酒曲中乳酸菌的筛选及其在板栗糯米饮料发酵中的应用

Screening of Lactic Acid Bacteria from Jiuqu and Its Application in the Fermentation of Chestnut Glutinous Rice Beverage

为筛选出适合植物基质发酵的优良乳酸菌。本文以米曲为目标乳酸菌的供体,筛选高产酸、耐胃肠环境能力良好的乳酸菌,并评估了乳酸菌的抗氧化活性及其在板栗糯米饮料中的发酵能力。从酒曲中共分离出84株乳酸菌,其中有38株的产酸量≥10 g/L;在进一步的耐酸耐胆盐、模拟胃肠实验中,共筛出3株乳酸菌株;经16S rDNA鉴定这3株乳酸菌均为戊糖片球菌(Pediococcus pentosaceus)。菌株DH16发酵上清液的DPPH自由基、羟自由基清除率和SOD酶活力最高,分别为98.56%、42.27%和20.3 U/mL;完整细胞悬液中,菌株DH20的DPPH自由基清除率最高(22.49%),菌株DH16的羟自由基清除率最高(22.77%)。利用3株乳酸菌作为发酵剂所得的板栗糯米饮料口感均衡、抗氧化能力较强,因此本文筛出的3株乳酸菌在植物基饮料开发方面具有良好的应用前景。

In order to screen the excellent lactic acid bacteria suitable for plant substrate fermentation.In this paper,rice koji was used as the donor of target lactic acid bacteria,to screen lactic acid bacteria with high acid yield and good tolerance to gastrointestinal environment.And the antioxidant activity of lactic acid bacteria and its fermentation ability in chestnut glutinous rice beverage were evalutated.The results showed that 84 strains of lactic acid bacteria were isolated from Jiuqu,of which 38 strains produced acid≥10 g/L.In further acid-tolerant,bile salt-tolerant and simulated gastrointestinal tests,three target strains were screened.All the three strains of lactic acid bacteria were identified as Pediococcus pentosaceus though 16 S rDNA.In the fermentation supernatant,the DPPH radical scavenging rate,hydroxyl radical scavenging rate and SOD enzyme activity of strain DH16 were the highest,which were 98.56%,42.27% and 20.3 U/mL respectively.In the intact cell suspension,the DPPH radical scavenging rate of strain DH20 was the highest(22.49%),and the hydroxyl radical scavenging rate of strain DH16 was the highest(22.77%).The chestnut glutinous rice beverage separately fermented by three strains of lactic acid bacteria has a balanced taste and strong antioxidant capacity.Therefore,the three strains of lactic acid bacteria screened in this paper have a good application prospect in the development of plant-based beverages.