Natural valuable compound extraction from onion by-products using a pulsed electric field

Abstract

Onion by-products, a waste generated from fruit processing industry, is a potential source of phenolic compounds that are known for their anti-oxidative properties. The influence of pulsed electric field (PEF) treatment on the bioactive compounds from onion by-products at different pulse voltage (PV); 2000, 4000, 6000Vand number of pulse (NP); 40, 50, 60 has been investigated. Response surface methodology, based on a Face-Centered Experimental Design (FCED) was used to determine optimal PEF treatment and optimize extraction yield, antioxidant strength, total phenolic compound (TPC),and quercetin content. The experimental data were fitted to a second-order polynomial equation and also profiled into the corresponding 3-D contour plots. Optimal extraction conditions were as follows:PV were 4102.97 V and and NP 51.43. Under these conditions, TPC, DPPH, FRAP,Quercetin and extraction yield were 48.912 ± 6 mg/kg, 50.366 ± 1 %, 465.414 ± 5 µmFe2/l, 31.761 ± 0.5 mg/100g and 88.107 ± 1% ; respectively and matching well with the predicted value. The results demonstrated that PEF could be a very effective method for continuous extraction of natural compounds.

Green Extraction Methods for Extraction of Polyphenolic Compounds from Blueberry Pomace

“…Bansal et al [ 49 ] also showed that PEF extraction of quercetin from Emblica Officinalis is an effective treatment for the extraction of flavonols compared to conventional methods. Furthermore, Teherani et al [ 50 ] proposed PEF (4.1 kV) as a very effective method for extraction of quercetin from onion by-products. Concerning the other two methods, higher extraction yields of flavonols with HVED were achieved in ethanol-based solvent at the frequency of 50 Hz for 15 min, while US-assisted extraction showed to be more efficient in methanol-based solvent after 15 min at 80 °C (121.90 and 98.63 µg/g of dw, respectively).…”

A Review on the Potential Bioactive Components in Fruits and Vegetable Wastes as Value-Added Products in the Food Industry

“…Total polyphenol content increased by 49.15%, 35.25%, and 44.36%, respectively, at the optimum electric field strengths of 1.4 kV/cm for V. vinifera and 1.2 kV/cm for S. scardica and C. sativus . Tehrani et al [ 80 ] extracted valuable compounds in onion ( Allium cepa L.) waste using a pulsed electric field (PEF). TPC, DPPH, FRAP, quercetin, and extraction yield were 48.912 ± 6 mg/kg, 50.366 ± 1%, 465.414 ± 5 µmFe 2 /l, 31.761 ± 0.5 mg/100 g, and 88.107 ± 1% respectively.…”