Chenghai Liu

Drying Properties and Parameters of Blue Honeysuckles Pulp under Foam Assisted Microwave Drying Conditions

The drying properties and optimal parameters of foamed blue honeysuckles pulp under microwave drying conditions were studied. The microwave power, loading mass and thickness were selected as the influencing factors, and objective factors were content of anthocyanin, vitamin C, moisture and values of color of the final blue honeysuckles powder. The drying process may be divided into three stages: acceleration stage, slow decline stage and quick decay stage. The initial drying phase lasted until the moisture content was less than 4 kg/kg. The constant drying phase was long when the influencing factor was loading mass. The deceleration drying phase is short in all conditions. This study achieve the continuous production of blue honeysuckles powder and the optimum experiment parameters were obtained as follows, the content of anthocyanin in honeysuckle powder is 64.58 mg/g, the content of vitamin C is 14.604 mg/g, moisture ratio is 9.88 % and the color value is 9.78 with the microwave power at 8.86 kW, loading mass at100 g and the thickness at 4mm.

Effect of the Microwave Irradiated Treatment on the Wine Sensory Properties

An instantaneous microwave irradiation method was applied to treat young dry red wine in order to accelerate the desired aging process during storing wine for the improvement of its taste quality. Effects of the microwave power and irradiation duration on the wine sensory property were investigated. Experimental results showed that microwave treatment had a significant effect on taste and total score, but no obvious effect was found on appearance, fragrance, fragrance duration and overall assessment. The influence of irradiation duration was significant on appearance, fragrance and total score, while not obvious on other indexes. The optimum conditions were obtained with microwave power 420 W and irradiation duration 5 min, and the result was corresponding to the content of chemical constituents of treated wine.

Effect of microwave energy dissipation on drying process of berry puree under microwave foam drying conditions

ABSTRACT Microwave foam drying (MFD) is a novel drying technology particularly for the drying of agricultural products with high viscosity and thermal-sensitive components. The effect of dissipation of microwave energy on the drying process of berry puree was investigated in MFD conditions. The results show that the dissipation of microwave energy induces the vapor pressure inside the berry puree to improve the formation of bubbles. The changes of pressure inside bubbles of berry puree follow Sine equations. The favorable conditions of bubbles formation inside berry puree are the temperature of 70–80°C with the corresponding viscosity of 70–80 pa s and moisture content of 80–85% (wb). The dissipation of microwave energy in berry puree tends to decaying trend due to the changes of dielectric properties. Moisture content has the most significant positive effect on both dielectric constant and dielectric loss factor of berry puree, followed by the density, and the drying temperature has the least but significant effect on both indicators. The focusing phenomenon of microwave irradiation depended on the dielectric properties determines the distribution of temperature of berry puree. The findings in current work contribute to a better understanding the MFD behavior of berry puree and will help to optimize the drying conditions of MFD for enhancing energy efficiency and drying quality.

Puffing Characteristics of Blackcurrant Leather Under Microwave Vacuum Conditions

In order to obtain the blackcurrant snack with high quality and efficiency, the puffing characteristics of blackcurrant leather under microwave vacuum conditions were investigated using single factor experimental method. The puffing characteristics, repersented by the moisture content and expansion ratio were determined in the different vacuum pressure, initial moisture content and the microwave power. The results show that both the microwave power and initial moisture content have significant effect on the moisture content. And no significant effect of the vacuum pressure on the final moisture content was found. For the initial moisture content of 35 %（w.b.）, the optimum processing parameters for maximum expansion ratio with 200% were obtained in the condition of microwave power of 2.48 kW and vacuum pressure of 70 kPa.