29D-25 |
Effect of flour protein content and dough moisture content on the physical characteristics of pea flour extrudates |
S. D. HOOD and R. T. Tyler. Dept. of Applied Microbiology & Food Science, Univ. of Saskatchewan, 51 Campus Dr., Saskatoon, SK S7N 5A8, Canada Canada is a major producer and exporter of pulse crops (pea, bean, lentil, etc). However, despite the significant nutritional advantages associated with the consumption of pulses, which are high in protein, lysine and fibre but low in fat, these crops see limited use as food in Canada (and in the USA). In this study, the expansion characteristics of pea flours containing various levels of protein were investigated as a first step in the development of expanded snack and breakfast foods. Pea flour was chosen in the raw material for the study as flours varying widely in protein content are commercially available. Pea flour containing 6-24% protein was obtained by blending air-classified pea starch and pea flour in various proportions. Extrusion trials were conducted on a co-rotating twin-screw extruder equipped with a 2x5mm die. Dough moisture ranged from 15 to 24%. Expansion index was determined by dividing the extruder diameter (determined with a caliper) by the extruder die orifice diameter. Bulk density was calculated from the weight and volume of extrudate pieces. Lower dough moisture levels and lower flour protein contents resulted in the highest expansion ratio and lowest bulk density. Dough moisture was the primary determinant of expansion ratio. The effect of protein content was more obvious at lower dough moistures. This study revealed that the potential exists to develop expanded products from lower protein field pea ingredients and, in all likelihood, other pulse ingredients. Further research is required to determine sensory characteristics and optimal extrusion conditions for product development of expanded products.
Session 29D, Food Engineering: Thermal processes
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