Chareekhot K.,King Mongkuts University of Technology Thonburi |
Techavuthiporn C.,King Mongkuts University of Technology Thonburi |
Techavuthiporn C.,Postharvest Technology Innovation Center Commission of Higher Education |
Techavuthiporn C.,Christian University of Thailand |
And 6 more authors.
Journal of Horticultural Science and Biotechnology | Year: 2014
Immature Carica papaya fruit of three cultivars ('Krang', 'Kaek Noul', and 'Kaek Dum') known to be suitable for processing as papaya shreds were harvested 60 - 70 d after anthesis. 'Krang' had the largest fruit among the three cultivars. The mean fruit firmness values for intact 'Krang', 'Kaek Noul', and 'Kaek Dum' papaya fruit were 95.2 N, 99.4 N, and 109.7 N, respectively. The mean rates of respiration and ethylene production in intact fruit were not significantly different among the three cultivars.The flesh of 'Krang' fruit had the highest L* and hue angle (h°) values (68.1 and 112.8, respectively), and the flesh of 'Kaek Dum' was more yellow in colour than the flesh of the other two cultivars, expressed as a b* value of 8.9. During storage at 10°C and 85 - 90% relative humidity, shreds of 'Kaek Dum' fruit flesh retained the highest average shear force values, followed by 'Kaek Noul' and 'Krang'. Shreds of 'Krang' fruit showed a relatively higher loss of fresh weight than 'Kaek Dum' or 'Kaek Noul' (3.7 - 5.8%, 2.4 - 3.2%, and 1.1 - 2.2%, respectively), and this loss appeared to correlate with the microstructure of the parenchyma cells. The cellular morphology of shredded fruit was observed using a scanning electron microscope (SEM). The SEM revealed that parenchyma cells in 'Krang' were larger than those in 'Kaek Noul' and 'Kaek Dum'. On day-6, fruit flesh shreds of 'Kaek Noul' and 'Kaek Dum' scored higher than those of 'Krang' in a trained, ten-person panel test on a nine-point hedonic scale for overall acceptance, with values of 5.0, 4.3, and 3.6, respectively. 'Kaek Noul' and 'Kaek Dum' papaya fruit were therefore better suited for processing into shreds and had a longer storage-life of 6 d. Although, initially, 'Krang' fruit had the best appearance and a high L* value after peeling, these features were lost during storage at 10°C and reduced the storage-life to only 4 d.