Application of edible coatings on fresh and minimally processed fruits: a review

Ultrasound and autoclave-deacetylated Achatina fulica shell chitosan: Characterisation and effect on tomato and cucumber fruit qualities during storage

Chitosan from African giant snail (Achatina fulica) shells derived through autoclave- (SSC_A) or ultrasound-assisted (SSC_U) deacetylation was characterised and evaluated for quality and shelf life of tomatoes and cucumbers over 10 days of ambient (26 ± 2 °C) and refrigerated (4 ± 2 °C) storage. A 64.03 and 54.41% deacetylation degrees were achieved for SSC_A and SSC_U, respectively with the SEM showing uniform surface morphologies. Moisture loss in tomatoes was effectively moderated by SSC_A and SSC_U treatments as depicted by higher weight retention (93.65% and 81.80%) compared to untreated samples (58.52%) after 10 days of refrigerated storage. Autoclave-derived chitosan significantly retained colour of tomato and cucumber. Ascorbic acid retentions were 88.76% and 87.34%, and 86.40% and 77.01% for SSC_A and SSC_U-treated tomatoes at ambient and refrigerated storage, respectively. Yeast and mould growths were completely inhibited for 10 days of refrigerated storage. Chitosan treatment enhanced quality and shelf life of tomatoes and cucumbers in the order SSC_A > SSC_U > control.

Edible coatings as osmotic dehydration pretreatment in nutrient-enhanced fruit or vegetable snacks development: A review

Edible coatings (ECs) are thin layers applied on food to protect it and improve quality. They are made from bio-based materials such as polysaccharides, proteins, lipids, or their composites. The incorporation of functional agents, such as bioactive compounds, vitamins, or antimicrobials into the EC, has been investigated to control the shelf life of many food products from horticulture ones to processed food. Osmotic dehydration (OD) as a mild technology may also positively impact the availability of innovative fruit snacks and consequently influence consumer health. Combination of the EC with the OD aims to remove water through the semipermeable membrane while limiting the transfer of solutes from the dehydrated tissue and in the opposite direction from the osmotic solution to the food. The development trend of the snack market is expanding, especially with health-promoting properties. Consumers pay increasing attention to quality of food and its beneficial effects on health. This review attempts to provide the advancement of recent studies on the application of the EC before the OD of different fresh or fresh-cut fruit and vegetables. A fundamental theory related to the methodology of creating the EC, their composition, and the influence on the physicochemical properties of products that are osmo-dehydrated to a medium water content or additionally dried to a low water content have been described. Efforts have been exerted to introduce hydrocolloids used in the production of the EC, including new sources of biopolymers such as agricultural waste and by-products. The perspectives of using ECs in the technology of producing pro-healthy snacks are emphasized.

Maintaining the Quality and Storage Life of Button Mushrooms (Agaricus bisporus) with Gum, Agar, Sodium Alginate, Egg White Protein, and Lecithin Coating

Button mushrooms have a very short shelf life after harvesting and are sensitive to mechanical damage and browning. This can be a severe problem in enlarging the market and the long-distance exportation of this product. In this respect, edible coatings could be an alternative treatment to extend the shelf life of button mushrooms, maintaining their quality during long-term storage. The aim of this study was to investigate the impact of gum, agar, sodium alginate, egg white protein, and lecithin on the postharvest weight loss, color, browning, respiration rate, ethylene production, and storage life of button mushrooms. The results showed that the above-mentioned edible coatings are a promising way to extend the life and maintain the quality of button mushrooms. Significant differences (p < 0.05) were observed between the control and edible coating-treated samples in all parameters. Sodium alginate and gum were more effective in preventing weight loss, coloring, and browning than other edible coatings. On the other hand, the respiration rate and ethylene production were more suppressed by the agar and lecithin coatings compared to the others. In conclusion, it can be recommended that the above-mentioned edible coatings could be used as novel coatings in commercial treatments for maintaining the quality of button mushrooms during a long-term storage period.

Edible films and coatings for shelf life extension of mango: a review

Edible films and coatings are eco-friendly promising materials for preserving the quality and extending the shelf life of fresh and minimally-processed fruits. They can form protective layers around fruits, regulate their respiration rates, and protect them from loss of water, tissue softening, browning, and microbial contamination. Edible films and coatings have many advantages over other post-harvest treatments. They can add commercial value to fruits by enhancing their appearance, and act as carriers of functional ingredients, such as antioxidants, antimicrobial agents and nutraceuticals. Mango, a highly perishable tropical fruit, has a short post-harvest life, which limits transport to distant markets. Application of edible films and coatings on mango fruits is an effective method to preserve their quality and safety. This paper provides an overview of desirable properties for films and coatings, and recent development in different edible coatings for both fresh and minimally-processed mango. The most popular edible coating materials, such as chitosan, waxes, starch, gums, and cellulose used for mango are reviewed. The commercialization of coating formulations and equipment used for application of coatings are discussed. The environmental impacts, safety aspects, and the challenges encountered are outlined. The opportunities to use other coating materials, such as aloe-vera gel, microbial polysaccharides, and photosynthetic microorganisms are also examined.

Recently isolated food-derived antihypertensive hydrolysates and peptides: A review

Hypertension is a non-communicable disease characterized by elevated blood pressure, and a prominent metabolic syndrome of modern age. Food-borne bioactive peptides have shown considerable potencies as suitable therapeutic agents for hypertension. The peptide inhibition of the angiotensin I-converting enzyme (ACE) from its default biochemical conversion of Ang I to Ang II has been studied and more relatively adopted in several studies. This review offers an examination of the isolation of concomitant proteins in foods, their hydrolysis into peptides and the biofunctionality checks of those peptides based on their anti-hypertensive potentialities. Furthermore, critical but concise details about methodologies and analytical techniques used in the purification of such peptides are discussed. This review is a beneficial literature supplement for scholars and provides functional awareness material for the food-aligned alternative therapy for hypertension. In addition, it points researchers in the direction of adopting food materials and associated by-products as natural sources for the isolation biologically active peptides.

Nanotechnology and its challenges in the food sector: a review

Antibacterial activity of nanoparticles has received significant attention worldwide because of their great physical and chemical stability, excellent magnetic properties, and large lattice constant values. These properties are predominate in the food science for enhancing the overall quality, shelf life, taste, flavor, process-ability, etc., of the food. Nanoparticles exhibit attractive antibacterial activity due to their increased specific surface area leading to enhanced surface reactivity. When nanoparticles are suspended in the biological culture, they encounter various biological interfaces, resulting from the presence of cellular moieties like DNA, proteins, lipids, polysaccharides, etc., which helps antibacterial properties in many ways. This paper reviews different methods used for the synthesis of nanoparticles but is specially focusing on the green synthesis methods owing to its non-toxic nature towards the environment. This review highlights their antibacterial application mainly in the food sector in the form of food-nanosensors, food-packaging, and food-additives. The possible mechanism of nanoparticles for their antibacterial behavior underlying the interaction of nano-particles with bacteria, (i) excessive ROS generation including hydrogen peroxide (H₂O₂), OH^- (hydroxyl radicals), and O^- ₂ ² (peroxide); and (ii) precipitation of nano-particles on the bacterial exterior; which, disrupts the cellular activities, resulting in membranes disturbance. All these phenomena results in the inhibition of bacterial growth. Along with this, their current application and future perspectives in the food sector are also discussed. Nanoparticles help in destroying not only pathogens but also deadly fungi and viruses. Most importantly it is required to focus more on the crop processing and its containment to stop the post-harvesting loss. So, nanoparticles can act as a smart weapon towards the sustainable move.