Effect of Enzymatic Lactose Hydrolysis on the Quality and Texture of Full-Fat Curd Cheese Produced Without Whey Separation

Lactic acid bacteria (LAB) play a crucial role in acid-curd cheese production by driving milk protein coagulation and forming metabolites that determine texture, safety, and flavor. This study investigated the effect of enzymatic lactose hydrolysis using β-D-galactosidase (Maxilact LX5000) on the quality of full-fat curd cheeses (16.5% and 20.8% dry matter) produced without whey separation. Cheeses were manufactured with or without prior lactose hydrolysis, inoculated with a mesophilic Flora Danica starter culture, and stored for 28 days at 4 °C. Chemical composition, sugar profile (HPLC), pH, LAB viability, textural properties (hardness, adhesiveness, and water-holding capacity), and sensory attributes were determined. Lactose hydrolysis completely eliminated lactose and increased glucose and galactose concentrations, without significant changes in protein, fat, or pH level. In our data, lactose was undetectable in hydrolyzed samples across storage, glucose/galactose exhibited only minor fluctuations, and LAB counts and pH remained stable, indicating a largely stable sugar profile and limited microbial activity under refrigeration. Hydrolyzed samples showed improved texture, especially higher hardness and moisture retention in low-dry-matter variants, while sensory characteristics were comparable to the control and free from excessive sweetness. These results demonstrate that enzymatic lactose hydrolysis is an effective tool for producing lactose-free curd cheese without compromising quality. This process can be recommended for sustainable whey-free cheese manufacture aimed at lactose-intolerant consumers.