超声波预处理对甘薯（IPOMEA BATATAS）渗透脱水及油炸的影响研究
发布时间：2018-08-09 15:57
【摘要】：甘薯是一种含有极其丰富营养物质的农作物,例如淀粉、纤维、类胡萝卜素、维生素C和矿物质。食用甘薯对健康有很多益处,例如增强视力、提高免疫力、降低血糖指数,同时甘薯还具有抗氧化和抗炎作用。中国是最大的甘薯生产国,而美国是最大的甘薯出口国。甘薯的食用方式各种各样,例如蒸煮、油炸、焙烤、甘薯泥、甘薯面条等。因为甘薯易腐败的性质,在收割之后甘薯一般经过干燥处理便可贮藏较长时间。使用传统方法对甘薯进行干燥存在一些弊端,例如营养物质的流失、结构和质地的破坏、操作费用昂贵以及干燥所需时间较长等。因此,为了保存甘薯中的营养物质和一些其他理化性质,渗透式脱水方法很有发展前景。超声波是一种简便有效而且同时不会影响到环境的新型技术,可以广泛应用到食品生产加工过程中,例如辅助提取、水解、脱气、冻结及乳化过程。超声波可以有效地强化传质、缩短加工时间,在尽可能减少原料使用的同时提高产品的产率。本文涉及三种应用于甘薯加工的试验方法,包括超声波辅助蒸馏水浸泡(UD)甘薯样品,无超声渗透脱水(OD)以及超声波辅助渗透脱水(UOD)。实验的第一部分包括如下目的:首先确定和优化超声辅助渗透甘薯脱水(UOD)加工过程的技术参数;进一步确定在甘薯渗透脱水过程中超声波预处理对传质动力学和扩散系数的影响;探讨超声波预处理对渗透脱水的甘薯样品的质地、颜色、结构、类胡萝卜素和维生素C含量的影响。实验的第二部分着重研究对经过上述预处理之后的甘薯样品进行油炸实验,包括如下目的:探讨超声预处理减少油炸甘薯中含油率的可能性;探讨经过预处理的甘薯样品在深度油炸时的传质动力学;确定超声预处理对油炸甘薯的结构、质地及颜色动力学的影响;探讨超声预处理对油炸甘薯的感官和营养含量(类胡萝卜素和维生素C)的影响。在优化超声波辅助甘薯渗透脱水的过程中,超声波频率为20-50 kHz,超声波预处理时间为10-30 min,同时在30oC的处理温度下,蔗糖的浓度为20-60%(w/v)。根据实验需求不同超声探头的直径范围在1-3cm之间。响应参数由脱水量、固形物增量以及物料减少量来表示。结果表明,当超声波频率从20-35khz时,脱水量和物料减重量均增加,随后随着频率的继续增加(35-50khz)而减少。超声波频率、预处理时间和蔗糖浓度均被证明对脱水量有很重要的影响,预处理时间和蔗糖浓度同时也被证明对物料减少量有重要影响。对于固形物增量而言,只有蔗糖浓度对其有显著性影响。经过优化,获得的最佳参数为:超声频率33.93khz、超声处理时间30min、蔗糖溶液浓度35.69%(w/v)。在该最优加工条件下,脱水量和物料减少量达到最大值,分别为21.62%和17.23%;固形物增量达到最小,为4.40%。这说明低频率超声波有利于甘薯的渗透脱水,同时也减少了甘薯渗透脱水时蔗糖的使用量。超声预处理对甘薯渗透脱水的传质动力学、结构、类胡萝卜素和维生素c的含量有一定的影响。在本实验中,超声探头的直径为2cm、频率为28khz、最大功率为300w。在室温下(30oc),超声预处理时间分别为20、30、45和60min。用阿苏阿拉模型用来确定动力学参数。所建模型的拟合相关系数为0.92-0.98、卡方值小于0.6、均方根误差小于0.9、平均相对偏差小于10%,说明该模型能与实验数据高度匹配。相比蒸馏水超声(ud)和无超声渗透脱水(od),采用超声辅助渗透脱水预处理(uod)明显具有较高的传质系数(0.0690/min;0.0456/min),较高的脱水平衡值(33.11%)和固形物增量(6.5487%),及较好的样品结构。相比ud和uod,经过od处理的样品含有最高的类胡萝卜素保留量。但是超声被证明在ud和uod预处理样品时可以提高样品中维生素c的保留量。对超声预处理如何影响渗透脱水之后甘薯的扩散系数、质地和颜色进行了进一步的研究。在所有的预处理中,水分含量和溶质的扩散系数的范围分别为2.89×10-10-4.95×10-10和1.17×10-10-1.67×10-10m~2s~(-1)。经过uod处理后的样品的水分扩散率明显高于(p0.05)经过od(32.82%)和ud(41.62%)处理。同时经uod处理的样品质地也发生了最大程度的改变,相比未处理的样品松软了92.47%。结果进一步表明,经过ud处理的甘薯样品其亮度(l*)增加而红色色度(a*)减小;而经过uod处理的甘薯样品其黄色色度(b*)和颜色浓度(c*)同时增加。甘薯样品经过uod处理显示出最大的总色差(Δe)。结果进一步表明,未经过任何预处理的甘薯样品的平均色度值(ho)为66.24o,而经过UD、OD和UOD处理过的甘薯样品平均色度值的范围分别为为64.49-71.9o,63.41-72.62o和54.68-61.39o。经过预处理的甘薯样品分别在130、150、170℃的油温下油炸2、4、6、8和10 min。一级反应的动力学模型与该过程中样品的水分损失和油量吸收的传质速率高度匹配(R2范围在0.82-0.98之间)。经过UOD及OD预处理的甘薯样品被证明水分含量最低,而经过UD处理的甘薯样品的含油量在油温150和170℃时最低,分别为65.11和71.47%。在150和170℃时,所有经过预处理的样品的k值均高于未经过与处理的样品。因此,该结果表明,超声波预处理在深度油炸中可以有效地降低样品含油量。实验探讨了超声波预处理对油炸甘薯的质地、颜色、结构、类胡萝卜素和维生素C的含量、感官评定的影响。部分甘薯样品在130、150、170 的油温下分别油炸2、4、6、8和10 min,研究其质地和颜色的变化情况;其他样品在150oC的油温下油炸6 min,研究其结构、类胡萝卜素和维生素C的含量及感官评定的变化情况。结果表明,相比未经过预处理的样品,经过UD处理的甘薯样品的最大标准化F值无显著性的变化(p0.05);而经过UOD及OD预处理的甘薯样品有显著性的变化(p0.05),同时甘薯样品的硬化速度也远远高于未处理的样品。尤其是经过UOD处理的样品相比其他更有优势,例如亮度高、红色色度低、黄色色度适中、总色差小。甘薯样品的质地及颜色动力学呈温度依赖性,在本实验中用活化能来表示。经过OD处理的甘薯样品相比未处理样品的类胡萝卜素含量有显著性的变化(p0.05),而经过UOD和UD处理的样品较对照组无显著性差异(p0.05)。维生素C含量的变化情况与类胡萝卜素大致类似。结果进一步表明,相比对照组,UD处理的样品在油炸之后其结构中仅仅只含有极少油量,或者没有油残留。这也证实了以前实验的结果,经过UD预处理的样品含油量要低于其他方法与处理的样品。感官分析还表明了未经处理的样品和超声预处理的样品之间并没有显著性的差异。从上述情况中可以明显看出超声波预处理可以很好地应用于工业渗透脱水和甘薯油炸的生产过程,可以有效地提高甘薯的干燥程度并能减少油炸过程中产品的吸油量。
