Edible Coating and Pulsed Light to Increase the Shelf Life of Food Products

Abstract

The application of edible coatings (EC) in combination with pulsed light (PL) treatments represents an emerging approach for extending the shelf life of highly perishable but high value-added products, such as fresh-cut fruits and vegetables. The surface of these products would benefit from the protective effects of ECs and the PL decontamination capability. This review describes in detail the fundamentals of both EC and PL, focusing on the food engineering principles in the formulation and application of EC and the delivery of efficient PL treatments and the technological aspects related to the food characterization following these treatments and discussing the implementation of the two technologies, individually or in combination. The advantages of the combination of EC and PL are extensively discussed emphasizing the potential benefits that may be derived from their combination when preserving perishable foods. The downsides of combining EC and PL are also presented, with specific reference to the potential EC degradation when exposed to PL treatments and the screening effect of PL transmittance through the coating layer. Finally, the potential applications of the combined treatments to food products are highlighted, comparatively presenting the treatment conditions and the product shelf-life improvement.

Polysaccharide-Based Active Coatings Incorporated with Bioactive Compounds for Reducing Postharvest Losses of Fresh Fruits

“…The dipping compared to conventional spraying or electrospraying is more beneficial for coating fruits with complex and rough surfaces, resulting in excellent uniformity [68]. Dipping generally forms a thick coating layer on the fruit surface and may effectively reduce microbial load, contamination, respiration rate, and mechanical damage and prevent physiological changes of coated fruits [69,70].…”

“…Brushing of BECs is generally carried out manually by experienced operators and includes several factors to minimize manual error of BEC application and ingredient quality to achieve better coating layer uniformity [15]. The efficiency of BECs is also affected by the roughness of the fruit surface and geometry, viscosity, surface tension, density, drying temperature, and relative humidity [70]. The degree of spreading or wettability of BECs can be characterized on the surface of fruit by contact angle measurements that maintain mechanical equilibrium of the coating drops under the influence of mainly three surface tension forces-solid-liquid, liquid-vapor, and solid-vapor interfaces-to assess the adhesion properties of coating solutions on the fruit surfaces [70,72].…”

“…The efficiency of BECs is also affected by the roughness of the fruit surface and geometry, viscosity, surface tension, density, drying temperature, and relative humidity [70]. The degree of spreading or wettability of BECs can be characterized on the surface of fruit by contact angle measurements that maintain mechanical equilibrium of the coating drops under the influence of mainly three surface tension forces-solid-liquid, liquid-vapor, and solid-vapor interfaces-to assess the adhesion properties of coating solutions on the fruit surfaces [70,72]. The ideal case of a contact angle value equal to 0° corresponds to a hydrophilic solid surface where total wetting conditions can be attained by an aqueous solution.…”

The Use of Nanocellulose in Edible Coatings for the Preservation of Perishable Fruits and Vegetables

“…ECs are usually applied on highly perishable products, such as fresh and fresh-cut fruits and vegetables, to extend the shelf life and to preserve their quality and minimize losses through controlling physiological, biochemical or oxidation processes. To enhance their efficiency and functionality, ECs can be loaded with different bioactive compounds (as illustrated in Figure 2) to develop specific functionalities, such as antimicrobial, antibrowning, antioxidant, coloring, and flavoring, or even nutritive actions [205].…”

Optimization of flaxseed cake pectin extraction and Shelf-life prediction model for pear fruits preserved by pectin edible coating

“…Therefore, edible coatings tend to act as a protective layer around the surface of fruits and vegetables, limiting respiration and thereby delaying spoilage. [9,10]. The application of pectinbased edible coating for persimmon [11], tomatoes [12], apricot [13] and potato chips [14], recently published.…”