Use of Melilotus officinalis extracts with antioxidant potential in a protective coating for tomatoes

Abstract. The goal of the research was to evaluate the effect of a protective coating for tomatoes enriched with Melilotus officinalis extracts with pronounced antioxidant activity. The Methods. The extraction conditions were optimized: the dried plant material was ground to a particle size of 0.2-0.5 mm, the raw material to extractant ratio was 1:100, and the extraction time was 5 days. The content of phenolic compounds, flavonoids, and antioxidant activity of the extracts were determined by spectrophotometric methods. The Results. The extracts obtained using 10% and 50% ethyl alcohol demonstrated a high content of phenols (33.7 mg/g) and flavonoids (1.74 mg/g), respectively. The highest antioxidant activity (89.8%) was recorded in the extract obtained with 50% ethyl alcohol. The study of the effect of the protective coating on the preservation of tomatoes showed that during storage without cooling, the daily weight loss was 1.1±0.1% for uncoated samples and 0.9±0.1% for coated samples. During refrigeration storage, the weight loss was less pronounced: after 7 days, the difference between the samples with and without the coating was 0.7%. During the first 3 days of storage, the weight of the tomatoes decreased uniformly for all samples, but starting from the 4th day, the uncoated tomatoes began to lose weight much faster compared to the samples treated with a protective coating. The coating with the addition of extracts demonstrated the greatest efficiency: the weight loss without cooling and in a cooled state was 5.7% and 1.7%, respectively, while for tomatoes without coating, these figures were 7.3% and 2.3%. Conclusion. The data obtained indicate the potential of using protective coatings with Melilotus officinalis extracts to increase the shelf life of tomatoes and reduce weight loss.