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| Author(s): |
Ana Elisa de Godoy
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2009-01-29 |
| Examining board members: |
Angelo Pedro Jacomino;
Lilian Amorim;
Anita de Souza Dias Gutierrez
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| Advisor: | Angelo Pedro Jacomino |
| Abstract | |
Brazil is the biggest worldwide producer of papaya fruit supplying the local market and with high potential to export to the international market. However, papaya fruit shows one of the highest loss indexes, since it can easily perish. In addition, the postharvest handling is injurious and the consequences are mechanical injuries. The aim of the present study is to identify and characterize the mechanical injuries that occur in Golden papaya fruits, and to evaluate the injuries effects on the quality of the fruits. The mechanical injuries identified were abrasion, cuts and bruises, which were reproduced in Golden papaya fruits at early ripening stage. Abrasion was caused by 200 mesh sandpaper in 6 cm2 of peel surface area. Cut injury was obtained by cutting fruits at 30 mm length and 5 mm depth. Bruises were produced in the papayas by impact. The fruits were dropped from 2 m height onto a hard surface. Each fruit was injured twice in the opposite sides at the widest diameter region and it was injured with only one type of injury. Intact fruits were considered as control. Injured areas were marked and fruits were stored at 22±1ºC and 85±5% RH for 10 days. Color parameters, physico-chemical analysis, electrolyte leakage and ACC oxidase activity were evaluated every 2 days after the mechanical injuries were applied. Respiratory activity and ethylene production were evaluated daily. Magnetic resonance images were taken 4 days after the mechanical injuries were reproduced. The experimental designs used were completely randomized and in factorial experiments for each variable analyzed. Hue angle, luminosity and chroma values were affected by abrasion. Injured areas did not develop the typical yellow color, showed by higher Hue angle values. In addition, the luminosity and chroma values were lower in injured areas. Abrasion and impact injuries were responsible for flesh firmness decrease and higher water loss. Total titratable acidity was higher in fruits that were submitted to mechanical injuries during storage. Impact injury accelerated the respiratory activity and the ethylene production. ACC oxidase activity in papaya fruits submitted to abrasion and impact injuries showed higher activity than fruits submitted to cut injuries or intact fruits. Electrolyte leakage was higher in fruits injured in the first days of storage, while for intact fruits it was only after 6 days of storage. Electrolyte leakage showed that mechanical injuries accelerated fruit ripening which showed a faster membrane integrity loss. Magnetic resonance images showed that the fruits were affected by mechanical injuries since they lost membrane integrity characterized by the increase in free water content represented by injured areas with clear tones. The quality of Golden papaya fruits was affected by the mechanical injuries, mainly due to the impact and the abrasion injuries. (AU) | |
| FAPESP's process: | 06/05928-8 - Effects of mechanical injuries on physiology, biochemistry and quality of papaya fruit from Solo group |
| Grantee: | Ana Elisa de Godoy |
| Support Opportunities: | Scholarships in Brazil - Master |