Irlinger Françoise, Keribin Christine, Sarthou Anne-Sophie, Laroche Béatrice, Helinck Sandra
Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91120 Palaiseau, France.
Université Paris-Saclay, CNRS, INRIA, Laboratoire de Mathématiques d'Orsay, 91405 Orsay, France.
Int J Food Microbiol. 2025 Nov 2;442:111363. doi: 10.1016/j.ijfoodmicro.2025.111363. Epub 2025 Jul 23.
This study investigates pink discoloration defects in French bloomy rind soft cheeses, which can negatively affect product appearance, consumer acceptance, and lead to economic losses. Two batches of cheese from the same processing plant were analyzed: one with visible pink discoloration and one without, allowing for comparative analysis. A multi-omics approach was applied, combining microbial profiling (16S rRNA and ITS2 sequencing) and metabolomics (GC-MS and LC-MS) to identify the factors linked to the defect. Three microbial species showed significant differences in abundance depending on sample type (spoiled and unspoiled) and location on the cheese surface: Penicillium camemberti, Psychrobacter group, and Paeniglutamicibacter gangotriensis. A positive correlation was observed between this group and salt concentration, as well as with multiple metabolites such as butanoic acid, acetic acid, aldehydes, ketones, esters, and terpenes. Notably, P. gangotriensis had never previously been detected in cheese. To test its role, model cheeses were inoculated with or without six strains of P. gangotriensis isolated from cheeses. Model cheeses containing the bacteria developed pink discoloration after 14 days of ripening, while controls remained unchanged after 20 days. These results strongly suggest that P. gangotriensis is responsible for the pink defect. Further research is needed to confirm this hypothesis by identifying the pigment's chemical structure and understanding the biotic and abiotic conditions that promote its production.
本研究调查了法国软质表面有白霜的奶酪中的粉色变色缺陷，这种缺陷会对产品外观、消费者接受度产生负面影响，并导致经济损失。对来自同一加工厂的两批奶酪进行了分析：一批有明显的粉色变色，另一批没有，以便进行对比分析。采用了多组学方法，结合微生物分析（16S rRNA和ITS2测序）和代谢组学（气相色谱-质谱联用和液相色谱-质谱联用）来确定与该缺陷相关的因素。根据样品类型（变质和未变质）以及奶酪表面位置，三种微生物物种在丰度上表现出显著差异：卡门青霉、嗜冷杆菌属和冈底斯谷氨酰胺杆菌。观察到该菌群与盐浓度以及多种代谢物（如丁酸、乙酸、醛、酮、酯和萜类）之间存在正相关。值得注意的是，此前从未在奶酪中检测到冈底斯谷氨酰胺杆菌。为了测试其作用，在模型奶酪中接种或不接种从奶酪中分离出的六种冈底斯谷氨酰胺杆菌菌株。含有该细菌的模型奶酪在成熟14天后出现粉色变色，而对照在20天后保持不变。这些结果有力地表明，冈底斯谷氨酰胺杆菌是造成粉色缺陷的原因。需要进一步研究来通过确定色素的化学结构并了解促进其产生的生物和非生物条件来证实这一假设。
