干酪乳杆菌对农家干酪抗氧化活性及在其模拟胃肠道中存活能力的研究

Effect of Cottage Cheese Containing Lactobacillus casei on the Antioxidant Activity and Survival in Simulated Gastrointestinal Conditions

摘要:

本研究利用向农家干酪加入干酪乳杆菌的方式，研究农家干酪的抗氧化活性及在模拟胃肠道中乳酸菌的存活能力。通过对DPPH自由基、羟自由基的清除的能力以及对铁的还原能力指标的测定，利用PH 4.6-SN及12%TCA-SN进行抗氧化活性分析。结果表明：在第30 d时，DPPH自由基的清除能力达到最高值，为316 μM Trolox，还原能力为0.647；羟自由基的清除率在第25 d时最高达到54.38%，在第30 d时有所下降。在对第20 d的农家干酪的水溶性提取液的冷冻干燥粉进行抗氧化活性的评价时，抗氧化活性得到提高；综上所述，添加干酪乳杆菌的农家干酪在储藏期内抗氧化活性显著增强。选择第20 d的农家干酪进行模拟胃肠道的存活能力研究，发现活菌数降低了5 log10 cfu/g，最终为7 log10 cfu/g，可起到益生作用。因此，加入干酪乳杆菌显著提高农家干酪抗氧化活性，农家干酪可以起到益生作用。

Abstract:

Cottage cheese containing Lactobacillus casei was produced to study its antioxidant activity and the viability of L. casei under simulated gastrointestinal conditions. The antioxidant activity was measured based on the capacity for scavenging DPPH and hydroxyl radicals and the ferric-reducing ability, which were analyzed using PH4.6-SN and 12% TCA-SN. The results show that on the 30th day, the DPPH-scavenging capacity reached the highest value, equivalent to 316 μM Trolox, and the reducing power was 0.647. The highest value for the scavenging of hydroxyl radicals was 67.45%, which was achieved on the 25th day, but decreased on the 30th day. The freeze-dried powder of the water-soluble extract showed increased antioxidant activity on the 20th day. In conclusion, the antioxidant activity of cottage cheese containing L. casei increased significantly during storage. Under conditions that simulated the gastro-intestinal tract, the viability of probiotic bacteria in cottage cheese decreased by 5 log10cfu/g and eventually reached 7 log10cfu/g, thus producing a beneficial effect. Therefore, adding L. casei could significantly increase the antioxidant activity of cottage cheese and have a beneficial effect.