Effects of Incorporated Emulsifiers Into Noodles on V-amylose Formation, Digestibility, and Structural Characteristics.

Abstract

There is growing interest in developing low glycemic alternatives to starchy foods. In this study, two emulsifiers, namely sodium stearoyl lactylate and egg yolk, were incorporated into the formulation of noodles (EYN and SSLN), and their effects on V-amylose formation, digestibility and structural characteristics of the noodles were investigated. The emulsifiers facilitated V-amylose formation in the noodles, indicated by the complexing indices. The EYN and SSLN exhibited markedly high resistant starch contents compared to the control noodle. The logarithm of slope plot analysis showed that the EYN and SSLN had low first-phase rate constants compared to the control noodles, suggesting a barrier effect to digestive enzymes exerted by V-amylose. The SSLN and EYN displayed a mixture of B- and V-type patterns with higher crystallinities and two distinct spectral features of the bands at 2854cm- 1 and 1746cm- 1 compared to the control noodles. Polarized light micrographs of the SSLN and EYN exhibited vague contours of numerous irregularly shaped starch fragments with strong birefringence. These results suggest that forming V-amylose crystals in the SSLN and EYN was responsible for their increased resistance to digestion through reformulating emulsifiers in modifying their nutritional functionalities.