体外消化/Caco-2细胞模型分析发酵对面粉铁生物利用率的影响

中国居民膳食以谷物为主食,谷物中铁吸收率低是造成营养性贫血的主要原因,适当的加工方式可缓解谷物中植酸、多酚等物质对铁生物利用率(Fe bioavailability,FeBV)的影响。为考察酵母发酵对面粉FeBV的影响,采用体外消化/Caco-2细胞模型。结果表明,面团在发酵后pH值呈下降趋势,酸度呈上升趋势;多酚、植酸含量降低,植酸酶活性升高,以上各指标在发酵前后差异均具有统计学意义(P0.05)。发酵后面粉样品的FeBV增加约5%~38%,大多数面粉FeBV发酵前后比较,差异具有统计学意义(P0.05)。结论:发酵可降低面粉的pH值,增加酸度,有利于面粉多酚和植酸的降解以及植酸酶活力的升高,可有效提高面粉FeBV。

Effects of Fermentation on Iron Bioavailability in Wheat Flour Assessed with an in Vitro Digestion/Caco-2 Cell Model

Cereals are the most important staple crops in China. However, cereals are low in iron (Fe) absorption, which is attributed as the major reason of nutritional anemia. Proper processing can relieve the inhibition of substances like phytic acid and polyphenol in grains on iron bioavailability (Fe BV). In this experiment, an in vitro digestion/Caco-2 cell model was used to assess the impact of yeast fermentation on Fe BV in wheat flour. Results demonstrated that after fermentation, the pH of wheat flour dough declined and consequently the acidity showed a rising trend. In addition, the contents of polyphenol and phytic acid declined and the phytase activity increased. All the above changes were statistically significant (P < 0.05). Fe BV of flour samples increased by 5%–38% after fermentation, with significant differences (P < 0.05) being observed for most wheat flours compared with that measured before fermentation. Fermentation can reduce the pH of wheat flour and increase the acidity, thereby promoting the degradation of polyphenol and phytic acid, increasing phytase activity, and effectively improving Fe BV in wheat flour.