Establishment of the optimal harvest time in apricot ('Orangered' and 'Bergarouge') by means of a new index based on vis spectroscopy.

In apricot fruit (Prunus armeniaca L.), establishing the optimal harvest time is crucial since fruit quality and shelf-life potential are closely related to the ripening stage at harvest. In order to develop a non-destructive index for monitoring the progression of ripening in apricot, the difference in absorbance between two wavelengths near the chlorophyll-a absorption peak (670 and 720 nm; Index of Absorbance Difference, I AD ) was related to the time course of changes in fruit quality parameters (flesh firmness, soluble solids content, flesh elasticity) occurring during ripening. Four-year trials on two cultivars ('OrangeRed' and 'Bergarouge') showed that the I AD was able to segregate fruits according to their ripening stage. Moreover, the index value corresponding to the optimal harvest time remained constant in different years, independently of quality parameters (soluble solids content, flesh firmness or elasticity). Fruit graded according the I AD also showed different consumer acceptance, the fruit with the lowest index score being the most appreciated.