Lenz Romina M, Guitián M Virginia, Villalva Fernando J, Goncalvez de Oliveira Enzo, Soria M Cecilia, Audisio M Carina, Ibarguren Carolina
Instituto de Investigaciones para la Industria Química, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Salta (INIQUI-CONICET-UNSa), Av. Bolivia 5150, A4408FVY Salta, Argentina.
Facultad Ciencias de la Salud, Universidad Nacional de Salta (UNSa), Av. Bolivia 5150, A4408FVY Salta, Argentina.
Int J Food Microbiol. 2025 Feb 16;430:111062. doi: 10.1016/j.ijfoodmicro.2025.111062. Epub 2025 Jan 11.
Listeria monocytogenes can contaminate refrigerated ready-to-eat foods, such as cheeses. Enterocins, with a strong listericidal effect, constitute a natural alternative to control this pathogen in food. To optimize their antimicrobial action in food matrices, bacteriocins can be immobilised in edible coatings through spray drying technology which allows the large-scale production of microcapsules of bioactive molecules. The aim of this work was to evaluate the antimicrobial effectiveness of Enterococcus avium DSMZ17511 bacteriocins, obtained in a low-cost culture broth (HS-L), spray-dried assaying different thermoprotective materials (maltodextrin, cheese whey and brea gum), and incorporated into agar-based active coatings applied on goat cheese pieces artificially contaminated with L. monocytogenes 99/287. The bacteriocin solution (BS) powders, labelled HS-L BS, maintained the antimicrobial activity even after 90 days of storage, with titres up to 128,000 UA/g, with the least thermoprotective effect exerted by brea gum (64,000-32,000 UA/g). An increase in antimicrobial titre was observed for all bacteriocin powders after 3 months, despite storage conditions; probably due to a release effect from the encapsulated bacteriocin or a combined release and gradual dehydration effect of the encapsulating matrix. Also, the dried products stored at 25 °C hydrated easily, while refrigeration or freezing did not affect the powders texture. For coatings applied on fresh goat cheese, only a difference of 0.5 log cfu/mL was observed between the viability of L. monocytogenes in the contaminated active-coated cheese and the control without coating. Instead, for the commercial goat cheese, with a drier matrix, the viability values stood 1.0 log cfu/mL below the control uncoated cheeses for up to 10 days. These spray dried bacteriocin powders provide an alternative for their application as food biopreservatives, since stable dehydrated products were obtained, with prolonged antimicrobial activity, and with verified inhibitory action in a food matrix.
单核细胞增生李斯特菌可污染冷藏即食食品，如奶酪。具有强大杀李斯特菌作用的肠球菌素是控制食品中这种病原体的天然替代品。为了优化它们在食品基质中的抗菌作用，可通过喷雾干燥技术将细菌素固定在可食用涂层中，该技术能够大规模生产生物活性分子微胶囊。这项工作的目的是评估从低成本培养基（HS-L）中获得的鸟肠球菌DSMZ17511细菌素的抗菌效果，将其喷雾干燥，测试不同的热保护材料（麦芽糊精、奶酪乳清和黄原胶），并将其掺入应用于人工污染单核细胞增生李斯特菌99/287的山羊奶酪片的琼脂基活性涂层中。标记为HS-L BS的细菌素溶液（BS）粉末即使在储存90天后仍保持抗菌活性，效价高达128,000 UA/g，黄原胶的热保护作用最小（64,000 - 32,000 UA/g）。尽管储存条件不同，但所有细菌素粉末在3个月后抗菌效价均有所增加；这可能是由于包封的细菌素的释放效应或包封基质的联合释放和逐渐脱水效应。此外，储存在25°C的干燥产品很容易水化，而冷藏或冷冻并不影响粉末的质地。对于应用于新鲜山羊奶酪的涂层，在污染的活性涂层奶酪中单核细胞增生李斯特菌的活力与未涂层的对照之间仅观察到0.5 log cfu/mL的差异。相反，对于商业山羊奶酪，其基质较干燥，在长达10天的时间里，活力值比未涂层的对照奶酪低1.0 log cfu/mL。这些喷雾干燥的细菌素粉末为其作为食品生物防腐剂的应用提供了一种替代方案，因为获得了稳定的脱水产品，具有延长的抗菌活性，并且在食品基质中具有经过验证的抑制作用。
