Microwave‐assisted extraction in goji berries: effect on composition and bioactivity, evaluated through conventional and nonconventional methodologies

Abstract

Summary This study aimed to evaluate the effect of microwave‐assisted extraction (MAE) parameters on the composition and bioactivity of goji (Lycium barbarum) extracts. Extracts were obtained under a central composite design combination of experimental conditions, and characterised through HPLC‐DAD; their bioactive capacity was ascertained for antimicrobial and antioxidant capacity, the later by spectrophotometric [2,2‐azinobis (3‐ ethylbenzothiazoline‐6‐sulfonic acid) diammonium salt‐radical scavenging activity assay – 413–748 mg ascorbic acid equivalents/100 g DW and oxygen radical absorbance capacity – 1901–2292 mg trolox equivalents/100 g DW] and electrochemical (DNA‐based sensor – 3571–6602 mg ascorbic acid/100 g DW) methods. The quantitative profile of phenolic compounds was strongly dependent on MAE conditions. Significant correlations were found between the presence of several flavonoids and solvent composition, as well as between phenolic acids with methoxy group and the response to DNA‐based sensor. Results may improve targeted extractions for specific compounds, leading to the achievement of extracts richer in antioxidant capacity, as well as in the tailoring of the biosensor response sensitivity to the composition of the extracts under analysis.

Subcritical water extraction as an environmentally-friendly technique to recover bioactive compounds from traditional Serbian medicinal plants

“…compound behavior in cellular environment through the measurement of its protection to DNA oxidative damage (Carvalho et al, 2016). Moreover, the use of electrochemical sensors for measuring antioxidant activity of plant samples has received growing interest.…”

Valorization of apple tree wood residues by polyphenols extraction: Comparison between conventional and microwave-assisted extraction

“…A Shimadzu HPLC system equipped with a LC-20AD prominence pump, a DGU-20AS prominence degasser, a CTO-10AS VP column oven, a SIL-20A HT prominence autosampler, and a SPD-M20A photodiode array detector (Kyoto, Japan) was used to analyze the apple wood extracts according to Carvalho et al (2016) and Rubilar et al (2007). A Phenomenex Gemini C18 column (250 mm × 4.6 mm, 5 μm) and a guard column with the same characteristics maintained at 25 °C with a gradient program were used for the separation of phenolic compounds.…”

Assessment of the Antioxidant Capacity of Commercial Coffee Using Conventional Optical and Chromatographic Methods and an Innovative Electrochemical DNA-Based Biosensor

“…Phenolic compounds can be split into two main groups: (i) the phenolic acids, comprising hydroxylated derivatives of benzoic and cinnamic acids; and (ii) flavonoids, which include flavanols, flavones, flavanones, flavanols, anthocyanins and isoflavone [ 6 , 27 ].…”

“…The surface was smoothed against a plain white paper while a slight manual pressure was applied to the piston. Since CP oxidizes when exposed to air, for each analysis a new CPE surface was freshly prepared [ 6 ].…”

“…Studies have shown that our diet plays a major role in acquiring antioxidants to combat the reactive nature of free radicals [ 2 ]. To that end, numerous experiments have been conducted in different foods [ 6 , 7 ] and beverages [ 7 , 8 , 9 , 10 , 11 , 12 ] to determine which matrix exhibits a higher antioxidant activity to counteract and/or prevent further damage to the biological system.…”