Meloni Maria Pina, Piras Francesca, Siddi Giuliana, Migoni Mattia, Cabras Daniela, Cuccu Mario, Nieddu Gavino, McAuliffe Olivia, De Santis Enrico Pietro Luigi, Scarano Christian
Department of Veterinary Medicine, University of Sassari, Via Vienna, 2, 07100 Sassari, Italy.
Cooperativa Allevatori Ovini Formaggi Soc. Coop. Agricola, Loc. "Perda Lada" Fenosu, 09170 Oristano, Italy.
Foods. 2023 Oct 16;12(20):3797. doi: 10.3390/foods12203797.
The composition and physicochemical characteristics of short-aged Pecorino Sardo PDO (Protected Designation of Origin) cheese makes it permissive to growth. The PDO product specification stipulates that this cheese is produced with whole sheep's milk inoculated with cultures from the area of origin. Therefore, the use of bioprotective cultures for the inhibition of pathogens in PDO cheeses is allowed only if autochthonous microorganisms are used. Furthermore, bioprotective cultures are generally used on the cheese surface to prevent the outgrowth of , the application of which can be time-consuming and require specialist technical knowledge. In this study, we examine the direct addition of bioprotective cultures to the cheese vat and compare the activity of a commercial bioprotective culture () and an autochthonous lactic acid bacterium with bioprotective properties ( sups), for the inhibition of in Pecorino Sardo PDO cheese. Three types of Pecorino Sardo PDO cheese were made with bioprotective cultures added directly to the cheese milk along with the starter inoculum: PSA, with the commercial bioprotective culture; PSB, with the autochthonous bioprotective culture; and a CTRL cheese with no bioprotective culture. A challenge test was performed on each of these cheeses by artificially contaminating the cheese surface with (2 Log10 CFU/g). Three batches of each cheese type were analyzed to enumerate mesophilic and thermophilic lactic acid bacteria and to investigate the growth potential of during manufacturing, at the end of ripening, at the end of shelf-life, and after 180 days from cheese production. Both bioprotective cultures tested in this study showed inhibitory action against the pathogen with 0.3-1.8 Log10 CFU/g (colony-forming unit per gram) reduction levels. The autochthonous organism, , was as effective as the commercially supplied culture, and the addition of the bioprotective cultures to the cheese-making procedure offered protection against . The direct addition of bioprotective cultures to the making procedure of Pecorino Sardo PDO cheese is a potentially innovative strategy to improve the safety of this product.
短期成熟的佩科里诺·萨尔多法定产区（PDO，受保护的原产地名称）奶酪的成分和理化特性使其易于生长。PDO产品规范规定，这种奶酪是用接种了来自原产地培养物的全脂羊奶制作的。因此，只有使用本地微生物时，才允许在PDO奶酪中使用生物保护培养物来抑制病原体。此外，生物保护培养物通常用于奶酪表面以防止其生长，其应用可能耗时且需要专业技术知识。在本研究中，我们研究了将生物保护培养物直接添加到奶酪缸中，并比较了一种商业生物保护培养物（）和一种具有生物保护特性的本地乳酸菌（亚种）对佩科里诺·萨尔多PDO奶酪中抑制作用的活性。制作了三种类型的佩科里诺·萨尔多PDO奶酪，将生物保护培养物与发酵剂接种物一起直接添加到奶酪牛奶中：PSA，添加商业生物保护培养物；PSB，添加本地生物保护培养物；以及不添加生物保护培养物的对照奶酪。对每种奶酪进行挑战试验，通过用（2 Log10 CFU/g）人工污染奶酪表面。对每种奶酪类型的三批样品进行分析，以计数嗜温性和嗜热性乳酸菌，并研究在制作过程中、成熟结束时、保质期结束时以及奶酪生产后180天时的生长潜力。本研究中测试的两种生物保护培养物均显示出对病原体的抑制作用，降低水平为0.3 - 1.8 Log10 CFU/g（每克菌落形成单位）。本地生物体与商业供应的培养物一样有效，并且在奶酪制作过程中添加生物保护培养物可提供针对的保护。将生物保护培养物直接添加到佩科里诺·萨尔多PDO奶酪的制作过程中是提高该产品安全性的一种潜在创新策略。
