title: Development of pectin films with pomegranate juice and citric acid.
abstract: The influence of pomegranate juice (PJ, replacing water as solvent) and citric acid (CA) on properties of pectin films was studied. PJ provided the films with a bright red color, and acted as a plasticizer. Increasing PJ/water ratio from 0/100 to 100/0 resulted in enhanced elongation (from 2% to 20%), decreased strength (from 10 to <2 MPa) and modulus (from 93 to <10 MPa), increased water vapor permeability (WVP, from 3 to 9 g.mm.kPa(-1).h(-1).m(-2)), and decreased insoluble matter (IM, from 35% to 24%). Although a crosslinking effect by CA was not confirmed, it has been suggested to occur from its effects on films. CA noticeably increased IM (from <10% to almost 40%); moreover, when measured on a dry film basis, the CA effects presented a noticeable tendency to increases strength and modulus, and to decrease WVP. The red color density was decreased by CA, suggesting a destabilization of anthocyanins.
authors.affiliation: Embrapa Tropical Agroindustry, R. Dra. Sara Mesquita, 2270, Fortaleza, CE, CEP 60511-110, Brazil. Electronic address: henriette.azeredo@embrapa.br.
authors.forename: Henriette M C
authors.initials: HM
authors.lastname: Azeredo
authors.affiliation: University of Cordoba, Avd. Medina Azahara, 5, 14071 Cordoba, Spain. Electronic address: rosmorcar@gmail.com.
authors.forename: Rosario
authors.initials: R
authors.lastname: Morrugares-Carmona
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Wellner
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Cross
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
authors.forename: Balazs
authors.initials: B
authors.lastname: Bajka
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney, Norwich NR4 7UA, UK.
authors.forename: Keith W
authors.initials: KW
authors.lastname: Waldron
mesh_terms: D000872:Anthocyanins; D001704:Biopolymers; D019343:Citric Acid / Q000737:chemistry*; D029561:Lythraceae / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*; D010968:Plasticizers / Q000032:analysis*
chemical_list: D000872:Anthocyanins; D001704:Biopolymers; D010968:Plasticizers; D019343:Citric Acid; D010368:Pectins
keywords: Anthocyanins; Biopolymers; Crosslinking; Edible films; Polysaccharides