Optimization of the ultrasound-based extraction of bioactive compounds from green pepper using response-surface methodology

FAVRE, LEONARDO CRISTIAN; ROLANDELLI, GUIDO; MSHICILELI, NDUMISO; DOS SANTOS FERREIRA, CRISTINA; VAN WYK, JESSY; BUERA, M. PILAR

Congreso; XVII CONGRESO CYTAL / XXI CONGRESO ALACCTA 2019; 2019

In order to satisfy the increasing demands of developing natural or preservative-free food products, food industry is facing the challenge to develop products avoiding the use of synthetic additives. Green pepper (Piper nigrum) is a natural source of functional compounds, with antioxidant activity, being piperine one of the main bioactive compounds responsible of this property, which is also related to the antiglycant activity. Ultrasound-assisted extraction (USAE) is considered an eco-friendly technique and is more efficient than the traditional techniques, which allows reducing the extraction times. Since cyclodextrins are capable to form inclusion complexes with both hydrophilic and hydrophobic molecules, aqueous β-cyclodextrins (βCD) solutions are proposed as extraction agents in replacement of organic solvents. The aim of this work was to optimize the extraction conditions of bioactive compounds from green pepper, in aqueous media, employing USAE in βCD media, through the multiresponse-surface methodology. A Box-Behnken design was applied, using the independent variables βCD concentration (0 ? 15 mM), sonication time (0.5 ? 15 min) and agitation temperature (20 ? 50 ºC). The response variables analyzed were: total polyphenols content (TPC) by the Folin-Ciocalteau method, antioxidant capacity by the DPPH? assay (free radical scavenging of the 2,2-diphenyl-1-picrylhydrazyl radical) and the ferric reducing/antioxidant power (FRAP method). βCD concentration was the variable that most affected the reducing capacity, TPC and the antioxidant capacity of the extracts. Increasing the extraction temperature improved the TPC, but diminished both the antioxidant capacity and reducing power when low βCD concentrations were used. This could be related to the thermal sensitivity of the bioactive compounds from green pepper. To achieve a desirability of 0.96, the quantitative experimental factors were: 15 mM of βCD concentration, 5 min of sonication time and 41 ºC as extraction temperature. From these results, ultrasound-assisted and βCD-based extraction procedures could be optimized, preserving bioactive molecules from green pepper in order to avoid organic solvents and long extraction times. These extracts, with multi-functional properties for mitigating deteriorative reactions in foods, can be applied to design innovative formulations for the development of functional food ingredients.