Emerging trends in pectin extraction and its anti-microbial functionalization using natural bioactives for application in food packaging

Background: Pectin (E-440) a naturally occurring complex heteropolysaccharide found in the cell wall and middle lamella of plants is widely used as a hydrocolloid, stabilizer, emulsifier, encapsulant, and gelling agent in foods. In addition, pectin is also a promising nutraceutical ingredient for drug delivery and formation of nanoemulsion. The unique structure of pectins is due to the presence of various hydroxyl and carboxyl groups along its backbone which enables for easy modification and functionalization with various bioactive compounds. Functionalization of the pectin for enhancing antimicrobial properties and its application in active packaging films is the current area of research. Scope and approach: This review discusses the advances in pectin extraction using innovative extraction strategies like microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), enzyme-assisted extraction (EAE), subcritical water extraction (SWE), high pressure extraction (HPE) and hybrid extraction methods like ultrasound-microwave assisted extraction (UMAE) and ultrasound-enzyme assisted extraction (UEAE). Functionalization of pectin with fatty acids, phenolics, essential oils and nanomaterials for enhancing antimicrobial properties has been critically highlighted in the present review. Mechanism of action and molecular basis of antimicrobial properties of pectin-based films integrated with the aforementioned functional compounds is conceptually illustrated. Key findings and conclusion: Ultrasound, microwave and enzyme assisted are efficient and environmentally friendly methods for pectin extraction. A selective combination of innovative extraction methods enables pectin with distinctive structural features, enhanced yield and bioactivity. Functionalization of pectin with phenolics and nanomaterials have promising prospects in the fabrication of novel active packaging films with enhanced antimicrobial properties.