Effect of Storage and Heat Treatment of Milk Destined for Cheese Production on Its Oxidative Characteristics

Carmela Tripaldi,Salvatore Claps,Sabrina Di Giovanni,Luca Buttazzoni,Simona Rinaldi,Giuliano Palocci

doi:10.3390/dairy2040046

Abstract

The oxidative stability of milk and dairy products is a very interesting topic for the dairy industry due to the growing demand for foods containing bioactive compounds with positive health effects. The aim was to evaluate the oxidative stability of milk intended for cheese production. The effect of storage time, heat pre-treatment, and milk pasteurization temperature on the characteristics of milk and cheese was investigated. The cheese samples were produced with pasteurized milk at both 72 and 77 °C for a time of 15 s using three types of milk: raw fresh milk processed within 48 h of milking, raw stored milk processed within 96 h, and thermized milk that was heat-treated upon arrival at the dairy and processed within 96 h of milking. In total, three repetitions were carried out for each type of milk and pasteurization. Samples of milk before and after pasteurization and cheese at 14 days of storage were analyzed. Antioxidant activity decreased from starting milk to milk after pasteurization to final cheese. The longer storage time of the milk had significant effects on the antioxidant stability of the cheese (64.95 vs. 59.05% of antioxidant activity). Thermization of the milk further reduced the stability of the cheese (54.05% of antioxidant activity). The greater antioxidant stability of fresh milk and cheeses produced with fresh milk is the first result that encourages the production of cheese from a milk that best preserves its original characteristics.

Highlights

In high-income countries, especially European ones, some dairy products may have characteristics designed to satisfy the demands of the consumer who is increasingly inclined to choose products with certain sensory or nutritional characteristics or made with methods that respect the environment and animal welfare
The results show that raw milk had the fat and protein content slightly higher than average data provided by the National Association of Italian Friesian and Jersey Breed (ANAFIJ) [29], respectively 3.79 and 3.35%, for the year 2020
Kant et al [54] reported that up to 3 days of storage there are no significant changes in the antioxidant activity measured by diphenyl-2-picrylhydrazyl radical (DPPH) assay in both raw and pasteurized milk while at 6 days of storage there is an increase in the level of oxidation

Summary

Introduction

In high-income countries, especially European ones, some dairy products may have characteristics designed to satisfy the demands of the consumer who is increasingly inclined to choose products with certain sensory or nutritional characteristics or made with methods that respect the environment and animal welfare. As part of its quality policy, European legislation has protected the names of foods with unique characteristics linked to their geographical origin (starting from EEC Regulation 2081/92) [2] through the Protected Designation of Origin (PDO) and Protected Geographical Indication (PGI). The obligation on the label of the origin of the product has been extended to all dairy products (EU Regulation No 1169/2011) [3]. Some of these measures have helped to increase the added value of some dairy products. By “fresh” milk, we mean raw milk processed within 48 h of milking, as it is practiced in drinking milk called “fresh pasteurized milk” and “high-quality fresh

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