Gökhan Kavas

Production and Selected Properties of Bioghurt Made from Goat Milk and Cow–Goat Milk Mixtures by Ultrafiltration and Addition of Skim Milk Powder

Abstract In this study, bioghurt was produced from goat milk (A) and 70% goat–30% cow (B), 50% goat–50% cow milk (C) mixtures, and stored 14 days at 4 ± 1°C. Two concentration methods of ultrafiltration (UF) and skim milk powder addition (MP) were applied to milk mixtures, therefore six different bioghurt samples were obtained. Selected physical, chemical, microbiological, and sensory properties of bioghurt samples were analyzed at 1st, 7th, and 14th day of storage. Effects of milk type, concentration method, and storage period on physico-chemical and microbiological properties of samples were investigated. The effect of concentration method on titratable acidity (°SH), penetration value, and whey off values of all bioghurts was significant (p < 0.05). The milk type had no significant effects on total solids, fat content, titratable acidity, pH, and whey off values of bioghurts (p > 0.05), but only the protein contents of bioghurt concentrated with skim milk powder showed significant (p < 0.05). The sensory evaluation showed that bioghurt produced with the mixture of 50% goat milk + 50% cow milk and concentrated by addition of skim milk powder had the highest overall scores.

Use of ginger essential oil-fortified edible coatings in Kashar cheese and its effects on Escherichia coli O157:H7 and Staphylococcus aureus

In this study, edible coating (WPIG) was produced by using 1.5% (w/v) sorbitol + 5% (w/v) whey protein isolate (WPI) + 0.5% (w/v) alginate and 1.5% (v/v) ginger essential oil. Kashar cheese samples were artificially contaminated with Escherichia coli O157:H7 and Staphylococcus aureus at a level of 106 cfu/mL. After coating some of the Kashar samples with edible coating, all samples were stored at 4 °C for 30 days. Antimicrobial activities and selected physical-chemical parameters were assessed on the 1st, 7th, 15th and 30th days of storage. WPI was found to have good water barrier properties, which improved with the addition of 1.5% (v/v) ginger essential oil to the coating, and WPIG was determined to have antimicrobial effects. During storage, Escherichia coli O157:H7 and Staphylococcus aureus levels increased in the control samples, while they decreased in the coated samples.