Articles
Determination of optimum harvest maturity for five apple cultivars using the chlorophyll absorbance index
Article number
1261_32
Pages
219 – 224
Language
English
Abstract
Prediction of the optimum harvest date and storability of apples is an important concern for the fruit industry in Scandinavia.
Streif index, firmness or only starch conversion are commonly used methods.
To replace these with a more practical and non-destructive method, a portable spectrometer (DA meter, chlorophyll absorbance index (IAD)) was used to determine the optimum harvest date and storage potential for five apple cultivars grown in a cool climate.
There was a very strong negative correlation between harvest date and IAD value in all cultivars.
IAD values also showed a strong negative correlation with fruit respiration.
However, the relationship was stronger in Discovery, Rubinola and Santana than in Aroma and Karin Schneider. Streif index values showed very close relationships with IAD in all five apple cultivars.
Apples harvested with IAD values of 0.8-1.8 had Streif index values of 0.14-0.20, which corresponds to an adequate threshold for harvesting apples for long-term storage.
After four months in cold storage, fruits with higher IAD value at harvest showed higher firmness in all cultivars except Rubinola, and slower softening in Aroma, Rubinola and Santana. Only in Aroma and Karin Schneider did IAD show a negative correlation, with a decline in soluble solids content during storage.
Negative correlations were also found between IAD values at harvest or after storage and the occurrence of fungal decay.
Since fruit respiration rate increases with advanced maturity while Streif index decreases, determination of IAD can be a very promising technique to predict the storage potential of apples and to identify high-quality fruit.
Streif index, firmness or only starch conversion are commonly used methods.
To replace these with a more practical and non-destructive method, a portable spectrometer (DA meter, chlorophyll absorbance index (IAD)) was used to determine the optimum harvest date and storage potential for five apple cultivars grown in a cool climate.
There was a very strong negative correlation between harvest date and IAD value in all cultivars.
IAD values also showed a strong negative correlation with fruit respiration.
However, the relationship was stronger in Discovery, Rubinola and Santana than in Aroma and Karin Schneider. Streif index values showed very close relationships with IAD in all five apple cultivars.
Apples harvested with IAD values of 0.8-1.8 had Streif index values of 0.14-0.20, which corresponds to an adequate threshold for harvesting apples for long-term storage.
After four months in cold storage, fruits with higher IAD value at harvest showed higher firmness in all cultivars except Rubinola, and slower softening in Aroma, Rubinola and Santana. Only in Aroma and Karin Schneider did IAD show a negative correlation, with a decline in soluble solids content during storage.
Negative correlations were also found between IAD values at harvest or after storage and the occurrence of fungal decay.
Since fruit respiration rate increases with advanced maturity while Streif index decreases, determination of IAD can be a very promising technique to predict the storage potential of apples and to identify high-quality fruit.
Publication
Authors
I. Tahir, E. Vangdal
Keywords
apple (Malus domestica), chlorophyll absorbance index (IAD), Streif index, quality, respiration
Groups involved
Online Articles (39)