Effect of expansion by 'Intensification of Vaporization by Decompression to the Vacuum' (IVDV) on polyphenol content, expansion ratio, texture and color changes of Australian chickpea

摘要

"Intensification of Vaporization by Decompression to the Vacuum" (IVDV) is proposed as a pre-treatment for texturizing biological products. It consists in exposing humid products to high steam pressure, reached within 1 s, for a defined time followed by a rapid decompression to the vacuum. It was studied in the aim of expanding chickpeas. Response surface methodology was applied to study the effect of operating parameters (initial water content (W = 15.2-48.8 g/100 g DM), steam pressure (P = 4.5 x 10(5)-9.5 x 10(5) Pa) and processing time (t = 6.6-23.4 s)) on polyphenols content, expansion ratio, hardness, work done and color. High P liberated bound polyphenols mainly when combined with high W, while high t caused their denaturation. Expansion was greatly increased by P and t and to different extents by their quadratic effects and interactions. It depended on the product's rheological properties and the quantity of steam generated upon decompression. P and t provoked textural changes by decreasing hardness, while W increased compactness. Color underwent significant changes after seeds had dried tending to yellow. IVDV is a good texturizing process which preserves a part of chickpea's polyphenols and provides it with some color, appreciated during post-treatments