This research aimed to investigate the process of pistachios solar drying in two different conditions of the designed dryer (recycle and without recycle modes). As well, in this study, the drying kinetics curves of pistachio were drawn and its dewatering behavior was monitored by empirical models. Furthermore, the mass transfer rate (MTR) of the examined product during drying in two noted modes was determined by Fick’s 2nd law. Maximum, minimum, and average values of collector output air temperature were recorded 54.20, 32.30, and 42.99oC & 47.10, 30.70, and 40.03oC in air recycle and without air recycle modes, respectively. The results dedicated that, 18.75 % saving in drying time was obtained for air recycle mode compared with without air recycle mode. Also, the obtained data revealed that the drying rate of pistachio nut under recycle mode was higher than that of pistachio nut under without recycle mode, especially during the first hours of drying. Moreover, the empirical modeling showed that the Parabolic and Diamante et al. models were found to be the most suitable for describing drying curve of the thin layer solar drying process of whole pistachio nut under recycle and without recycle modes, respectively. In addition, the highest value of effective moisture diffusivity was observed in solar dried pistachio nut under air recycle mode with the Deff value of 2.26×10-6 m2/h (R2=0.9265). Manuscript profile

Understanding the kinetic mechanisms of fatty acid (FA) degradation and microbial growth rate (MGR) in seafood products is crucial. This research investigated the interactive effect of propolis addition (at different concentrations) and storage time on the kinetics of FA oxidation and its inhibitory role in suppressing bacterial and fungal growth in frozen fish burgers (FFB) stored at -18°C. The degradation of FA (or microbial growth) in FFB during storage followed zero-order kinetics. After three months of storage, the lowest growth rates (log10 CFU/g) of total viable count (3.66) and fungi (2.43) were observed in FFB treated with the highest propolis concentration (P-IV), corresponding to the lowest peroxide value degradation rate (k0=0.0462 meq O2/kg oil/day) and the highest sensory evaluation scores. Overall, the addition of 0.4% propolis to FFB and storage at -18°C for up to 86 days (the best shelf life) effectively prevented lipid oxidation and microbial growth while improving sensory quality. Manuscript profile