Ibrahim Rasha A, Abd El-Salam Baraka A, Alsulami Tawfiq, Ali Hatem S, Hoppe Karolina, Badr Ahmed Noah
Dairy Research Department, Food Technology Research Institute, Agricultural Research Centre, Giza 12619, Egypt.
Food Science & Nutrition Department, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia.
Foods. 2023 Sep 24;12(19):3548. doi: 10.3390/foods12193548.
The milk's natural flora, or the starter, can preserve cheesemaking and allow for microbial competition. This investigation aimed to improve cheese safety and assess its characteristics using probiotic cell pellets (LCP) or cell-free extracts (CFS). Cheese samples were collected from different areas to investigate the current contamination situation. Six CFSs of probiotics were assessed as antifungal against toxigenic fungi using liquid and solid media and their aflatoxin reduction impact. The most effective CFS was chosen for cheese coating in nanoemulsion. Coated cheese with CFS, LCP, and LCP-CFS was assessed against control for changes in chemical composition, ripening indications, rheological properties, and microbiology. Results showed significant contamination levels in the collected samples, and toxic fungi were present. CFS has aflatoxins reducibility in liquid media. During cheese ripening, uncoated cheese showed higher fat, protein, salt content, soluble nitrogen, total volatile fatty acids, tyrosine, and tryptophan contents than coated samples, except for LCP-coating treatment. Cheese rheology indicated that coating treatments had the lowest hardness, cohesiveness, gumminess, chewiness, and springiness compared to uncoated cheese. Uncoated cheese had the highest yeast and mold counts compared to the treated ones. The LCP-CFS-coated cheese showed no cells for up to 40 days. Uncoated Ras cheese recorded slightly lower flavor, body, texture, and appearance scores than coated cheeses. In conclusion, coating cheese with nanoemulsion has antifungal and antiaflatoxigenic properties, even for LCP, CFS, and CFS-LCP, which could extend cheese shelf life.
牛奶中的天然菌群或发酵剂可维持奶酪制作过程并促进微生物竞争。本研究旨在通过使用益生菌细胞颗粒(LCP)或无细胞提取物(CFS)来提高奶酪安全性并评估其特性。从不同地区收集奶酪样本以调查当前的污染情况。使用液体和固体培养基评估了六种益生菌无细胞提取物对产毒真菌的抗真菌能力及其对黄曲霉毒素的降低作用。选择最有效的无细胞提取物用于纳米乳液形式的奶酪涂层。对用无细胞提取物、细胞颗粒以及二者混合物涂层的奶酪与对照奶酪进行了化学成分、成熟指标、流变学特性和微生物学方面变化的评估。结果显示,所收集的样本污染水平较高,且存在有毒真菌。无细胞提取物在液体培养基中具有黄曲霉毒素还原能力。在奶酪成熟过程中,除了细胞颗粒涂层处理外,未涂层的奶酪在脂肪、蛋白质、盐含量、可溶性氮、总挥发性脂肪酸、酪氨酸和色氨酸含量方面均高于涂层样本。奶酪流变学表明,与未涂层奶酪相比,涂层处理的奶酪硬度、内聚性、胶黏性、咀嚼性和弹性最低。与经过处理的奶酪相比,未涂层奶酪的酵母和霉菌数量最多。用细胞颗粒与无细胞提取物混合物涂层的奶酪在长达40天内均未检测到细胞。未涂层的拉斯奶酪在风味、质地、口感和外观评分方面略低于涂层奶酪。总之,用纳米乳液对奶酪进行涂层具有抗真菌和抗黄曲霉毒素生成的特性,即使是对于细胞颗粒、无细胞提取物以及二者混合物而言,这都可以延长奶酪的保质期。