Effect of a New Chemical Formula on Postharvest Decay Incidence in Citrus Fruit

Abstract

Postharvest diseases caused by Geotricum candidum (sour rot), Penicillium digitatum (green mould), and P. italicum (blue mould) are the most important negative factors affecting handling and marketing of citrus fruits in Egypt. A new formula containing stevia leaf powder and a mixture of the three commercial chemical active ingredients: ketoconazole, fluconazole, and itraconazole has been successfully applied. Either chitosan or water wax were used as carriers, against fruit mould pathogenic fungi under laboratory and storage conditions. Results of the in vitro test showed that a complete reduction in linear fugal growth was observed when the ingredients of the new formula were used individually at a concentration of 400 μg/ml each, while a mixture of all the tested chemicals had a superior effect with all fungal growth completely inhibited with the use of the mixture at a concentration of 100 μg/ml. Similar results were recorded on citrus fruits which were coated with the suggested formula of chitosan or wax containing chemical compounds as a semi applicable technique using navel orange peel discs. Furthermore, the obtained results were confirmed using in vivo testing on navel orange and lime fruits, under artificial inoculation conditions of the pathogenic fungi within a storage period extended for four weeks. The proposed approach provides the treated agricultural products with long acting protection against microbial invasion and even association. This formula could be used as a fungicide alternative for protecting the agricultural products which have high moisture contents. The formula can be used against mould pathogens to prolong the healthy shelf life of the agricultural products. Such a treatment is safe, cheap, easily applied, and without residues which are harmful to people and the environment.

Inhibitory effect of chitosan on growth of the fungal phytopathogen, Sclerotinia sclerotiorum, and sclerotinia rot of carrot

“…1). These results were similar to previous findings on the antifungal activity of chitosan against several other fungal pathogens, such as Aspergillus parasiticus (Cota-Arriola et al 2011), Geotricum candidum (El-Mougy et al 2012), Alternaria alternata (Reddy et al, 2000), Fusarium solani and Sclerotium rolfsii (Eweis et al 2006). Several complex mechanisms were proposed in these previous studies to explain the antifungal activity of chitosan.…”

Shelf life extension of fresh fruit and vegetables by chitosan treatment

“…and tomatoMuñoz et al, 2009 Potato Yong-Cai, et al, 2009El-Mougy et al, 2012El Ghaouth et al, 2000 Bautista Baños et al, 2004;Chien and Chou, 2006;El-Mougy et al, 2012 Penicillium expansum El Ghaouth et al, 2000Sivakumar et al, 2005a;Liu et al, 2007;Yu et al, 2007 Tankan citrus fruitChien and Chou, 2006; El-Mougy et al, 2012 Peach, strawberries, papaya, tomato El Ghaouth et al, 1992a; Bautista Baños et al, 2004; Park et al, 2005; Guerra-Sánchez et al, 2009; García-Rincón et al, 2010; Hernández-Lauzardo et al, 2010; Ramos-García et al, 2012 Sclerotinia sclerotiorum Carrot Cheah et al, 1997; Molloy et al, 2004; Ojaghian et al, 2013 Physiological changes that can occur in temperate fruit after chitosan treatment. Application of chitosan on fruit and vegetable to control foodborne microorganisms.…”

Effect of humic acid, seaweed extract and essential oils as antioxidants on pre-and post-harvest quality of red radish plants

“…Afterwards, postharvest quality and storage parameters represented by weight loss percentage, post-harvest decay percentage and dry matter percentage were estimated. Weight loss percentage (WLP %) was estimated according to the following equation: 27 Dry matter percentage (DMP %) was estimated as described by Lee. 28 After drying in the oven at 60˚C until weight stability, moisture percentage was calculated according to the equation:…”