乳酸菌发酵对莲藕全粉浆品质的影响

Effects of lactic acid bacteria fermentation on the quality of lotus root whole powder slurry

中文关键词:  莲藕全粉  乳酸菌  理化性质  品质

英文关键词:lotus root whole powder slurry  lactic acid bacteria  physical and chemical quality  organoleptic properties

中文摘要:

      目的 探究乳酸菌发酵对莲藕全粉浆品质的影响。方法 分别采用植物乳杆菌(Lactobacillus plantarum, Lp)、嗜酸乳杆菌(Lactobacillus acidophilus, La)、类干酪乳杆菌(Lactobacillus caseioides, Lc)以及3者的复合菌(compound bacteria, Cb)对莲藕全粉浆进行发酵, 测定发酵过程中的乳酸菌菌落数和pH变化, 并比较不同乳酸菌发酵对莲藕全粉浆理化品质及感官特性的影响。结果 Lp、Lc和Cb分别发酵12、6和8 h时, 莲藕全粉浆中的活菌数均达到8.00 log CFU/mL以上, pH从6.20±0.06下降到4.13±0.24。相比于未发酵莲藕全粉浆, Lp、La和Cb发酵均能使浆液的红色度(a*)显著降低。乳酸菌发酵均能使浆液黏度增加, 其中, La发酵的活菌数最多(9.40 log CFU/mL), 且黏弹性最大; 发酵后还原糖含量从609.11 mg/L下降到337.85~459.06 mg/L。发酵前后总酚变化不显著, 总黄酮含量从243.33 mg/L下降至144.77~200.95 mg/L。发酵积累了有机酸, 有机酸含量从2817.17 μg/mL增加到4164.11~5180.92 μg/mL。其中, 经过Lp发酵的乳酸、柠檬酸含量最高。在发酵莲藕全粉浆中共检出16种游离氨基酸, 氨基酸含量最高的是精氨酸。此外, 除Lp, 其余发酵组鲜味氨基酸总量显著上升(P<0.05)。不同乳酸菌发酵均能显著提高莲藕全粉浆的抗氧化性, 并改善其风味和口感。结论 本研究结果可为乳酸菌发酵莲藕全粉研发提供理论依据。

英文摘要:

      Objective To explore the effects of lactic acid bacteria fermentation on the quality of lotus root whole powder slurry. Methods The lotus root whole powder slurry was fermented separately by Lactobacillus plantarum (Lp), Lactobacillus acidophilus (La), Lactobacillus caseioides (Lc), and a composite of these 3 bacteria (Cb). The changes in the number of lactic acid bacteria and pH during fermentation were measured, and the effects of different lactic acid bacteria fermentation on the physicochemical quality and sensory characteristics of lotus root whole slurry were compared. Results When Lp, Lc and Cb were fermented for 12 , 6 and 8 h, respectively, the number of viable bacteria in the whole slurry of lotus root reached more than 8.00 log CFU/mL, and the pH decreased from 6.20±0.06 to 4.13±0.24. Fermentation by lactic acid bacteria also enhanced the viscoelasticity of the lotus root whole powder slurry. Notably, the La-fermented sample exhibited the highest viable bacteria count (9.40 log CFU/mL) and viscoelasticity. Apart from the Lc group, the red color values (a*) of the other three fermented lotus root whole powder slurry groups was decreased compared to the unfermented samples. Post-fermentation, the reducing sugar content decreased from 609.11 mg/L to 337.85–459.06 mg/L, the total phenol content remained unchanged, while the total flavonoid content decreased from 243.33 mg/L to 144.77–200.95 mg/L. Organic acids accumulated during fermentation, with organic acid content rising from 2817.17 μg/mL to 4164.11–5180.92 μg/mL. Additionally, the Lp-fermented sample demonstrated the highest lactic acid, citric acid content. The 16 kinds of free amino acids were detected in the fermented slurry, with arginine being the most abundant. Except for the Lp group, all other fermentation groups showed a significant increase in the total amount of umami amino acids (P<0.05). The fermentation of different lactic acid bacteria could significantly improve the antioxidant activity, flavor and taste of lotus root whole powder slurry. Conclusion The results can provide theoretical basis for the research and development of lotus root whole powder fermented by lactic acid bacteria.