微波真空与真空冷冻干燥组合生产脱水果蔬
摘要
本课题研究了微波真空与真空冷冻组合干燥(先微波真空后冷冻干燥)代替纯冷冻干燥生产脱水蔬菜和水果,研究发现采用微波真空与真空冷冻组合干燥能够生产出优质的脱水果蔬,既能保持产品的色、香、味和营养,又能保持产品较好的外形和质构,同时能较大幅度地降低能耗。
为了找到微波真空与真空冷冻干燥串联的最佳工艺参数组合,首先研究了微波真空干燥果蔬体积收缩的数学模型,针对不同果蔬品种提出相应的微波真空干燥工艺参数;通过响应面分析,得到微波真空干燥相关结论:功率密度一定时,水分损失与干燥时间成正相关关系,收缩系数与水分损失、功率密度成负相关关系,收缩系数与厚度近似成正相关关系。
将微波真空干燥的最佳工艺参数与真空冷冻干燥工艺参数进行相关组合,然后通过正交试验得到胡萝卜片和苹果片的最佳组合干燥工艺参数:胡萝卜片,微波真空干燥阶段的真空度3.0—4.5 Kpa,微波功率密度0.82 W/g,胡萝卜片厚度8 mm,水分损失40%,收缩系数达到65%,冷冻干燥阶段加热板程序为,初始加热板温度设定为-15 oC,干燥12h,后升温至5 oC,干燥3 h,再升温至15 oC,干燥1 h,最后温升至30 oC至干燥终点。苹果片,微波真空干燥阶段的真空度3.0—4.5 Kpa,微波功率密度0.82 W/g,厚度8 mm,水分损失50%,收缩系数达到55%,冷冻干燥阶段加热板程序为,初始加热板温度设定为-12 oC,干燥11 h,后升温至0 oC,干燥3 h,再升温至15 oC,干燥1 h,最后温升至30 oC至干燥终点。
对各种干燥方法进行产品质量和单位能耗及成本进行了分析和对比,得出微波真空与真空冷冻组合干燥生产的脱水果蔬产品质量接近纯真空冷冻干燥产品质量,与纯真空冷冻干燥相比,微波真空与真空冷冻组合干燥生产的脱水胡萝卜片能耗可降低56%,利润增加18%,脱水苹果片能耗可降低20%,利润增加10%。
本课题研究表明:微波真空与真空冷冻干燥组合,可以生产出优质的脱水果蔬,产品质量能够比较接近纯真空冷冻干燥,且能耗和干燥成本降低。
The combination of microwave vacuum drying (MVD) and freeze drying (FD) has been investigated to replace freeze drying alone in dehydration of fruits and vegetables. The study showed that this combined drying (CD) can produce high-quality end-products, which not only have original color and the nutrition, but also keep the desirable shape and the texture. Furthermore, the energy consumption of this combined drying method decreased greatly.
In order to optimize the parameters of CD for dehydrated fruits and vegetables, the mathematical models of shrinkage are developed on the base of MVD experiments, and the technical parameters for drying fruits and vegetables are suggested. The MVD experiments showed that, at a fixed power density, water loss is proportional to the drying time, and the shrinkage coefficient is inversely proportional to the loss of water and power density, while it is proportional to the thickness of samples approximately.
The parameters of MVD and FD are then matched and optimized, and the best parameters of CD are obtained by orthogonal experiments. The technical parameters for carrot is: vacuum pressure,3.0—4.5 K Pa;microwave power density , 0.82 W/g and the amount of water,dehydrated by MVD in advance about 40%. As a result, the shrinkage coefficient of carrot will be 65%. While during FD, the setting of heating plate procedure are: keeping the temperature at -15 o C for 12 h at first, then increasing to a temperature of 5 o C for 3 h, then at 15 o C for 1h ,finally keeping 30 o C till the end point of drying for carrots. The technical parameters for apple is: vacuum pressure,3.0—4.5 K Pa; microwave power density, 0.82 W/g; the loss of water by MVD, about 50%. The shrinkage coefficient of apple slices is about 55%. During FD, the setting of heating plate procedure are: keeping the temperature at -12 o C for 11 h, then increasing to a temperature of 0 o C for 3 h, then lasting 1h at 15 o C, finally keeping 30 o C till the end point of drying for apples.
