Chessa Luigi, Paba Antonio, Dupré Ilaria, Daga Elisabetta, Fozzi Maria Carmen, Comunian Roberta
Agris Sardegna, Servizio per la Ricerca nelle Produzioni Animali, Associated Member of the JRU MIRRI-IT, Loc. Bonassai SS 291 km 18.600, 07100 Sassari, Italy.
Microorganisms. 2023 Mar 23;11(4):823. doi: 10.3390/microorganisms11040823.
Commercial starter cultures, composed of high concentrations of a few species/strains of lactic acid bacteria (LAB), selected based on their strong technological aptitudes, have been developed to easily and safely carry out food fermentations. Frequently applied to industrial productions, selected starter LAB easily become the dominant microbiota of products, causing a dramatic decrease in biodiversity. On the contrary, natural starter cultures, which usually characterize the most typical and Protected Designation of Origin (PDO) food products, are constituted by a multitude and an indefinite number of LAB species and strains, both starter and nonstarter, thus contributing to preserving microbial biodiversity. However, their use is not risk-free since, if obtained without heat treatment application, natural cultures can contain, together with useful, also spoilage microorganisms or pathogens that could be allowed to multiply during fermentation. In the present study, an innovative method for the production of a natural starter culture directly from raw ewe's milk, inhibiting the growth of spoilage and potentially pathogenic bacteria without applying any heat treatment, was described. The culture developed show a good degree of microbial biodiversity and could be applied to both artisanal and industrial scales, guaranteeing safety, quality constancy, technological performance reproducibility, preserving biodiversity and peculiar sensory characteristics, usually linked to traditional products, while overcoming the problems associated with the daily propagation of natural cultures.
商业发酵剂由少数几种基于强大技术能力挑选出的乳酸菌（LAB）高浓度组成，已被开发用于轻松、安全地进行食品发酵。常用于工业生产的精选发酵LAB很容易成为产品的主要微生物群，导致生物多样性急剧下降。相反，天然发酵剂通常是最典型的受保护地理标志（PDO）食品的特征，由大量且数量不确定的LAB物种和菌株组成，包括发酵剂和非发酵剂，因此有助于保护微生物多样性。然而，其使用并非没有风险，因为如果在不进行热处理的情况下获得，天然发酵剂除了含有有益微生物外，还可能含有腐败微生物或病原体，这些微生物可能在发酵过程中繁殖。在本研究中，描述了一种直接从生羊奶中生产天然发酵剂的创新方法，该方法无需进行任何热处理即可抑制腐败菌和潜在病原菌的生长。所开发的发酵剂显示出良好程度的微生物多样性，可应用于手工和工业规模，保证安全性、质量稳定性、技术性能可重复性，保护生物多样性和通常与传统产品相关的独特感官特性，同时克服与天然发酵剂日常传代相关的问题。
