from this legune awaits further research developments. 

Cerny, K. Hoa, D.Q. Dinh, N.L. Zelena, H. Proc.2nd Internat. Winged Bean Seminar, 1981, Columbo, Sri Lanka. (in press). 

Gandjar, I. Proc. 1st Internat. Winged Bean Seminar, 1978, Manila, Philippines, 1980, pp. 330-34. 

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