The quality、cost and the energy consumption of different drying methods are compared with FD, the quality of carrot and apple slices dehydrated by CD is near to that of FD, the cost of CD is reduced by 56% and its interest is increased by 18% in producing dehydrated carrot slices, and the cost of CD is reduced by 20% and its interest is increased by 10% in producing dehydrated apple slices.
The combination of MVD and FD may be used as a alternative method to dehydrate fruits and vegetables in both good quality and low cost.
为了找到微波真空与真空冷冻干燥串联的最佳工艺参数组合,首先研究了微波真空干燥果蔬体积收缩的数学模型,针对不同果蔬品种提出相应的微波真空干燥工艺参数;通过响应面分析,得到微波真空干燥相关结论:功率密度一定时,水分损失与干燥时间成正相关关系,收缩系数与水分损失、功率密度成负相关关系,收缩系数与厚度近似成正相关关系。
将微波真空干燥的最佳工艺参数与真空冷冻干燥工艺参数进行相关组合,然后通过正交试验得到胡萝卜片和苹果片的最佳组合干燥工艺参数:胡萝卜片,微波真空干燥阶段的真空度3.0—4.5 Kpa,微波功率密度0.82 W/g,胡萝卜片厚度8 mm,水分损失40%,收缩系数达到65%,冷冻干燥阶段加热板程序为,初始加热板温度设定为-15 oC,干燥12h,后升温至5 oC,干燥3 h,再升温至15 oC,干燥1 h,最后温升至30 oC至干燥终点。苹果片,微波真空干燥阶段的真空度3.0—4.5 Kpa,微波功率密度0.82 W/g,厚度8 mm,水分损失50%,收缩系数达到55%,冷冻干燥阶段加热板程序为,初始加热板温度设定为-12 oC,干燥11 h,后升温至0 oC,干燥3 h,再升温至15 oC,干燥1 h,最后温升至30 oC至干燥终点。
对各种干燥方法进行产品质量和单位能耗及成本进行了分析和对比,得出微波真空与真空冷冻组合干燥生产的脱水果蔬产品质量接近纯真空冷冻干燥产品质量,与纯真空冷冻干燥相比,微波真空与真空冷冻组合干燥生产的脱水胡萝卜片能耗可降低56%,利润增加18%,脱水苹果片能耗可降低20%,利润增加10%。
本课题研究表明:微波真空与真空冷冻干燥组合,可以生产出优质的脱水果蔬,产品质量能够比较接近纯真空冷冻干燥,且能耗和干燥成本降低。
The combination of microwave vacuum drying (MVD) and freeze drying (FD) has been investigated to replace freeze drying alone in dehydration of fruits and vegetables. The study showed that this combined drying (CD) can produce high-quality end-products, which not only have original color and the nutrition, but also keep the desirable shape and the texture. Furthermore, the energy consumption of this combined drying method decreased greatly.
In order to optimize the parameters of CD for dehydrated fruits and vegetables, the mathematical models of shrinkage are developed on the base of MVD experiments, and the technical parameters for drying fruits and vegetables are suggested. The MVD experiments showed that, at a fixed power density, water loss is proportional to the drying time, and the shrinkage coefficient is inversely proportional to the loss of water and power density, while it is proportional to the thickness of samples approximately.
