Life Sciences Research

(An International Journal)


Pages: 21-27

Date of Publication: 30-Nov--0001

Effect of Fusarium musae on cell wall degrading enzymes, total soluble sugar and total phenol content of infected banana fruits

Author: T. T Baria, K. B. Rakholiya

Category: Research Article

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In this study, the effect of inoculation of Fusarium musae on ripe and unripe banana fruits was observed. Phenylalanine ammonia lyase (PAL) activity was higher in unripe inoculated fruits (73.22 U h-1 g-1 protein) than uninoculated (58.42 U h-1 g-1 protein), while it decreased in ripe inoculated (9.15 U h-1 g-1 protein) and uninoculated fruits (3.35 U h-1 g-1 protein) after 72 h of storage. Polyphenol oxidase (PPO) activity of uninoculated (2.3 U min-1 g-1 protein) was more or less similar to inoculated (3.0 U min-1 g-1 protein) fruits after 72 h of storage. However, in uninoculated and inoculated semi-ripe fruits, PPO activity was increased about 16.0 folds and 18 foldsafter 72 h incubation, respectively. At the 0 h incubation the PPO activity was 4.61 fold higher in ripe fruits as compared to semi-ripe fruits, but it was increased after 72 h in both inoculated and uninoculated semi-ripe fruits. Peroxidase (POX) activity was higher in ripe fruits (48.85-120.9 __ampersandsignmu;mol guaiacol min-1 g-1 protein) than in semi-ripe fruits (8.65-60.9 __ampersandsignmu;mol guaiacol min-1 g-1 protein) up to72 h of storage. The POX activity was enhanced after inoculation with F. musae in all ripening stages. The degree of increase in infected unripe, semi-ripe and ripe was 11.71, 7.0 and 2.47 fold higher respectively than uninoculated fruits. Total soluble sugar content was higher (208.65mg/g fresh weight) in ripe uninoculated fruits and still further decreases (195.87mg/g fresh weight) in inoculated fruits and lowest in uninoculated unripe fruits after 72 h of storage. 9.22 fold increases in total soluble sugar content was observed in unripe inoculated fruits followed by unripe uninoculated fruits and semi-ripe fruits. Total phenol content was higher in unripe fruits (15.71mg/g fruit weight) than semi-ripe (13.49mg/g fruit weight) and ripe fruits (10.59mg/g fruit weight) at initial time. The phenol content was decreased with increasing storage period in uninoculated fruits and further decreased in inoculated fruits in all three stages.

Keywords: Fusarium musae, PAL, POX, PPO, total phenol, total soluble sugar