黑加仑果浆微波辅助泡沫干燥特性

Drying characteristics of blackcurrant pulp by microwave-assisted foam mat drying

为了研究微波辅助泡沫干燥方法对黑加仑果浆脱水的适用性,该文选择了合适黑加仑果浆起泡添加剂,并研究了起泡黑加仑果浆的微波干燥特性。选择食品级单甘酯和大豆分离蛋白作为起泡剂,发现其添加量对黑加仑果浆起泡特性有显著的影响,添加6.0%单甘酯和3.0%大豆分离蛋白作为起泡剂,以0.5%的羧甲基纤维素10mL作为稳定剂,结果表明,加入这组添加剂的果浆在搅拌6min时,得到的泡沫果浆具有较高膨胀性和稳定性。采用微波辅助泡沫干燥方法对起泡黑加仑果浆进行干燥,试验发现,随着初始微波强度的增大和料层厚度减小,物料的干燥强度显著增加。对比试验的结果表明,微波泡沫干燥速度及干品的色泽品质均优于热风泡沫干燥的。在连续带式微波干燥设备中,起泡黑加仑果浆推荐工艺参数为:初始微波强度14.0W/g,料层厚度5mm。因此,微波辅助泡沫干燥技术适用于黑加仑果浆脱水加工。

In order to study the feasibility of microwave-assisted foam mat drying method for the dehydration blackcurrant pulp, a reasonable foaming additive formula was determined and the microwave-assisted foam mat drying characteristics of blackcurrant pulp were analyzed. The concentration of glyceryl monostearate （GMS） and soy protein isolated （SPI） with food grade, selected as the foaming additive, had obvious effects on the foaming properties of blackcurrant pulp. A reasonable foaming additive formula for the blackcurrant pulp with optimum expansion and high stability was developed that the 6% GMS and 3% g SPI as foam inducers and the 10 mL carboxylic methyl cellulose （CMC） with concentration of 0.5% as foam stabilizer, accompanying with the stirring time of 6 min. The experimental results of microwave assisted foam mat drying method showed that the drying intensity of foamed blackcurrant pulp increase with the increase of initial microwave intensity and the decrease of thickness of material layer. Contrasting the microwave with conventional hot air as the heat source for the foam mat drying of blackcurrant pulp, the qualities of dried blackcurrant product in terms of drying rate, color and appearance dried by microwave method are superior to that dried by the hot air. The parameters including the initial microwave intensity of 14.0 W/g and thickness of material layer of 5 mm are recommended for the continuous microwave belt dryer to dry the foamed blackcurrant pulp. Therefore, microwave assisted foam mat drying is suitable for the dehydration processing of blackcurrant pulp.