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Antifouling Nanoparticle Coatings for Post-Harvest Food Preservation

Gokuraju Thriveni1*, Hari Murthy1 and CH. Anusha2

1Department of Electronics and Communication Engineering, School of Engineering and Technology, CHRIST (Deemed to be University), Bengaluru, Karnataka, India

2Department of Mechanical Engineering, Vignan Institute of Technology and Science - Deshmukhi, Hyderabad, Telangana, India

Abstract

The reports of the World Food Preservation Center exhibit that the entire number of inhabitants in the globe will reach 9.6 billion by the year 2050. With the increasing population, there is a growing pressure on agricultural produce which is further amplified by the losses between harvest and retail (~17%) and other wastages (~17%). Globally, this is a major concern, and thus, there is no surprise to look into current research developments in food preservation. This chapter provides comprehensive reports on the recent trends in various nanoparticle coatings for the aforementioned application. Silicon dioxide (SiO2), titanium dioxide (TiO2), and zinc oxide (ZnO) nano regime coatings on silicon substrate and polymer substrates have been discussed for antifouling applications. This chapter is categorized as follows: Section I delivers the introduction about the significance of food preservation in reference to the reported statistics. In section II, the discussion starts with the materials and methods for post-harvest food saving. Major recent advances in terms of materials or methods to increase the shelf life of cuisine are portrayed in the same section II. Section III entails the appropriate computational methods to envision the interaction of food residuals with coated nanolayers through sensing. The final section (IV) delivers a guideline on feasible research implications to address the shortcomings in food preservation from a broader perspective.

Keywords: Nanoparticles, food preservation, zinc oxide nanoparticles, sensing, nanocoatings, antifouling, food monitoring, food waste

1.1 Introduction

Food waste is a highly common occurrence in our day-to-day life which has a significant impact on society, economy, and environment [1]. According to a United Nations (UN) report published in 2021, an estimated 931 million tons of food refuse was produced widely in 2019 [2]. There are almost 690 million people who do not have access to a full meal every day [3] which makes the food waste even more alarming. Wasted food also implies resource misutilization including water and land. Reducing food waste is a paramount requirement under the UN Sustainability Goals to address concerns about food security, water scarcity, global warming, and pollution. After harvesting the produced food is composed of crude resources that are prone to severe warehouse surroundings before they are parceled up and moved to the merchandise [4]. A significant quantity of post-harvest products is bygone during manufacturing, transit, packing, and other arbitrator steps. Moisture content in the produce along with the plant hormones and microbial infestation are major causes of food spoilage.

There is a need to protect post-harvest products from deleterious conditions. The GDP of India is expected to grow 10% annually with food processing covering 32% of the total food market and employing over 1.7 million people [5]. It has been observed that a “one-shoe-fits-all” approach is not feasible due to the wide range of optimal conditions for different crops.

One approach for food preservation is through smart packaging with features incorporated into it such as antifouling, antioxidant, antibacterial, freshness sensors, and pH monitors. Another method to enhance the shelf life is through coatings that repel water and grease, thereby acting as barrier coatings against humidity.

1.2 Materials Support Post-Harvest

Nanomaterial films serve the task of upgrading tastiness and aliment resistance to the extension of pathogens on the exterior of foods [6, 7]. Silicon is a well-known element in the semiconductor industry with atomic number 14 that can be derived from silicon dioxide (SiO2) which is abundant on Earth [8]. SiO2 has recorded extensive approaches toward environment- friendly photocatalysis for marine antifouling applications [9]. Silicon is the most common constituent that exists widely in the surface soil layer of the earth, commonly in the form of silica SiO2 in nature. In the present scenario, nano- and microscale SiO2 are employed in the food industry and other fields commonly because of their desired end such as high specific surface area, low toxicity, biocompatibility, optical transparency, and chemical/water/thermal stability [10].

