45I-19 |
Nutritional quality of drum-processed and extruded composite supplementary foods |
T. C. E. MOSHA, M. R. Bennink, and P. K. W. Ng. Dept. of Food Science & Human Nutrition, Michigan State Univ., Suite 106 F Malcolm Trout FSHN Bldg., East Lansing, MI 48824-1224 Infrequent feeding of children is one of the underlying causes of acute and severe under-nutrition in developing countries. Availability of fully cooked “instant”, culturally acceptable, and inexpensive supplementary foods made from locally grown ingredients would help mitigate child under-nutrition through increased feeding frequency. This study evaluated the nutritional quality of “instant” composite diets cooked by extrusion and drum-processing. Five supplementary diets, namely corn-bean meal, bean meal, rice-bean meal, corn-bean-sardine meal and rice-bean-sardine meal were formulated according to the FAO/WHO/UNU (1985) guidelines. The corn, rice, beans and sardines were extruded (maximum product temperature – 1330C) or drum-processed (product temperature – 1030C). Cooking doneness was evaluated by percent starch gelatinization and residual esterase activity while biological qualities -- true protein digestibility and growth/rehabilitation potential -- were evaluated using Sprague Dawley weanling rats. Our results showed that starch gelatinization and residual esterase activity were not significantly different (p > 0.05) between the extruded and drum-processed diets. Relative to open kettle cooking, starch gelatinization was 95 - 100% in extruded and 92 - 100% in drum-processed diets. Inactivation of esterase activity ranged from 93 to 100% in extruded and 83 to 100% in drum-processed diets. The true protein digestibilities were significantly (p< 0.05) higher when extruded diets compared to drum-processed diets were fed to animals. Average true protein digestibility was 91% (range 87 - 95%) for the extruded and 87% (range 82 - 94%) for the drum-processed diets. Animals fed extruded diets showed slightly greater growth rates during normal and rehabilitation phases compared to those fed drum-processed diets. These results suggest that extrusion cooking of bean-based foods resulted in diets of slightly higher nutritional quality than drum-processing. However, both processing methods produced foods meeting the required nutritional quality. Equipment availability and energy costs will dictate the ultimate method of choice.
Session 45I, Nutrition: General
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