Abstract:

In this study, alcohol was used to decolorize citrus peel powder, and then neutral water was used to separate water insoluble dietary fiber from the decolorized citrus peel powder. The separation process was optimized through orthogonal test design and the physical and chemical characteristics of obtained water insoluble dietary fiber (IDF) were investigated. The results showed that optimal separation conditions of IDF are as follows: material to water ratio (g/ml) 1:30, extraction temperature 70 ℃ and extraction time 90 min. The water holding capacity and expansion capability of IDF increase with temperature rising, but decrease with concentrations of sodium chloride solution and glucose solution declining. In neutral medium, water holding capacity and expansion capability of IDF exist, weak acidic or alkaline condition results in their increase, whereas they decrease with acidity or alkalinity increasing.

Key words: citrus peel, insoluble dietary fiber, water holding capacity, expansion capability