Effects of nine-steam-nine-bask processing on the bioactive compounds content, bioaccessibility, and antioxidant capacity of Polygonatum cyrtonema Hua

• Published in: Journal of functional foods 2024-06, Vol.117, p.106236, Article 106236
• Main Authors: Wang, Xiling, Cheng, Yanan, Zheng, Bing, Chen, Yi, Xie, Jianhua, Hu, Xiaobo, Qin, Xiaoting, Song, Jiajun, Qiu, Yue, Yu, Qiang
• Format: Article
• Language: English
• Subjects: Antioxidant activity; Bioaccessibility; In vitro digestion; Major bioactive substances; Nine-steam-nine-bask processing; Polygonatum cyrtonema Hua
• ISSN: 1756-4646; 2214-9414
• DOI: 10.1016/j.jff.2024.106236

[Display omitted] •The TPC, TSaC, and RSC of PCH increased with the number of steam-bask times.•The highest bioaccessibility of total phenol was found in the NSNB sample.•The TPC and RSC of the NSNB sample were the highest during digestion.•The NSNB sample showed the highest antioxidant activity in various aspects.•TPC and RSC of PCH were closely related to the DPPH value and the ABTS value. The traditional ‘nine-steam-nine-bask’ method of Polygonatum cyrtonema Hua (PCH) has been controversial due to nine-cycle requirement. This study employed in vitro digestion to investigate changes in bioactive substances, bioaccessibility, and antioxidant activity of PCH at different steam-bask times. It revealed the correlation between bioactive substances and antioxidant activity in PCH, and validated the ‘nine-steam-nine-bask’ process’s efficacy. In undigested samples, total phenol content (TPC), reducing sugar content (RSC), and DPPH and ABTS activities increased with more cycles, peaking in the nine-cycle sample at 7.627 mg GAE/g DW, 465.333 mg GE/g DW, 17.698, and 36.986 μmol VCE/g DW. Similar trends were observed throughout digestion. Total sugar (755.96 mg GE/g DW) and total saponin content (1.35 mg DE/g DW) plateaued during gastrointestinal digestion. Correlation analysis further revealed close relationships between bioactive substances and antioxidant activity. Multivariate statistical analysis confirmed that nine cycles maximized the distinction between steam-bask and non-steam-bask PCH.