Combined use of steam explosion, alkali, and microbial methods improving the yield, structure and properties of soluble dietary fiber from bamboo shoot shells

Abstract

Developing an effective method for extracting soluble dietary fiber (SDF) from bamboo shoot shell (BSS) is of great significance for the resource utilization of BSS. Here, we proposed the combinational strategy of steam explosion (SE), alkaline extraction (AE), and microbial extraction (ME) to enhance BSS-SDF yield. The highest yield of 28.28 % was achieved, and the properties of SDF were improved as follows: 1.4 g/g oil holding capacity (OHC), 0.61 g/g water holding capacity (WHC), 1.56 mmol/g glucose adsorption capacity (GAC), 87 % ABTS+ scavenging capability, and 74 % DPPH⋅ scavenging capability. The mechanism of the strategy was uncovered to understand the synergic effects on SDF production. SE destroyed lignin molecules and promoted AE to further hydrolyze the molecules of lignin and hemicellulose, resulting in a sparse and porous architecture. This is beneficial for Lactobacillus to utilize insoluble dietary fiber to make smaller size of SDF with various structures. Hopefully, the findings will be generalized in other SDF production.

Keywords: Alkaline extraction; Bamboo shoot shell; Microbial extraction; Soluble dietary fiber; Steam explosion.