Harun Kesenkaş

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.

Enrichment of probiotic ice cream with different dietary fibers: Structural characteristics and culture viability

This study evaluated the effect of 5 dietary fibers (apple, orange, oat, bamboo, and wheat) on the physicochemical, rheological, and textural characteristics; sensory properties; and culture viability of probiotic ice cream stored at -18°C for 180 d. The presence of orange and apple fibers increased the titratable acidity, decreased the lightness (color) value of the ice creams, and enhanced the red and yellow coloration. Compared with the control sample, the consistency indices and apparent viscosities of the experimental samples increased with the addition of all dietary fibers except oat fiber. The highest viscosity was obtained in the sample fortified with apple fiber, whereas the ice cream containing orange fiber showed the highest hardness after d 60 of storage. The addition of orange and apple fibers significantly increased melting resistance; however, panelists did not generally like these samples in terms of taste-flavor. All ice creams had viable counts of Lactobacillus acidophilus of ≥7 log cfu/g during storage except the samples with orange and bamboo fiber. Bifidobacterium lactis counts were also found to be >6 log cfu/g in those samples until d 150 of storage.