Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, Brecce Bianche, 60131 Ancona, Italy.
Centre of Excellence for Digitalisation of Microbial Food Safety Risk Assessment and Quality Parameters for Accurate Food Authenticity Certification, University of Donja Gorica, Podgorica, Montenegro.
Food Res Int. 2024 Dec;197(Pt 1):115169. doi: 10.1016/j.foodres.2024.115169. Epub 2024 Sep 30.
The present study aims to deepen the knowledge of the microbiota, gross composition, physico-chemical and morpho-textural features, biogenic amines content and volatilome of Njeguški cheese, one of the most popular indigenous cheeses produced in Montenegro. Cheese samples were collected in duplicate from three different batches produced by three Montenegrin artisan producers. For the first time, the microbiota of Njeguški cheese was investigated using both culture-dependent techniques and metagenomic analysis. Coagulase positive staphylococci viable counts were below the detection limit of the analysis (<1 log cfu g). Salmonella spp., Listeria monocytogenes and staphylococcal enterotoxins were absent. However, relatively high viable counts of Enterobacteriaceae, Escherichia coli, Pseudomonadaceae and eumycetes were detected. Metataxonomic analysis revealed a core microbiome composed of Lactococcus lactis, Streptococcus thermophilus, Debaryomyces hansenii, and Kluyveromyces marxianus. Furthermore, the detection of opportunistic pathogenic yeasts such as Magnusiomyces capitatus and Wickerhamiella pararugosa, along with the variable content of biogenic amines, suggests the need for increased attention to hygienic conditions during Njeguški cheese production. Significant variability was observed in humidity (ranging from 38.37 to 45.58 %), salt content (ranging from 0.70 to 1.78 %), proteins content (ranging from 21.42 to 25.08 %), ash content (ranging from 2.97 to 4.05 %), hardness, springiness, and color among samples from different producers. Gas chromatography-mass spectrometry analysis showed a well-defined and complex volatilome profile of the Njeguški cheese, with alcohols (ethanol, isoamyl alcohol, phenetyl alcol), esters and acetates (ethyl acetate, ethyl butanoate, isoamyl acetate), ketones (acetoin, 2-butanone), and acids (acetic, butanoic, hexanoic acids) being the main chemical groups involved in aroma formation. This research will provide new insights into the still poorly explored identity of Njeguški cheese, thus serving as a first baseline for future studies aimed at protecting its tradition.
本研究旨在深入了解微生物群、总组成、物理化学和形态结构特征、生物胺含量和Njeguški 奶酪的挥发物，Njeguški 奶酪是黑山生产的最受欢迎的本土奶酪之一。从三个不同批次的三个黑山手工生产商那里采集了奶酪样本。首次使用培养依赖技术和宏基因组分析研究了 Njeguški 奶酪的微生物群。凝固酶阳性葡萄球菌的活菌数低于分析的检测限（<1 log cfu g）。未检出沙门氏菌、单核细胞增生李斯特菌和葡萄球菌肠毒素。然而，检测到较高数量的肠杆菌科、大肠杆菌、假单胞菌科和真菌。分类群分析显示，核心微生物组由乳球菌 lactis、嗜热链球菌、德巴利酵母和马克斯克鲁维酵母组成。此外，还检测到机会性致病性酵母，如巨形酵母和副卡瓦酵母，以及生物胺含量的变化，这表明在 Njeguški 奶酪生产过程中需要更加注意卫生条件。不同生产商的样品之间的湿度（38.37 至 45.58%）、盐含量（0.70 至 1.78%）、蛋白质含量（21.42 至 25.08%）、灰分含量（2.97 至 4.05%）、硬度、弹性和颜色存在显著差异。气相色谱-质谱分析显示，Njeguški 奶酪具有明确而复杂的挥发物谱，主要的化学物质包括醇（乙醇、异戊醇、苯乙醇）、酯和乙酸酯（乙酸乙酯、丁酸乙酯、异戊酸乙酯）、酮（乙酰丙酮、2-丁酮）和酸（乙酸、丁酸、己酸）。这项研究将为仍未被充分探索的 Njeguški 奶酪身份提供新的见解，从而为未来旨在保护其传统的研究提供第一个基准。
