Valorization of Tomato Seed By-Products as a Source of Fatty Acids and Bioactive Compounds by Using Advanced Extraction Techniques

Abstract

In this work, lipids and bioactive compounds from tomato seed by-products were extracted and compared by using advanced extraction techniques, such as microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). The influence of different extraction parameters, including extraction temperature (T), time (t) and solvent volume (V) for MAE as well as extraction temperature (T), pressure (P) and flow rate (F) for SFE-CO2, was evaluated on tomato seed oil (TSO) yield and fatty acids composition using response surface methodology (RSM). Optimum extraction conditions for MAE were 56.2 °C, 29.0 min, and 67.6 mL, whereas conditions of 60.2 °C, 400.0 bar, and 64.6 g min−1 were found for SFE-CO2. Under these conditions, higher TSO extraction yields were obtained by MAE compared to SFE-CO2 (25.3 wt% and 16.9 wt%, respectively), while similar fatty acids profiles were found by GC in terms of FAMEs composition: methyl palmitate, methyl stearate, methyl oleate, and methyl linoleate, accounting for around 80 wt% of unsaturated fatty acids. TSO MAE extracts showed high DPPH• radical scavenging activity which was related to the presence of tocopherols; in particular γ-tocopherol, which was found as the dominant homologue (260.3 ± 0.6 mg kgTS−1) followed by a lower amount of α-tocopherol (6.53 ± 0.12 mg kgTS−1) by HPLC-DAD. The obtained results suggested that tomato seeds are an interesting source of bioactive compounds with potential use in a wide range of nutritional and food applications, increasing the added value of this by-product, which is currently underexploited.

Evaluation of Selected Medicinal, Timber and Ornamental Legume Species’ Seed Oils as Sources of Bioactive Lipophilic Compounds

“…The differences observed in tocochromanol content can be attributed to a different oil extraction protocol [ 43 ]; tocochromanol content tends to increase in cases of drought stress [ 31 ].…”

Tomato seed extract promotes health of the gut microbiota and demonstrates a potential new way to valorize tomato waste

“…One remarkable benefit of this agricultural product is the ability to process it into products that are both flavorful and stable at ambient temperatures for a long period of time [ 2 , 5 , 6 ]. The increased popularity of these products, coupled with the burden of waste disposal and need for nutritious components to feed a growing population, calls for novel strategies to utilize and/or repurpose tomato waste generated from processing [ 5 , 7 – 10 ]. Here, tomato seed extract isolated from pomace was tested for its ability to modulate the gut microbiota for potential prebiotic applications, in an effort to provide a new avenue for the valorization of tomato waste products.…”

“…Although tomatoes are often eaten fresh, they are more commonly consumed as processed products, such as tomato puree, paste, or sauce, which can be used further to create a number of tomato-based dishes and prolongs shelf-life [2,5,6]. While this is advantageous to the consumer, tomato processing generates an estimated 5.4-9 million tons of waste a year, largely in the form of pomace containing the skins, some pulp, and tomato seeds, which is often discarded or used as an additive for animal feed [5,[7][8][9][10][11][12]. However, tomato seeds (5-10% of pomace) are highly nutritious, 32% protein, 27% fat, and 18% fiber, and rich in phytochemicals and phenolic acids, and other bioactive compounds [12][13][14].…”

Microwave-Assisted Extraction/UHPLC-Q-Orbitrap-MS-Based Lipidomic Workflow for Comprehensive Study of Lipids in Soft Cheese

“…MAE in food analysis was useful for the extraction and determination of labile flavor compounds [16] or active molecules, successively used in the food, cosmetic, and pharmaceutical industries [17,18]. Moreover, MAE was used for total and healthy lipid recoveries and for essential oils, evaluating total fats, fatty acid composition, and volatile compounds together with other indices as cytotoxic, antioxidant, anti-inflammatory, or antimicrobial properties in different matrices [19][20][21][22][23]. Furthermore, Liu et al compared conventional and green extraction methods on oil yield, physicochemical properties, and lipid compositions, specifically fatty acids, triacylglycerols, and lipid concomitants (squalene, β-sitosterol, and tocopherols) in pomegranate seed oil [24].…”