高维生素C柿叶茶膏浸提和干燥工艺研究

Study on Extraction and Drying Technology of High Vitamin C Persimmon Leaf (Diospyros kaki L.f.) Tea Cream

茶膏为一种新兴速溶饮品,因饮用方便,最大程度保持原茶品质风味深受消费者喜爱。柿叶富含维生素C(Vc)、多酚等活性物质,具有多种保健功能,通常被加工成传统代用茶饮用。开发富含Vc的速溶柿叶茶膏前景广阔。该文精选柿叶茶原料,探讨了浸提条件与干燥方式对柿叶茶膏感官品质和Vc等主要品质成分的影响。结果表明,柿叶茶膏浸提条件掌握:温度75℃,时间60min,料液比1∶20g/m L,柿叶水浸出物浸出量可达到27.68%,Vc浸出量2.89%,多酚浸出量8.02%。干燥方式以真空冷冻干燥为佳,真空冷冻干燥的风味品质优于自然风干的茶膏,速溶性好,且其Vc、多酚保留更多,营养保健功能更强。

Tea cream,a newly developed instant drink,is very popular for consumers because of its convenient for drinking and keeping the flavor of the original tea to the greatest extent. Persimmon leaf contains rich physiologically active substances,such as vitamin C（Vc）,polyphenols and other active substances,and usually is processed into traditional tea for drinking. The development of Vc-rich instant tea cream using persimmon leaf might be prospective. In this paper,the influence of extraction conditions and drying methods on sensory quality,contents of water extract,Vc,polyphenol of persimmon leaf tea cream were investigated,the results showed that the optimum extract conditions were： temperature 75℃,time 60 min,and the ratio of solid to liquid 1 ∶20 g/m L,with the leaching rate of water extract from persimmon leaves being 27.68%,the VC being 2.89% and the polyphenols being 8.02%. Comparing to nature air dried tea cream,vacuum freeze-dried tea cream had the better quality,with better flavor and solubility in water,more Vc,polyphenols retained.