[Abstract]:Sweet potato is a crop with extremely rich nutrients, such as starch, fiber, carotenoid, vitamin C and minerals. Eating sweet potatoes has many benefits for health, such as enhancing vision, improving immunity, reducing blood sugar index, and also having antioxidant and anti-inflammatory effects. China is the largest producer of sweet potatoes, and America It is the largest exporter of sweet potatoes. Sweet potatoes are eaten in a variety of ways, such as cooking, frying, baking, sweet potato, sweet potato noodles, etc. because the sweet potato is easy to corrupt and can be stored for a long time after harvesting. There are some disadvantages, such as the flow of nutrients, using traditional methods. Loss, destruction of structure and texture, high cost of operation, and longer drying time. Therefore, in order to preserve nutrients in sweet potatoes and some other physical and chemical properties, osmotic dehydration is very promising. Ultrasound is a new and efficient technology that can not affect the environment at the same time, and can be widely used in food. During the process of production, such as auxiliary extraction, hydrolysis, degassing, freezing and emulsification, ultrasonic can effectively strengthen mass transfer, shorten processing time, reduce the use of raw materials as much as possible while increasing the yield of the product. This paper involves three kinds of experimental methods applied to sweet potato processing, including ultrasonic assisted distilled water soaking (UD) sweet potato samples No ultrasonic osmotic dehydration (OD) and ultrasonic assisted osmotic dehydration (UOD). The first part of the experiment includes the following purposes: first, to determine and optimize the technical parameters of ultrasonic assisted osmotic sweet potato dehydration (UOD) processing, and to further determine the effect of ultrasonic pretreatment on the mass transfer dynamics and diffusion coefficient during the process of osmotic dehydration of sweet potato; The effects of ultrasonic pretreatment on the texture, color, structure, carotenoid and vitamin C content of the sweet potato samples with osmotic dehydration were investigated. The second part of the experiment focused on the frying experiment of sweet potato samples after the pretreatment, including the following purposes: To explore the possibility of reducing the oil content in sweet potato by ultrasonic pretreatment. The effect of ultrasonic pretreatment on the structure, texture and color dynamics of deep fried sweet potato was determined, and the effects of ultrasonic pretreatment on sensory and nutritional content of sweet potato (carotenoid and vitamin C) were investigated. The ultrasonic assisted sweet potato osmotic dehydration was optimized. In the process, the ultrasonic frequency is 20-50 kHz and the ultrasonic pretreatment time is 10-30 min. At the same time, the concentration of sucrose is 20-60% (w/v) at the temperature of 30oC. The diameter range of the ultrasonic probe is between 1-3cm. The response parameters are represented by the dewater, the solids increment and the material reduction. When the wave frequency is from 20-35khz, the amount of dehydration and material weight decrease, and then decreases with the increase of frequency (35-50khz). The ultrasonic frequency, the pretreatment time and the sucrose concentration have been proved to have an important effect on the dewatering. The pretreatment time and the concentration of sucrose have also been proved to have an important effect on the reduction of material. The optimum