BIOAVAILABILITY OF CARBOHYDRATE MATERIAL STORED IN TROPICAL FRUIT SEEDS

Properties of starches derived from seeds obtained from tropical fruit s used by the pulping industries were characterised and their response to enzyme attack ascertained. Despite similarity of the tissue from w hich starch was obtained, seeds starches varied depending upon the bot anical source in all of the structural and physicochemical properties measured except in the pattern by which enzymes attack the native gran ule. Morphologically the granules were very different, possessing a va riety of shapes and sizes; the composition and size of the macromolecu lar fractions were also distinct. The hydration properties and suscept ibilities of the granules were found to be different, which was surpri sing considering the similarity in physiological function of the starc hes. Similarly, the susceptibility of intact granules to enzyme attack was different in extent, though all of the granules should undergo a similar pattern of attack, namely surface erosion. Correlation analysi s revealed an apparent lack of correlation between the enthalpy of gel atinisation, assumed to represent degree of crystallinity, and enzyme susceptibility or swelling. It was concluded that, despite the existen ce of an underlying mechanism of hydrolysis, shaving of the granule su rface and structural characteristics unique to a particular species ma y dominate. Copyright (C) 1996 Elsevier Science Ltd