Nanocomposites: An Innovative Technology for Fruit and Vegetable Preservation

Nowadays, the preservation shelf life of food and food products while maintaining higher nutritional and functional attributes is a big concern around the world. As a result, about one-third of foods produced are discarded as wastage globally due to several factors, such as physical, biological, etc.; food wastage directly impacts on the environment and is responsible for the emission of 6% greenhouse gases (GHGs) (Amicarelli et al., 2021). According to the Food and Agriculture Organization (FAO), the total food losses, including fruits and vegetables (F&V) (40–45%), fish and seafoods (35%), and cereals (30%), respectively, occur throughout the supply chain (Marston et al., 2021). Postharvest losses in F&V have greater impacts on the economy of country as well as the environment. With increasing consumer awareness about food safety and quality for health concerns, they are preferred eco-friendly packaging materials with high barrier properties to maintain physiochemical and sensorial properties of F&V. Numerous methods such as cold storage, heat treatment, modified atmosphere packaging (MAPs), controlled atmosphere packaging (CAPs), high hydrostatic pressure, and chemical-based preservation methods have been used for preservation shelf life of fresh produces for longer period. These methods have several limitations and disadvantages. On the other side, edible packaging (coating/films) prepared using polysaccharide, protein, and lipid-based biopolymers is also potential for extending the shelf life of fresh produce, but they also have several limitations (Kumar & Neeraj, 2019; Suhag et al., 2020). Recently, nanotechnology utilization in food processing and packaging sector has gained more attention due to its barrier, functional, and antimicrobial activities. Therefore, nanocomposites (composites of nanomaterials) are considered a potential strategy to maintain the stability of the F&V because of its barrier (water loss, oxidation, and UV) properties at cheap price in comparison with polymer alone (Sagar et al., 2022; Vasile 2018). Several types of nanomaterials such as nanotubes, nanofibers, nanoplates, nanoparticles (NPs), and nanocrystals have been used for the development of nanocomposites for food applications. It is expected that the nanomaterials market will be reach up to 100 billion by year 2025 (Allan et al., 2021; Future market; Research and market, 2020). There are numerous industries, such as Honeywell International Inc. (USA), Mitsubishi gas chemical Inc. (Japan), Clariant Ltd. (Swaziland), Emco Packaging System (UK), Paper Pak Ind. (Canada), Bernard Tech. Inc. (USA), Cryovac Div. (USA), Ripesense Ltd. (New Zealand), Multifilm Packaging (N-coat), George Weston Foods, Saty Fresh Ltd., and others provide different types of nanomaterials commercially for application in food sectors as an antimicrobial agent, O2/CO2 scavenger, moisture/gas barrier, ethylene scavenger, and freshness indicator (Kondle et al., 2022). Therefore, several researchers have suggested that the use of nanotechnology or nanomaterials such as metal/metal oxides, gold (Au), iron oxide (Fe3O4), silver (Ag), titanium oxide (TiO2), copper oxide (CuO), zinc oxide (ZnO), calcium carbonate, and others for the development of nanocomposites with metal, ceramic, and polymer matrices for different applications. Therefore, the nanocomposite with biopolymers such as polysaccharides, proteins, and lipids are one of the most effective and sustainable approaches for shelf-life extension of fresh produce (Khan et al., 2016; Mujahid et al., 2022; Odetayo et al., 2022). Nanocomposite biopolymers are biodegradable in nature, nontoxic with higher stability, and have particle size between 0 and 100 nm in size and act as a carrier of active agents, which possess antimicrobial and antioxidant activities and help in minimizing the lipid oxidation and scavenging the free radicals (Sarfraz et al., 2020). The nanocomposites exhibit good physical, mechanical, thermal, barrier, optical and antimicrobial properties, which make it suitable for fresh produce shelf-life extension by maintaining their higher nutrition and sensory attributes (Arora & Padua, 2010). The concept of nanocomposites was first addressed in the early 1950s, and nanocomposites of polyamide were reported in as early as 1976 (Okpala, 2013). Most of the inorganic NP such as Ag, TiO2, ZnO, and others are widely used in the food packaging industries as detectors, antimicrobial agents, and to lengthen the shelf life of produce (Kondle et al., 2022). Hence, the present study aimed to explore the role of nanocomposites in shelf-life enhancement of F&V with their mechanism. The different types of nanocomposites and their preparation methods with their advantage in shelf-life extension of fresh produce have also been discussed briefly. Different databases such as Google Scholar, ResearchGate, ScienceDirect, Web of Science, PubMed, etc., were used to congregate the information using different keywords (nanotechnology, nanocomposites, food packaging, fresh produces, postharvest management, fruits, vegetables).