The parameters of MVD and FD are then matched and optimized, and the best parameters of CD are obtained by orthogonal experiments. The technical parameters for carrot is: vacuum pressure,3.0—4.5 K Pa;microwave power density , 0.82 W/g and the amount of water,dehydrated by MVD in advance about 40%. As a result, the shrinkage coefficient of carrot will be 65%. While during FD, the setting of heating plate procedure are: keeping the temperature at -15 o C for 12 h at first, then increasing to a temperature of 5 o C for 3 h, then at 15 o C for 1h ,finally keeping 30 o C till the end point of drying for carrots. The technical parameters for apple is: vacuum pressure,3.0—4.5 K Pa; microwave power density, 0.82 W/g; the loss of water by MVD, about 50%. The shrinkage coefficient of apple slices is about 55%. During FD, the setting of heating plate procedure are: keeping the temperature at -12 o C for 11 h, then increasing to a temperature of 0 o C for 3 h, then lasting 1h at 15 o C, finally keeping 30 o C till the end point of drying for apples.
The quality、cost and the energy consumption of different drying methods are compared with FD, the quality of carrot and apple slices dehydrated by CD is near to that of FD, the cost of CD is reduced by 56% and its interest is increased by 18% in producing dehydrated carrot slices, and the cost of CD is reduced by 20% and its interest is increased by 10% in producing dehydrated apple slices.
The combination of MVD and FD may be used as a alternative method to dehydrate fruits and vegetables in both good quality and low cost.
引文
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2.徐小东,崔政伟.农产品和食品干燥技术及设备的现状和发展[J].农业机械学报,2005, 36(12): 171-174.
3.于勇,胡桂仙,王俊.脱水蔬菜的研究现状及展望[J].粮油加工与食品机械,2003,4: 63-63.
4.崔政伟,杨以清.微波真空干燥大蒜片的研究[J].农产品加工,2004,9:38-39.
5.赵丽芹,韩玉梅,杨勃.我国脱水蔬菜生产现状及发展[J].食品工业,2002,2:21-22.
6.李瑜,许时婴.不同干燥方法对干燥大蒜品质的影响[J].食品与发酵工业,2006, 32(7): 32-37.
7.汤大卫.微波真空干燥技术在食品中的应用[J].加工技艺,1999, 8: 30-31.
8.胡光华,张进疆,王喜鹏.胡萝卜微波真空干燥试验研究[J].干燥技术与设备,2005,3(4):176-178
9. N Ramos, Teresa RS, Brandao, etc. Integrated approach on solar drying. pilot convective drying and microstructural changes[J]. Journal of Food Engineering, 2005,67:195-203.
10. Kuek Tze Lee,Mohammed Farid,Sing Kiong Nguang.The mathematical modeling of the rehydration characteristics of fruits[J]. Journal of Food Engineering,2006,72:16-23.
11. Erik Torringa, Erik Esveld, Ischa Scheewe, etc. Osmotic dehydration as a pre-treatment before combined microwave-hot-air drying of mushrooms[J]. Journal of Food Engineering, 2001,49 :185-191.
12. Moreira, RG Palau. Simultaneous heat and mass transfer during the deep fat frying of tortilla chips[J]. Journal of Food Process Engineering, 1995,18:307-320.
13. S Azzouz, A Guizani, W Jomaa, etc. Moisture diffusivity and drying kinetic equation of convective drying of grapes[J]. Jounal of food Engineering,2002,55:323-330.
14. Md Azharul Karim, MNA Hawlader. Drying characteristics of banana: theoreticalmodeling and experimental validation[J]. Journal of Food Engineering, 2005,70:35-45.
15. MS Hatamipour, D Mowla, Shrinkage of carrots during drying in an inert medium fluidized bed[J]. Journal of Food Engineering, 2002,55:247-252.
16. Feng H,Tang J. Microwave finish drying of diced apples in a spouted bed. Journal of Food science,63:679-683.
17.王俊,巢炎,王剑平.辐照苹果的干燥特性研究[J].农业工程学报,2001,3(17):97-98.
18.田红萍.胡萝卜渗透脱水和微波干燥组合试验研究[D]: [硕士学位论文].杭州:浙江大学生物系统工程和食品科学学院,2003
19.崔政伟.微波真空干燥的数学模拟及其在食品加工中的应用[D]: [博士学位论文].无锡:江南大学食品学院,2004.
