高产植酸酶乳酸菌发酵对黑豆面包蛋白质品质及烘焙特性的影响

Effect of High-yield Phytase Lactic Acid Bacteria Fermentation on Protein and Baking Quality of Black Bean Sourdough Bread

从实验室获得1株高产植酸酶乳酸菌(L-19)并应用于黑豆酸面团面包,同时选用不产植酸酶的乳酸菌(K-12)作为对照。通过分析面包氨基酸组成和营养指标、蛋白质体外消化率、质构特性、超微结构和感官评定,研究其对黑豆酸面团面包蛋白质营养及烘焙学特性的影响。结果表明:添加乳酸菌黑豆酸面团后,面包蛋白营养和烘焙品质都得到了明显改善,其中L-19酸面团面包(L-19SDB)效果最显著。与黑豆面包(BB)相比,L-19SDB植酸含量下降60.68%,蛋白质体外消化率由64.70%升高至73.93%,总氨基酸含量提高73%。同时与其他3组相比,L-19SDB有更好的氨基酸特征:其必需氨基酸与总氨基酸之比、必需氨基酸指数和生物价均为最高。面包烘焙品质方面,相比黑豆面包BB,L-19SDB和K-12SDB比容分别提高了31.45%和23.59%,硬度降低了68.79%和56.59%。通过ImageJ分析发现,L-19SDB芯囊组织更加均匀,感官评价总体可接受度最高(7.72分)。

Pediococcus acidilactici L-19,a strain capable of phytase with high yield,was used as a starter culture for black bean sourdough bread production.The effects of the starter culture on the protein nutritional quality and baking properties of black bean sourdough bread were studied by measuring amino acid composition,nutritional properties,in vitro protein digestibility(IVPD),textural characteristics,ultrastructure and sensory properties.The phytase negative strain K-12 was used as a control.The results showed that after addition of black bean sourdough fermented by lactic acid bacteria,both the protein nutritional quality and baking properties of bread were significantly improved,with the most significant effect being observed in black bean bread prepared using(L-19SDB).Compared with control black bean bread(BB),phytic acid content of L-19SDB was decreased by 60.68%while IVPD was increased from 64.70%to 73.93%,and total amino acid content was increased by 73%.Moreover,as compared with the other three groups,L-19SDB had a better amino acid profile in terms of the ratio of essential amino acids to total amino acids(E/T),essential amino acid index(EAAI)and biological value(BV).Compared with BB,L-19SDB and K-12SDB showed an increase in specific volume of 31.45%and 23.59%and a decrease in hardness of 68.79%and 56.59%,respectively.ImageJ analysis results showed that the stomatal distribution of L-19SDB crumb was more uniform and this bread had the highest overall acceptability(7.72 points out of 9).