Microwave‐assisted extraction in goji berries: effect on composition and bioactivity,evaluated through conventional and nonconventional methodologies |
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Authors: | Ana P Carvalho Marta Mendes Manuela M Moreira Diana Cruz Júlia M C S Magalhães M Fátima Barroso M J Ramalhosa Abel Duarte Luís Guido Ana M Gomes Cristina Delerue Matos |
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Affiliation: | 1. Instituto Superior de Engenharia do Porto, Porto Polytechnic Institute, REQUIMTE/LAQV, Porto, Portugal;2. Chemistry and Biochemistry Department, Sciences Faculty, REQUIMTE/LAQV, Porto University, Porto, Portugal;3. Chemical Engineering Department, Engineering Faculty, REQUIMTE/LAQV, Porto University, Porto, Portugal;4. Center for Biotechnology and Fine Chemistry, Portuguese Catholic University, Porto, Portugal |
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Abstract: | 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. |
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Keywords: | Bioactive compounds biosensor electrochemical methods HPLC‐DAD
Lycium barbarum
microwave‐assisted extraction spectrophotometric methods |
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