**5. Latest technologies to ensure safety and to increase shelf life of the fresh cut fruits and vegetables**

#### **5.1 Chemical treatment**

#### *5.1.1 Dipping in disinfectants*

Washing of the fresh produce is done to remove dirt and to reduce the microbial contamination during processing. Sanitation and post harvest handling effects the microbial population on the quality of fresh cut produces. Washing of vegetables and fruits results in insignificant decrease in microbial population. Use of disinfectants and sanitizers like peroxyacetic acid, chlorine, hydrogen peroxide, sodium chloride or ozone can do reduction to 1–2 log units in the initial population of the microorganism on the fresh produce. Chlorine is used as the most commonly used sanitizer for washing purposes. Chlorine concentration from 50 to 200 ppm is used for washing fruits and vegetables [27]. Despite chlorine is used as the disinfectant for decontamination, it has been in several European countries due to chemical hazards associated with it [28]. There are many alternatives used to chlorine nowadays. Chlorine dioxide (ClO2) is approved to use in flumes water for washing of fresh produce. It is highly effective at neutral pH. Chlorine dioxide is also responsible for formation hazardous by product such as chlorate and chlorite. 200 ppm of chlorine dioxide is used for sanitization of equipments while 3 ppm is used for the washing of uncut produce. Another chlorine based sanitizer acidified sodium chlorite has strong oxidizing capacity. This chemical is approved by United States Environment Protection Agency (USEPA) and United State Food and Drug Administration (USFDA).500-1200 ppm of concentration is used

## *Fresh Cut Fruits and Vegetables Disinfection Pretreatment: A Novel Approach to Extend Fresh… DOI: http://dx.doi.org/10.5772/intechopen.107525*

in dipping and spraying process on fresh fruits and vegetable, including fresh-cut. Sodium hypochlorite (NaOCl) is widely known as liquid bleach due to its bleaching property. It has various properties and globally used at household and industrial level in different concentration. NaOCl exihibits broad spectrum anti microbial activity and is used as disinfectant for various purposes. 0.5% solution of NaOCl is known as strong chlorine solution is used for areas disinfecting with body fluids. Weak chlorine solution is a 0.05% of NaOCl is used for washing hands. Study was done to compare the effectiveness of 100 mg\l of sodium hypochlorite (SH) and 500 mg\l acidified sodium chlorite (ACH) on the prevention of enzymatic browning and growth of microbial population on fresh cut produce. ACH washing reduce the microbial contamination and prevent the browning of fresh cut produce during storage. 500 mg/l ACH is effective against ant browning and anti microbial treatment of fresh cut produce [29].

#### *5.1.2 Acid electrolyzed water*

Acid electrolyzed water technique was initially developed in Japan. In this technique the diluted salt solution is passed through the containing anode and cathode separated by the membrane. Inanode side of the cell AEW is produced and results in the production of certain ions like HOCl<sup>−</sup> , OCl<sup>−</sup> , Cl2 gas [30]. AWE is used as the disinfectant alternative to chlorine to its antimicrobial property and minimum effect on the nutritional quality of the food and health of the person. AWE provides the ensurance to the shelf life extension and safety of the fresh cut fruits and vegetables [31]. AWE act as effective technique for the inactivation of microorganism. Recently, slightly acid electrolyzed water is gaining popularity due to its less adverse effects on human health and strong bactericidal efficacy than the acid electrolyzed water [32]. Another application of AEW is NEW (neutral electrolyzed water). Function of NEW is same as AEW except that the product produced at anode is redirected to cathode and resulted into the formation of neutral solution [33]. Free Cl- and OH- ions create the high oxidation and reduction potential which result in bactericidal property [34].

#### *5.1.3 Nanoparticles*

Nanotechnology is another emerging field in science. This technique is now being used in preservation of fresh cut fruits and vegetables. In nanotechnology nanosized particles that are in the range of 1–100 nm in dimension are used to alter the physical and chemical properties of the specific material [35]. Nanopartices of various materials have been used. Silver nanoparticles has been used as antimicrobial agent in the preservation. Due this antimicrobial property these nanoparticles damage broad spectrum of microorganisms by various mechanism such as activation of antioxidant enzymes, DNA damage, depletion of antioxidant molecules, structural changes in nuclear membrane and cell wall [36]. Coating of silver nanoparticles-PVP on green asparagus leads to extended shelf life of 25 days at 2°C and 20 days at 10°C respectively [37]. Hybrid of cellulose-silver nanoparticle in combination with MAP is beneficial for the preservation of melon stored at 4°C for 10 days by retarding the senescence of melon [38]. Apart from silver nanoparticle, nanoparticles of TiO2 and ZnO are also used in the preservation of fruits and vegetable. Nanoemulsions is one of application came under the category of nanoscience. Nanoemulsionresults in higher stability in terms of coalescence of oil droplet, gravitational separation, enhanced activity of emulsified oils, flocculation and higher surface area to droplet volume ratio [39]. Nanoemulsions of lemongrass and oregano oil results in the reduction of microbial population to several units [9]. Likewise, an edible coating of lemongrass oil is responsible for the inactivation of *E. coli* on fresh cut apple during storage [40]. Food industries are benefitted a lot from the antimicrobial nanomaterials but safety issues to use them at commercial level are of more concern. These nanoparticles penetrate into product tissue and alter the chemical composition. Therefore, further study is required to before commercializing this technology.
