Effects of Pulsed Electric Fields on Anthocyanin Extraction Yield of Blueberry Processing By-Products

Abstract

In order to improve the comprehensive utilization of blueberries, extraction of anthocyanin from blueberry processing by-products (BPBs) by pulsed electric field (PEF) was investigated. Response surface methodology was employed to optimize the conditions of the anthocyanin extraction yield (AEY) from BPB, and a regression mathematical model was established to describe the experimental data for AEY in the investigation. The optimized parameters of anthocyanin extraction were that solvent of 60% ethanol (acidified with 0.1% [v/v] hydrochloric acid), liquid to liquid ratio of 1:6 (mL/mL), pulse number of 10 ea and electric field strength of 20 kV/cm. The quantity extracted anthocyanin reached 223.13 mg/L BPB. Compared with the ultrasound extraction, PEF treatment as an emerging technology increased the AEY at a lower extraction temperature and at a shorter extraction time. PRACTICAL APPLICATIONSBlueberries are a richer source of anthocyanin than other fruits and vegetables, but different processed products and production modes generate large amounts of blueberry by-products, resulting in a waste of resource. Extraction of these compounds from blueberry processing by-products may be a broad application prospect for food industry. Our results indicated that pulsed electric field method can not only improve the AEY but also reduce the extraction temperature and shorten the extraction time, improving the additional value of blueberries and the reference for the comprehensive utilization of blueberry.

Green Extraction Methods for Extraction of Polyphenolic Compounds from Blueberry Pomace

“…32 µg/g of dw) compared to the other two methods was observed in the extract obtained with PEF-assisted extraction in methanol-based solvent after 100 pulses and 20 kV/cm. These results are in agreement with Zhou and Huang [ 14 ], who also noticed that increasing the electric field intensity up to 20 kV/cm leads to an increase in the content of anthocyanins in the extract. The most optimal conditions for the extraction of anthocyanins by PEF in their case were at an electric field intensity of 20 kV/cm, acidified (0.1% of hydrochloric acid) 60% ethanol, and a liquid to liquid ratio of 1:6 (mL/mL).…”

“…Besides that, strong UV radiations and active radicals are also generated; however, if electric field intensity is moderate, it will influence only cell destruction efficacy rather than oxidase compounds such as polyphenols [ 13 ]. The enhanced electrohydraulic phase occurs during the transition of pre-breakdown to breakdown phase, causing several effects: strong shock waves, strong UV radiations, production of highly concentrated free radicals, bubbles with plasma inside, and strong liquid turbulence [ 13 , 14 , 15 ]. The named effect can cause product fragmentation, mechanical destruction of cell tissues as well as cell oxidation [ 16 ].…”

“…However, electric field strength up to 20 kV/cm should be employed in order to achieve good extraction results from e.g., seeds and stalks where lignification can occur [ 24 ]. PEF has been used for the extraction of polyphenols from blueberry processing by-products [ 14 ], orange peel [ 25 ], purple-fleshed potato [ 26 ], grape seed [ 27 ], and grape by-products [ 28 ].…”

Natural Antioxidants in Foods and Medicinal Plants: Extraction, Assessment and Resources

“…This slight temperature increment confirmed that pulsed electric field processing provided a non-thermal condition. The improvement of extraction efficiency using PEF technology has been demonstrated in the extraction of antioxidants from food and medicinal plants, such as polyphenols from Norway spruce bark [ 130 ]; anthocyanin from blueberry processing by-products [ 131 ]; quercetin and ellagic acid from Emblica officinalis juice [ 132 ]; anthocyanin from red cabbage [ 133 ]; lutein from Chlorella vulgaris [ 134 ]; and beta-carotene from carrot pomace [ 135 ]. The electric field strength plays an important role in solute extraction.…”

Application of Response Surface Methodology to Optimize Microwave-Assisted Extraction of Total Phenolic Compounds From Caucasian Whortleberry

“…A large number of MAE studies have been reported for the extraction of biological compounds including phenolic compounds from eucalyptus leaves (Gharekhani et al, 2012), broccoli (Jokic et al, 2012), grape seeds (Krishnaswamy et al, 2013), chokeberry (Simic et al, 2016), cabbage (Sookjitsumran et al, 2016), barberry (Ardestani et al, 2016). In addition, there are several articles which focus on the extraction of anthocyanins from blueberries (Zheng et al, 2013;Zhou et al, 2015). However, the microwave-assisted extraction of phenolic compounds from Caucasian whortleberry is lacking in literature.…”