Research On The Comparison Of Three Kinds Of Drying Methods And The Storage Properties With Gastrodia Elata Powder

Gastrodia elata is a kind of agriculturalandsidelineproduct which has many active ingredients. Gastrodia elata powder is direct dried product of gastrodia elata tuber, and it can be final product as well as addictive of health-care food. Meanwhile, it is an ideal nutrition product to the general population. The drying technology research has great economic and practical significance for gastrodia elata powder sensory properties and its’ preserving of active components, the actual production application of gastrodia elata powder. Researching storage properties of gastrodia elata powder has important guiding significance for its application value and shelf life. This study used G.elata.BI.f elata as raw material, and researched three different drying methods (vacuum drying, oven drying, freeze dying) on the effects of gastrodia elata powder quality, then made system analysis of storage properties of gastrodia elata powder. The results were:(1) Effect of three kinds of drying methods on the quality of RhizomaVacuum oven drying’s temperature had significant influence(0.01<P<0.05) on sensory value of gastrodia elata powder, p-hydroxybenzyl alcohol content, and it had extremely significant effect(P<0.01) on powder rehydration ratio, raw polysaccharide content and chromatic aberration. But it had no significant influence on gastrodin content(P>0.05). Whenvacuum degree was 0.09Mpa, The optimal dryingtemperature of vacuum oven drying were45℃.Oven drying’s temperature had significant influence(0.01<P<0.05) on powder rehydration ratio and chromatic aberration, and it had extremely significant(P<0.01) effect on raw polysaccharide, sensory value, gastrodin content. But it had no significant(P>0.05) influence on p-hydroxybenzyl alcohol. The optimal drying temperature of oven drying were 55℃.Pre-freezing temperature of freeze dying had significant influence(0.01<P<0.05) on p-hydroxybenzyl alcohol content, and it had extremely significant(P<0.01) effect on raw polysaccharide, chromatic aberration, gastrodin content. But it had no significant influence(P> 0.05) on powder rehydration ratio and sensory value. The optimal Pre-freezing temperature of freeze drying were-20℃.(2) The choice of optimal drying methodAccording to the compare of sensory properties and physical and chemical qualities on the gastrodia elata powder produced by three optimal methods,we can make sure:oven drying>Freeze drying>Vacuum oven drying.The optimal drying method which is most suitable for middle and small-sized enterprises was oven drying under 55℃.(3) Research on the storage properties of gastrodia elata powderUnder the temperature of 40℃ and 50℃, storage time had extremely significant effect(P< 0.01) on chromatic aberration, moisture content, extractum content, raw polysaccharide, gastrodin content, p-hydroxybenzyl alcohol and sum of gastrodin and p-hydroxybenzyl alcohol.Gastrodia elata powder’s moisture content was main limiting factor of storage time. The shelf life of gastrodia elata powder with 10% water were 615d and 552d respectively under the temperature of 20℃ and 25℃.That is,The shelf life of gastrodia elata powderwere 1.5 years at room temperatures (20～25℃).