parameters are the ultrasonic frequency 33.93khz, the ultrasonic treatment time 30min, the sucrose solution concentration 35.69% (w/v). Under the optimal processing conditions, the dehydration amount and the material reduction reach the maximum value of 21.62% and 17.23% respectively, and the solids increment reaches the minimum, 4.40%. shows that low frequency ultrasound is beneficial to the osmotic dehydration of sweet potato, but also reduces the use of sucrose when the sweet potato is permeated and dehydrated. The ultrasonic pretreatment has a certain influence on the mass transfer kinetics, structure, carotenoid and vitamin C in the osmotic dehydration of sweet potato. In this experiment, the diameter of the ultrasonic probe is 2cm and the frequency is 28K Hz, the maximum power is 300W. at room temperature (30oC). The ultrasonic pretreatment time is 20,30,45 and 60min. used to determine the kinetic parameters respectively. The fitting correlation coefficient of the model is 0.92-0.98, the square value is less than 0.6, the root mean square error is less than 0.9 and the average relative deviation is less than 10%, which shows that the model can be highly matched with the experimental data. Compared with distilled water ultrasound (UD) and non ultrasonic osmotic dehydration (OD), ultrasonic assisted osmotic dehydration preconditioning (UOD) obviously has higher mass transfer coefficient (0.0690/min; 0.0456/min), higher dehydration balance (33.11%) and solid increment (6.5487%), and better sample structure. Compared to UD and UOD, OD treated samples contain the highest Carotenoid retention. However, ultrasound has been shown to increase the retention of vitamin C in samples with UD and UOD pretreatment. Further research on how ultrasound pretreatment affects the diffusion coefficient, texture and color of sweet potatoes after osmotic dehydration. The peri were 2.89 * 10-10-4.95 * 10-10 and 1.17 x 10-10-1.67 x 10-10m~2s~ (-1) respectively. The moisture diffusion rate of the samples treated by UOD was significantly higher than that of (P0.05) after OD (32.82%) and UD (41.62%) treatment. Meanwhile, the texture of the samples treated by UOD also changed to the maximum degree. The result of the soft 92.47%. results compared to the untreated sample was further indicated. The brightness (l*) of the samples treated with UD and the red color (a*) decreased, while the yellow color (b*) and the color concentration (c*) of the sweet potato samples treated by UOD increased at the same time. The sweet potato samples showed the maximum total chromatic aberration (delta E) after UOD treatment. HO) for 66.24o, the range of average chromaticity values of sweet potato samples treated by UD, OD and UOD is the kinetic model of the reaction of 2,4,6,8 and 10 min. 1 at the temperature of the pre treated sweet potato at the oil temperature of 130150170 degrees centigrade, respectively, for 64.49-71.9o, 63.41-72.62o and 54.68-61.39o., respectively, and the water loss and oil absorption of the samples during the process. The mass transfer rate was highly matched (R2 range between 0.82-0.98). The samples of sweet potato treated by UOD and OD were proved to have the lowest water content, while the oil content of the sweet potato