According to the US Food and Drug Administration (FDA), titanium dioxide nanoparticles (TiO2) are safe to utilize in individual meals and manufacturing [11]. TiO2 possesses microbicidal tasks and productive film workability [12]. The white nanosized titanium dioxide particles (nano-TiO2) or transparent are safe and present the best viral sterilization and impediment task [13]. It states that nano-TiO2 and nano-SiO2 composite coatings might possibly sustain post-harvest qualities such as decomposing regard, reduction value, and compression by impeding the extension of bacteria. Furthermore, chitosan consists of nanosized TiO2 film indicating an ethylene degradation task manifests UV light, impeding the ripening process, and persuading changes in the product quality [14, 15]. Nano-TiO2 was widely utilized in the food, pharmaceutical, cosmetic, and chemical industries because of its high resistance, nonpoisonous, germicidal task, and isolated photocatalytic properties [13].

Zinc oxide nanoparticles (ZnO-NPs) also plays a major role in post- harvesting foods by attacking the food pathogens to increase shelf life, increasing food quality that directly influences individual health [16]. ZnONPs constructively fight dangerous microorganisms and prevent food contagion along adsorbent-influence laminate impairment and ROS-moderated essential pathogenic that results in being the most efficient disinfectant force resistant to microbes found in food [17]. It is explained that the experimental appeal of a ZnO interruption restrains 0.3% citric acid at a distinct gathering (0, 1, 3, 5, and 8 mM) in Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, and Bacillus cereus that markedly reserved a development about tension throughout the way of 12 h. Interlude of ZnO with 5 mM and 8 mM citric acid is more constructive for each tension; 5 mM and 8 mM ZnO are determined to a great extent of development in mango smoothie. Following, it is defined that the ZnO-NPs are able to lower the primary development compute of tension in the mango emulsion [18].

ZnO-NPs possess undeviating contact accompanied by cell exterior bitter cellular membranes that eventually get in and produce free radical damage over the pathogen chamber, which depicts the unease of unit development to unit expiry. Many scientists recommend that ZnO-NPs are a constructive germicide means enclosed by a sustenance safeguarding the area. ZnO-NPs are frequently employed just like a cleansing factor for various implements, vessels used in cuisine manufacturing in expectation of effect along with the decay of food poisonous virulent [19].

ZnO-NPs not only indicate antimicrobic tasks but also prevail steady underneath unfavorable circumstances, like high temperature and high pH values. In recent advancements, ZnO-NPs are considered “generally recognized as safe (GRAS)” by the US FDA for both human and animal consumption [19, 20].

Bio detection systems belonging to ZnO-NPs are employed effectively to identify the various viruses and pollutants in cuisine and aqua in the container [21]. ZnO-NPs are able to control other crucial characteristics of edibles, like vapor amount, immersion, substrate, dispersible, and concept [22]. To ease the possibility of pollutants through viruses prior to or subsequent to extract, it is important to primarily acknowledge the contact of accumulation time and meteorological conditions on a contagious populace among slightly decadent foods [22].

ZnO-NPs are also involved in safeguarding and conserving greenness and nutritiousness in regard to sustenance [23]. It is demonstrated that the application of ZnO-NPs (0, 0.1, 0.5, and 1 g/kg) is conservative for guiding bacterial and physicochemical decay about mayonnaise throughout a frozen repository within the duration of 6 months. Furthermore, ZnO-NPs to mayonnaise concluded at detained development about pathogens, conservation of real and alkaline properties, and enhanced serviceable life in contrast to the regulate (0 g/kg) [24].

After conducting further investigation, it is examined that the antimycotic task of ZnO-NPs is inimical to twofold post-harvest product fungi viruses, B. cinerea and P. expansum. The implementation in regard to the process of ZnO-NPs upon the progress of mold filaments was also analyzed. It concludes that absorption of ZnO-NPs higher with 3 mmol L-1 remarkably hinders through widening either B. cinerea or P. expansum. Nevertheless, the nanoparticles were established in an effort to occur greater efficiently in comparison to B. cinerea than P. expansum [25].

The glucose oxidase GOx/ZnONP mist has been put in for the post-harvest remedy toward peach. The restraint and...