Tiberius Ilie Opruța

The present study was designed to determine the changes in the chemical composition of kefir enriched with encapsulated volatile oils by enzymatic methods and the antimicrobial activity of volatile oils. Using encapsulated volatile oils (fennel, mint, and lavender) and cow’s milk, we created three different forms of kefir. To highlight the antiseptic capacity of the volatile oils, we performed their antimicrobial analysis on three types of molds (Geotrichum candidum, Penicillium expansum, Aspergillus niger) and one Gram-negative bacterium (Escherichia coli). The technique used to determine antimicrobial activity was Kirby–Bauer. The changes in the chemical composition of kefir samples with encapsulated volatile oils were analyzed using enzymatic methods and were compared with a control sample of kefir. The main analyzed chemical compounds were lactose, D-glucose, D-galactose, acetic acid, ethanol, L-lactic acid, and L-glutamic acid. The kefir samples enriched with volatile oils obtained superior results compared to the control sample during the whole analysis period. The main advantage of using encapsulation is that the bioactive compounds of the volatile oils are gradually released in the kefir sample due to the protection provided by sodium alginate. As a result, products with high nutritional values were obtained that are beneficial to the consumer’s health and have a longer shelf life thanks to the volatile oils’ antimicrobial properties.

(1) Background: Natural antioxidants are health products found in many plants and may have a therapeutic effect on various diseases caused by oxidative stress. The purpose of this research is the antioxidant analysis of some kefir samples enriched with volatile oils extracted from three aromatic plants; (2) Methods: The volatile oils were extracted from lavender, fennel and mint. Four samples of kefir were made: kefir enriched with encapsulated lavender volatile oil, kefir enriched with encapsulated mint volatile oil, kefir enriched with encapsulated fennel volatile oil and a control sample without volatile oils. The analysis took place in three periods of storage: on the first day, on the 10th day and the 20th day; (3) Results: The antioxidant activity of kefir samples had decreased during the storage. The kefir sample with fennel and lavender volatile oil had the highest antioxidant activity, while the control sample had the lowest activity; (4) Conclusions: We can conclude that the volatile oils add value to the finished product.