ABSTRACT Dietary fiber (DF) and phenolics are commonly used as two distinct natural active components to modify the properties of starch, particularly its digestibility. Their interaction causes property changes in related conjugates/complexes, but it remains unknown whether the pattern includes starch regulation. Given that citrus peel fiber is known for its abundant bound phenolics (BP), this study aimed to evaluate the effects of the presence or absence of BP in lemon peel soluble DF, as well as individual BP, on gelatinized corn starch (CS) properties. Compared with the fiber‐phenolic conjugate (SDF‐P), CS supplemented with 8% dephenolized fiber (dp‐SDF) exhibited a weaker reduction in viscosity during gelatinization. Furthermore, the viscoelasticity, structural strength, and freeze‐thaw stability of gelatinized gels in dp‐SDF group were improved. While 8% BP supplementation decreased the hardness and chewiness of gels compared to the blank, it improved the storage/loss modulus and stability in the first few freeze‐thaw cycles. In vitro simulated digestion tests showed that all three components increased resistant starch content in freeze‐dried gelatinized samples, thereby enhancing overall digestibility resistance. BP had the strongest effect, whereas SDF‐P was the least effective. Characterization of crystal, molecular, and microscopic structures revealed that they all formed reinforced structural networks with CS, though differential structural modifications likely contributed to their varying capacities to inhibit digestibility. This study highlights the critical role of phenolic conjugation in how DF affects the physicochemical properties and digestibility of starch, while providing novel insights into developing lemon peel for improving processing and nutritional attributes of starchy foods.
Sun et al. (2026) studied this question.