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Chelating and free radicals scavenging activities of extra virgin olive oil (EVOO) enriched by Myrtus communis phenolic compounds (McPCs), α-tocopherol and Butylated hydroxytoluene (BHT) were evaluated using chemical assays, 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Oxygen radical absorbance capacity (ORAC), and biological model as 2,2'-azobis (2-aminopropane) dihydrochloride (AAPH) or Fe/Ascorbic acid (Fe/AsA) system mediated peroxidation of l-α-phosphatidylcholine aqueous dispersions stabilized by bile salts (BS) under simulated intestinal conditions (pH 7.4). McPC-EEVOO increased significantly the neutralization of DPPH radical and AAPH-derived radicals in ORAC assay more than α-tocopherol and BHT. The phospholipid stability increased by a factor of 33.6%, 34.8%, 19.3% and 10.7% for myrtle microwave assisted extraction (MAE) and conventional extraction (CE) extracts, α-tocopherol and BHT, respectively, as compared to the control (EVOO without enrichment) in Fe/AsA system. But a slightly additive effect was observed when AAPH system was used. Our observation showed that McPCs may interact positively with EVOO to inhibit phospholipid peroxidation, and thus, McPC-EEVOO could be a potential functional food.

This investigation presented presents the drying characteristics, and aimed to predict the drying kinetics of tomato slices (Lycopersicon esculentum MILL.) using convection and microwave methods. Hot air drying was carried out in a ventilated oven at 50, 60, 80, and 100°C temperatures and microwave drying was performed in domestic microwave using 300, 500, 800, and 900 W powers. Twenty‐two mathematical models were undertaken to predict the drying kinetics and the best model was chosen based on the highest R2 values and the lowest root mean square error (RMSE) and χ2 values. Drying kinetics, drying rate variation, diffusivity and energy consumption of both methods were evaluated. Fernando and Amarasinghe model and Sledz model were the best models for convective and microwave drying processes, respectively. Effective moisture diffusivity varied from 0.28 × 10−9 to 2.81 × 10−9 and from 1.32 × 10−9 to 21.52 × 10−9, while the activation energy was 27.64 kJ/mol and 5.71 W/g for convective and microwave drying processes, respectively. The energy consumption increases with increasing temperature or power, the reverse was observed for energy efficiency. Microwave drying process has the advantage of drying time reduction, low‐energy consumption, and high‐drying efficiency at a moderate high‐power level (900 W). Hence, it is recommended to apply this innovative process for drying tomato slices.

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Candida apicola and Aspergillus niger strains were isolated and identified from Deglet-Nour dates, and their loads were determined on the fruit surface. The thermal inactivation of their spores was evaluated between 42 and 70C. The estimated D values for C. apicola and A. niger were D50 = 2.3 ± 0.4 min and D50 = 22.1 ± 2.1 min, respectively. The zT values obtained were 9.4 ± 2.6 and 9.6 ± 1.0C for C. apicola and A. niger, respectively. The experimental survival spores obtained on the date surface during non-isothermal treatment were compared with the simulated data based on the Bigelow method and on pasteurization value calculations. C. apicola and A. niger spores can be inactivated by relatively low temperatures. Validation shows that this model and its parameters can be used to optimize pasteurization of these fungal spores on the surface of fruits using the temperature-time profile data. These thermal treatments can pasteurized date surface while minimizing the color date degradation. PRACTICAL APPLICATIONSThis study contributes to the design and control of an effective heat treatment against the fungi that cause particular safety and spoilage problems during the preservation and packaging of fragile fresh fruits such as fresh dates.

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The survival of Escherichia coli ATCC 25922 in orange juice treated with microwave and/or ultrasound was evaluated; Weibull model was fitted to survival curves to describe inactivation kinetics; and the effect of combined microwave‐ultrasound treatments was assessed. Ultrasonic treatment (42 kHz) has no significant effect on the survival rate reduction (1.3 log for 60 min of sonication) of E. coli. However, sonication can increase the efficiency of microwave inactivation. The use of ultrasound as pre‐treatment was more effective than when used in post‐treatment, that is, a reduction of 8.0 log was achieved by a combination of ultrasound (20 min) followed by a microwave (900 W/30 s), while 4.0 log was obtained when these both processes were reversed. The scale parameter α estimated from microwave‐inactivation kinetics combined with an ultrasound pre‐treatment was found to be lower than those obtained with a post‐treatment, which, in turn, are lower than those estimated for microwave or ultrasound alone. These results demonstrate the effectiveness of ultrasound as a pre‐treatment to improve the inactivation of E. coli by microwave processing in orange juice beverages. Practical applications High‐temperature short‐time (HTST) type processes are preferred by the food industry to reduce the adverse thermal degradation in food quality while ensuring food safety for liquid food. The microwave heating is fast and can significantly reduce the come‐up time to the desired process temperature. The hydrodynamic action of ultrasound on microorganisms is a great potential to improve microbial decontamination efficiency by microwave processing. This study contributes to the design and control of an effective combination treatment of ultrasound and microwave to improve pasteurization processes for orange juice beverages.