Valorization of Defatted Cherry Seed Residues from Liquor Processing by Matrix Solid-Phase Dispersion Extraction: A Sustainable Strategy for Production of Phenolic-Rich Extracts with Antioxidant Potential

Abstract

The integrated valorization of food chain waste is one of the most promising alternatives in the transition to a sustainable bioeconomy. Thus, an efficient solid-phase matrix dispersion extraction method, using experimental factorial design and response surface methodology, has been developed and optimized for the recovery of polyphenols from defatted cherry seeds obtained after cherry liquor manufacture and subsequent fatty acid extraction, evaluating the effect of each processing step on the composition and phenolic content of sweet cherry residues. The phenolic extracts before fermentation showed the highest content of total polyphenols (TPC) and flavonoids (TFC) (3 ± 1 mg QE·g−1 and 1.37 ± 0.08 mg GAE·g−1, respectively), while the highest antioxidant capacity was obtained in the defatted seed extracts after both fermentation and distillation. In addition, high-performance liquid chromatography coupled to a quadrupole time-of-flight mass spectrometer (HPLC-ESI-QTOF-MS) was used to determine the phenolic profile. Dihydroxybenzoic acid, neochlorogenic acid, caffeic acid, and quercetin were the main phenolics found, showing differences in concentration between the stages of liquor production. The results underline the prospective of cherry by-products for obtaining phenol-rich bioactive extracts for possible use in different industrial sectors, offering a feasible solution for the cascade valorization of cherry agri-food waste.

The Potential of Plum Seed Residue: Unraveling the Effect of Processing on Phytochemical Composition and Bioactive Properties

“…This is attributed to the potential extraction of other hydrophilic components of the seeds during Soxhlet extraction, which enriches the content of defatted seeds. That being so, the lower content of defatted seed in PAFD may be related to its lower content of hydrophilic compounds, such as proteins, sugars, and even polyphenols [ 12 ].…”

“…Furthermore, these results are in line with data found in the literature. The fat content of plum seeds of the variety P. domestica L. extracted by Soxhlet using n -hexane as a solvent usually varies between 30 and 38.7%, w [ 6 , 12 ]. Concerning the effect of processing on oil content, Rodríguez-Blázquez et al [ 12 ] demonstrated that defatted P. avium L. seed residues decreased their content during brandy processing, thereby increasing their oil content.…”

“…In this context, both the oil extracted from the seeds and the by-product of defatted seeds could present numerous bioactive compounds with excellent properties or activities, such as polyphenols, tocopherols, and unsaturated fatty acids, among others [ 6 , 12 , 27 ]. Hence, exploring their nutritional value and potential content has become an emerging requirement for the scientific community.…”

“…Oil extraction from plum seeds was performed following standard Soxhlet extraction [ 28 ] and the after-treatment described by Rodríguez-Blázquez et al [ 6 , 12 ]. Approximately 15 g of plum seed with a particle size of less than 1 mm were extracted with 150 mL of n -hexane (seed-solvent ratio (1:10)) under reflux at 69 °C for 6 h (6–8 cycles per hour).…”

“…Nevertheless, after the oil extraction process, a second-generation biowaste is generated, namely defatted plum seeds, which may contain compounds with positive biological activities for the human organism such as phenolic compounds [ 12 ]. Among the phenolic compounds found in defatted plum seeds, the main ones were rutin (64–5670 μg·g −1 ), 2,3-dihydroxybenzoic acid (400–3780 μg·g −1 ), gallic acid (143–1890 μg·g −1 ), catechin and epicatechin (1070 and 9.5 μg·g −1 , respectively), syringic acid (8.7–900 μg·g −1 ), chlorogenic acid (250–300 μg·g −1 ), and caffeic acid (3–300 μg·g −1 ) [ 13 , 14 ].…”