Effect of frozen and refrigerated storage on proteolysis and physicochemical properties of high-moisture citric mozzarella cheese

Abstract

High-moisture mozzarella is one of the most-exported Italian cheeses worldwide, but its quality is affected by storage. Freezing is regarded as a solution to decrease product waste, extend market reach, and increase convenience, but its effect on quality has to be estimated. In this study, the details related to proteolysis, physicochemical properties, and sensory quality parameters of high-moisture mozzarella as a function of frozen storage (1, 3, and 4 mo) and subsequent refrigerated storage after thawing (1, 3, and 8 d) were evaluated. Frozen cheeses stored at −18°C showed a higher extent of proteolysis, as well as different colorimetric and sensory properties, compared with the fresh, nonfrozen control. Sensory evaluation showed the emergence of oxidized and bitter taste after 1 mo of frozen storage, which supports the proteolysis data. The extent of proteolysis of frozen-stored cheese after thawing was greater than that measured in fresh cheese during refrigerated storage. These results help better understand the changes occurring during frozen storage of high-moisture mozzarella cheese and evaluate possible means to decrease the effect of freezing on the cheese matrix.

Impact of Freezing on the Microbiological Quality and Physical Characteristics of Buffalo Mozzarella Cheese

“…In particular, the panel test allowed us to verify the worsening of both the inner and outer part of the product, thus confirming previous studies [ 20 , 29 ]. About whiteness, its increase toward yellow color during the freezing storage is probable due to the modifications of the milk characteristics; while the increased hardness of the BMC was probably due to casein hydrolysis.…”

“…At the beginning of the experiment, also the fresh matrices were subjected to the casein extraction process. After the extraction, all samples were analyzed by SDS PAGE as reported by Alinovi et al [ 20 ]. The protein standard used for molecular weight determination was Precision Plus Protein Standards Dual Color (Bio-Rad, Hercules, CA, USA).…”

“…The quali-quantitative physical analysis was carried out for each BMC sample, as reported by Alinovi et al [ 20 ]. Seven trained panelists (three men and four women), with previous experiences, regarding the sensory analysis of BMC, were enrolled for this study.…”

“…In this way, 35/35 indicates a “strong presence” of the attribute, while 7/35 indicates an “absence” of the attribute. Samples of BMC were portioned in 10 mm cubes for this analysis [ 20 ]. The analysis was carried out at the beginning of the research (0 day) and at the end (11 months).…”

Ripening of Nostrano Valtrompia PDO Cheese in Different Storage Conditions: Influence on Chemical, Physical and Sensory Properties

“…Accordingly, the use of the natural starters did not group producers 2 and 4; therefore, the use of natural straters could not be considered a characterizing point of Nostrano Valtrompia cheesemaking production because of the low dosage and the high bacterial count of the autoctonous microflora that can develop during the early stage of cheesemaking. Differences among producers that can be related to the relatively high variability of cheesemaking steps (Table 1) were intentionally blocked into the statistical model [42,43] in order to more accurately observe differences related to the ripening time and the different warehouses.…”