Edible coatings used for conservation of minimally processed vegetables: a review

Abstract

The minimally processed vegetable (MPV) market has been growing in recent decades. This growth is related to the change in lifestyle and eating habits of consumers who seek practical and healthy food for consumption. Maintaining the characteristics and quality of MPVs is a significant challenge for producers and traders. Minimal processing steps increase the perishability of these MPVs, thus increasing oxidative reactions and their metabolic rate. The research focused on the development of technologies that reduce these reactions gained prominence. Edible films and coatings produced from natural sources have emerged as alternative packaging for food applications and have received attention due to their advantages, such as their biodegradable and renewable nature, availability, and cost. The use of edible coatings for the preservation of vegetables in the postharvest condition, whether intact or minimally processed, has been identified as an emerging technology of great potential as they can control the internal atmosphere of MPVs. Biopolymers such as polysaccharides, lipids, and proteins have been evaluated in the formulation of these coatings. The choice of appropriate material will depend on the characteristics of the plant, the biopolymer, and the intended objectives of the film. This review aims to present some application examples, the main types of edible coatings, and the application techniques used in MPVs based on the literature, to assist a choice that can generate greater coating efficiency.

Aflatoxin, microbial contamination, sensory attributes, and morphological analysis of pistachio nut coated with methylcellulose

“…It can be attributed to the effects of packaging type, storage in the incubator at a constant temperature, and coating agent, which acted as a good moisture insulator that leads to the lowest moisture loss during the storage period. Also, possible hydrophobic particles present in MC coating act as a barrier agent and reduced surface vapor, limited water migration, and retarded moisture loss during storage (Guimarães et al., 2020). On the other hand, the control sample showed an enhanced total of aflatoxins due to the lack of an appropriate coating compared with other treatments.…”

“…Results showed that the total aflatoxin content of coated samples with 0.1% and 0.5% of MC solution was reduced significantly during the storage so that they could not be detected after four months of storage period. The reason can be traced back to moisture and temperature conditions that are two crucial factors for aflatoxin production; however, this research temperature (Guimarães et al, 2020). On the other hand, the control sample showed an enhanced total of aflatoxins due to the lack of an appropriate coating compared with other treatments.…”

Material de base orgânica como alternativa para embalagem de produtos alimentícios

“…Matérias-primas renováveis como polissacarídeos (amido, pectina, alginato, carboximetilcelulose e quitosana), proteínas (glúten de trigo, isolado de proteína de soro de leite, caseinato e proteína de soja) e lipídeos (ceras e ácidos graxos) ou uma combinação destes têm sido estudados para preparar filmes e revestimento comestíveis biodegradáveis. Contudo, vários estudos relatam que os polissacarídeos de diferentes fontes são materiais promissores para o preparo de filmes e revestimentos com comportamento sob medida, considerando que são polímeros naturais, não tóxicos e biodegradáveis (Enujiugha et al, 2018;Guimarães et al, 2020;Schmid et al, 2018).…”

Antifungal edible coatings for fruits based on zein and chitosan nanowhiskers

“…Application of natural bioactive molecules is an alternative to the use of synthetic fungicides to control post‐harvest disease in edible fruits (Demartelaere et al., 2017; Zakaria, 2021). Edible polymers with the incorporation of nanometric structures by emulsion or simple dispersion have largely been used in coating not only for the preservation of the sensory properties of fruits but also to exert antimicrobial effects to avoid post‐harvest losses caused by microorganisms (Bautista‐Baños et al., 2017; Guimarães et al., 2020; Wang et al., 2017). Moreover, the use of active packaging can be an alternative to overcome many of the abovementioned problems.…”