Noufeu Tchouli, Li Yueqin, Toure Ndeye Fatou, Yao Hui, Zeng Xiaoqun, Du Qiwei, Pan Daodong
State Key Laboratory for Quality and Safety of Agro-Products, Ningbo University, Ningbo 315211, China.
College of Food Science and Engineering, Ningbo University, Ningbo 315800, China.
Foods. 2025 Feb 22;14(5):743. doi: 10.3390/foods14050743.
Lactic acid bacteria (LAB) play a vital role in food fermentation and probiotics microeconomics. Freeze-drying (FD) is a commonly used method for preserving LAB powder to extend its shelf life. However, FD induces thermal, osmotic, and mechanical stresses that can impact the glycometabolism of LAB, which is the process of converting carbohydrates into energy. This review explores the effect of FD on glycometabolism, factors influencing glycometabolism, and feasible strategies in the FD process of LAB. During the three stages of FD, freezing, primary drying or sublimation, and second drying, the glycolytic activity of LAB is disrupted in the freezing stage; further, the function of glycolytic enzymes such as hexokinase, phosphofructokinase, and pyruvate kinase is hindered, and adenosine triphosphate (ATP) production drops significantly in the sublimation stage; these enzyme activities and ATP production nearly cease and exopolysaccharide (EPS) synthesis alters during the secondary drying stage. Factors such as strain variations, pretreatment techniques, growth medium components, FD parameters, and water activity influence these changes. To counteract the effects of FD on LAB glycometabolism, strategies like cryoprotectants, encapsulation, and genetic engineering can help preserve their glycometabolic activity. These methods protect LAB from harsh FD conditions, safeguarding glycolytic flux and enzymatic processes involved in carbohydrate metabolism. A deeper understanding of these glycometabolic changes is essential for optimizing FD processes and enhancing the use of LAB in food, medicine, and biotechnology, ultimately improving their performance upon rehydration.
乳酸菌（LAB）在食品发酵和益生菌微观经济学中发挥着至关重要的作用。冷冻干燥（FD）是保存LAB粉末以延长其保质期的常用方法。然而，冷冻干燥会引发热、渗透和机械应力，这些应力会影响LAB的糖代谢，即碳水化合物转化为能量的过程。本综述探讨了冷冻干燥对糖代谢的影响、影响糖代谢的因素以及LAB冷冻干燥过程中的可行策略。在冷冻干燥的三个阶段，即冷冻、一次干燥或升华以及二次干燥过程中，LAB的糖酵解活性在冷冻阶段受到破坏；此外，己糖激酶、磷酸果糖激酶和丙酮酸激酶等糖酵解酶的功能受到阻碍，并且在升华阶段三磷酸腺苷（ATP）的产生显著下降；在二次干燥阶段，这些酶的活性和ATP的产生几乎停止，并且胞外多糖（EPS）的合成发生改变。菌株变异、预处理技术、生长培养基成分、冷冻干燥参数和水分活度等因素会影响这些变化。为了抵消冷冻干燥对LAB糖代谢的影响，诸如使用冷冻保护剂、包囊化和基因工程等策略有助于保持其糖代谢活性。这些方法可保护LAB免受冷冻干燥恶劣条件的影响，保障糖酵解通量以及碳水化合物代谢中涉及的酶促过程。深入了解这些糖代谢变化对于优化冷冻干燥过程以及增强LAB在食品、医药和生物技术中的应用至关重要，最终可改善其复水后的性能。
