Physical properties and chemical forces of extruded corn starch fortified with soy protein isolate. (8th September 2017)

• Record Type: Journal Article
• Authors: Chen, Biying; Yu, Chen; Liu, Junfei; Yang, Yuling; Shen, Xinchun; Liu, Shaowei; Tang, Xiaozhi
• Is Part Of: International journal of food science & technology. Volume 52:Number 12(2017)
• Page Start: 2604
• Page End: 2613
• Publication Date: 2017-09-08
• Subjects: Chemical forces -- corn starch -- correlation analysis -- physical properties -- soy protein isolate; Food industry and trade -- Periodicals; 664
• DOI: 10.1111/ijfs.13547
• Languages: English
• ISSNs: 0950-5423

Abstract

Summary: The effect of soy protein addition on physical properties of extruded corn starch was studied. The correlations between the chemical bonds in proteins and the physical properties of extrudates were analysed. Increasing soy protein isolate content resulted in higher expansion ratio (ER) but lower bulk density (BD), hardness, water solubility index (WSI), degree of starch gelatinisation (DSG), content of sulphydryl (SH) groups and protein solubility in phosphate buffer. In the other hand, increasing the processing temperature resulted in higher ER, water absorption index, DSG, contents of the SH group and disulphide (SS) bond but in lower specific mechanical energy, BD, hardness and WSI. The results indicated that changes in the chemical bonds in proteins had a significant effect on the apparent physical properties of extrudates. More protein–protein and protein–starch cross‐linking reactions occurred through new chemical linkages, such as the nondisulphide covalent bonds and hydrogen bonds, which are beneficial to the expansion of starch‐based products. Abstract : The addition of SPI to corn starch based extrudates resulted in a higher quality of starch based snack foods. More protein‐protein and protein‐starch cross‐linking reactions occurred through new chemical linkages.