COOKING QUALITY, NUTRITIVE VALUE, SENSORY CHARACTERISTICS AND SHELF LIFE OF WHOLE AND DEHULLED SOYBEANS.
AuthorCABRAL, LAIR CHAVES.
AdvisorTinsley, Ann M.
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractWidespread protein-calorie malnutrition in many countries has stimulated interest in direct use of whole soybeans. However, acceptability of this protein/calorie-rich food is limited by several factors such as prolonged cooking time, poor texture and lack of consumer familiarity. Direct use of soybeans might be more acceptable if beans were dehulled prior to use. The objective of this investigation was to study the cooking quality, nutritive value, sensory characteristics and shelf life of dehulled soybeans in comparison with whole soybeans. The soaking time of whole soybeans was four times greater than that of dehulled soybeans (12 to 3 hr, respectively). Solid losses during soaking were greater for dehulled beans than for whole beans (8.6% and 0.7%, respectively), but cooking times (5.9 to 6.1 hr) were not significantly different. Whether raw or cooked, bean types did not significantly differ for PER, NPR and apparent digestibility. After cooking, there were significant increases in all nutritional parameters studied. Dry dehulled beans were significantly preferred over whole beans, but cooking reversed this preference. Both soybean types were stored in lots of 500 g polyethylene bags up to 6 mo at two environmental conditions (25°C, 75% RH, env. l; and 38°C, 90% RH, env. 11) and sampled monthly. Moisture content of whole and dehulled beans increased significantly during storage, however, rate of moisture increase was greater when both soybean types were stored under env. II. Cooking time of whole and dehulled beans increased linearly with storage duration. Storage environment affected the rate/extent of this increase (19%, env. I; 87%, env. II). Trypsin inhibitor activity decreased during storage; cooking destroyed this activity in all samples. PERs of dehulled beans were reduced by storage under both conditions, whereas those of whole beans were influenced only by env. II. For both soybean types, NPR and apparent digestibility values were independent of storage treatment. Color and odor of dry samples were adversely affected by storage duration under env. II. The increased color associated with storage under env. II. was less pronounced after samples were cooked. No practical limitation was found for dehulled beans in relation to whole beans and several advantages were suggested. Dehulled soybeans may constitute another alternative for increasing direct consumption of this protein/calorie-rich food.
Degree ProgramNutritional Sciences