**8. Use of bio control agents**

*Modern Fruit Industry*

propanoid and flavonoid metabolism [47].

**7. Irradiation and LED light**

Recently, a new approach of edible coating "layer by layer coating (LBL)" is getting attention which is an electrostatic deposition technique. It is worked by combining the chitosan with other polysaccharides, like carboxymethyl cellulose (CMC). The aim of LBL was effective control the properties and functionality of material by depositing oppositely charged polyelectrolytes [47]. LBL edible coating including the five nanolayers of pectin and chitosan exhibited better quality in terms of weight loss, total soluble solids and titratable acidity in Tommy Atkins' mangoes [48]. Arnon et al. [49] reported in many citrus fruits (mandarins, "Navel" oranges, and "Star Ruby" grapefruit) that bilayer coating with CMC/chitosan slightly maintained fruit firmness. It was reported in strawberry that coating based on chitosan and carboxymethyl cellulose (CMC), (1%) found effective to prevents the loss of firmness and aroma volatiles and it also reduces the primary (involved in carbohydrate, amino acids and fatty acids metabolism) and secondary metabolites (involved in carotenoid, terpenoid, phenyl-

Fresh fruits and vegetables contain around more than 80–90% moisture. The production of fruits and vegetables has significantly reached to beyond the desired level. Despite, a significant portion of these fruits is getting spoiled due to attack of different micro-organisms during harvesting, handling and storage. Several attempts have been made to control of these microbial population. But due to risk of health hazards, nonchemical approaches emphasized over chemical methods. Food irradiation is one of the major nonthermal methods to control the disinfestations. This is a cold treatment which is highly effective against fungal, bacterial and molds. This process involves the use of ionized radiations like gamma rays, X-rays and electron beam over the food surface. Food and Drug Administration (FDA) permitted the maximum dose limit of 1 kGy for fresh fruits and vegetables [78]. Irradiation can help in delaying of ripening, reduced fruit firmness, reduced rate of respiration and ethylene and lower enzymatic activities which extend the shelf life of fruits like mango, pear, peach, strawberry, Nagpur mandarin, acid lime, etc. [50–53]. Irradiation is also helpful against many quarantine pests like *Bactrocera dorsalis* in papaya, fruit fly and stone weevil in mango [54, 55]. It was also reported that a dose of <150 Gy is sufficient to control tephritid fruit flies [55]. Similarly, Bustos et al. [56] reported that a dose of 100 and 150 Gy are enough to kill third instar larva of Mexican fruit fly and Mediterranean fruit fly in mango as a quarantine treatment. Ladaniya et al. [53] found that the irradiation dose of 1.5 kGy was delayed the Penicillium rot in Nagpur mandarin with higher total soluble solids. Now a days, lighting based on light emitting diodes (LEDs) is one of the main emerging technologies in horticulture to enhance quality and inhibit diseases in fruits and vegetables after harvesting. LBL able to induce disease resistance in different fruit crops such as in citrus fruits against *P. digitatum*, when fruits were exposed to LBL for

(Ballester and Lafuente [57]), in *Vitis vinifera* against *B.* 

(Ahn et al. [79]). LED blue light induces fruits ripening by

(Gong et al. [58]) and in banana at 464–474 nm (Huang

ethylene production in strawberry, in citrus fruits (Ballester and Lafuente [57]), in

et al. [59]). Likewise it was found that LED light had positive effect on the quality in terms of the accumulations of ascorbic acid content, total sugar and phenols in banana (Huang et al. [59]), increase total sugar content, total phenols ascorbic acid and enhances antioxidant enzyme activities (catalase, superoxide dismutase and ascorbate peroxidase) in strawberry (blue (470 nm) light at an intensity of

**32**

40-mol m<sup>−</sup><sup>2</sup>

3 days with 70 l mol m<sup>−</sup><sup>2</sup>

*cinerea* at 80-mol m<sup>−</sup><sup>2</sup>

peaches at 40 mol m<sup>−</sup><sup>2</sup>

s<sup>−</sup><sup>1</sup>

s<sup>−</sup><sup>1</sup>

s<sup>−</sup><sup>1</sup>

s<sup>−</sup><sup>1</sup>

) (Xu et al. [60]).

All fruits and vegetables are prone to fungal and bacterial infection during storage. Due to postharvest microbial infection a significant part of fresh produce is lost during the handling, transportation and storage [80, 81]. The high moisture content and injuries make them more perishable and susceptible against microbial spoilage. Some postharvest diseases cause major breakdown in whole bulk and reduce the value of produce. The major postharvest diseases include soft rot, gray mold, anthracnose, stem end rot, blue mold, green mold, etc. that may cause huge loss. Several chemical and nonchemical approaches implemented to reduce the above said infection and to control of diseases. However, nonchemical approaches are getting more attention including use of essential oils, plant extracts and other plant based fungicides, use of bioagents. The use of bioagents is more helpful and ecofriendly approach in this line which has host specific mechanism. In this food safety line, several products were made by isolating different microorganism which as parasitic mechanism against wide range of disease causing harmful microorganisms. Some of the commercially available bioagents formulations are given in the **Table 2**.

Uses of some safe bioactive compounds have been proved beneficial in bringing down the physiological activities of fruits during transportation, storage and minimizing the overall qualitative and quantitative losses. Many antagonist species have been identified and inoculated over various fruit surface to control several disease causing microorganisms. It was reported that *Bacillus subtilis* can be used to control green mold in citrus and brown rot of stone fruits [61, 62]. Another species *Trichoderma harzianum* act as antagonist against gray mold of strawberry, grape and anthracnose of banana [63, 64]. The use of present natural mechanism of disease control could be proven a better alternatives without harm to environment and human.


*Above formulations are on the basis of availability in the market with their commercial formulations.*

#### **Table 2.**

*Some common commercially available bioagents formulations.*
