Ultrasound has been widely used as a new kind of auxiliary extraction technique in food industry, but its effect cannot be ignored on the potential degradation of the extracted target compound. In this paper, a model extraction solution was constructed with the standard gallic acid as target compound to be extracted, and its change was monitored by using high performance liquid chromatography (HPLC) under different ultrasonic extraction conditions, namely, solvent types, extractant concentrations, extraction time, extraction temperature, ultrasound power and frequency, in order to understand the effect of ultrasound on the extract during ultrasonic extraction and provide an objective evaluation of ultrasonic extraction of polyphenols. The results indicate that ultrasonic parameters had definite effect on the degradation of gallic acid during ultrasonic extraction, which implies that the extraction yield should not be over-focused in actual extraction applications of ultrasound, more attention should be paid to the potential degradation of the extracted target compound induced by ultrasound.

Ultrasound is regarded as a potential alternative method for improving the quality of some wines. This study was initiated with the objective of evaluating the effects of ultrasound on some important physicochemical properties of red wine such as chromatic characteristics (CC), electrical conductivity (EC), pH, titratable acidity (TA), total phenolic compounds (TPCs) and DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity (DFRSA). The operational parameters assessed were ultrasound power, ultrasound frequency, exposure time and bath temperature. Results illustrated that there were significant changes in CC, EC and TPC while pH and TA hardly changed except for samples treated at high temperatures. DFRSA was correlated to TPC during ultrasonic treatment. Application of principal component analysis to the experimental data suggested that exposure time was the factor with the greatest ability to induce changes on wine. Results suggested that ultrasound may be applied to improve some physicochemical properties of red wine.

In this paper, the effect of drying temperature was investigated on the drying kinetics of the debittered and skin-removed apricot kernels, and the thin-layer drying model was also constructed by fitting the eight mathematical models such as Henderson and Pabis, Logarithmic, Midilli et al. and Approximation of diffusion model, Among them, the Midilli et al. and Approximation of diffusion models were selected to describe the drying characteristics of apricot kernels due to their relatively higher coefficient of determination (R²), and lower chi-square (χ²) and root mean square error (RMSE). Beyond that, the moisture loss and the effective moisture diffusivity (D_eff) of the kernels during drying were also described and estimated by Fick’s second law and the data obtained, getting a range of 1.39×10⁻⁸ to 3.5×10⁻⁸ m²/s, respectively. The temperature dependence of the diffusivity coefficients was described with the activation energy (Ea) value of 16.5 kJ/mol. All these results are beneficial for better understanding and controlling the drying of apricot kernels.