*Alternative Green and Novel Postharvest Treatments for Minimally Processed Fruits… DOI: http://dx.doi.org/10.5772/intechopen.111978*

**Table 6.** *Calcium (Ca2+) treatments on some fresh fruits and vegetables (FFVs).*

also be combined with other methods such as safe GRAS chemicals (e.g., bicarbonate salts and ethanol), Modified Atmosphere Packaging (MAP), Controlled Atmosphere (CA), microbial biocontrol agents, plant extracts (e.g., leaf extracts of essential oils, and edible coatings to provide an effective control system against postharvest decay development, chilling injury, and quality loss [6, 7, 61–63].

Hot Water Treatment (HWT) is the simplest among heat treatments, and it has three categories: batch, continuous, and drainage systems: Hot water treatment may be applied either solely or in combination with other treatments in controlling postharvest disease infestation and rot development of FFVs [6, 60]. Several studies on hot water treatment have been reported on fruits such as banana, mango, papaya, nectarine, peach, papaya, lime, and melon. In these studies, hot water treatments were between 42°C and 60°C for a maximum and minimum duration of 30 and six (6) minutes, respectively, depending on the type of fruit. These treatments mostly controlled disease and rot causing pathogens. Nonetheless, longer exposure times caused injuries to some fruits [6]. Generally, fruits and vegetables tolerate water temperatures of 50–60°C for a duration of 10 minutes. The duration of dipping and immersion can last longer (>1 hour), and temperatures can be less than 50°C for insects disinfestation of FFVs. However, for antifungal treatments, temperatures are greater than 50°C, and the dipping time is shorter (minutes) [7].

Hot water rinsing and brushing is another heat method that cleans and disinfects freshly harvested produce at a relatively high temperature of 45–62°C. The produce is passed over revolving brushes for a short time (15–25 seconds). This is a commercial method that reduces decay development, maintains fruit quality, and prolongs the shelf life of treated fruits and vegetables. Cold storage after hot water rinsing and brushing was found to intensify the effect of the treatment [6].

Vapour or moist hot air, is a heat treatment whereby a fine mist and air are forced under circulation, which forms heated, vapour-saturated air that raises the temperature of the commodity to a required level for a specified duration. By means of condensation of vapour on the produce, latent heat is released, resulting in a quick but even increase in temperature, thus preventing damage [6]. Temperatures normally range from 40 to 50°C [7]. The fresh produce is cooled immediately after the treatment to prevent heat injury to the product [6, 7]. This treatment normally reduces decay susceptibility by killing insects' eggs and larvae [6, 7], enabling some fresh produce (e.g., basil) to be stored at temperatures that usually result in considerable injuries [6].

Steam heating involves a moist hot air treatment that uses water at about 100°C for 2–3 seconds. Steam-based systems such as steam jets coupled with electrical steamdrying elements and reflectors produce high-temperature heating above the rotating produce for 3 seconds. After the treatment, the produce is hydro-cooled. Cooled produce (e.g., carrots) showed a significant reduction in sensitivity to post-storage soft rots caused by *Sclerotinia sclerotiorum* [6]. Information on the effect of some heat treatments for FFVs are provided in **Table 7**.

#### **2.7 Methyl Jasmonates treatments**

Methyl Jasmonate (MeJa) is an endogenous phytohormone, a signalling molecule, and a volatile compound vital for regulating and mediating various processes and defence responses against biotic and abiotic stresses. It is a derivative of jasmonic acid. MeJa has been used to prevent postharvest diseases, increase bioactive compounds, maintain fruit quality, and prolong the shelf life of fresh produce [6, 59, 69–72].


#### *Alternative Green and Novel Postharvest Treatments for Minimally Processed Fruits… DOI: http://dx.doi.org/10.5772/intechopen.111978*


**Table 7.** *Heat treatments of some fresh fruits and vegetables (FFVs).*



*Methyl jasmonates treatments on some fresh fruits (FFs).*
