Response surface evaluation of microwave-assisted extraction conditions for Lycium barbarum bioactive compounds. (February 2016)

• Record Type: Journal Article
• Authors: Mendes, Marta; Carvalho, Ana P.; Magalhães, Júlia M.C.S.; Moreira, Manuela; Guido, Luís; Gomes, Ana M.; Delerue-Matos, Cristina
• Is Part Of: Innovative food science & emerging technologies. Volume 33(2016)
• Page Start: 319
• Page End: 326
• Publication Date: 2016-02
• Subjects: Antioxidant capacity -- Goji berry -- MAE -- Response surface methodology -- Solvent dielectric properties -- Temperature; Food -- Biotechnology -- Periodicals; Food industry and trade -- Technological innovations -- Periodicals; Aliments -- Biotechnologie -- Périodiques; Food -- Biotechnology; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.ifset.2015.12.025
• Languages: English
• ISSNs: 1466-8564

Abstract

Abstract: The effects of microwave-assisted extraction (MAE) on the qualitative and quantitative composition of extracted bioactive phytochemicals are strongly dependent on specific operational conditions. The impact of temperature, extraction time, and solvent dielectric properties on the MAE of antioxidant compounds from goji berry is hereby reported and discussed. Results were evaluated in terms of antioxidant capacity (ascertained by ABTS and ORAC assays), complemented with quantification of total phenolics content (TPC), and characterization of extracts through HPLC. Furthermore, the effect of storage temperature was also studied. Results revealed that temperature and solvent properties exert a significant effect on TPC and ORAC assays, whereas irradiation time plays a key role in the preparation of extracts to be evaluated through ABTS. The effect of solvent properties is tentatively explained considering the dielectric properties of methanol and water, whereas the observed effect of temperature could be explained by its influence on the solubility of phenolic compounds. Industrial Relevance: A careful selection of operational conditions during MAE, designed for a specific antioxidant assay, allows an increase in the bioactivity of the resultant extracts, which may become important in terms of industrial applications. Highlights: MAE of goji berries was evaluated through RSM. Temperature and solvent properties exert significant effect in TPC and ORAC assays. Irradiation time plays a key role in preparation of extracts evaluated through ABTS. Effect of solvents is tentatively explained by their dielectric properties. Effect of temperature is correlated with solubility of phenolic compounds.