Evaluation of structural and functional properties of citrus pectin film enriched with green tea extract

• Published in: Polymer engineering and science Vol. 63; no. 8; pp. 2522 - 2533
• Main Authors: Wei, Huan, Pascall, Melvin A.
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.08.2023; Society of Plastics Engineers, Inc; Blackwell Publishing Ltd
• Subjects: Analysis; antioxidant; Antioxidants; Chemical properties; Citrus; Citrus fruits; Elongation; foods; Glass transition temperature; Green tea; green tea extract; Hydrogen bonding; Loss modulus; Low concentrations; Materia medica, Vegetable; Mechanical properties; Moisture effects; packaging; Pectin; pectin films; Permeability; Plant extracts; Tea; Tea (Plant); Thickness; Water vapor; United States
• ISSN: 0032-3888; 1548-2634
• DOI: 10.1002/pen.26393

The effects of green tea extract (GTE) concentrations (0%, 1%, 2%, 3%, 4%, and 5%) on the thicknesses, mechanical strengths, storage/loss moduli, glass transition temperatures (Tg), chemical structures, morphologies, antioxidant activities, moisture contents, and gas permeabilities of low methoxyl pectin films were investigated in this study. A decrease in the percent elongation and moisture contents accompanied by an increase in the tensile strengths, Tg and elastic and storage moduli were observed with increasing, but low concentrations of GTE in the pectin films. This rate of change slowed at higher GTE concentrations. The thicknesses of the pectin films were not significantly affected by the concentrations of GTE. The FTIR results showed increasing ester and hydrogen bonding formations with increasing concentrations of GTE from 0% to 2% in the pectin. When the GTE concentration increased from 2% to 5%, there was an increase in ester, but a decrease in the H‐bonding. The x‐ray diffraction results showed that the crystallinity of the films increased as a result of increasing GTE contents. The results of the antioxidant activities and oxygen and water vapor barrier properties showed an enhancement due to the higher concentrations of GTE. Therefore, GTE can be incorporated into low methoxyl pectin in order to make films with desired mechanical strength, gas barrier, and antioxidant properties. The antioxidant efficacy and the influence of green tea extract (GTE) on the mechanical, barrier, and morphological properties of pectin films were investigated in this research. The results showed that increased the antioxidant abilities of the film without a significant impact on its functionality for as a stand‐alone packaging film.