The present study evaluated the efficiency of an edible coating of alginate and erythrosine in the preservation of ricotta cheese submitted to the technique of Photodynamic Inactivation of Microorganisms (PDIM). Three treatments were evaluated: samples of cheese coated with alginate solution, with alginate solution and 10 μmol/L erythrosine and with 100 μmol/L erythrosine. Mechanical properties, water vapor sorption, solubility and permeability and the release of erythrosine in aqueous medium were characterized. The antimicrobial effect of the coatings followed by photodynamic application was evaluated during cheese storage for 21 days. The coated cheese samples were physico-chemically analysed during 21 days of storage. Salmonella and S. aureus were not detected in any cheese samples, but a 1 log cycle reduction in the Coliform count was only observed when 100 μmol/L erythrosine was used. The PDMI technique did not induce lipid oxidation in cheese samples. The presence of 100 μmol/L reduced tensile strength by 25% at rupture. The water solubility and water vapor permeability of the roofs were not affected by the addition of erythrosine. The application of edible coatings in combination with PDIM is a good alternative to extend the shelf life of ricotta cheese without compromising sensory attributes and nutritional characteristics.

本研究评估了可食用的藻酸盐和赤藓红涂层在采用光动力灭活微生物 (PDIM) 技术保存乳清干酪方面的效率。评估了三种处理方法：涂有藻酸盐溶液、藻酸盐溶液和 10 μmol/L 赤藓红和 100 μmol/L 赤藓红的奶酪样品。表征了机械性能、水蒸气吸附、溶解度和渗透性以及赤藓红在水介质中的释放。在奶酪储存 21 天期间评估涂层的抗菌效果以及光动力应用。在 21 天的储存期间，对涂层奶酪样品进行了物理化学分析。沙门氏菌和金黄色葡萄球菌在任何奶酪样品中均未检测到，但仅在使用 100 μmol/L 赤藓红时观察到大肠菌群计数减少 1 个对数周期。PDMI 技术不会在奶酪样品中诱导脂质氧化。100 μmol/L 的存在使断裂时的拉伸强度降低了 25%。屋顶的水溶性和水蒸气渗透性不受添加赤藓红的影响。可食用涂层与 PDIM 结合使用是延长乳清干酪保质期而不影响感官特性和营养特性的良好选择。