Cross-linked modifications of starches from colored highland barley and their characterizations, digestibility, and lipolysis inhibitory abilities in vitro

To promote the stability and functionality of native starch from colored highland barley (CHBS), the cross-linked modifications with sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) and citric acid were conducted to prepare CHB resistant starches (CHRSs), whose physicochemical characteristics, digestibility, and lipolysis inhibitory potential were also assessed. Results showed that the resistant starch amounts in CHBS were significantly increased after cross-linking and differed slightly among CHRSs. Citric acid modification of CHBS resulted in significantly higher amylose amounts, solubilities, swelling powers, and water-binding capacities than those under STMP/STPP modification within the cultivars (p < 0.05), with their crystalline patterns of A-type (white and blue) and CB-type (black). STMP/STPP modified CHBS exhibited higher degrees of crystalline regions with B-type crystalline patterns. Due to the differences in structural properties and structure-based morphology, STMP/STPP cross-linked CHBS showed lower digestibility and citric acid cross-linked CHBS exhibited higher lipolysis inhibitory activities. Besides, the cross-linked modifications demonstrated more enhancements in functionalities of starches from white and blue cultivars than black cultivar.