功能性乳酸菌发酵赤小豆乳的理化及抗氧化特征

Physicochemical and Antioxidant Characteristics of Rice Bean Milk Fermented by Functional Lactic Acid Bacteria

赤小豆作为“全谷物”作物,具有很高的营养和药用价值。利用功能性乳酸菌发酵赤小豆乳开发新型功能食品可充分利用其营养成分。研究分析了赤小豆乳发酵过程中植物乳杆菌Lp-G18的生长特性、理化特性、植物化学物质及体外抗氧化活性的动态变化。结果表明,植物乳杆菌LpG18具有利用赤小豆乳作为发酵基质的潜力,其菌落总数从5.02 lg cfu/mL增加至8.11 lg cfu/mL。相比未发酵的赤小豆乳,发酵48 h后,赤小豆乳中pH值、可滴定酸、还原糖、可溶性蛋白、平均粒径和γ-氨基丁酸等理化特性变化显著(P<0.05)。此外,发酵48 h后赤小豆乳中总黄酮和总多酚等植物化学物质含量比未发酵赤小豆乳提高了1.2倍和2.2倍,且DPPH自由基和羟自由基清除能力增加了20.52%和14.17%。该结果为豆制品深加工及其附加值的提高提供了有效思路和数据基础。

Rice bean,a kind of“whole grain”crop,contains high nutritional and medicinal values.Rice bean fermentation by functional lactic acid bacteria is a meaningful study for development of novel functional foods.The dynamic changes of Lactobacillus plantarum Lp-G18 growth characteristics,physicochemical properties,phytochemical substances and in vitro antioxidant activities of rice bean milk were analyzed during the fermentation.The results show that L.plantarum Lp-G18 had the potential of utilizing rice bean milk as the fermentation substrate,which the total number of colonies increased from 5.02 lg cfu/mL to 8.11 lg cfu/mL.Compared with unfermented rice bean milk,after 48 h of fermentation,the physicochemical characteristics such as pH value,titratable acid,reducing sugar,soluble protein,mean particle size andγ-aminobutyric acid in rice bean milk changed significantly(P<0.05).In addition,the content of phytochemicals substances such as total flavonoids and total polyphenols in rice bean milk after fermentation for 48 h increased by 1.2,2.2 times compared with that of the unfermented rice bean milk,and the scavenging capacity of DPPH free radicals and hydroxyl radicals increased by 20.52%and 14.17%.This study provides an effective idea and data basis for the deep processing and the increase of the added value of soy products.