Effect of storage at -20°C on the sensory profile of vacuum packed semi-hard ewe´s milk cheeses

Resumen

The objective of this research was to analyze the effect of storage (90 and 180 d at -20°C) on the sensory profile of vacuum-packed ripened (45 d) ewe’s milk cheeses. Fat content, total protein and moisture of the cheese were determined before freezing and after 90 d of frozen storage. A panel of trained sensory assessors evaluated 15 sensory descriptors: sheep odor, dry fruit odor, salty and sour tastes, flavor intensity, buttery flavor, sheep flavor, piquant, persistence, elasticity, hardness, friability, solubility, adhesiveness and creaminess, using an intensity scale of seven points by quantitative descriptive analysis. Storage at -20°C produced significant differences (P<0.05) in sensory profile with respect to the control, which was more pronounced at six than at three months of frozen storage. At six months, cheeses showed odor defects (butyric acid, rancid and/or alcohol) and off-flavor (butyric acid). In contrast, no significant differences (P>0.05) were found in the chemical variables analyzed after three months of storage. In conclusion, frozen storage for three months had minimal effects on the sensory attributes of the cheeses, with most of the defects occurring after six months of storage. Therefore, vacuum-packed ewe’s milk cheese ripened 45 d can be safely stored for three months at -20°C.