Determination of Olive Maturity Stage and Optimal Harvest Interval of ‘Kalinjot’ Cultivar Using Destructive and Non-Destructive Methods

This study investigated the maturity and optimal harvest interval of the ‘Kalinjot’ olive cultivar in the Vlora region. Fruit samples were collected from six randomly selected trees over nine harvest dates at 10-day intervals from September to December 2024. Physical, chemical, and instrumental analyses were conducted to evaluate parameters related to olive ripening and oil quality. Destructive methods measured the fruit diameter, fresh weight, maturity index, flesh firmness, and detachment index, while non-destructive techniques assessed the color and absorbance indices using portable Vis/NIR devices. Chemical analyses determined the fruit moisture, oil content, and total polyphenols. The results showed that the fruit diameter, fresh weight, and oil content increased with ripening, whereas the flesh firmness and detachment index decreased significantly. A negative correlation between the maturity index and color index was observed, along with strong positive correlations between the Kiwi-Meter’s IAD values, maturity index, and oil content. The optimal harvest interval was identified when olives reached up to 25.42% oil content and 1820.89 mg GAE/kg FW total polyphenols, ensuring both the technological and nutritional quality of the oil.