Edible films from pectin: Physical-mechanical and antimicrobial properties - A review

Pectin is one of the main components of the plant cell wall chemically constituted by poly α1-4-galacturonic acids. According to its degree of esterification with methanol, pectin can be classified as high methoxyl pectin or low methoxyl pectin. In food industry, pectin is listed as generally recognized as safe (GRAS) by the Food and Drug Administration and is used as gelling, stabilizing, or thickening agent in food products such as jams, yoghurt drinks, fruity milk drinks, and ice cream. Due to its biodegradability, biocompatibility, edibility, and versatile chemical and physical properties (such as gelation, selective gas permeability, etc), pectin is a suitable polymeric matrix for the elaboration of edible films intended as active food packaging. Active packaging is a packaging system which possesses attributes beyond basic barrier properties that are achieved by adding active ingredients in the packaging material and/or using functionally active polymers. When the packaging system has antimicrobial activity, the packaging limits or prevents the microbial growth by extending the lag period and reducing the growth rate of microorganisms. This review describes the main methods for elaborating pectin edible films, principal characterization techniques for determining their physical-mechanical properties, and applications of pectin edible films as antimicrobial food packaging. Finally, legislation and future trends regarding the use of pectin edible films are also discussed.