Influence of household conditions on the shelf-life and polyphenolic-related health claim of Cobrançosa extra virgin olive oil

This study examines how typical household conditions after bottle opening affect the physicochemical, sensory, and bioactive properties of cv. Cobrançosa extra virgin olive oil (EVOO), attempting to define kinetic models to predict the shelf-life (SL) during domestic use. For 9 weeks, EVOO amber glass bottles (750 mL), exposed to light ( n = 5) or darkness ( n = 5), at 18 ± 2 ºC, were opened/shaken daily to simulate household use, with oil removed weekly. In light-exposed samples, the peroxide value (PV) imposed EVOO declassification at week five, with intense rancidity at week eight (≥ 3.5), rendering the oil unsuitable for consumption. On the contrary, light-protected oils had only a downgrade to virgin olive oil due to a K 232 rise. Acidity was preserved, as was the health claim supported by tyrosol/hydroxytyrosol polyphenols. Kinetic models (zero-, first-, and second-order) supported on the oxidation indicators (PV, K 232 , or K 268 ), allowed determining reaction rates by linear regression (correlation coefficients: 0.942 to 0.997). For light-exposed oils, PV was the most reliable indicator of SL, predicting from a second-order TRUL model a preservation of the EVOO grade for 35 ± 2 days, in agreement with the experimental SL (28–35 days). For light-protected oils, K 232 was the most accurate SL indicator, predicting a SL of 49 ± 4 days using a zero-order TRUL model, consistent with the experimental SL (49–56 days). The models were validated using SL literature data from cvs. Arbequina, Istarska Bjelica, and Buža olive oils, confirming their applicability to various cultivars and highlighting oxidation’s role, particularly photo-oxidation, in EVOO degradation during domestic use.