Dairy products, including cultured dairy products such as cheese and yogurt, are susceptible to fungal spoilage. Traditionally, additives such as potassium sorbate have been used to control fungal spoilage; however, with consumer demand for clean-label products, other strategies to control fungal spoilage (e.g., biopreservatives) are increasingly being used in dairy formulations. In order to help the dairy industry better evaluate biopreservatives for control of fungal spoilage, we developed a challenge study protocol, which was applied to evaluate 2 commercially available protective cultures for their ability to control yeast and mold spoilage of Greek yogurt. Greek yogurt formulated with and without protective cultures was inoculated with a cocktail consisting of 5 yeasts and 1 mold to yield inoculum levels of 10¹ and 10³ cfu/g of yogurt. The inoculated yogurts were stored at 7°C and fungal counts as well as time to visible growth, on the yogurt surface, of mycelium mold colonies or yeast were determined over shelf-life. Whereas fungal concentrations increased to spoilage levels (≥10⁵ cfu/g) in all yogurt formulations at both inoculum levels by d 23 of storage at 7°C, no surface mold was observed over 76 d in any of the products formulated with protective cultures. Control yogurts without biopreservatives all showed surface mold by d 23. In order to allow industry to better evaluate the business effects of improved control of surface mold growth that can be achieved with protective cultures, we developed a Monte Carlo simulation model to estimate consumer exposure to visible mold growth in yogurt formulated without fungal inhibitors. Our model showed that initial mold contamination rate has the largest effect on the model outcome, indicating that accurate data on contamination rates are important for use of these models. When air plates were used, in a proof-of-concept approach, to estimate initial contamination rates in a small yogurt manufacturing operation, our model predicted that 550 ± 25.2 consumers (±standard deviation) would be exposed to visible mold growth for every 1 million cups of yogurt produced. With initial contamination rate data for individual facilities, this model could be used by industry to estimate the number of consumers exposed to visible mold spoilage and could allow industry to better assess the value of mold-control strategies.

乳制品，包括培养的乳制品，如奶酪和酸奶，容易受到真菌的破坏。传统上，诸如山梨酸钾之类的添加剂已被用于控制真菌腐败。然而，随着消费者对清洁标签产品的需求，在乳制品配方中越来越多地使用其他控制真菌变质的策略（例如生物防腐剂）。为了帮助乳制品行业更好地评估生物防腐剂以控制真菌变质，我们制定了一项挑战研究方案，该方案被用于评估2种市售保护性培养物控制酵母和霉菌腐败希腊酸奶的能力。在装有和没有保护性培养液的希腊酸奶中接种5种酵母和1种霉菌组成的混合物，接种量为10 ¹和10 ³ cfu / g酸奶。将已接种的酸奶保存在7°C下，并测定其在整个货架期内菌丝霉菌菌落或酵母菌的真菌计数以及在酸奶表面上可见生长的时间。而真菌的浓度提高到腐败的水平（≥10 ⁵在7 d d d储存后，所有两种酸奶制剂中的所有酸奶配方中的cfu / g cfu / g（cfu / g），在用保护性培养物配制的任何产品中，在76 d内均未观察到表面霉菌。到23天，不含生物防腐剂的对照酸奶都显示出表面霉菌。为了使工业界更好地评估通过保护性培养可以实现的改善表面霉菌生长控制的商业效果，我们开发了蒙特卡洛模拟模型来估计消费者接触不含真菌抑制剂的酸奶中出现明显的霉菌生长。我们的模型表明，初始模具污染率对模型结果的影响最大，表明准确的污染率数据对于使用这些模型很重要。当使用气垫时，以概念验证的方式，为了估算小型酸奶生产过程中的初始污染率，我们的模型预测，每生产100万杯酸奶，将有550±25.2名消费者（±标准偏差）暴露在可见的霉菌生长下。借助单个设施的初始污染率数据，该模型可以被工业界用来估计暴露于可见的模具变质的消费者数量，并且可以使工业界更好地评估模具控制策略的价值。