Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università Politecnica delle Marche, via Brecce Bianche, Ancona, Italy.
Department of Agricultural, Forest, and Food Science, University of Turin, Largo Paolo Braccini 2, Grugliasco, Torino, Italy.
Food Res Int. 2022 Apr;154:111019. doi: 10.1016/j.foodres.2022.111019. Epub 2022 Feb 17.
The aim of the present study was to obtain information on the occurrence of bacteria and eumycetes in ready-to-eat fermented liver sausages manufactured by 20 artisan producers located in the Marche Region (Italy). To this end, culture-dependent analyses and metataxonomic sequencing were carried out. Physico-chemical parameters and volatilome of the fermented liver sausages were also studied. Finally, the presence of hepatitis E virus (HEV) was also assessed via real-time-RT-(q)PCR assays. Active microbial populations mainly represented by lactic acid bacteria, enterococci, coagulase-negative cocci, and eumycetes were detected. Enterobacteriaceae, Pseudomonadaceae, and sulfite-reducing anaerobes were not detected in most of the samples. Latilactobacillus sakei dominated in all the analyzed samples, reaching abundances up to 80%. Staphylococcus xylosus and Staphylococcus equorum were also detected. Among minority bacterial taxa, Weissella spp., Leuconostoc spp., Macrococcus caseolyticus, Brochothrix thermosphacta, Staphylococcus succinus, Lactobacillus coryniformis, Lactiplantibacillus plantarum, Lactococcus garviae, Psychrobacter spp., and Carnobacterium viridans were detected. The mycobiota was mainly composed by Debaryomyces hansenii that was present in all samples at the highest frequency. Among minority fungal taxa, Aspergillus spp., Penicillium spp., Kurtzmaniella zeylanoides, Candida spp., Yamadazyma spp., Scopulariopsis spp., Yarrowia spp., and Starmerella spp. were detected. Interestingly, associations between some taxa and some physico-chemical parameters were also discovered. The absence of HEV in all the samples attested a high level of safety. Finally, most of the VOCs detected in the analyzed fermented liver sausages belonged to six classes as: terpenoids, aldehydes, ketones, alcohols, esters, and acids. Nitrogen compounds, sulfur compounds, phenols, hydrocarbons, lactones, furans, and aromatic hydrocarbons were also identified. Several significant relationships were observed between mycobiota and VOCs.
本研究旨在获取意大利马尔凯地区 20 家手工生产的即食发酵肝香肠中细菌和丝状真菌的分布信息。为此，我们进行了基于培养的分析和分类组学测序。还研究了发酵肝香肠的理化参数和挥发物。最后，还通过实时 RT-(q)PCR 检测来评估戊型肝炎病毒 (HEV) 的存在。检测到以乳酸菌、肠球菌、凝固酶阴性球菌和丝状真菌为主的活跃微生物种群。大多数样品中未检出肠杆菌科、假单胞菌科和亚硫酸盐还原厌氧菌。在所有分析的样品中，都以片球菌属的戊糖片球菌为主，丰度高达 80%。还检测到葡萄球菌属的葡萄球菌和马红球菌。在少数细菌分类群中，检测到魏斯氏菌属、肠球菌属、巨球菌属、解淀粉芽孢杆菌、嗜热链球菌、乳杆菌、植物乳杆菌、乳球菌、假单胞菌属和海氏肠球菌。真菌群主要由在所有样品中出现频率最高的汉逊德巴利酵母组成。在少数真菌分类群中，检测到曲霉属、青霉属、节菱孢属、假丝酵母属、耶氏酵母属、枝孢属、帚霉属、酵母属和星状酵母属。有趣的是，还发现了一些分类群与某些理化参数之间的关联。所有样品中均未检测到 HEV，这证明了其具有较高的安全性。最后，在分析的发酵肝香肠中检测到的大多数 VOC 属于六类：萜烯类、醛类、酮类、醇类、酯类和酸类。还鉴定出了含氮化合物、含硫化合物、酚类、烃类、内酯类、呋喃类和芳烃类。在真菌群和 VOC 之间观察到了几个显著的关系。
