1、乾燥保存Preservation by Control of Moisture,黃顯宗東吳大學M202,第三部份：食品保存與微生物,http:/.tw/product_content.aspx?ProdId=039,http:/ et al., 1980,Sarcina and Staphylococcus,http:/www.towson.edu/gekpenyo/images/sarcina.gif,http:/www.avma.org/onlnews/javma/nov03/031115a.asp,Aspergillus niger,http:/www.sci.muni.cz/mikro
2、b/Miniatlas/asp-ni.htm,http:/www.cbs.knaw.nl/ICPA/ASPNIG2.JPG,http:/res2.agr.ca/winnipeg/storage/images/lo-res/mould/aspe06-l.jpg,Aspergillus glaucus,http:/www.ukneqasmicro.org.uk/ag.htm,http:/res2.agr.ca/winnipeg/storage/images/lo-res/mould/aspe02-l.jpg,Xeromyces bisporus,世界上最耐乾的菌水活性可以在0.6常現都是在0.80
3、 以上Xeromyces spp.一種黴菌,可可粉罐裡的Aspergillus,低水活性對微生物的影響,減慢/抑制孢子發芽減慢生長速度降低產毒提高抗熱性體內累積 free amino acids and poly-alcohol (glycerol, mannitol, arabitol),蔬菜的乾燥與還原,食品乾燥過程與濕度的變化與測量,Water activityWater contentHysteresis,水活性 Water Activity,水活性 Water Activity微生物可以自由利用的水Aw=ERH/100=p/p0食品中水活性不等於水含量 Water Content,S
4、orption Isotherm,Adsorption IsothermDesorption IsothermHysteresis “Flask” hypothesis,測量Aw的方法,Gravimetric methodsHygroscopicity of SaltsHygrometric instruments 如LiCl的導電度改變, Dew point的偵測,http:/.au/food_industry_analysers.htm,Water Content的測量,Direct MethodThermogravimetric analysisAzeotropic distillati
5、onKarl-Fisher methodGCRefractometryIndirect Method利用含水量對 Conductivity, sonic, ultrasonic waves的反應等,Method of Drying,Sun-dryingKiln , tunnelsDrum dryingSpray dryingFoam-matVacuum dryingFreeze dryingSmoking : “ Case hardening “ phenolicsHydrophilic ：糖、鹽等,Spray Drier,http:/www.mansol- mix果乾果醬，表面長黴菌濃縮果汁
6、蜜糖,食物含水量的分類,Dry food , 20%Intermediate-moisture food , 2040%Wet Food 40%,乾燥前後食品的含水量,加工後的處理,抗濕抗氧化,安全之水活性,0.725為較安全之水活性,Ayres et al., 1980,Dried Foods 的微生物,考慮因素原料種類與成份原來微生物量加工的過程事後的保存黴菌、酵母菌細菌：Spore formers , lactic acid , bacteria , micrococci , Coliforms , staphylococci 等,請思考,如何準確計數乾燥食品裡的微生物量？如何減少速食麵裡調味包的微生物量？,http:/.tw/comment/90907,請思考,為何乾香菇和新鮮的香菇味道等感官上很不相同？,http:/
