Search

The combined effect of active shielding packaging and relative phase sweeping on heating performance in a dual-port solid-state microwave heating process was evaluated. Four types of heating strategies that combine two factors (passive and active packaging and fixed and sweeping relative phase) were used in heating a tray of 300 g gellan gel sample for 3 min. The temperature distributions at the top and middle layers of the heated samples were collected and analyzed for heating uniformity index (HUI) and power absorption efficiency (PAE). The results showed that both active shielding package and relative phase sweeping can individually improve the HUI while maintaining high PAE. The packaging factor and relative phase factor showed a significant interaction effect (p = 0.0021) in influencing HUI but not PAE, highlighting the necessity of considering both factors (packaging and relative phase) when optimizing the microwave heating uniformity. The combination of active packaging and sweeping relative phase is a robust heating strategy that delivers the best heating performance that is significantly better than or similar to other combinations of packaging and relative phase strategies. [ABSTRACT FROM AUTHOR]

The effect of microwave power levels on the drying attributes of Jaya fish (Aspidoparia jaya) in a microwave dryer was investigated in this study. Microwave power levels of 100, 180, 300, and 450 W were used to dry 50 g of fish samples, and the drying kinetics were evaluated. Higher microwave power levels resulted in faster drying when increased from 100 to 450 W. The moisture ratio of fish during drying was calculated, and the data obtained were applied to 5 well known thin-layer mathematical models of drying, namely Approximate diffusion, Modified Henderson and Pabis, Two-Term, Logarithmic, and Midilli et al. model. Model constants and coefficients were calculated by nonlinear regression techniques. All the models were validated using statistical parameters namely; Coefficient of determination (R2), Root Mean Square Error (RMSE), Chi-square (χ2), and Standard Sum of Error (SSE). The Midilli et al. model gave an excellent fit to the experimental data of all the models evaluated. The effective diffusivity was calculated using Fick's diffusion equation, and the value varied from 1.40 × 10−9 to 1.08 × 10−8 m2/s. The activation energy and the diffusivity constant were found to be 4.656W/g and 1.22 × 10−8 m2/s, respectively. [ABSTRACT FROM AUTHOR]

Gundruk is a fermented green leafy vegetable product prepared from fresh leaves of local vegetables called Rayo—sag (Brassica campestris), mustard (Brassica juncea), and cauliflower (Brassica oleracea) indigenous to the Nepali people. Fresh gundruk was prepared in a glass jar by fermenting the Brassica juncea leaves anaerobically for 16 days and the changes in biomass, lactic acid, and pH were evaluated after every 24 hr. The viable cell count increased from 6.03 × 104 cfu/g to 9.55 × 108 cfu/g after 3 days and then decreased gradually to remain constant after 8 days with 6.31 × 107 cfu/g until the end of fermentation. The lactic acid increased by about 12.58 times in 12 days and remained constant for the rest of the fermentation period. Unlike this, pH decreased from 6.59 to 3.71 on the 9th day of fermentation and then increased slightly till the last day of fermentation. The data obtained were fitted to two most widely accepted microbial growth models: Modified Gompertz, and Logistic model and three well‐known lactic acid production models: Luedeking‐ Piret, Monteagudo et al., and Balannec et al. model for lactic acid fermentation. Based on nonlinear regression analysis, Modified Gompertz, and Monteagudo et al. model gave a better fit to describe microbial growth and lactic acid production, respectively. The growth‐associated and non‐growth‐associated coefficients were determined to be 0.1104 and 0.0042, respectively, using Monteagudo et al. model. The findings revealed that lactic acid production in gundruk is a mixed type. [ABSTRACT FROM AUTHOR]

Objective: Food-borne pathogens are a major cause of illnesses, death and expenses. Their occurrence in meat and other food is considered a global health problem. The burden of food-borne disease is increasing due to antimicrobial resistance which represents a greater risk of treatment failure. However, very little is known about the antibiotic resistance profile of food-borne pathogens in Nepal. This study was conducted to examine the antibiotic resistance profile of common food-borne bacterial pathogens isolated from raw meat sold in Nepal. A total of 83 meat samples were collected from the market and analyzed. Results: The prevalence of Staphylococcus aureus, Escherichia coli, Salmonella, Shigella, and Vibrio were 68%, 53%, 35%, 6%, and 6% respectively. The resistance of Salmonella was most frequently observed to amoxicillin (100%), tetracycline (24%), chloramphenicol (11%), and nalidixic acid (11%). S. aureus was resistant to amoxicillin (100%) followed by tetracycline (63%), nalidixic acid (17%), and cefotaxime (13%) respectively. Vibrio isolates resisted amoxicillin (100%), tetracycline (40%) and chloramphenicol (20%). Shigella expressed the highest resistance to amoxicillin (100%), followed by chloramphenicol (80%), tetracycline (60%) and nalidixic acid (20%). E. coli exhibited the highest resistance to amoxicillin (100%), followed by tetracycline (93%), nalidixic acid (25%) and cefotaxime (19%). [ABSTRACT FROM AUTHOR]