Comprehensive investigation into the effects of yeast dietary fiber and temperature on konjac glucomannan/kappa-carrageenan for the development of fat analogs

In this study, yeast dietary fiber (YDF) was incorporated into konjac glucomannan/kappa-carrageenan (KGM/κ-KC) for the development of fat analogs, and the impact of YDF on the gelation properties and behavior of KGM/κ-KC composite gels was assessed. YDF improved the composite gel whiteness value, and affected the mechanical properties of the composite gel, especially enhancing its hardness, and decreasing its chewiness, elasticity, and gel strength, making it more similar to porcine back fat. When the yeast dietary fiber content was 0.033 g/mL and the heating temperature was 80 °C (T80-2), the textural properties of the composite gel were closest to porcine back fat. The frequency sweep results suggested that YDF incorporation led to enhancement of the intermolecular interaction and intermixing and interaction among more easily at higher processing temperatures (80 °C and 90 °C). By scanning electron microscopy, the fatty surface of porcine back fat was flat and covered with a large amount of oil, while KGM/κ-KC/YDF composite gels developed a dense, stacked network structure. YDF caused more fragmented, folded, and uneven structures to emerge. Overall, YDF could influence the gel behavior of KGM/κ-KC composite gels, and change their colors and mechanical properties. This work could serve as a guide for preparing fat analogs with KGM/κ-KC composite gels.