Effect of Pasteurization and Ripening Temperature on Chemical and Sensory Characteristics of Traditional Motal Cheese

The production of cheese can be made from either pasteurized or non-pasteurized milk, depending on the country or dietary habits. In this work, the effect of pasteurization of milk on the progress of the physicochemical properties, fatty acids profile and lipid oxidation of cheese throughout a maturation period of 90 days is presented. This research was carried out on two types of Graviera cheese produced in Greece, one made from raw milk and the other from pasteurized milk. The proximal composition of each sample was evaluated, the fatty acids profile was analyzed by Gas Chromatography, whereas lipid oxidation was determined on the basis of the formation of malondialdehyde (MDA). Significant differences (p < 0.05) in the values of pH, fat and density between raw and pasteurized milk were observed. The physicochemical parameters during the ripening of the cheeses showed significant differences according to the type and the stage of maturation. Specifically, the two types of cheese differed significantly (p < 0.05) in terms of pH, protein, fat in dry matter (FDM), and water-soluble nitrogen/total nitrogen (WSN/TN). Although the fatty acids profile was similar for the two types of cheese, differences were observed during the ripening stages as well as between the milk and the final product. The lipid oxidation levels increased during maturation, whereas they seemed to be lower in the pasteurized cheeses. Therefore, it can be concluded that the use of raw or pasteurized milk affects the physicochemical characteristics, fatty acids profile and lipid oxidation of Graviera cheese during ripening.

Section: Resultsmentioning

confidence: 99%

Physicochemical Characteristics, Fatty Acids Profile and Lipid Oxidation during Ripening of Graviera Cheese Produced with Raw and Pasteurized Milk

Ioannidou¹,

Maggira²,

Samouris³

2022

“…Our results also showed that Enterobacteriaceae species were present in all the samples studied, whether made of raw or pasteurized milk, although with varying abundances. Dairy products made from pasteurized milk are usually inoculated with starter cultures to initiate fermentation after the native microbiota of the milk has been deactivated [ 25 ]. In our case, no starter cultures were added to our labneh Ambaris samples prepared with artisanally pasteurized milk (PMSs).…”

Section: Discussionmentioning

confidence: 99%

Artisanal Household Milk Pasteurization Is Not a Determining Factor in Structuring the Microbial Communities of Labneh Ambaris: A Pilot Study

Khalil

Couderc

Yvon

et al. 2022

Labneh Ambaris is a traditional Lebanese dairy product traditionally made using raw goat’s milk in earthenware jars, but recently the use of artisanally pasteurized milk was introduced for safety reasons. In this study, 12 samples of labneh Ambaris were studied, six made using raw goat’s milk and six others using artisanally pasteurized goat’s milk. These samples were collected during fermentation and their microbial compositions were analyzed. The 16S V3–V4 and the ITS2 regions of the rDNA were sequenced by DNA metabarcoding analyses for the identification and comparison of bacterial and fungal communities, respectively. The samples had high microbial diversity but differences in samples microbiota were unrelated to whether or not milk was pasteurized. The samples were consequently clustered on the basis of their dominant bacterial or fungal species, regardless of the milk used. Concerning bacterial communities, samples were clustered into 3 groups, one with a higher abundance of Lactobacillus helveticus, another with Lactobacillus kefiranofaciens as the dominant bacterial species, and the third with Lentilactobacillus sp. as the most abundant species. Species belonging to the Enterobacteriaceae family were detected in higher abundance in all raw milk samples than in artisanally pasteurized milk samples. As for fungal communities, the samples were clustered into two groups, one dominated by Geotrichum candidum and the other by Pichia kudriavzevii.

“…Although, the ability of L. parabuchneri to produce biofilms at colder temperatures was strain dependent, the strong biofilm producers formed notable biofilm biomass at 12 °C and 24 °C, a result of some importance given the temperatures associated with cheesemaking, especially during ripening [ 51 , 52 , 53 ].…”

Section: Resultsmentioning

confidence: 99%

Characterization of the Biofilms Formed by Histamine-Producing Lentilactobacillus parabuchneri Strains in the Dairy Environment

Sarquis

Bajrami

Mizaikoff

et al. 2023

Lentilactobacillus parabuchneri, a lactic acid bacterium, is largely responsible for the production and accumulation of histamine, a toxic biogenic amine, in cheese. L. parabuchneri strains can form biofilms on the surface of industry equipment. Since they are resistant to cleaning and disinfection, they may act as reservoirs of histamine-producing contaminants in cheese. The aim of this study was to investigate the biofilm-producing capacity of L. parabuchneri strains. Using the crystal violet technique, the strains were first categorized as weak, moderate or strong biofilm producers. Analysis of their biofilm matrices revealed them to be mainly composed of proteins. Two strains of each category were then selected to analyze the influence on the biofilm-forming capacity of temperature, pH, carbon source, NaCl concentration and surface material (i.e., focusing on those used in the dairy industry). In general, low temperature (8 °C), high NaCl concentrations (2–3% w/v) and neutral pH (pH 6) prevented biofilm formation. All strains were found to adhere easily to beech wood. These findings increase knowledge of the biofilm-forming capacity of histamine-producing L. parabuchneri strains and how their formation may be prevented for improving food safety.