Thermal stabilities of lycopene and β-carotene in tomato pulp and pink grapefruit juice

Optimization of lycopene spray drying encapsulation in basil seed gum: Boosting bioavailability and mayonnaise stability

This study aimed to improve lycopene stability and bioavailability in food products. Lycopene, a potent antioxidant, often has poor stability and undesirable organoleptic properties. Therefore, the impact of basil seed gum (BSG) concentration and spray drying inlet temperature (IT) on the physicochemical, bioaccessibility, and antioxidant properties of encapsulated lycopene emulsion (ENL) was investigated using Central Composite Design (CCD)-Response Surface Methodology (RSM). Optimal encapsulation conditions were IT = 141.96 °C and BSG = 19.507 %. The ENLs had an average particle size of 147.56 nm, a polydispersity index (PI) of 0.263, and a zeta potential of -21.37 mV, indicating good colloidal stability. Antioxidant activity varied slightly during the four weeks of storage (a 9.65 % increase followed by a 13.6 % decrease), but it remained stable overall. Incorporating ENL into mayonnaise significantly reduced the acid value (2.78 mg KOH/g), the anisidine index (12.43), the peroxide value (7.13 meq/kg), and the TBARS index (0.534), and improved color parameters, reducing brightness (79.94) and whiteness (70.64) while masking lycopene's strong yellow and red hues. This study highlights BSG-encapsulated lycopene's potential to improve oxidative stability and sensory properties, offering a natural and effective method to enhance lycopene stability, bioavailability, and sensory acceptance in various food applications.

Potency of Dimethyl Dicarbonate on the Microbial Inhibition Growth Kinetics, and Quality of Passion Fruit (Passiflora edulis) Juice during Refrigerated Storage

This study aimed to investigate the effectiveness of dimethyl dicarbonate (DMDC) at various concentrations (0-250 ppm) in inhibiting the growth of Escherichia coli TISTR 117 and spoilage microbes in passion fruit juice (PFJ) and its impact on the physicochemical and antioxidant quality of the juice during refrigerated storage. The highest log reduction in the total viable count, yeast/molds and E. coli was attained in PFJ samples with 250 ppm of DMDC (p ≤ 0.05) added. Microbial growth inhibition by DMDC followed the first-order kinetic model with a coefficient of determination (R2) and inhibition constants (k) ranging from 0.98 to 0.99 and 0.022 to 0.042, respectively. DMDC at 0-250 ppm showed an insignificant effect on pH, °Brix, color (L*, a*, b*), ascorbic acid, total phenolic compound (TPC), total flavonoid content, and antioxidant activity (DPPH, FRAP) (p > 0.05). Control (untreated PFJ), DMDC-250 ppm, and pasteurized (15 s at 72 °C) samples were subjected to 27 days of cold storage at 4 °C. A decreasing trend in pH, total soluble solid, ascorbic acid content, DPPH and FRAP values were observed in all the samples during refrigerated storage. However, the DMDC-250 ppm sample showed a better prospect in physicochemical quality changes compared to the pasteurized and untreated control PFJ samples. ΔE values showed marked changes in the control sample than the DMDC-250 ppm and pasteurized samples at 27 days of storage. Additionally, the total viable count and yeast/mold count were augmented during storage, and an estimated shelf-life of the control, DMDC-250 ppm, and pasteurized samples was approximately 3, 24 and 18 days, respectively. In conclusion, DMDC at 250 ppm could ensure microbial safety without affecting the quality attributes of PFJ during 24 days of storage at 4 °C.

Mathematical Modeling of Thin-Layer Drying Kinetics of Tomato Peels: Influence of Drying Temperature on the Energy Requirements and Extracts Quality

Tomato drying implies high energy consumption due to the high moisture content, and limiting drying temperatures is necessary to avoid carotenoid degradation. To explain the mechanism of moisture transport through the material and to scale up the drying process, drying experiments are needed and supported by mathematical modeling. For the Rila tomato peel drying process, ten thin-layer mathematical models were formulated based on experimental data for six temperatures (50-75 °C) and validated by statistical analysis. Considering the slab geometry of the peels sample and Fick's second law of diffusion model, the calculated effective moisture diffusivity coefficient values Deff varied between 1.01 × 10-9-1.53 × 10-9 m2/s with R2 higher than 0.9432. From the semi-theoretical models, Two-term presents the best prediction of moisture ratio with the highest R2 and lowest χ2 and RMSE values. Using the experimental data on extract quality (carotenoid content), two degradation models were formulated. Increasing the drying temperature from 50 °C to 110 °C, a degradation of 94% for lycopene and 83% for β-carotene were predicted. From the energy analysis, a specific energy consumption of 56.60 ± 0.51 kWh is necessary for hot-air drying of 1 kg of Rila tomato peel at 50 °C to avoid carotenoid degradation.