Influence of milk-clotting enzymes of animal and microbial origin on the quality and shelf life of soft cheeses

A comparative test was carried out for milk-clotting enzymes (MCE) of animal origin (Naturen® Extra), microbial origin (Marzyme®) and MCE based on recombinant camel chymosin (Chy-max® M) in the production of soft cheese “Lyubitelskiy”. By the end of the shelf life of the cheeses (12 days at a temperature of 3 ± 1 °C), differences were noted in the degree of proteolysis (DP) and the value of the complex modulus G*, which were the following ones for cheeses produced with MCE of the brands: Naturen® — DP = 17.86 ± 0.24%; G* = 4164 ± 587 Pa; Marzyme® — DP = 17.98 ± 0.49%; G* = 4581±786 Pa; Chy-max® M — DP = 9.85 ± 0.63%; G* = 7949 ± 1157 Pa. Cheeses made with Chy-max® M MCE had a denser texture than cheeses made with MCE of Naturen or Marzyme, which did not differ significantly in consistency. In the studied cheeses, the severity of the bitter taste was proportional to the content of water-soluble peptides with a mass of 0.5–3 kDa. Cheeses with Marzyme® MCE had a more intense bitterness than cheeses with Naturen® MCE. There was no bitter taste in cheeses produced with MCE of Chy-max® M. It was concluded that in the production of soft cheeses, recombinant camel chymosin can be used to increase the shelf life, and MCE of microbial origin can be recommended to replace more expensive MCE of animal origin.

Effect of grated coconut and water ratio and commercial cheese starter percentage on characteristics of soft cheese made from coconut milk

The aim and objective of this research was to produce a soft cheese made from coconut milk and to examine the effect of grated coconut:water ratio (1:1, 1:2 and 1:3) and percentage of commercial cheese starter culture (1% and 1.5%) on its characteristics. The study was conducted using a factorial randomized block design. After two weeks of storage at 4°C, the cheeses (18 samples) were analysed for total lactic acid (LAB) counts, pH, and fat content. The lowest-fat coconut cheese was analysed for proximate and spreading ability. The results showed that the grated coconut:water ratio had a significant effect (P≣0.01) on the total LAB counts, pH value, and fat content of the cheese. The optimum formulation for soft cheese was selected based on the lowest pH (4.64) and fat content (42%) which was reached by using coconut and water 1:1. However, the spreading ability of this cheese could be improved by optimising the growth of starter cultures, water removal and adding stabilizers.

Dairy Processing: The Soft Spreadable Cheese Xygalo Siteias

The aim of cheese manufacturers is to produce high quality and safe products. Along the food chain of “milk to cheese and food products”, milk is collected, transferred, and managed in a standardized manner; processing results in safe, ready-to-eat products, of high nutritional quality. Soft, acid cheeses are prepared in various regions of Greece, mainly from ewe milk, goat milk, or their mixtures. They are produced from the rennet and/or acid coagulation of thermally-treated, full-fat milk undergoing acidification/curdling and ripening. Xygalo Siteias is a Greek soft cheese, produced in the area of Siteia, Crete, where it was recognized as PDO in 2011. It is close—more in texture and less in taste—with other cream cheeses PDO of Greece, such as Pichtogalo of Chania, and Katiki Domokou, still it differs in the preparation technique as well as in its physicochemical, biochemical, microbiological, and organoleptic characteristics. In this review, we focus on the processing and characteristics of Xygalo Siteias, mentioning perspectives for the further microbiological characterization of the product, the determination of its shelf-life in combination with new packaging-materials, as well as the attention it deserves as a food important for breeders, the local economy, and consumers, since it is associated with the Cretan-Mediterranean diet type.

Compositional and Functional Characteristics of Feta-Type Cheese Made from Micellar Casein Concentrate

