33A-9 |
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L. L. NIBA, Dept. of Human Nutrition, Foods & Exercise, Virginia Polytechnic Institute & State Univ., 319 Wallace Hall, Mail Code 0430, Blacksburg, VA 24061-0430 Resistant starch and the soluble fiber components beta-glucans and fructans are associated with prevention and management of diet-related diseases such as colorectal cancer and diabetes. While cereal grains are primary sources of these physiologically beneficial carbohydrates, roots such as chicory root and tubers have been shown to be potential sources. Plantain (M. paradisaca) is a major dietary component in parts of Latin America, the Caribbean and Africa. This study aimed to determine the levels of these complex carbohydrates in unripe plantain and assess the effect of heating. Chipped unripe plantain was either cooked at 60 °C or 100 °C, or autoclaved at 120 °C or 130 °C for 60 min, then freeze dried. Pulverized material was assayed for glucose and sucrose by the AACC (1983) procedure, beta-glucan content by the method of McCleary and Mugford (1992), fructan content by the McCleary and Murphy (2000) procedure and resistant starch content by the AOAC 2002.02 procedure. Glucose content in raw plantain was 0.97 g/100 g and 1.62 g/100 g in cooked plantain. Sucrose content was 2.63 g/100 g in raw plantain and 3.87 g/100 g in autoclaved plantain (120 °C). Fructan content decreased from 0.67 g/100 g to 0.59 g/100 g with processing. There was minimal change in beta-glucan content (0.72 g/100 g). Resistant starch content in raw plantain was 53.6 g/100 g and decreased with autoclaving at 120 °C (3.69 g/100 g). It is apparent therefore, that unripe raw plantain has considerably high levels of resistant starch, and much smaller amounts of beta-glucans and fructans. In addition, while fructan and beta-glucan content is not greatly affected by moist heat, resistant starch is susceptible to changes with increased processing temperature. This is possibly due to gelatinization and enhanced solubilization of plantain resistant starch with processing.
Session 33A, Carbohydrate: General
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