TY - GEN

T1 - Use of Chitosan and Vanillin as Edible Coating in Managing Tomato Fruit Rot and Quality

AU - Safari, Zahir Shah

PY - 2021/1/20

Y1 - 2021/1/20

N2 - Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. It can be consumed as fresh, cooked or processed. Tomato is principally high in carotenoids, lycopene, vitamins and phenolics compounds that are excellent in reduction of cardiovascular disease and risk of cancer. Being a climacteric crop, it has a relatively short postharvest life, which are caused by several factors including transpiration, postharvest diseases, accelerated ripening, and senescence that triggered losses in quantity and quality. Tomato is very susceptible to the infection initiated by Fusarium fruit rot. The quality maintenance of tomato fruit and control of postharvest diseases are the major challenges in postharvest handling. Chemicals are widely used to control this disease. Inaptly, it leads to detrimental effects on human health, environment and increase disease resistant. Hence, to overcome this problem, chitosan and vanillin could be an alternative to disease control, maintain fruit quality and prolong shelf life. The aim of this research was to evaluate the antimicrobialiiactivity of chitosan and vanillin towards the isolated pathogen and to investigate its effect as edible coating on tomato fruit postharvest quality. In the first study, pathogen was isolated and identified morphologically and molecularly and antifungal effect was tested against isolated pathogen in vitro. Fusarium oxysporum was found to be the casual pathogen for tomato fruit. The result of in vitro study portrayed the ability of vanillin to suppress the pathogen growth to the tune of 82% and chitosan 57%. Second study was on the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot, and defense related enzymes (PAL, PPO and POD). The experiment was conducted using completely randomized design (CRD) in factorial arrangement (8-treatment × 15 days of storage). Different concentration of chitosan and vanillin was used as edible coating on tomato and stored at 26 ± 2 oC and 60 ± 5 relative humidity. The analysis was evaluated at 3 days interval. Treatments 1% chitosan + 15 mM vanillin and 1.5% chitosan + vanillin has controlled disease incidence by 70.84, 75%, and severity 65 and 70%, and maintained constant PAL, PPO and POD enzyme activity. The third investigation was carried out on the potential of chitosan and vanillin coating on tomato fruit physico-chemical quality during storage at 26±2 ºC and 60 ± 5% relative humidity. The experiment was conducted using (CRD) in factorial arrangement (7-treatment × 25 days of storage). Different concentrations of chitosan and vanillin was used as edible coating. The analysis was evaluated at 5 days interval. The result revealed treatments 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin significantly reduced disease incidence by 75% and 74,16% and severity 75% and 79% respectively, delay loss in weight up to 90%, reduced changes in firmness, soluble solids concentration, and color score. It also reduced the rate of respiration and ethylene production. Furthermore, it preserve constant and low fruit ascorbic acid content, antioxidant properties, and prolong shelf life of tomato up to 25 days.

AB - Tomato Lycopersicon esculentum Mill. is one of the most cultivated and widely consumed vegetables in the world. It can be consumed as fresh, cooked or processed. Tomato is principally high in carotenoids, lycopene, vitamins and phenolics compounds that are excellent in reduction of cardiovascular disease and risk of cancer. Being a climacteric crop, it has a relatively short postharvest life, which are caused by several factors including transpiration, postharvest diseases, accelerated ripening, and senescence that triggered losses in quantity and quality. Tomato is very susceptible to the infection initiated by Fusarium fruit rot. The quality maintenance of tomato fruit and control of postharvest diseases are the major challenges in postharvest handling. Chemicals are widely used to control this disease. Inaptly, it leads to detrimental effects on human health, environment and increase disease resistant. Hence, to overcome this problem, chitosan and vanillin could be an alternative to disease control, maintain fruit quality and prolong shelf life. The aim of this research was to evaluate the antimicrobialiiactivity of chitosan and vanillin towards the isolated pathogen and to investigate its effect as edible coating on tomato fruit postharvest quality. In the first study, pathogen was isolated and identified morphologically and molecularly and antifungal effect was tested against isolated pathogen in vitro. Fusarium oxysporum was found to be the casual pathogen for tomato fruit. The result of in vitro study portrayed the ability of vanillin to suppress the pathogen growth to the tune of 82% and chitosan 57%. Second study was on the effect of chitosan and vanillin coating in vivo on Fusarium oxysporum fruit rot, and defense related enzymes (PAL, PPO and POD). The experiment was conducted using completely randomized design (CRD) in factorial arrangement (8-treatment × 15 days of storage). Different concentration of chitosan and vanillin was used as edible coating on tomato and stored at 26 ± 2 oC and 60 ± 5 relative humidity. The analysis was evaluated at 3 days interval. Treatments 1% chitosan + 15 mM vanillin and 1.5% chitosan + vanillin has controlled disease incidence by 70.84, 75%, and severity 65 and 70%, and maintained constant PAL, PPO and POD enzyme activity. The third investigation was carried out on the potential of chitosan and vanillin coating on tomato fruit physico-chemical quality during storage at 26±2 ºC and 60 ± 5% relative humidity. The experiment was conducted using (CRD) in factorial arrangement (7-treatment × 25 days of storage). Different concentrations of chitosan and vanillin was used as edible coating. The analysis was evaluated at 5 days interval. The result revealed treatments 1% chitosan + 15 mM vanillin and 1.5% chitosan + 15 mM vanillin significantly reduced disease incidence by 75% and 74,16% and severity 75% and 79% respectively, delay loss in weight up to 90%, reduced changes in firmness, soluble solids concentration, and color score. It also reduced the rate of respiration and ethylene production. Furthermore, it preserve constant and low fruit ascorbic acid content, antioxidant properties, and prolong shelf life of tomato up to 25 days.

KW - Agriculture

KW - Postharvest quality

M3 - Master's thesis

ER -