不同干燥程度草果果实形态及种仁挥发油的变化规律

The Changes of Fruit Morphology of Amomum tsaoko with Different Drying Degrees and Volatile Oil of Seed Kernel

草果药食同源,主要化学成分为挥发油,具有调味和温中燥湿的功效。文章比较了不同干燥程度草果果实形态、种仁挥发油得率和挥发油成分在含量和组分上的差异。收集50℃烘干0,12,24,36,48 h的果实样品,记录果实形态的各项指标,采用水蒸气蒸馏法测定不同烘干程度草果种仁挥发油得率,并利用气相色谱-质谱(GC-MS)联用技术分析其挥发油成分及含量的异同。结果表明,在干燥过程中果实果皮厚度及重量呈下降趋势,12~24 h下降最明显,种仁重量变化较平稳;种仁挥发油得率呈线性升高,至48 h恒重时,挥发油得率最高为2.72 mL/g;种仁中共鉴定出38种化合物,在0~48 h 5个时间段分别检测出26,23,21,22,26种成分;主要包含烯烃类16种、醛类7种、芳香烃类3种、醚类1种、醇类11种;干燥程度不同导致(1R)-(+)-α-蒎烯等化合物含量减少至未检测出;1,8-桉叶素等有效成分的相对百分含量呈先上升后下降的趋势;α-水芹烯的含量则先下降后上升,峰值出现在48 h(4.71%);正新醛的相对百分含量变化基本保持不变。低温烘干处理对提高种仁挥发油得油率及其化学成分构成具有重要的影响,这为解释草果鲜品和干品的香气成分差异提供了参考依据,为该物种干燥加工奠定了一定的理论基础。

A.tsaoko is homologous in medicine and food,and the main chemical component is volatile oil,which has the effect of warming spleen and stomach for dispelling dampness.In this paper,the differences of fruit morphology of A.tsaoko with different drying degrees,volatile oil yield of seed kernel and the content and composition of volatile oil components are compared.The fruit samples dried at 50℃for 0,12,24,36,48 h are collected,and the indexes of fruit morphology are recorded.The volatile oil yield of A.tsaoko seed kernel with different drying degrees is determined by steam distillation,and the differences of volatile oil components and content are analyzed by gas chromatography-mass spectrometry(GC-MS).The results show that during the drying process,the thickness and weight of pericarp are decreased,and the decrease is most obvious from 12 h to 24 h,the change of seed kernel weight is stable;the volatile oil yield is increased linearly,and the highest yield of volatile oil is 2.72 mL/g at 48 h constant weight;a total of 38 compounds are identified in seed kernel,and 26,23,21,22,26 compounds are detected in 5 periods from 0 h to 48 h respectively,mainly containing 16 kinds of alkenes,7 kinds of aldehydes,3 kinds of aromatic hydrocarbons,1 kind of ether and 11 kinds of alcohols;the content of compounds such as(1R)-(+)-α-pinene decreases to undetected due to different drying degrees.The relative percentage of 1,8-eucalyptin and other active components shows a trend of firstly increasing and then decreasing.The content ofα-carvene firstly decreases and then increases,and the peak value appears at 48 h(4.71%).The change of the relative percentage of n-neotaldehyde remains unchanged.The low-temperature drying treatment has an important effect on the oil yield and chemical composition of essential oil from seed kernel,which has provided a reference basis for explaining the difference of aroma components between fresh and dry products,and laid a certain theoretical basis for the drying process of this species.