Natural Extracts from Eugenia brasiliensis Lam Leaves to Improve the Shelf-Life of Fresh Tomatoes

Abstract

In this work, hydroalcoholic extracts were obtained from leaves of Eugenia brasiliensis to be evaluated for the content of bioactive compounds and applied to fresh tomatoes for preservation. Analyzes of total phenolics, flavonoids, antioxidant and antibacterial activity, and toxicity were performed. Tomatoes were treated with the extracts by immersion in an aqueous solution at 200, 600, and 1000 mg/L and evaluated for 28 days for total soluble solids, titratable acidity, maturation index ascorbic acid content, weight loss, and visual test. The presence of gallic acid, rutin, and quercetin was identified in all extracts. The extracts obtained by water and ethanol at 25% e 50% showed better results regarding phenolic compounds; antioxidant and antimicrobial activity. However, the 25 and 50% ethanol extracts were the only ones that showed toxicity. The treatments proposed for the conservation of tomatoes, in concentrations superior to 600 mg/L, showed promising results, mainly in the protection of the fruits regarding the loss of water and, consequently, visual depreciation due to the appearance of wrinkles. Thus, most proposed treatments demonstrated viability because of conserving organoleptic properties of fresh tomatoes.

Exploring the Potential of Microextraction in the Survey of Food Fruits and Vegetable Safety

“…The authors used methanol (MeOH) as the extraction solvent and achieved LODs of 0.005-5 µg g −1 . De Souza et al [99] also used SLE for the analysis of gallic acid, rutin, and quercetin in tomato samples. The reported method, however, involved 1 h of stirring during the SLE step.…”