The Effect of Freezing Sheep's Milk on the Meltability, Texture, Melting and Fat Crystallization Profiles of Fresh Pasta Filata Cheese

Innovative Covering Liquids Stabilising Water-Fat Leachate from Fresh Mozzarella Cheese Used as Pizza Topping

This study analyses the possibility of changing the composition of the covering liquid in which mozzarella cheese is stored. The characterisation of mozzarella cheese consumed fresh and during later culinary use as a pizza topping was carried out. Mozzarella cheese from cow's milk and reconstituted sheep's milk were used for this study. The cheese was stored in whey-based covering liquid to which single or double amounts of lactose and/or citric acid (w/w) were added. The results obtained during laboratory analysis showed that the addition of lactose and/or citric acid to the covering liquid significantly impacted the mass of the cheese and the changes that can occur during later culinary use. The observed changes in the cheese during storage in the covering liquid were confirmed by the characteristics of the liquid itself. The smallest mass changes were related to cheeses stored in a covering liquid with double the amount of lactose and a single amount of citric acid. This cheese also displayed positive changes in all assessed descriptors (texture, melt, and colour). The amount of leachate from the cheese was small and occurred relatively late after unpacking and quartering. Based on the results of the study, changes made to the composition of the covering liquids can positively affect the characteristics of mozzarella cheese. Additionally, this data allows for the creation of specialised mozzarella cheeses that can pique the consumer's interest.

Effects of Freezing Raw Yak Milk on the Fermentation Performance and Storage Quality of Yogurt

In this study, the effects of freezing yak milk at -20 °C and -40 °C for 30, 90 and 180 days on the fermentation characteristics and storage quality of the corresponding yogurt were discussed. The results showed that, compared with that of yogurt made from fresh yak milk, the lactic acid bacteria (LAB) growth and acid production rate of the yogurt in the -20 °C group decreased at 90 d. The water-holding capacity, viscosity and hardness decreased during storage, and a sour taste was prominent, while no significant changes were observed in the -40 °C group. At 180 d of freezing, the post-acidification of the yogurt in the -20 °C and -40 °C groups increased after 21 d of storage. Compared with the -40 °C group, the -20 °C group showed a significant decrease in LAB counts, a decrease in pH value to 3.63-3.80 and poor texture and sensory quality.

Production of Sensorily Acceptable Pasta Filata Cheese with Partial Substitution of Sheep's Milk Powder in Different Forms

The presented study analyzed the possibility of pasta filata cheese production using sheep's milk powder in different forms and substitution amounts with fresh cow's milk. For the production of the pasta filata cheeses that were analyzed in the research, sheep's milk powder and reconstituted sheep's milk were used for partial substitution with fresh cow's milk in the amount of approx. 20, 30 and 40 percent (v/v). The obtained results showed that the more sheep's milk in the form of powder in the mixture, the lower the cheese's moisture content. The fat and protein content in the whey after the production of cheeses from mixtures was lower than after the production of cheeses from reconstituted sheep's milk only. Cheeses produced entirely from reconstituted sheep's milk displayed the highest fat loss. The greatest cheese yield was observed for cheeses from mixtures with sheep's milk powder and entirely from reconstituted sheep's milk. Pasta filata cheeses made from a mixture of cow's milk and sheep's milk powder that was not reconstituted were much less acceptable to consumers than reconstituted milk powder cheeses, especially those with 40% and 30% added powder. Sensory profile analysis showed that the addition of sheep's milk to the mixture, regardless of the form, affected the appearance, consistency, and flavor of the produced pasta filata cheeses. Mixing cow's milk with sheep's milk powder created the possibility of modeling the final cheese quality and yield.

Effect of Packaging and Portioning on the Dynamics of Water–Fat Serum Release from Fresh Pasta Filata Soft Cheese

The aim of the present study was to analyze the impact of cheese fragmentation and packaging on the dynamics of water–fat serum released from pasta filata cheese made from cow’s milk and its mixture with sheep’s milk. The addition of sheep’s milk reduced the amount of leachate from the vacuum-packed cheeses and did not cause as much loss of gloss as in the case of cow’s milk cheeses. This was also reflected in the microscopic images of the cheese samples. Consumers showed less acceptance of cow’s milk pasta filata cheeses than cheeses made with a mixture of cow’s and sheep’s milk (they had the same fat content, acidity, hardness, and oiling-off, but better stretching). The data describing water–fat serum release from pasta filata cheese within 24 h of unpacking was modeled with the use of the feed-forward artificial neural networks, whose architecture is based on Multi-Layer Perceptron with a single hidden layer. The model inputs comprised four independent variables, including one quantitative (i.e., time) and the other qualitative ones, which had the following states: type of raw material (cow’s milk, cow-sheep’s milk), way of sample portioning (whole, quarters, slices), packing method (vacuum packed and packed in brine).