REDUCING THE RISK OF SPOILAGE CAUSED BY BACILLUS CEREUS IN COW'S AND GOAT'S MILK YOGURT WITH BERRIES PUREE

The objective of this study was to investigate the impact of adding aronia (Aronia melenocarpa), raspberry (Rubus idaeus), and strawberry (Fragaria xananassa) in the form of 10% puree to a mixture of cow's and goat's milk in order to reduce the risk of spoilage caused by activity of Bacillus cereus in yoghurt made from a mixture of cow's and goat's milk. During the fermentation process (360 min.), changes in water activity, pH, moisture content, bacterial growth curve were monitored. The results showed a decrease in water activity, pH, and moisture content. Adding aronia puree to yoghurt yielded the most significant results for water activity modification (0.971-0.868), pH (5.31- 4.28), moisture content (85.12-81.55 %), and optical density (0.19-0.34). Also, the investigation of the kinetics of the Bacillus cereusgrows indicated that the stationary phase was reached at 360 minutes, resulting in a total population of 5.5·1013 c.f .u./g. Microscopic examination revealed Gram-positive strains of lactic acid bacteria, arranged in chains of varying lengths, in an amount of 139·102 c.f.u./g. Antimicrobial activity showed a zone of inhibition with a diameter of 18.5±0.1 mm in aronia yoghurt, a zone of inhibition with a diameter of 16.2±0.2 mm in raspberry yoghurt and a zone of inhibition with a diameter of 15.2±0.1 mm in strawberry yoghurt compared to classic yoghurt which showed a zone of inhibition with a diameter of 12.1±0.2 mm

A Study on the Fruiting and Correlation between the Chemical Indicators and Antimicrobial Properties of <i>Hippophae rhamnoides</i> L.

Sea buckthorn is a promising species that, under the conditions of Eastern Europe, has shown high productivity and is also a good and possible source of a wide range of bioactive compounds that have a positive effect on the human body, especially polyphenols and carotenoids. Due to the content of biologically active substances in sea buckthorn (Hippophae rhamnoides L.), the species is of growing interest to scientists, the food industry, the pharmaceutical industry, the cosmetics industry and consumers. The aim of this study is to investigate the productivity and the correlation between the chemical composition and the antibacterial effect of four cultivars of sea buckthorn (Clara, Dora, Cora, Mara), cultivated in the Republic of Moldova. Sea buckthorn fruits were harvested at the stage of full ripening. Berry samples were frozen at minus 25 °C, stored for 6 months and whole fruits of sea buckthorn were studied. All quantitative characteristics were calculated in terms of absolutely dry raw material (dry weight). The sea buckthorn cultivars tested were found to have a different carotenoid contents (1.79–48.92 mg/100 g), ascorbic acid contents (74.36–373.38 mg/100 g), organic acids (malic acid 5.8–13.4 mg/100 g, citric acid 0.08–0.321 mg/100 g, succinic acid 0.03–1.1 mg/100 g), total dry matter contents (16.71–24.54%), titratable acidities (2.15–8.76%) and pH values (2.73–3.00). The antimicrobial activity of sea buckthorn, evaluated by the diameter of the inhibition zone, constituted for Bacillus pumilus 3.70–15.91 mm/g−1 for whole sea buckthorn fruits and 13.33–26.67 mm/g−1 for sea buckthorn purees