Li Changkun, Song Jihong, Kwok Lai-Yu, Wang Jicheng, Dong Yan, Yu Haijing, Hou Qiangchuan, Zhang Heping, Chen Yongfu
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education P.R.C. Inner Mongolia Agricultural University, Synergetic Innovation Center of Food Safety and Nutrition, Huhhot 010018, P. R. China.
J Dairy Sci. 2017 Apr;100(4):2512-2525. doi: 10.3168/jds.2016-11864. Epub 2017 Feb 16.
This study aimed to evaluate the influence of 9 Lactobacillusplantarum with broad-spectrum antibacterial activity on fermented milk, including changes to the fermentation characteristics (pH, titration acidity, and viable counts), texture profile, relative content of volatile compounds, and sensory evaluation during 28-d storage at 4°C. First, L. plantarum IMAU80106, IMAU10216, and IMAU70095 were selected as candidates for further study because of their excellent coagulation and proteolytic activities. Subsequently, these L. plantarum strainswere supplemented to fermented milk produced by commercial yogurt starters (Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus) and a panel of parameters reflecting product quality was subsequently monitored during 28 d of postfermentation storage. The pH value and titration acidity of the fermented milk mildly fluctuated, whereas the L. plantarum viable counts remained stable along the storage period. Fourteen key volatile compounds were detected in the fermented milk by gas chromatography-mass spectrometry, and some flavor compounds were uniquely present in the L. plantarum-supplemented fermented milk (including 2,3-pentanedione, acetaldehyde, and acetate). No significant difference was shown in the sensory evaluation scores between samples with or without L. plantarum supplementation, but a gradual decrease was observed over storage in all samples. However, when L. plantarum was added, apparent shifts were observed in the overall quality of the fermented milk based on principal component analysis and multivariate ANOVA, particularly in the texture (adhesiveness) and volatile flavor compound profiles (acetaldehyde). Compared with L. plantarum IMAU80106 and IMAU10216, both the texture and volatile flavor profiles of IMAU70095 were closest to those of the control without adding the adjunct bacteria, suggesting that IMAU70095 might be the most suitable strain for further application in functional dairy product development. The current work has explored the potential of applying L. plantarum in fermented milk by performing thorough physical and chemical characterization. Our work is of intense interest to the dairy industry.
本研究旨在评估9株具有广谱抗菌活性的植物乳杆菌对发酵乳的影响，包括在4°C下储存28天期间发酵特性（pH值、滴定酸度和活菌数）、质地剖面、挥发性化合物相对含量以及感官评价的变化。首先，由于植物乳杆菌IMAU80106、IMAU10216和IMAU70095具有优异的凝乳和蛋白水解活性，被选为进一步研究的候选菌株。随后，将这些植物乳杆菌菌株添加到由商业酸奶发酵剂（嗜热链球菌和德氏保加利亚乳杆菌）生产的发酵乳中，并在发酵后储存的28天内监测反映产品质量的一系列参数。发酵乳的pH值和滴定酸度略有波动，而植物乳杆菌的活菌数在储存期间保持稳定。通过气相色谱-质谱联用仪在发酵乳中检测到14种关键挥发性化合物，一些风味化合物仅存在于添加植物乳杆菌的发酵乳中（包括2,3-戊二酮、乙醛和乙酸酯）。添加或不添加植物乳杆菌的样品在感官评价得分上没有显著差异，但所有样品在储存过程中得分均逐渐下降。然而，添加植物乳杆菌后，基于主成分分析和多变量方差分析，发酵乳的整体质量出现明显变化，特别是在质地（粘附性）和挥发性风味化合物谱（乙醛）方面。与植物乳杆菌IMAU80106和IMAU10216相比，IMAU70095的质地和挥发性风味谱与未添加辅助细菌的对照最接近，这表明IMAU70095可能是功能乳制品开发中最适合进一步应用的菌株。目前的工作通过进行全面的物理和化学表征，探索了植物乳杆菌在发酵乳中的应用潜力。我们的工作对乳制品行业具有重要意义。
