酸浆水中3种菌株的产酸能力及抗氧化活性

Titratable acidity and antioxidant activities of fermented Tofu whey

为了获得优质的豆腐凝固剂,应用从自然发酵的酸浆水中分离的3个菌株(解淀粉杆菌L5、L6以及阿米塞毕赤氏酵母Y),分别进行单菌、双菌和三菌发酵试验,研究其产酸能力和抗氧化活性。结果表明:两个解淀粉乳杆菌菌株均可在豆腐黄浆水生长产酸,其中菌株L6发酵豆腐黄浆水产酸能力更强,35℃发酵60 h后,酸度达到65.11oT,而3个菌株进行组合发酵时也有较强的产酸能力,在发酵60 h后,酸度也达到65.44oT。经过解淀粉乳杆菌L6发酵后,酸浆水还原Fe3+的能力和清除DPPH自由基的能力略有增加,螯合Fe2+的能力显著增强,在发酵48 h时达到54.45%;与L6不同,解淀粉乳杆菌L5发酵制备的酸浆水螯合Fe2+的能力随着发酵时间延长而明显下降;阿米塞毕赤氏酵母Y发酵制备的酸浆水具有良好的还原Fe3+的能力、清除DPPH自由基的能力以及螯合Fe2+的能力;当3个菌株组合发酵时,其产酸能力以及酸浆水还原Fe3+的能力、清除DPPH自由基的能力和螯合Fe2+的能力均比L6+Y双菌株发酵制备的酸浆水强。综合得出,在发酵豆腐黄浆水产酸和抗氧化能力方面,单菌株L6最优,组合发酵时L5+L6+Y为最优。

In order to obtain tofu coagulator of high quality,investigated the titratable acidity and antioxidant activities of the fermented tofu whey by 3 strains of Lactobacillus amylolyticus L5,L6 and Pichia amethionina Y,which were separated and purified from natural fermented tofu whey,with the single,double and three strains as starters.The results indicated that both of the Lactobacillus were able to grow and produce acid in the tofu whey,the titratable acidity of fermented tofu whey by L6 for 60 h reached 65.11 oT at the temperature of 35 ℃,displaying a better capacity in producing acids,while,it also reached 65.44 oT when the tofu whey was fermented by the starter of L5 ＋ L6 ＋ Y under the same condition.The ability of reducing Fe3 ＋and scavenging DPPH radical of fermented tofu whey by L6 increased slightly,but the power of iron（II）-chelating significantly enhanced,with the power of 54.45%.In contrast,the power of iron（II）-chelating of fermented tofu whey by L5 decreased with the increasing fermentation time.The abilities of producing acids,reducing Fe3 ＋,iron（II）-chelating and DPPH radical scavenging of fermented tofu whey by L5 ＋ L6 ＋ Y were strong than those by L6 ＋ Y.In summary,Lactobacillus amylolyticus L6 was the best strain to produce acid and antioxidant activities in tofu whey among the 3 single strains,while,L5 ＋ L6 ＋ Y was the best combination among the multi-strain starters.