The physicochemical and simulated digestive characteristics of yam flours processed by different thermal processing methods

Ya Huang; Mei Deng; Xuchao Jia; Lihong Dong; Fei Huang; Qin Ma; Mingwei Zhang; Shan Liang; Yanxia Chen; Fengjuan Li; Ruifen Zhang

doi:10.1016/j.foodchem.2026.149101

The physicochemical and simulated digestive characteristics of yam flours processed by different thermal processing methods

Food Chem. 2026 Apr 2:514:149101. doi: 10.1016/j.foodchem.2026.149101. Online ahead of print.

Authors

Ya Huang¹, Mei Deng², Xuchao Jia³, Lihong Dong³, Fei Huang³, Qin Ma³, Mingwei Zhang³, Shan Liang³, Yanxia Chen³, Fengjuan Li⁴, Ruifen Zhang⁵

Affiliations

¹ Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China; College of Food Science and Engineering, Tianjin University of Science &Technology, Tianjin 300457, China.
² Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
³ Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China.
⁴ College of Food Science and Engineering, Tianjin University of Science &Technology, Tianjin 300457, China.
⁵ Sericultural & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China. Electronic address: ruifenzhang@163.com.

PMID: 41965952
DOI: 10.1016/j.foodchem.2026.149101

Abstract

This study investigated the digestibility and colonic fermentation characteristics of Dioscorea fordii flours processed by steaming-refrigeration (SRY), extrusion-refrigeration (ERY), and baking (BY). SRY and ERY exhibited 31.19% and 18.52% higher resistant starch contents than BY, likely due to the higher degree of starch structural order. Simulated digestion indicated medium estimated glycemic indices (eGI) for SRY (67.38) and ERY (68.48), and a high eGI for BY (75.69). Allantoin was well preserved across all thermally processed yam flours. Saponins and polyphenols decreased by 19.15% and 28.86% in ERY, respectively. Simulated digestion and fermentation revealed that BY released more bioaccessible bioactive components, while SRY and ERY promoted greater production of short-chain fatty acids (SCFAs) and enriched beneficial bacteria, including Bifidobacterium and Ligilactobacillus. Steaming-refrigeration and extrusion-refrigeration effectively modulate starch digestibility of yam flour and may benefit glucose metabolism through enhanced SCFA production and probiotic enrichment. They are more suitable for processing glucose-friendly foods.

Keywords: Colonic fermentation; Digestibility of starch; Estimated glycemic index; Yam flour.