不同干燥方式的苦瓜粉品质特性及香气成分比较

为探究苦瓜粉适宜的干燥方式,采用日晒干燥、热风干燥、真空冷冻干燥和喷雾干燥等4种干燥方式对新鲜苦瓜进行干燥处理,并对干燥后苦瓜粉的加工性质(水分含量、溶解性、色泽、叶绿素含量)、营养成分(总酚、黄酮、皂苷)和香气成分进行评价。结果表明:不同干燥方式下苦瓜粉的加工性质和营养成分具有显著性差异(p<0.05),其中喷雾干燥苦瓜粉的加工性质明显优于其余3种干燥方式,水分含量最低(4.34%),冲调性最好(64.07%),叶绿素含量最高,色泽最优;真空冷冻干燥苦瓜粉营养成分(多酚、黄酮、皂苷含量分别为45.32 mg/g、19.15 mg/g、18.04 mg/g)均优于其他方式,喷雾干燥的苦瓜粉营养成分仅次于冷冻干燥;热风干燥和日晒干燥的苦瓜粉加工品质和营养成分相对较差。新鲜苦瓜和4种干燥处理的苦瓜粉共检测出107种香气成分,其中新鲜苦瓜检出42种,日晒、热风、真空冷冻、喷雾干燥苦瓜粉分别为48、42、36、50种,但仅有7种共有香气成分。醇类和醛类相对含量较高,占60%以上。综合对比,喷雾干燥和真空冷冻干燥处理的苦瓜粉品质优于热风干燥和日晒干燥。本研究结果为苦瓜粉进一步的加工和利用提供了理论依据。

Quality Characteristics and Aroma Components of Bitter Gourd (Momordica charantia L.) Powder Dried by Different Methods

With the purpose of choosing suitable drying process for the development of bitter gourd powder, the effects of four drying methods including sun drying, heat air drying, vacuum freeze drying, spray drying on processing property (moisture content, solubility, color, chlorophyll content), nutrition components (total phenolics, total flavonoid, saponin) and aroma components of bitter gourd powder were investigated. The results showed that the processing property and nutrition components of bitter gourd powder by different drying methods were significantly different (p<0.05). The processing properties of bitter gourd powder by spray drying process were better than other three drying methods, with the lowest moisture content (4.34%), the best solubility (64.07%), the highest chlorophyll content and the best color. The nutrition components of bitter gourd powder by vacuum freeze drying were significantly higher than the other three drying methods (the content of total phenolics, total flavonoid, saponin were 45.32 mg/g, 19.15 mg/g and 18.04 mg/g respectively). The number of nutrition components in the spray-dried bitter gourd powder was just second to that in the vacuum freeze-dried bitter gourd powder. Bitter gourd powder by sun drying and heat air drying had the poor processing property and nutrition components. A total of 107 aroma components were identified, 42, 48, 42, 36 and 50 of which were detected in fresh bitter gourd and bitter gourd powder by sun drying, heat air drying, vacuum freeze drying, spray drying, respectively. But only 7 identical compounds were identified in them. Alcohols and aldehydes compounds were dominantly present in them, accounts for more than 60%. All the above results suggested that the quality of bitter gourd powder by spray drying and vacuum freeze drying were superior to the sun drying and heat air drying. Through this study, it provides theoretical basis for further processing and utilization of bitter gourd powder.