20.姜元欣,许时婴,王璋.南瓜渣的微波真空干燥[J].食品与发酵工业,2004,10:58-62.
21.刘玉环.胡萝卜片的真空冷冻干燥加工工艺及研究[J].食品科技,2006(3):52-54.
22.郑艺梅,郑琳,华平.不同干燥方式对发芽糙米品质的影响[J].食品工业科技,2005(26):55-56.
23.崔政伟,许时婴,孙大文.微波真空干燥技术的进展[J].粮油加工与食品机械,2002(7):28-30.
24. C Ratti. Hot air and freeze-drying of high-value foods[J]. Journal of Food Engineering, 2001, 49: 311-319.
25. M S Hatamipour, D Mowla. Shrinkage of carrots during drying in an inert medium fluidized bed[J]. Journal of Food Engineering, 2002,55:247-252.
26.Piotr p Lewicki, Dorota Witrowa-Rajchert, Jolanta Mariak. Changes of structure during rehydration of dried apples[J]. Journal of Food Engineering, 1997,32:347-350.
27. L Mayor, AM Sereno. Modelling shrinkage during convective drying of food materials: a review [J].Journal of Food Engineering ,2004,61:373–386.
28. Lima AGB, Queiroz.Simutaneous moisture transport and shrinkage during drying solids with ellipsoidal configuration[J]. Chemical Engineering Journal, 2002,86:83-85.
29. Cui ZW, Xu SY, Dehydration of galic slices by combined microwave-vacuum drying andair drying[J].drying technology, 2003,21 :1173-1184.
30. Md Azharul Karim, MNA Hawlader. Drying characteristics of banana: theoretical modeling and experimental validation[J]. Journal of Food Engineering, 2005,70:35-45.
31. C Ratti. Hot air and freeze-drying of high-value foods[J]. Journal of Food Engineering, 2001, 49: 311-319.
32. S Azzouz, A Guizani, W Jomaa, etc. Moisture diffusivity and drying kinetic equation of convective drying of grapes[J]. Journal of food Engineering,2002,55:323-330.
33.邹兴华.太湖银鱼的真空冷冻和真空微波联合干燥[D]: [硕士学位论文].无锡:江南大学食品学院,2005.
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35.张愍,王瑞.果蔬微波联合干燥技术研究进展[J].干燥技术与设备,2005,3(3):107-111.
36.邓红,王小娟.不同干燥方法对苹果片品质的影响[J].食品科技,2007,2:(84-87).
37.韩清华,李树君,马季威.微波真空干燥膨化苹果脆片的研究[J].农业机械学报,2006,37(8):156-158.
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2.徐小东,崔政伟.农产品和食品干燥技术及设备的现状和发展[J].农业机械学报,2005, 36(12): 171-174.
3.于勇,胡桂仙,王俊.脱水蔬菜的研究现状及展望[J].粮油加工与食品机械,2003,4: 63-63.
4.崔政伟,杨以清.微波真空干燥大蒜片的研究[J].农产品加工,2004,9:38-39.
5.赵丽芹,韩玉梅,杨勃.我国脱水蔬菜生产现状及发展[J].食品工业,2002,2:21-22.
6.李瑜,许时婴.不同干燥方法对干燥大蒜品质的影响[J].食品与发酵工业,2006, 32(7): 32-37.
7.汤大卫.微波真空干燥技术在食品中的应用[J].加工技艺,1999, 8: 30-31.
8.胡光华,张进疆,王喜鹏.胡萝卜微波真空干燥试验研究[J].干燥技术与设备,2005,3(4):176-178
9. N Ramos, Teresa RS, Brandao, etc. Integrated approach on solar drying. pilot convective drying and microstructural changes[J]. Journal of Food Engineering, 2005,67:195-203.
10. Kuek Tze Lee,Mohammed Farid,Sing Kiong Nguang.The mathematical modeling of the rehydration characteristics of fruits[J]. Journal of Food Engineering,2006,72:16-23.
