Filters
Lactose Content and Selected Quality Parameters of Sheep Milk Fermented Beverages during Storage
The aim of the research was to evaluate lactose content and rheological, physical, chemical, and organoleptic parameters during the storage of fermented beverages made from sheep’s milk. The research was carried out on natural, probiotic, and Greek-type yogurts, as well as kefir. The products were made using the thermostat method from the milk of 42 East Frisian sheep in the middle lactation period, in duplicate. Lactose contents, active and titratable acidity, color by the L*a*b*C*h* system, and rheological parameters (hardness, consistency, consistency, and viscosity) were tested, and organoleptic assessments were carried out on the first, seventh, fourteenth, and twenty-first days of storing the drinks at 4 °C. Of all drinks, the highest reduction in lactose after 21 days of storage was found to occur in kefir (52% reduction) and, among the yogurts, in the Greek yogurt (41% reduction). The product with the lowest lactose content, regardless of the storage period, was kefir. This indicates that kefir is more suitable than yogurt for people with partial lactose intolerance. Effects of both inoculation type and beverage storage time were shown to exist for all parameters. It was also found that kefirs suffered deterioration in most rheological parameters and, in general organoleptic evaluation in the final period of storage. Based on our analysis, the optimal storage time for natural yogurts and sheep’s milk kefirs at 4 °C was 21 and 14 days, respectively.
Processability of milk in the production of curd cheeses on family farms in the summer and winter seasons
The aim of the study was to compare quality of curd cheeses produced from raw and pasteurized milk in a family farm in the summer and winter seasons. Conducted analyses showed that the season of the year, in which milk was produced, influenced its chemical composition and selected quality attributes. In terms of milk processability a more advantageous composition and better quality attributes were found in winter compared to summer. Quality of produced curd cheeses was affected by the season of milk production as well as milk type (raw vs. pasteurized). In the winter season the yield of curd cheese was over 1.5-fold greater from pasteurized milk in comparison to the summer season. Curd cheeses produced from raw milk were firmer, more elastic and sliceable, while those produced from pasteurized milk were less cohesive and more suitable was spreads. The organoleptic analysis of curd cheeses showed that more advantageous consumer value was found for cheeses produced in the winter season.
How potentially sustainable solutions may be unsustainable in practice: carrot pomaces in common carp nutrition
Abstract The aim of this study was to evaluate the effects of carrot pomaces dried at two temperatures as a feed component on growth performance, environmental sustainability, and meat quality in common carp (Cyprinus carpio). Three diets were developed: a control without pomace (CON); CPL with 15.5% carrot pomace dried at 40°C and CPH with 23.6% carrot pomace dried at 120°C. A total of 240 two-year-old common carp (average body weight of individual: 1025 g) were randomly distributed into 12 tanks, four per treatment, including 20 fish per tank. The experiment was performed using an outdoor open flow aquaculture system. The growth trial lasted 60 days, after which fish samples were taken for analysis of meat quality parameters. There were no significant differences between groups in terms of the final body weight, protein efficiency ratio, or survival rate. However, in terms of weight gain, specific growth rate, and feed conversion ratio, fish fed the CPH diet exhibited significant worsening. Moreover, the fillets of fish from the CPH group exhibited a darker coloration compared to the CON diet. It is concluded that high temperature drying of carrot pomace added to carp diet negatively affected fish quality. It should be also emphasized that inclusion of the both carrot pomaces tested in this study significantly increased the usage of fish meal per kilogram of fish body weight gain. These results showed a reduced efficacy of using carrot pomace in practical and sustainable common carp nutrition.
Effect of herbal feed additives on goat milk volatile flavor compounds
The aim of this study is to investigate the effects of herbal supplements administered to goats on sensory quality and volatile flavor compounds in their milk. The experiment was conducted on sixty Polish white improved goats randomly allocated into five feeding groups (four experimental and one control) of twelve goats each. The trial lasted 12 weeks. The experimental animals received supplements containing a mixture of seven or nine different species of herbs at 20 or 40 g/animal/day. The control group received feed without any herbal supplements. Milk obtained from experimental and control groups of animals was characterized by a low content of aroma compounds, with only 11 chemical compounds being identified. Decanoic methyl ester, methylo 2-heptanone and methylo-butanoic methyl ester had the highest share in the total variability of the tested aroma compounds (PCA). During the sensory evaluation, the smell and taste of most of the samples were similar (p > 0.05). However, the addition of herbal feed supplements lowered the concentration of Caproic acid (C6:0), Caprylic acid (C8:0) and Capric acid (C10:0), which caused a significant reduction in the goaty smell of milk. The obtained results indicate that the studied herbal supplements can reduce the intensity of goaty smell and allow goat milk production without modification of other sensory features.