Twenty-seven Lactobacillus pentosus strains, and the undefined starter for table olives from which they were isolated, were characterised for their technological properties: tolerance to low temperature, high salt concentration, alkaline pH, and olive leaf extract; acidifying ability; oleuropein degradation; hydrogen peroxide and lactic acid production. Two strains with appropriate technological properties were selected. Then, table olive fermentation in vats, with the original starter, the selected strains, and without starter (spontaneous fermentation) were compared. Starters affected some texture profile parameters. The undefined culture resulted in the most effective Enterobacteriaceae reduction, acidification and olive debittering, while the selected strains batch showed the lowest antioxidant activity. Our results show that the best candidate strains cannot guarantee better fermentation performance than the undefined biodiverse mix from which they originate.

This study evaluated a multi-strain starter culture’s impact on the industrial-scale fermentation of “Tonda di Cagliari” table olives, comparing processes at ambient versus controlled (23–25 °C) temperatures. Controlled fermentation accelerated acidification, yielding lower pH levels, higher lactic acid bacteria (LAB) counts, and better control over Enterobacteriaceae. Starter inoculation ensured the attainment of safe pH levels (4.5 in non-inoculated samples). Regardless of processing temperature, starter-inoculated olives consistently yielded higher final concentrations of hydroxytyrosol (719.2 and 762.9 mg/kg inoculated, 480.7 and 326 mg/kg non-inoculated). Total phenolic content in olives remained higher throughout the fermentation process at the controlled temperature (3138 and 2112 mg/kg ambient temperature, 3458 and 3622 mg/kg controlled temperature). Olives maintained at controlled (higher) temperatures exhibited lower final moisture content and significantly reduced lipid content. While texture profiles were primarily affected by temperature, sensory acceptability was significantly influenced by both the starter inoculation and the fermentation temperature. These findings indicate that using microbial starters can potentially lower energy costs associated with heating processing rooms, particularly during colder seasons, while still ensuring food safety and enhancing nutraceutical value. Although the faster fermentation rate at controlled temperature did not substantially shorten overall marketing time, the starter eliminates the necessity for heating facilities to achieve a food-safe pH within a reasonable timeframe.

Following the 2021 Montiferru wildfire, one of the largest wildfire events in modern Italian history, assessing the suitability of olive-growing environments for high-quality extra virgin olive oil (EVOO) production is crucial for supporting sustainable agricultural restoration. This study models the spatial distribution and temporal stability of total polyphenol concentration in EVOO (cv. Bosana) across a complex Mediterranean landscape. Olive samples from georeferenced sites were collected during the 2022 (22 samples) and 2023 (37 samples) harvest seasons and processed using a standardized protocol. Spatial modeling was performed via Empirical Bayesian Kriging Regression Prediction (EBKRP), integrating seven bioclimatic and topographic covariates. Cross-validation demonstrated high predictive accuracy with negligible bias (RMSE = 53.3 and 58.8 mg kg⁻¹ for 2022 and 2023, respectively). While single-predictor correlations were weak, multi-variable analysis highlighted a strong interaction between topography and water balance driving phenolic accumulation. The mean prediction map identified regional hotspots approaching600 mg kg⁻¹ of polyphenols content in the obtained olive oils. Spatial overlay analysis successfully delineated “Stable High-Phenolic Core Areas” (>500 mg kg⁻¹ with interannual variation < 100 mg kg⁻¹), filtering out high-altitude marginal zones. This geostatistical approach provides a valuable territorial decision-making tool to support post-fire agricultural reconversion and the valorization of high-quality monovarietal EVOO terroirs.

Following the 2021 Montiferru wildfire, one of the largest wildfire events in modern Italian history, assessing the suitability of olive-growing environments for high-quality extra virgin olive oil (EVOO) production is crucial for supporting sustainable agricultural restoration. This study models the spatial distribution and temporal stability of total polyphenol concentration in EVOO (cv. Bosana) across a complex Mediterranean landscape. Olive samples from georeferenced sites were collected during the 2022 and 2023 harvest seasons and processed using a standardized protocol. Spatial modeling was performed via Empirical Bayesian Kriging Regression Prediction (EBKRP), integrating seven bioclimatic and topographic covariates. Cross-validation demonstrated high predictive accuracy with negligible bias for both years. While single-predictor correlations were weak, multi-variable analysis highlighted a strong interaction between topography and water balance driving phenolic accumulation. The mean prediction map identified regional hotspots exceeding 700 mg kg⁻¹ of polyphenols content in the obtained olive oils. Spatial overlay analysis successfully delineated “Stable High-Phenolic Core Areas” (>500 mg kg⁻¹ with interannual variation <100 mg kg⁻¹), filtering out high-altitude marginal zones. This geostatistical approach provides a valuable territorial decision-making tool to support post-fire agricultural reconversion and the valorization of high-quality monovarietal EVOO terroirs.

Extra virgin olive oil (EVOO) quality depends on both cultivar and extraction technology, particularly through their effects on minor bioactive compounds like phenolics and tocopherols. The objective of this study was to evaluate the impact of an innovative pre-conditioning technology (Protoreactor ^® ) on the chemical and sensory characteristics of EVOO obtained from Bosana and Semidana cultivars compared with a conventional extraction process. Olives harvested at similar maturity stages were processed using either a traditional malaxation system or a Protoreactor ^® -assisted extraction line. Oils were analyzed for standard quality parameters, phenolic profile, α-tocopherol content, and sensory attributes. Free acidity ranged from 0.21 to 0.47% and peroxide values between 7.2 and 9.5 meq O₂/kg. Strong cultivar × process interactions were observed. In Bosana oils, the Protoreactor ^® reduced acidity (0.47 to 0.38%) and increased total phenols by approximately 32 mg/kg compared to the traditional process. In contrast, Semidana oils showed higher acidity (0.21 to 0.26%) and a reduction in phenolic content (−68 mg/kg) under Protoreactor ^® processing. HPLC-DAD profiling revealed that differences were mainly driven by changes in secoiridoid derivatives (e.g. oleuropein aglycone and ligstroside aglycone). Sensory analysis confirmed these trends: Protoreactor ^® processing produced more balanced oils in Bosana but reduced the intensity of organoleptic attributes in Semidana (olive fruitness = 4.2). Overall, the results demonstrate that the effects of innovative extraction technologies cannot be generalized across cultivars. Protoreactor ^® processing provided measurable benefits for Bosana but proved less suitable for Semidana under the tested conditions, highlighting the need for cultivar-specific optimization of olive oil extraction technologies.