Multiple optimization of polyphenols content, texture and color of roasted chickpea pre-treated by IVDV using response surface methodology

Abstract

Intensification of Vaporization by Decompression to the Vacuum is considered as a texturizing pre-treatment for the production of roasted snack chickpea. It aims at providing an expanded crunchy product, having a nice appearance and color, and conserving its polyphenols content. Expansion is caused by a combination of different levels of initial water content (W), saturated steam pressure (P) and processing time (t). Response parameters were studied after roasting. Polyphenols were liberated and expelled under high W and P. P and t expanded the structure. The hardness of the grain decreased with P due to the formation of internal alveolation but increased with t because of the structure collapse. Color underwent browning with W, P and t. Results were confirmed by sensory analysis. Using response surface methodology, optimization was conducted in order to prepare a final product having a compromise between phenolic content, appearance, texture and color. The optimum was reached at: W = 37.8 g/100 g DM, P = 5.9 bar and t = 35 s.