蝦仁粉乾燥方法之研究

Research of Drying Methods for Shrimp Meat Powder

本研究在探討泰國蝦 （Macrobrachium rosenbergii） 仁於三種不同乾燥方 法之加工適性。研究結果顯示，乾燥速率以真空凍結乾燥最快達到平衡含水率。 當水活性 （water activity, aw） 大於 0.6 時，真空凍結乾燥生蝦仁粉 （vacuum freeze drying raw shrimp meat powder, VRP） 吸濕最快，熱風乾燥蝦仁粉 （hot air drying shrimp meat powder, HSP） 及平板乾燥蝦仁粉 （plate heater drying shrimp meat powder, PSP） 吸濕最慢。不論在 BET （Brunauer-Emmett-Teller） 或 GAB （Guggenheim-Anderson-de Boer） 方程式，VRP 均顯示具有較高之單分子層吸附 水含量 （monolayer moisture, Mm），其 Mm 值分別為 6.61%與 10.55%，而 HSP 之 Mm 值均為最低，分別為 6.03%與 8.66%。在色澤方面，三種乾燥方法所製 得的蝦仁粉之 L*值皆以貯存於 56.3%RH （relative humidity） 者高於貯存於 90.2%RH 者，a*與 b*值則反是。PSP 與 HSP 粒子形狀呈顆粒狀，而真空凍結 乾燥者則為纖維狀。以真空包裝貯存之 VRP 具有最低之 TBA （thiobarbituric acid） 值，顯示具有較佳的貯存安定性。而感官品評結果顯示，VRP 在嗅覺、 口味、口感和總體接受度上得分最高。

The purpose of this study was to research the dehydration processing properties of shrimp (Macrobrachium rosenbergii) meat. The results revealed that the vacuum freeze drying was the fastest method to reach the dehydration equilibrium moisture content. Absorption of vacuum freeze drying rawshrimp meat powder (VRP) was the fastest whereas those of the hot air drying shrimp meat powder (HSP) and plate heater drying shrimp meat powder (PSP) were the slowest when water activity (aw) was over 0.6. Regardless of BET (Brunauer-Emmett-Teller) or GAB (GuggenheimAnderson-de Boer) equation, the VRP has the highest monolayer bound water (Mm) values (6.61% and 10.55%, respectively) while the HSP has the lowest Mm values (6.03% and 8.66%, respectively). Regarding the color, the L* values of shrimp meat powder manufactured from three dehydration methods was higher when stored at 56.3%RH (relative humidity) than those stored at 90.2%RH; however, the a* and b* values were the opposite situations. The particle form of PSP and HSP were granulous whereas those of the vacuum freeze drying shrimp powders were fibrous. The vacuum packaging VRP has the lowest TBA (thiobarbituric acid) value meaning it possesses the best storage stability. Sensory evaluation results indicated that the VRP has the highest scores in olfactory, taste, texture, and overall acceptance.