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Olive pomace results from the production of olive oil. Even if olive pomace represents a potential environmental problem, it contains phenolic compounds, which are widely recognized for their beneficial properties for human health. In this study, an innovative and sustainable technological approach to extract phenolic compounds from fresh olive pomace, based on food-grade solvent instead of those usually adopted, is investigated. Characterization and shelf-life evaluation of the hydroalcoholic extracts obtained from the procedure developed for different industrial purposes were also carried out. The phenolic fractions of the different samples were studied with the Folin–Ciocâlteu method to quantify that the total reducing molecules and HPLC-MS/MS analysis was used to define the profile through the identification and quantification of 42 compounds, belonging to five chemical families. Regarding shelf-life, the hydroalcoholic extract showed no significant reduction in phenolic content, for both instrumental evaluations, retaining most of the phenolic compounds present in the raw material; negative attributes were not perceived by sensory evaluation. Thus, these lab-scale results can be the starting point to develop a procedure that is suitable for a real olive mill, representing a valorization strategy in a circular economy and the perspective of new business models.

Recently, application of high-pressure homogenization (HPH) treatments has been widely studied to improve shelf life and rheological and functional properties of vegetable and fruit juices. Another approach that has drawn the attention of researchers is the use of biocontrol cultures. Nevertheless, no data on their possible combined effect on fruit juices shelf life and functionality have been published yet. In this work, the microbial, organoleptic, and technological stability of extremely perishable carrot juice and its functionality were monitored for 12 and 7 days (stored at 4 and 10 °C, respectively) upon HPH treatment alone or in combination with a fermentation step using the biocontrol agent L. lactis LBG2. HPH treatment at 150 MPa for three passes followed by fermentation with L. lactis LBG2 extended the microbiological shelf life of the products of at least three and seven days when stored at 10 °C and 4 °C, respectively, compared to untreated or only HPH-treated samples. Moreover, the combined treatments determined a higher stability of pH and color values, and a better retention of β-carotene and lutein throughout the shelf-life period when compared to unfermented samples. Eventually, use of combined HPH and LBG2 resulted in the production of compounds having positive sensory impact on carrot juice.