Tomato Seed (Solanum lycopersicum) Meal Derived From Agrifood Waste as Functional Ingredient: Nutritional Value, Antioxidant and Antimicrobial Activities, and Functional Properties

Abstract

Agrifood wastes derived from fruits and vegetables are a major source of valuable bioactive compounds. They are therefore a potential functional ingredient that can be used for improving the physicochemical, and sensory, properties; health benefits; and shelf life of food. This study was aimed at evaluating the antioxidant and antimicrobial potential of tomato seed (Solanum lycopersicum) meal derived from agrifood waste to be used as a functional ingredient for food preservation. To this end, proximate composition, bioactive compounds, antioxidant activity, antimicrobial ability, and functional properties were evaluated using relevant methods. The seeds are the most nutrient-rich part of the tomato. They contain major macronutrients such as proteins (29.97%, dw), lipids (28.32%, dw), carbohydrates (17.19%, dw), and dietary fibers (20.93%, dw). They are rich in minerals (3.57%, dw), and bioactive molecules include total phenolic (4.8 mg/100 g) and carotenoids (with 43.65 μg/g for lycopene and 23.62 μg/g for β-carotene). Owing to their content of biomolecules, tomato seed meal extracts inhibited the growth of certain food-borne pathogens and food spoilage microorganisms with inhibition diameters of up to 25 cm. Methanolic extracts of these meals showed significant antioxidant activity (25.03% inhibition percentage of diphenyl-picryl-hydrazyl). Our findings highlight the importance of making better valorization of tomato seeds. Tomato seed meal has interesting potential as a functional ingredient, capable of improving the physicochemical properties, enriching the nutritional quality, and extending the shelf life of foods.