两种干燥方式对麦绿素粉品质的影响

Effect of Two Drying Methods on the Quality of Barley Grass Powder

以冷冻的嫩大麦苗为原料,研究真空冷冻干燥和喷雾干燥对麦绿素粉的溶解性、堆积密度、平均粒径、色差和关键组分叶绿素、黄酮、SOD酶活性及抗氧化性的影响。结果发现:在物理特性方面,喷雾干燥的麦绿素粉溶解性较好、堆积密度较大、平均粒径较小、色泽较暗;在关键组分方面,喷雾干燥的麦绿素粉的叶绿素含量、黄酮含量、SOD酶活性分别是真空冻干麦绿素粉的56.7%、68.1%、47.9%;抗氧化性方面,真空冷冻干燥的麦绿素粉还原力和清除DPPH自由基的能力均大于喷雾干燥粉。因此,要得到粒径小、溶解性好的麦绿素粉适宜选择喷雾干燥,若要得到营养价值高、色泽好的麦绿素粉适宜选择真空冷冻干燥。

Using frozen barley leaves as raw material,the effects of vacuum freeze-drying and spray drying on the solubility,bulk density,mean particle size,color difference and the key components of chlorophyll,flavonoids,SOD enzyme activity,and oxidation resistance of barley grass powder were studied in this paper. The results showed that spray-dried barley grass powder has better solubility,higher packing density,smaller mean particle size,and poor color in terms of physical characteristics.However,its content of the chlorophyll and flavonoids,and SOD enzyme activity of spray-dried powder were only 56.7%,68.1%,47.9% of vacuum freeze-dried powder,respectively. Moreover,the reducing power and DPPH·radical scavenging capacity of vacuum freeze-dried barley grass powder were greater than that of spray-dried powder. In summary,in order to get the barley grass powder with small size and good solubility,spray drying was a good choice,whereas vacuum freeze-drying was a suitable choice to obtain a high nutritional value and good color barley grass powder.