Ultrasound-Assisted Extraction, Chemical Characterization, and Impact on Cell Viability of Food Wastes Derived from Southern Italy Autochthonous Citrus Fruits

Abstract

Citrus fruits are one of the principal fruits used to produce juices. Over the years, these fruits have been recognized as new health-promoting agents. In this work, food wastes derived from autochthonous citrus fruits of Southern Italy, named Limone di Rocca Imperiale, Arancia Rossa Moro, and Arancia Bionda Tardivo from Trebisacce, were analyzed. After fresh-squeezing juice, peel and pomace were employed to obtain six different extracts using an ultrasound-assisted method in a hydroalcoholic solvent. The extracts were analyzed in terms of qualitative composition, antioxidant properties, and antiproliferative activity on MCF-7, MDA-MB-231, and BJ-hTERT cell lines. GC-MS and LC-ESI-MS analyses showed different compounds: of note, limonin-hexoside, neodiosmin, obacunone glucoside, and diacetyl nomilinic acid glucoside have been identified as limonoid structures present in all the samples, in addition to different polyphenols including naringenin-glucoside, hesperetin-O-hexoside-O-rhamnoside-O-glucoside, diferuloyl-glucaric acid ester, chlorogenic acid, and the presence of fatty acids such as palmitic, myristic, and linoleic acids. These extracts were able to exert antioxidant activity as demonstrated by DPPH and ABTS assays and, although at higher doses, to reduce the cell viability of different solid tumor cell lines, as shown in MTT assays.

Citrus Peel Extracts: Effective Inhibitors of Heterocyclic Amines and Advanced Glycation End Products in Grilled Pork Meat Patties

“…The total peak ion and UV chromatogram of citrus peels extract are shown in Figure 3 . The comparison of their retention times and MS data with previously reported data in the literature is shown in Table 5 [ 22 , 23 , 39 ]. Furthermore, the results were confirmed using the chemSpider database and phenol-Explorer database.…”

“…Citrus peels, which make up a substantial portion of the total fruit weight, remain as the predominant residue [ 21 ]. Citrus peels possess substantial quantities of biologically active polyphenols, particularly polymethoxylated flavonoids, which have demonstrated vital antioxidant characteristics [ 22 , 23 ]. In Eastern Asian regions, fresh citrus peels experienced dehydration and treatment to serve as a functional nutritional component [ 21 ].…”

Attempts to Create Products with Increased Health-Promoting Potential Starting with Pinot Noir Pomace: Investigations on the Process and Its Methods

“…In the literature, a wide variety of extraction techniques have been presented for extracting phenolics from plant-based materials. Examples include conventional SLE [ 30 , 41 ], SLE assisted with ultrasound [ 47 , 48 ], SLE assisted with microwave [ 49 , 50 ], and supercritical fluid extraction [ 51 , 52 ]. Each technique has advantages (or disadvantages) based on factors such as cost, ease of use, efficiency of extraction, selectivity of phenolics, requirement for specialized equipment and being environmentally friendly.…”

Cavitation-Effect-Based Treatments and Extractions for Superior Fruit and Milk Valorisation

“…The peel and pomace obtained after the fresh juice was squeezed were used to obtain extracts containing limonoids and various polyphenols, including naringenin or hesperetin, and fatty acids such as palmitic, myristic and linoleic acids. The ultrasound-assisted method (30 °C, 200 W, 40 kHz for 45 min) used a hydroalcoholic solvent and allowed the researchers to obtain some compounds with antioxidant activity that reduced the cell viability of different tumour cell lines, which allowed the recovery of waste [ 72 ].…”