Low Power Ultrasound-Assisted Extraction of Phenolic Compounds from Mandarin (Citrus reticulata Blanco cv. Sainampueng) and Lime (Citrus aurantifolia) Peels and the Antioxidant

Abstract

Mandarin and lime peels are rich sources of phenolic compounds including phenolic acids and flavonoids. The ultrasound-assisted extraction (UAE) proved to be an effective method in the extraction of phenolic compounds from plants due to its ability to save extraction time and increase extraction yields. In this research, factorial randomized complete experimental design has been used to investigate the effect of various factors on UAE using low power (50.93 W). Influence of citrus peel types and solvent types and concentrations on the total phenolic compounds, total flavonoids, and flavanone glycosides (hesperidin and naringin) were studied. Antioxidant activity of the extracts was measured by ferric reducing antioxidant potential (FRAP), azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. The optimum extraction conditions occurred when mandarin peel and 80 % acetone were used. In those conditions, the extract contained 3,083.61 mg gallic acid equivalent (eq) 100 g −1 dry weight (DW) of total phenolic compounds, 2,539.82 mg quercetin eq 100 g −1 DW of total flavonoid, 1,374.20 mg 100 g −1 DW of hesperidin, and the measured antioxidant activity was 0.61 mg mL −1 of DPPH IC 50 , 1.12 mg mL −1 of ABTS IC 50 , and 2,521.47 mg trolox eq 100 g −1 for FRAP. A strong correlation between total phenolic content and antioxidant activity was also observed.

Conventional and Emerging Extraction Processes of Flavonoids

“…Among the flavonoid compounds that have been extracted and recovered using this methodology are the following: Rutin, narcissin, nicotiflorin, epicatechin, epicatechin gallate, The UAE increased the yield of bioactive compounds and the yield of flavonoids were shown to be variable depending on the method of extraction, as well as on the type of plant material (Table 2B). Mainly phenolic compounds and flavonoids, as well as the reduction of extraction times, and another of the advantages of this methodology is that it improves the biological properties of the extracts [115]. The extraction of bioactive compounds depends on a variety of factors, such as the frequency used and usually between 20 kHz and 100 MHz [116], solvent selection, solvent concentration, solid-solvent ratio, temperature, and time extraction (Table 2B).…”

Innovative “Green” and Novel Strategies for the Extraction of Bioactive Added Value Compounds from Citrus Wastes—A Review

“…Specifically, the BAC obtained included total phenolic compounds, total flavonoids and two flavanone glycosides, hesperidin and naringin. The best results were achieved for mandarin peels, extracted with 80% of acetone, where 3 mg of GAE/100 g DW of total phenolic compounds were obtained, as well as 2.5 mg of quercetin EQ/100 g DW (total flavonoids), and 1.4 mg/100 g DW of hesperidin [ 111 ].…”

Optimization of Bioactive Substances in the Wastes of Some Selective Mediterranean Crops

“…Karsheva et al obtained extracts from mandarin peels, and examined the level of biophenols in their extract content [6]. Singanusong et al also found the antioxidant capacity of mandarin peels by various methods, and analyzed their total biophenolic substances [10]. Ateş et al extracted phenolic antioxidants by various advanced separation methods (microwave-assisted extraction and supercritical-CO 2 extraction), using mandarin peel as a raw material [11].…”