Effects of microwave and conventional heating on physicochemical, digestive, and structural properties of debranched quinoa starch-oleic acid complexes with different water addition

BackgroundA starch-lipid complex is a new type of resistant starch, which is of great importance for the prevention of chronic diseases such as diabetes. Most starch-lipid complexes usually need to be treated by heating to make them suitable for a variety of applications, and starch-based foods are generally not edible without a heat-treatment process. However, the digestion and structural properties of the starch-lipid complex will be changed after heating. In this study, microwave and conventional heating were used to treat debranched quinoa starch-oleic acid complexes (DQS-OA) with different water addition conditions, and the effects of the two methods on the physicochemical, digestive, and structural properties of DQS-OA were compared. ResultsThe results of in vitro digestibility showed that the resistant starch content (235.34-269.55 g kg(-1)) of the conventional heating-treated samples was significantly higher than that the microwave-treated samples (141.51-157.99 g kg(-1)). Moreover, after microwave treatment, the short-range molecular order and crystalline structure of DQS-OA were destroyed and the particle size became smaller. In contrast, the thermal stability, enthalpy, and crystallinity of the complexes after conventional heating were improved. The ratio at 1047/1022 cm(-1) of complexes has also been increased. ConclusionThis study demonstrated that conventional water-bath heating was better than microwave heating in increasing digestion resistance, improving the short-range and long-range molecular order, and promoting the formation of DQS-OA. With an increase in water addition, the influence of microwave or water-bath treatment on the properties of DQS-OA became greater. (c) 2023 Society of Chemical Industry.

Automated summary

This study compared the effects of microwave and conventional heating on the physicochemical, digestive, and structural properties of debranched quinoa starch-oleic acid complexes. The results showed that the resistant starch content was higher in the samples treated with conventional heating compared to microwave treatment. Additionally, microwave treatment led to changes in the molecular structure and particle size of the starch-lipid complexes, while conventional heating improved their thermal stability and crystallinity.