Influence of Short-Term Olive Fruit Storage Conditions on the Quality of Virgin Olive Oil: A Case Study of Three Cultivars (‘Kalinjot’, ‘Leccino’, and ‘Frantoio’) in Albania

This study examined the influence of short-term olive fruit storage on the quality of virgin olive oil (VOO) from three cultivars (‘Kalinjot’, ‘Leccino’, and ‘Frantoio’) grown in southwest Albania. Olive fruits were processed immediately after harvest, or after 10 days of storage under ambient conditions (20–22 °C) and refrigeration (5 °C). Oils were evaluated for physicochemical quality parameters (free acidity, peroxide value, and UV absorption indices), as well as bioactive and sensory-related compounds (bitterness index, chlorophylls, carotenoids, and total phenolic content). Results showed that immediate processing yielded the highest quality oils, with low free acidity (0.28–0.35%) and preserved bioactive compounds. Ambient storage led to marked deterioration, including significant increases in free acidity and peroxide values, loss of pigments, and 20–70% reduction in phenolic content, accompanied by decreased bitterness. In contrast, cold storage mitigated these effects, maintaining values closer to baseline and preserving sensory and functional attributes. ANOVA confirmed significant effects of storage duration, temperature, and cultivar on most parameters, with ‘Kalinjot’ exhibiting greater stability compared to ‘Frantoio’ and ‘Lecino’. These findings highlight that minimizing the interval between harvest and milling is critical for ensuring oil quality, while refrigerated storage offers a practical strategy to safeguard chemical and sensory characteristics when immediate processing is not feasible.