11. Erik Torringa, Erik Esveld, Ischa Scheewe, etc. Osmotic dehydration as a pre-treatment before combined microwave-hot-air drying of mushrooms[J]. Journal of Food Engineering, 2001,49 :185-191.
12. Moreira, RG Palau. Simultaneous heat and mass transfer during the deep fat frying of tortilla chips[J]. Journal of Food Process Engineering, 1995,18:307-320.
13. S Azzouz, A Guizani, W Jomaa, etc. Moisture diffusivity and drying kinetic equation of convective drying of grapes[J]. Jounal of food Engineering,2002,55:323-330.
14. Md Azharul Karim, MNA Hawlader. Drying characteristics of banana: theoreticalmodeling and experimental validation[J]. Journal of Food Engineering, 2005,70:35-45.
15. MS Hatamipour, D Mowla, Shrinkage of carrots during drying in an inert medium fluidized bed[J]. Journal of Food Engineering, 2002,55:247-252.
16. Feng H,Tang J. Microwave finish drying of diced apples in a spouted bed. Journal of Food science,63:679-683.
17.王俊,巢炎,王剑平.辐照苹果的干燥特性研究[J].农业工程学报,2001,3(17):97-98.
18.田红萍.胡萝卜渗透脱水和微波干燥组合试验研究[D]: [硕士学位论文].杭州:浙江大学生物系统工程和食品科学学院,2003
19.崔政伟.微波真空干燥的数学模拟及其在食品加工中的应用[D]: [博士学位论文].无锡:江南大学食品学院,2004.
20.姜元欣,许时婴,王璋.南瓜渣的微波真空干燥[J].食品与发酵工业,2004,10:58-62.
21.刘玉环.胡萝卜片的真空冷冻干燥加工工艺及研究[J].食品科技,2006(3):52-54.
22.郑艺梅,郑琳,华平.不同干燥方式对发芽糙米品质的影响[J].食品工业科技,2005(26):55-56.
23.崔政伟,许时婴,孙大文.微波真空干燥技术的进展[J].粮油加工与食品机械,2002(7):28-30.
24. C Ratti. Hot air and freeze-drying of high-value foods[J]. Journal of Food Engineering, 2001, 49: 311-319.
25. M S Hatamipour, D Mowla. Shrinkage of carrots during drying in an inert medium fluidized bed[J]. Journal of Food Engineering, 2002,55:247-252.
26.Piotr p Lewicki, Dorota Witrowa-Rajchert, Jolanta Mariak. Changes of structure during rehydration of dried apples[J]. Journal of Food Engineering, 1997,32:347-350.
27. L Mayor, AM Sereno. Modelling shrinkage during convective drying of food materials: a review [J].Journal of Food Engineering ,2004,61:373–386.
28. Lima AGB, Queiroz.Simutaneous moisture transport and shrinkage during drying solids with ellipsoidal configuration[J]. Chemical Engineering Journal, 2002,86:83-85.
29. Cui ZW, Xu SY, Dehydration of galic slices by combined microwave-vacuum drying andair drying[J].drying technology, 2003,21 :1173-1184.
30. Md Azharul Karim, MNA Hawlader. Drying characteristics of banana: theoretical modeling and experimental validation[J]. Journal of Food Engineering, 2005,70:35-45.
31. C Ratti. Hot air and freeze-drying of high-value foods[J]. Journal of Food Engineering, 2001, 49: 311-319.
32. S Azzouz, A Guizani, W Jomaa, etc. Moisture diffusivity and drying kinetic equation of convective drying of grapes[J]. Journal of food Engineering,2002,55:323-330.
33.邹兴华.太湖银鱼的真空冷冻和真空微波联合干燥[D]: [硕士学位论文].无锡:江南大学食品学院,2005.
34.孙恒,张浩,朱鸿梅,肖尤明,徐烈.微波冷冻干燥技术的发展和有待解决的问题[J].食品科学, 2005,26(4):256-270 .
35.张愍,王瑞.果蔬微波联合干燥技术研究进展[J].干燥技术与设备,2005,3(3):107-111.
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