A comparison among innovative plants for high quality extra-virgin olive oil production.

BACKGROUND: The cleaning operation of extra-virgin olive oil (EVOO), subsequent to its extraction, is generally performed by means of a vertical disc stack centrifuge separator causing qualitative damage due to increased oxidative alterations. However, previous works have demonstrated the great opportunity that settling represents in order to improve the EVOO quality performing the separation operation with minimal qualitative damage. RESULTS: A new patented prototype device (ROTASED, RS) has been used in the cleaning operation of extra-virgin olive comparing physical and chemical characterization of EVOO after 48 h from extraction and after 180 days of shelf-life. In addition, the results have been compared with those obtained using an assisted sedimentation (AS) plant and an enhanced sedimentation plant by hydrocyclone (H) from previous authors' works, in order to assess the improvement of EVOO quality that could be attained with respect to the use of the vertical disc stack centrifuge separator. CONCLUSION: The results show that after 48 h of storage the tested patented prototype device seems to be preferable, however, after 180 days of storage, the difference between H and RS device results similar in terms of improvement of the final olive oil quality. In addition, the method of principal component analysis can be used to evaluate the suitability of an olive cv. in terms of quality of extracted oil. © 2020 Society of Chemical Industry.

Microbiological Stability and Overall Quality of Ready-To-Heat Meals Based on Traditional Recipes of the Basilicata Region.

The quality of ready meals is affected by several factors that may impair stability and nutritional value. In this work, we evaluated the overall quality of four traditional meals (Basilicata region) prepared according to the cook&chill method, packaged in air or modified atmosphere packaging (MAP; 70% N2 and 30% CO2), and stored at 4 °C for seven days. The shelf-life was determined by Listeria monocytogenes challenge testing and inactivation by microwave (MW) heating was assessed. The counts at the production day were excellent in three meals out of four, whereas one had high levels of spoilage and pathogens both as soon as the preparation and after seven days. MAP was partially effective only against the growth of the aerobic mesophilic species, whereas sensory analysis revealed that MAP may preserve many of sensory attributes. The average shelf-life of the meals ranged from 11 to 13 days, however, the potential shelf-life was undetectable in one out four meals, as L. monocytogenes growth was inhibited two days after the inoculum. In the inoculated meals, MW heating provided a partial inactivation (25%) of the pathogen. The overall quality of type the meals was partially satisfactory; post-cooking contaminations may affect the microbial load and reduce the palatability over the storage period and, above all, may involve biological hazards which consumers' habits may not be able to eliminate.

Models for the rapid assessment of water and oil content in olive pomace by near-infrared spectrometry.

BACKGROUND: The measurement of the water and oil content in olive pomace is crucial for controlling the olive-oil extraction process. The use of near-infrared (NIR) spectra could allow the measurement of the oil and water content in olive pomace. RESULTS: Partial least squares for pomace oil content on a dry basis reached an error of 2.5% (±0.5). Principal component regression for pomace oil content on a wet basis reached an error of 3.7% (±0.5). Both were suitable for quantitative analysis. Principal component regression for pomace water content reached an error of 6.0% (±2.3), suitable for process control. The relationship between 'ratio of standard deviation of calibration data to standard error of prediction data' and 'range of confident prediction error percentage' was investigated, it results of hyperbolic type, the constant of the hyperbolic equation depends on the product under analysis: for the olive pomace this constant is equal to 45.60 (±1.78). CONCLUSION: Near-infrared analysis confirmed the possibility of determining the oil and water content in the olive pomace, which is important in the olive oil extraction process control. A new algorithm was used, together with standard statistical algorithms, to identify and remove the less useful wavelengths from the model, improving the overall prediction performance. A new parameter (the 'range of confident prediction error percentage') has been proposed for estimating the model's prediction error in an objective way. © 2020 Society of Chemical Industry.

Preparation and characterization of microencapsulated phytosterols for the formulation of functional foods: Scale up from laboratory to semi-technical production.

Phytosterols were microencapsulated by spray drying in a shell represented by WPI, inulin and chitosan at four different combinations through the formulation of aqueous suspensions. Moreover, two concentrations of Tween 80 (1.25% and 2.50% w/w) and two inlet temperatures (125 °C and 155 °C) were tested. The effect of the different experimental conditions on the process yield and on the microcapsules properties was evaluated. A significant effect of all variables on the microcapsule properties was found. Accordingly, the best performance, with the maximum loading capacity of 25%, was obtained by using only WPI as shell material, Tween 80 at 1.25% and inlet temperature of 155 °C. The process was successfully scaled-up from laboratory equipment to a semi-technical scale keeping the optimal shell formulation and process conditions.

Models to improve the non-destructive analysis of persimmon fruit properties by VIS/NIR spectrometry.

BACKGROUND: Visible-near-infrared spectrometry is a technique suitable for assessing chemical and physiological properties of fruit. Some models of calibration/prediction have been tested in order to assess the feasibility of a visible-near-infrared sensor in order to monitor persimmon fruit colour, firmness, soluble solids, titratable acidity and soluble tannins. RESULTS: Five regression models were investigated: principal component, partial least squares, stepwise, support vector machines and ensembles of trees. These models were assessed by a 10-fold cross-validation with a new strategy for both outlier removal and wavelength reduction; furthermore, their statistical significance was evaluated by 100 Monte Carlo simulation runs. Principal component regression allowed us to build excellent and/or very good fit/prediction models. The results (in terms of RPD as standard deviation to performance standard error ratio) are: 9.23 (±0.26) for colour index, 10.18 (±0.37) for firmness, 7.15 (±0.28) for soluble solids content, 7.87 (±0.31) for titratable acidity and 8.91 (±0.33) for soluble tannins content. CONCLUSION: The proposed strategy, for outlier removal and wavelength reduction, allowed the achievement of useful results. Principal component regression fit/prediction capability produced excellent results. Conversely, partial least squares regression showed fair/poor results and the remaining tested models performed badly on real data. © 2017 Society of Chemical Industry.