Valorisation of tomato wastes for development of nutrient-rich antioxidant ingredients: A sustainable approach towards the needs of the today's society

Abstract

Nutrient-rich antioxidant ingredients were produced from tomato fruit wastes using a microwave-assisted extraction (MAE) process. Different conditions of extraction time (t), temperature (T), ethanol concentration (Et) and solid/liquid ratio (S/L) were combined in a circumscribed central composite design and optimized by response surface methodology. The model was statistically validated and used for prediction in the experimental range. Under the global optimal MAE conditions (t = 20 min, T = 180°C, Et = 47.4% and S/L = 45 g/L), it was possible to obtain an extraction yield of 75.5% and ingredients with high levels of sugars, proteins, phenolics, and flavonoids, and interesting antioxidant properties measured via ABTS• + scavenging activity and oxidative haemolysis inhibition assay (OxHLIA). The antioxidant capacity of the extracts was lower compared to the one of commercial food additives. However, the sustainably developed ingredients may be used in the fortification and functionalisation of food, as well as for incorporation in feed products. Industrial relevance: This study addresses current needs of the agri-food sector, namely the recycling of plant wastes and production of valuable extracts for the food/feed industry. A MAE process was developed and optimized to maximize the recovery of nutrients and antioxidants from tomato fruit wastes. The optimum processing conditions established in this study allowed a high extraction yield and reduced solvent consumption. MAE can be considered as a sustainable alternative to conventional extraction methods. These findings will contribute to promote a more sustainable bioeconomy in the agro-food sector.

Wild edible plants: Nutritional and toxicological characteristics, retrieval strategies and importance for today's society

“…-Application of innovative methods and technologies: Application of nonconventional and emerging treatments (innovative packaging systems, light treatments, irradiation, high pressures, pulsed electric fields, among others) for quality preservation and shelf-life extension of wild plant foods (Pinela et al, 2016a(Pinela et al, , 2016b(Pinela et al, , 2016c(Pinela et al, , 2016d, in order to promote their commercialization and the consumer's acceptance for minimally processed and new food products. Establishment of optimized protocols for recovery of high added-value compounds (polyphenols, terpenoids, polysaccharides, and others) from wild species and their by-products and production of enriched extracts to be used in industrial sectors (Pinela et al, 2017a(Pinela et al, , 2017b). -Development of new products, recipes and characteristic dishes:…”

Optimization of heat- and ultrasound-assisted extraction of anthocyanins from Hibiscus sabdariffa calyces for natural food colorants

“…The globalization of the industrial food sector, together with consumer's awareness about the existence of bio-based alternatives to the artificial additives, nowadays massively used, and with potential toxic effects in humans, has promoted the demand for food products formulated with natural ingredients recovered from plant materials (Carocho, Morales, & Ferreira, 2015;Martins, Roriz, Morales, Barros, & Ferreira, 2016). The scientific research in this area has gained international prominence (Almeida et al, 2018;Carocho et al, 2016;Pinela et al, 2017), as it is still necessary to expand the range of natural options and find new sources (e.g., plants, algae and insects), as well as to develop sustainable processes for an efficient recovery of the target compounds (e.g., anthocyanins, carotenoids, and beet derivatives).…”

Potato Peels as a Source of Novel Green Extracts Suitable as Antioxidant Additives for Fresh-Cut Fruits

“…Potato peels represent the major waste from the potato processing industry, and they can be revalorized as a source of functional and bioactive compounds with particular attention to phenolic acids [12]. Thus, potato waste represents promising cheap resources and its recovery and recycling within the food chain could be a sustainable strategy to address the present challenges of the industrialized world [13].…”