Legume Processing Effects on Dietary Fiber Components

Effects of different processes were studied on neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose, and lignin content of legumes. Chick peas, kidney beans, and lentils were soaked and cooked, simulating home processing. Values were recorded on a wet basis as a guide to calculating their contribution to the diet. Decrease in values was more pronounced in pressure-cooked chick peas and kidney beans with cooking liquid removed. In lentils, cooking liquid embedded, no difference between processes was observed. Amounts of dietary fiber components on a dry basis, of interest when legume meal is used as food supplement, increased for chick peas and beans, except for the hemicellulose of beans and lentils, which decreased.     

CHARACTERISTICS OF COOKED CHICKPEAS AND SOYBEANS DURING COMBINED MICROWAVE–CONVECTIVE HOT AIR DRYING

Moisture content, shrinkage, water activity (A_w), color and texture of cooked chickpeas and soybeans during convective, microwave and combined microwave–convective drying were studied. Combined drying was significantly (P < 0.05) faster than either convective or microwave drying, and resulted in less shrinkage of the dehydrated product. Rapid burning occurred when samples were dried below a A_w of 0.27 ± 0.07 for chickpeas (P < 0.05), and 0.13 ± 0.04 for soybeans (P < 0.05). Both chickpeas and soybeans displayed a transitional behavior in texture when dried to a A_w below 0.40 ± 0.10 (P < 0.05) for chickpeas, and below 0.63 ± 0.15 (P < 0.05) for soybeans, when samples became brittle. Shelf stable dehydrated chickpea and soybean products with low water activity (A_w = 0.35) and good visual quality could be obtained within 14 min of combination drying.     

GELLING AND COLOR PROPERTIES OF OSTRICH (STRUTHIO CAMELUS) EGG WHITE

The effect of temperature upon the denaturation process of ostrich egg‐white protein was studied, and it compared with that of commercial hen eggs. Turbidity and color properties evolution were used to determine this effect. In addition, egg‐white gels (from both ostrich and hen egg whites) were obtained by heat treatment at 80C, and these were characterized by means of color, textural properties and water‐holding capacity (WHC). Results showed that although 55C was the temperature for the start of coagulation in both types of egg white, only in hen egg white was the process completed at 65C. The gels obtained at 80C (both ostrich and hen egg‐white gels) presented a strong structure that would allow ostrich egg white to be used as a gelling agent in the food industry as it happens with hen egg white.