Changes in phenolic profile, physicochemical properties and sensory attributes of steamed bread fortified with golden kiwifruit (Actinidia chinensis) flour during processing.

BACKGROUND

Chinese steamed bread (CSB) is a traditional East Asian staple. Its texture and nutrition depend on the gluten and starch content of the wheat flour that it contains. Incorporation of golden kiwifruit, which is rich in dietary fiber, vitamin C, and phenolic antioxidants, offers a novel fortification strategy. It may improve dough functionality and sensory attributes and provide nutritional benefits while utilizing kiwifruit waste.

RESULTS

Increasing kiwifruit powder levels (0 - 500 g kg-1) significantly reduced protein and starch content, affecting the water absorption, mixing time, and rheology of dough. Incorporation of kiwifruit decreased pasting viscosities, starch gelatinization enthalpy and in vitro starch digestibility but increased phenolic content, antioxidant potential, and microbiological shelf life. Structural alterations and enzymatic activity during fermentation improved the extractability of phenolics and vitamin C, while thermal processing and storage led to degradation and reduced availability of the bioactives due to oxidation and starch retrogradation. Textural analysis revealed increased hardness and chewiness, attributed to dietary fiber and gluten network disruption, but staling rates declined. Color analysis indicated darker crumbs, aligning with sensory evaluation with lower acceptability.

CONCLUSION

Kiwifruit powder fortification markedly enhanced CSB's nutritional profile and modulated dough rheology, pasting properties and thermal behavior. Although kiwifruit flour disrupted gluten network formation, leading to firmer, less elastic bread and darker crumb, it greatly prolonged freshness by slowing starch retrogradation and microbial spoilage. An incorporation level of up to 200 g kg-1 kiwifruit flour offered an optimal balance between functional benefits and consumer acceptability, supporting its application in traditional bakery products. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.