Abstract:
The effects of 1-methylcyclopropene (1-MCP) and ethylene on fiber content and lignification ofasparagus cv. Brock improve were studied with two experiments. The first study was the effect of0, 50, 250, 500 and 1,000 ppb 1-MCP fumigation of asparagus for 12 hours and asparagus were storedat 20 oC, 90-95% RH. The results were found that 1-MCP fumigated could retard the increase of fibercontent and shear force within tip, middle and bottom parts of asparagus spear compared to control andthe bottom parts had 2 times higher fiber content and shear force than tip and middle parts. Moreover,peroxidase activity and lignin content were higher in bottom part than those of in the middle and tippart. However, asparagus fumigated with 500 ppb 1-MCP showed the best in retarding those changes.On the other hand unexpected result appeared that, 1-MCP fumigation increased the respiration rate andethylene production. The respiration rate of the tip was higher than middle and bottom parts ofasparagus spear. For the second experiment, the effect of combination between 1-MCP and ethylenefumigation on asparagus was studied. Asparagus was fumigated with 500 ppb of 1-MCP for 12 hoursbefore and after 100 ppm of ethylene fumigation for 3 hours. The experiment was observed at 20 oC,90-95% RH. It was found that only the fumigation with 1-MCP was the best in retarding the increase offiber content, shear force, peroxidase activity, lignin content, respiration rate, ethylene production, color changes and weight loss in every parts of asparagus spear. The bottom parts had higher lignin content, peroxidase activity and shear force than the other two parts. Peroxidase activity and lignin content in asparagus fumigated with ethylene before 1-MCP fumigation were found to be the highest.