Impact of Ohmic-Assisted Decoction on Bioactive Components Extracted from Yacon (Smallanthus sonchifolius Poepp.) Leaves: Comparison with Conventional Decoction

Abstract

Yacon (Smallanthus sonchifolius Poepp.) leaves are a potentially rich source of bioactive compounds, such as phenolic acids and flavonoids. In this study, the effect of the extraction method (ohmic-assisted decoction (OH-DE) and decoction (DE)), yacon cultivar (red and white), and leaf age (young and old) on the quality/quantity of extracted phytochemicals were investigated. Extraction yield, energy consumption, total phenolic content (TPC), total flavonoid content (TFC), ABTS and DPPH radical scavenging activity, and ferric reducing antioxidant power (FRAP) were determined. Additionally, HPLC-DAD was used to identify the major individual phenolic and flavonoid compounds of yacon leaves. The results showed that a three-way interaction of process-variables (extraction method×yacon cultivar×age of leaves) influenced the extraction yield, TPC, TFC, ABTS, and DPPH radical scavenging activity, and FRAP, significantly (p < 0.05). However, energy consumption of the extraction process was only affected by method of extraction (p < 0.05) and was halved when OH-DE was applied as compared to DE alone. Additionally, the phytochemical quality of extracts was either improved or comparable when OH-DE was used for extraction. Also, it was shown that yacon leaves contained considerable amounts of caffeic acid, chlorogenic acid, ferrulic acid, myricetin, p-coumaric acid, and rutin, while leaves of the red cultivar had higher contents of each compound compared to leaves of the white cultivar.

Extraction of tomato by-products’ bioactive compounds using ohmic technology

“…The combination of the different factors showed that to obtain higher levels of extraction of total phenolics treatment conditions should be as follow: 70 • C, during 15 min with 69.9% of ethanol. The combination of OH and temperature can be an effective alternative method for extraction of phenolic compounds, which supports other studies (El Darra et al, 2013;Khajehei et al, 2017;Loypimai et al, 2015;Pereira et al, 2016).…”

“…The application of a fast heating process may be important on the preservation of heat sensitive phenolic compounds. At the same time, the fast heating and electroporation effects can cause cellular heat stress and consequently structural damages, enhancing the release of certain phenolic compounds (Khajehei et al, 2017;Sakr and Liu, 2014;Sastry, 2008).…”

“…Relatively to rutin and kaempferol extraction, no significant difference was detected between 6 and 11 V cm −1 , while to naringenin there was significant differences between the electric fields applied. Joule effect can induce an electro and thermal-permeabilization of cell membranes, causing disturbances on their permeability, structural alterations, contributing in release of higher amounts of polyphenol compounds (Khajehei et al, 2017). In addition, it was detected two groups of polyphenols (rutin and kaempferol are flavonols and naringenin is a flavanone) with different structural comportments.…”

Yacon (Smallanthus sonchifolius Poepp. & Endl.) as a Novel Source of Health Promoting Compounds: Antioxidant Activity, Phytochemicals and Sugar Content in Flesh, Peel, and Whole Tubers of Seven Cultivars

“…Cajamarca, respectively. The results of previous studies regarding the individual flavonoids determined the presence of kaempherol, myricetin, quercetin and rutin in yacon leaves in various quantities depending on yacon cultivar, environmental conditions during cultivation, method of extraction and solvent used for extraction [ 42 , 43 ]. Simonovska et al (2003) investigated the individual flavonoids in yacon leaves and tubers and suggested that yacon tubers might contain quercetin and other flavonoids, which remained unknown in their study [ 37 ].…”

Andean roots and tubers crops as sources of functional foods

“…Dehydrated yacon leaves are recommended for preparation of infusions with antioxidant and antidiabetic properties (Villacrés et al, 2007;Andrade et al, 2014;Russo et al, 2015). The concentration of antioxidant phenols and flavonoids in the yacon leaves varies depending on the cultivars (red or white), the leaf age and the extraction process (Khajehei et al, 2017).…”