Active edible coating combined with novel pre-treatment technique for drying of foods: Mechanistic insights, enhancing drying performance and product quality

Active edible coating has gained significant attention for various applications and has recently been explored as a sustainable pretreatment approach for improving food products' drying performance and quality retention. This critical review explores the mechanistic understanding of diverse, active edible coating formulations and application techniques using novel pre-treatment approaches. This review focuses on enhancing drying performance and energy efficiency and retaining important nutritional attributes and microbial stability of dried food products. The application of edible coating as a pre-drying treatment has implications, notably affecting drying efficiency and significantly influencing coating and drying temperature. This approach was applied with other novel pre-treatments (ultrasound, ohmic heating, and osmotic dehydration) to enhance the drying efficiency and retain the stability of antioxidants, bioactive compounds, and vitamins. During drying, the maximum and minimum diffusion coefficients of the edible coated sample were obtained 1.70 x 10-9 m2/s and 9.53 x 10-11 m2/s, respectively. Ultrasound combined with coating treatment significantly reduced drying time by 31.11%. Active edible coating formulations enhanced these food qualities by synergistic interactions with plant-derived bioactive compounds and essential oils. It also minimizes the degradation of color (20%-30% reduction in total color change), texture and potentially reduces shrinkage by providing a more protective barrier. Moreover, it inhibits microbial growth and improves quality stability while storing dried food products. Furthermore, industrial relevance, sustainability, and regulatory outlook are discussed in this context. Future research should focus on in-depth synergistic interactions and refining formulations in this domain, including bio-based coating and nanocoating, optimization, and scale-up considerations.