Comparing Different Packaging Conditions on Quality Stability of High-Pressure Treated Serra da Estrela Cheeses during Cold Storage

Abstract

Serra da Estrela cheese with a Protected Designation of Origin (PDO) is a traditional cheese that is wrapped in paper without vacuum. High-pressure processing (HPP), which requires vacuum packaging of the cheese, has been used for its cold pasteurization to overcome safety issues. In this study, two packaging systems were studied: non-vacuum greaseproof paper wrapping package and vacuum packaging in plastic film. Lactococci, lactobacilli, enterococci, and total mesophiles reached ca. 8 log cfu g−1 and 4–6 log cfu g−1 in control (unpasteurized) and HPP-treated cheeses, respectively, with no significant differences between packaging systems. Spoilage microorganisms' viable cell numbers were reduced to <3 log cfu g−1 (quantification limit) in HPP-treated cheeses, independently of the packaging system. Yeasts and molds reached >5 log cfu g−1 in non-vacuum paper-wrapped cheeses. A vacuum-packaging system enabled better control of cheese proteolysis, which was revealed to be closer to that of the original control cheese values at the end of the 10-month storage period. In addition, cheese stored under vacuum film packaging became harder than non-vacuum paper-wrapped cheeses at each time point. Overall, conventional non-vacuum paper wrapping is adequate for short storage periods (<3 months), but for long periods vacuum packaging in plastic film is preferable.

Preparation and Characterization of Novel Chitosan Coatings to Reduce Changes in Quality Attributes and Physiochemical and Water Characteristics of Mongolian Cheese during Cold Storage

“…The crude protein content (total nitrogen × 6.38) was determined using an automatic Kjeldahl analyzer (Kjeltectm 8400, Foss, Hilerod, Denmark). The nitrogen content in fractions of pH 4.6-souble nitrogen (pH 4.6-SN) was determined using the macro-Kjeldahl method [22][23][24]. Then, the nitrogen content in fractions of 12% trichloroacetic acid-SN (12% TCA-SN) and 5% phosphotungstic acid-SN (5% PTA-SN) was tested according to the macro-Kjeldahl method.…”

Evolution of Qualitative and Quantitative Lipid Profiles of High-Pressure-Processed Serra da Estrela Cheese throughout Storage

“…High-pressure processing (HPP) is being increasingly applied and studied as a nonthermal alternative process to the conventional heat-based pasteurization processes used for dairy foods, including cheese, registering minimal deleterious effects on quality and a shelf-life extension up to 2-3-fold higher than the non-pasteurized counterparts [9]. However, the effects of HPP on cheese are dependent on the pressure intensity applied, the holding time used, and the ripening stage [10,11]. Only three studies were found that focused on the effect of HPP on lipolytic features during storage of raw cows' and ewes' milk cheeses [12][13][14].…”

“…In general, the effects of HPP on cheese characteristics are dependent on the pressure level applied, the length of treatment, and particularly the stage of ripening at which HPP was applied. For example, to enable the safe storage of Serra da Estrela cheese under refrigeration over a prolonged period of 15 months without modification of its sensory attributes, HPP (450 MPa or 600 MPa for 6 min or 9 min) was applied and its impacts on the cheese properties were assessed [11]. HPP also deaccelerated proteolysis and had little effect on texture parameters and sensorial attributes [10,11].…”

“…For example, to enable the safe storage of Serra da Estrela cheese under refrigeration over a prolonged period of 15 months without modification of its sensory attributes, HPP (450 MPa or 600 MPa for 6 min or 9 min) was applied and its impacts on the cheese properties were assessed [11]. HPP also deaccelerated proteolysis and had little effect on texture parameters and sensorial attributes [10,11]. However, since some of these changes (especially sensorial attributes) may be related to the lipids state and associated lipolysis extension in cheese, it is important and pertinent to study the effect of HPP on the qualitative and quantitative lipid profiles of cheese immediately after processing and throughout subsequent storage.…”