title: Optimisation of phenolic extraction from Averrhoa carambola pomace by response surface methodology and its microencapsulation by spray and freeze drying.
abstract: Optimised of the extraction of polyphenol from star fruit (Averrhoa carambola) pomace using response surface methodology was carried out. Two variables viz. temperature (°C) and ethanol concentration (%) with 5 levels (-1.414, -1, 0, +1 and +1.414) were used to design the optimisation model using central composite rotatable design where, -1.414 and +1.414 refer to axial values, -1 and +1 mean factorial points and 0 refers to centre point of the design. The two variables, temperature of 40°C and ethanol concentration of 65% were the optimised conditions for the response variables of total phenolic content, ferric reducing antioxidant capacity and 2,2-diphenyl-1-picrylhydrazyl scavenging activity. The reverse phase-high pressure liquid chromatography chromatogram of the polyphenol extract showed eight phenolic acids and ascorbic acid. The extract was then encapsulated with maltodextrin (⩽ DE 20) by spray and freeze drying methods at three different concentrations. Highest encapsulating efficiency was obtained in freeze dried encapsulates (78-97%). The obtained optimised model could be used for polyphenol extraction from star fruit pomace and microencapsulates can be incorporated in different food systems to enhance their antioxidant property.
authors.affiliation: Department of Food Engineering and Technology, School of Engineering, Tezpur University, Assam, India.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Saikia
authors.affiliation: Department of Food Engineering and Technology, School of Engineering, Tezpur University, Assam, India.
authors.forename: Nikhil Kumar
authors.initials: NK
authors.lastname: Mahnot
authors.affiliation: Department of Food Engineering and Technology, School of Engineering, Tezpur University, Assam, India. Electronic address: charu@tezu.ernet.in.
authors.forename: Charu Lata
authors.initials: CL
authors.lastname: Mahanta
mesh_terms: D000975:Antioxidants / Q000737:chemistry; D001205:Ascorbic Acid / Q000032:analysis; D065826:Averrhoa / Q000737:chemistry*; D001713:Biphenyl Compounds / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004339:Drug Compounding; D000431:Ethanol / Q000032:analysis / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry; D005524:Food Technology / Q000379:methods; D005612:Freeze Drying; D005638:Fruit / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D010636:Phenols / Q000032:analysis*; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D059808:Polyphenols / Q000032:analysis / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005290:Ferric Compounds; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D059808:Polyphenols; D011134:Polysaccharides; D000431:Ethanol; C008315:maltodextrin; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid
keywords: Antioxidant activity; Maltodextrin; Microencapsulation; Optimisation; Polyphenol; Pomace