Optimization of Hot-water Extraction of Dried Yacon Herbal Tea Leaves: Enhanced Antioxidant Activities and Total Phenolic Content by Response Surface Methodology

Abstract

Yacon (Smallanthus sonchifolius) is an herbal plant and its root has been historically consumed as a sweet vegetable in the Andes. With the research goal of establishing yacon leaves, grown in Japan, as a foodstuff with health benefits, we previously reported the antioxidant effects of yacon tea leaves using concentrated extracts. In this study, we determined the optimum conditions for regular hot-water extraction of yacon tea leaves, intended for normal consumption, aiming for higher activity in several antioxidant assays and total phenolic content (TPC). Response surface methodology was used to optimize the extraction by central composite design. Extraction temperature (ranging from 75.0 to 96.0 ℃) and time (from 2.00 to 5.50 min) were set as the two independent variables. Based on a composite desirability value of 0.863, the hot-water extraction of yacon tea at 89.3 ℃ for 2.50 min was found to be the optimized condition providing higher antioxidant activity and TPC.

Optimization of Berry Infusions with High Polphenol Content

“…In accordance with the findings of the literature, characteristics such as total phenolic substance content, total flavonoid content, antioxidant activity and anthocyanin content were investigated in studies on herbal, fruit, and other teas. To improve the qualitative properties of goji berry tea, it is aimed to enhance the total phenolic content, total flavonoid content, antioxidant activity, anthocyanin content, and condensed tannin content (Rittisak et al, 2022;Ueda et al, 2019;Irakli et al, 2018a;Liu et al, 2020).…”

Topinambur (Helianthus tuberosus) and yacon (Smallanthus sonchifolius): nutraceutical crops?

“…Yacón-based beverages were shown to improve diabetic status in rats. Yacón has been widely recognized as an excellent source of bioactive compounds, including prebiotics and antioxidants, [66][67][68] which may be beneficial to health. Experimental data indicate that prebiotics and some specific polyphenols could reduce the severity or incidence of degenerative diseases, such as diabetes.…”

Investigation of Total Polyphenol Content, Antioxidant Activity, and Carbohydrate-hydrolyzing Enzyme Inhibition of Yacon Leaves among Four Domestic Cultivars and a Peru Line for over Four Years

“…The tuberous roots of this plant have been consumed as a sweet vegetable, whereas most of the aerial part becomes harvest residue (Kabata et al 2006), though a portion of the leaves can be processed for local consumption as an herbal tea. In terms of functional benefits, yacon leaves have exhibited hypoglycemic effects in rat models (Aybar et al 2001, Baroni et al 2016; and also possess antioxidant (Valentova et al 2005, Ueda et al 2019a, antifungal (Lin et al 2003), and anticancer (Bai et al 2017, Mendoza et al 2017 activities.…”