Micellar casein concentrate (MCC) is a high protein ingredient (obtained by microfiltration of skim milk) with an elevated level of casein as a percentage of total protein (TP) compared to skim milk. It can be used as an ingredient in cheese making. Feta-type cheese is a brined soft cheese with a salty taste and acid flavor. We theorize that Feta-type cheese can be produced from MCC instead of milk, which can improve the efficiency of manufacture and allow for the removal of whey proteins before manufacturing Feta-type cheese. The objectives of this study were to develop a process of producing Feta-type cheese from MCC and to determine the optimum protein content in MCC to make Feta-type cheese. MCC solutions with 3% (MCC-3), 6% (MCC-6), and 9% (MCC-9) protein were prepared and standardized by mixing water, MCC powder, milk permeate, and cream to produce a solution with 14.7% total solids (TS) and 3.3% fat. Thermophilic cultures were added at a rate of 0.4% to MCC solutions and incubated at 35 °C for 3 h to get a pH of 6.1. Subsequently, calcium chloride and rennet were added to set the curd in 20 min at 35 °C. The curd was then cut into cubes, drained for 20 h followed by brining in 23% sodium chloride solutions for 24 h. Compositional analysis of MCC solutions and cheese was carried out. The yield, color, textural, and rheological measurements of Feta-type cheese were evaluated. Feta-type cheese was also made from whole milk as a control. This experiment was repeated three times. The yield and adjusted yield of Feta-type cheese increased from 19.0 to 54.8 and 21.4 to 56.5, respectively, with increasing the protein content in MCC from 3% to 9%. However, increasing the protein content in MCC did not show significant differences in the hardness (9.2–9.7 kg) of Feta-type cheese. The color of Feta-type cheese was less white with increasing the protein content in MCC. While the yellowish and greenish colors were high in Feta-type cheese made from MCC with 3% and 6% protein, no visible differences were found in the overall cheese color. The rheological characteristics were improved in Feta-type cheese made from MCC with 6% protein. We conclude that MCC with different levels of protein can be utilized in the manufacture of Feta-type cheese.

Nigella sativa oil: A promising prospective antifungal agent in the manufacture of low-salt soft cheese

The current work studied the in-vivo antifungal activity of Nigella sativa oil (NSO) in ultrafiltered low-salt soft cheese as a proposed replacement for the synthetic preservatives which become unacceptable by consumers. Four different concentrations of NSO were examined during the manufacture of the cheese (0.3, 0.5, 1, and 3 % w/w). The effect of NSO supplementation was examined in 3 parallel lines; a ninepoint hedonic scale was used in the sensorial evaluation of soft cheese free of the fungal inoculum, the physicochemical properties of soft cheese were determined during storage as well as anti-fungal effects of different concentrations of NSO on inoculated cheese with different species of fungi: Candida albicans (104 cfu/ml) and Aspergillus parasiticus (102 cfu/ml) before coagulation. The Nigella sativa oil expressed an antifungal activity by using different levels of NSO which significantly reduced and inhibited the growth of the fungal counts (1.4 log cfu/g for Candida albicans and 2.30 log cfu/g for Aspergillus parasiticus) started from 0.5% concentration of NSO on the 14th day of the storage. In addition, it exhibited different physicochemical properties of soft cheese depending on the level of used NSO. However, the Sensory evaluation of cheese samples revealed the acceptance of soft cheese samples with 0.3% and 0.5% of NSO.

Wheat and White Sorghum Supernatants as Alternatives to Calotropis procera Extract in Making Cheese

Plant coagulant, animal rennet and microbial coagulant are used as milk coagulating agents resulting in different cheese products. However, emphasis has been on the use of plant coagulant as opposed to that from animal source, rennet. Alternative milk coagulants are therefore investigated instead of animal enzymes. The use of vegetable extracts as milk coagulants has evolved in soft cheese processing. This study explored the potential of plant coagulants as an ideal choice in the production of cheese. Hence, the objective of this study was to evaluate the effects of the coagulants on the yield and proximate composition of cheese. To compare them with cheese coagulated with supernatants from fermented white sorghums (WSS) and wheat (WS) in the laboratory. The results were also compared with cheese coagulated with Calotropis procera leaf extract (CPE) in terms of yield, the percentage composition of total solids (TS), fat, protein, lactose ash and the pH of the cheeses. The same parameters were evaluated in the whey (by-product). The minerals, pH and the proximate components in WS and WSS were also compared. Maximum cheese yield was recorded at equal volumes of milk and coagulants. CPE was superior to these other two considering the constituents in all three cheeses. The chemical composition of CPE coagulant was superior to WS and WSS in terms of TS, fat, protein and ash but lower in moisture content compared with the other two. Protein content was higher in cheese prepared with CPE (22%) about six times the amount in raw milk and the least was WSS (12%). Moreover, the cheese made with CPE had the highest yield (31.76g) and differed significantly (P< 0.05) from WSS (28.87g) and WS (29.70g). Also, cheese made with WS (30.57g/ml) had the highest whey volume compared with WSS (28.11g/ml). However, increasing levels of each supernatant with a constant volume of raw milk (100ml) produced higher cheese yield at 100ml of the supernatant and 100ml of milk. Whey from WSS was the most acidic (5.85) of all the three produced but with increased acidity as the storage days increased. The study revealed that cheese with high nutritional quality can be produced with CPE, WSS and WS. The use of equal volume of coagulant (WSS or WS) to raw milk would give optimal cheese yield. This will promote the utilization of WSS and WS, which is naturally left as the waste product.