Garlic (Allium sativum L.) peel extracts: From industrial by-product to food additive

Garlic (Allium sativum L.) is a spice widely used both as food and for its medicinal effects, however, much of the research on A. sativum is limited to the study of the bulb, even though the garlic peel corresponds to 25% of total production and is generally discarded by industry. In order to obtain a use of this co-product, the objective of this work was to elaborate plant extracts from the peel of garlic (Allium sativum L.), using maceration and turbolization as extraction methods and water or hydroalcoholic solutions (50% and 70%) as solvents, evaluate the obtained extracts taking into account the content of bioactive compounds, the antimicrobial potential, antioxidant capacity and its toxicity against adult zebrafish (Danio rerio). The hydroalcoholic extracts of garlic peel had a higher content of bioactive compounds, showing a direct correlation to the result of the antioxidant potential of these extracts, which also showed bactericidal effect against S. aureus (ATCC 27,664) and L. monocytogenes (ATCC 19,115). These extracts did not show any toxic effect on A. salina and adult zebrafish, however, the assay with D. rerio showed a sedative effect when using extracts obtained with 70% ethanol (EMH70% and ETH70%). The extracts obtained with 50% ethanol had the best results combined with the absence of toxicity and sedative effect, demonstrating an excellent potential for a future application in the food matrix, due to the presence of bioactive substances and their antioxidant and antimicrobial effects.