Micronization of Small-Amount Preservatives

Natural preservatives are a global trend in the food industry. As a rule, they are traditional herbs or spices. Flavonoids inhibit microbial activity. However, they are effective only when their distribution in the food matrix is uniform. This uniformity is achieved by increasing their solubility, e.g., by micronization. The research assessed the feasibility and effectiveness of micronization of a plant preservative using a purified flavonoi d fraction obtained from defatted sea-buckthorn meal. The study featured samples of purified flavonoid fraction of sea-buckthorn meal with different dispersions. Their solubility, antioxidant properties, antimicrobial activity, and fungicidal effect were assessed by standard methods. Micronization under ultrasonic conditions and cryogenic grinding increased the solubility in water, ethyl, and oil. Ultrasonic micronization proved efficient as it produced particles of 1,400 nm under rational conditions, i.e., 50 W ultrasonic vibration in a 0.5% suspension for 10 min. The sample obtained in this way increased the rate of catalase reaction by 19% relative to the control sample while maintaining a constant rate of glutathione reduction. Its antioxidant activity increased fourfold. The samples demonstrated bacteriostatic activity against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, as well as fungistatic activity against Candida albicans. Purified flavonoid fraction of sea-buckthorn meal micronized under ultrasonic conditions can be recommended as a natural preservative in various food systems.