Evaluation of apple cultivars' resistance to apple scab (Venturia inaequalis Che.).

Content Provider	Semantic Scholar
Author	Szklarz, Michal
Copyright Year	2006
Abstract	One of the non-destructive techniques which have been developed to estimate fruit quality is time-resolved reflectance spectroscopy (TRS). TRS measures the absorption (μ a ) and scattering (μ s ') of pulses of laser light passing through the fruit. The absorption coefficient at 670 nm coincides with the absorption peak of chlorophyll, and has been used to estimate maturity of nectarines at harvest and to predict their softening rate during shelf life. A relatively low μ a at 670 nm indicates that the fruit is more mature and that it will soften earlier, whereas a relatively high μ a at 670 nm indicates that the fruit is less mature and that it will soften later. The aim of this research was to study the relationships between maturity of nectarines at harvest time as measured by TRS and its sugar and organic acid composition during shelf life. Nectarines of the cultivar 'Ambra' were harvested on the second commercial picking date (July 5, 2004). The fruit were sorted by size and were measured for their absorption coefficient (μ a ) using TRS at 670 nm. Fruit of each maturity class were randomized among the different samplings, so that the fruit from whole range of μ a was represented in each sample. Total soluble solids (TSS), titratable acidity (TA), sugars and organic acids were measured at harvest time and at various times during shelf life at 20°C. Data were statistically elaborated using step-wise multiple linear regression analysis. μ a had significant effect on the sugar and acid contents of fruit. As the fruit matured on the tree, total soluble solids, total sugars, the proportion of sucrose, the proportion of malic acid and the proportion of quinic acid increased. On the other hand, the proportion of fructose, the proportion of sorbitol, total acids and especially the proportion of citric acid decreased. During shelf life at 20°C, total acids decreased, and sugars were less affected. Therefore, individual fruits can be sorted according to fruit quality by using TRS to measure μ a at harvest time.
Starting Page	183
Ending Page	188
Page Count	6
File Format	PDF HTM / HTML
Volume Number	14
Alternate Webpage(s)	http://www.insad.pl/files/journal_pdf/journal_2006/Full19_2006.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article