samples treated by UD was lowest at oil temperature 150 and 170 C, and the K value of all pretreated samples was higher than that of 65.11 and 71.47%. at 150 and 170 degrees centigrade respectively. The results showed that ultrasonic pretreatment could effectively reduce the oil content of the samples during deep frying. The texture, color, structure, carotenoids and vitamin C content and sensory evaluation of the fried sweet potato with ultrasonic pretreatment were experimentally investigated. Some samples of sweet potato were respectively under 130150170 oil temperature. The texture and color change of 2,4,6,8 and 10 min were studied. Other samples were fried 6 min under the oil temperature of 150oC. The changes of the structure, carotenoid and vitamin C content and sensory evaluation were studied. The results showed that the maximum standardized F value of the sweet potato samples treated by UD was not significant compared to the untreated samples. The change of sex (P0.05); while the UOD and OD pre treated sweet potato samples have significant changes (P0.05), and the hardening rate of the sweet potato samples is much higher than that of the untreated samples. In particular, the samples treated by UOD have more advantages, such as high brightness, low red color, moderate yellow color, and small total color difference. The quality of sweet potato samples. The ground and color dynamics were temperature dependent. In this experiment, the activation energy was used to show that the carotenoids content of the samples treated by OD had significant changes (P0.05), but the samples treated with UOD and UD had no significant difference compared with the control group (P0.05). The changes of vitamin C content and carotenoids The results further showed that compared with the control group, the samples treated by UD only contained only very little oil, or no oil residue after the frying, which confirmed the results of the previous experiments, and the amount of oil pretreated by UD was lower than that of other methods and treated samples. Sensory analysis also showed that the samples were untreated. There is no significant difference between the samples and the samples treated by ultrasound. It is obvious from the above situation that the ultrasonic pretreatment can be well applied to the process of industrial osmosis dehydration and sweet potato frying, which can effectively improve the drying degree of sweet potato and reduce the oil absorption of the products during the frying process.
【学位授予单位】：江苏大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TS215
，
本文编号：2174594
[Abstract]:Sweet potato is a crop with extremely rich nutrients, such as starch, fiber, carotenoid, vitamin C and minerals. Eating sweet potatoes has many benefits for health, such as enhancing vision, improving immunity, reducing blood sugar index, and also having antioxidant and anti-inflammatory effects. China is the largest producer of sweet potatoes, and America It is the largest exporter of sweet potatoes. Sweet potatoes are eaten in a variety of ways, such as cooking, frying, baking, sweet potato, sweet potato noodles, etc. because the sweet potato is easy to corrupt and can be stored for a long time after harvesting. There are some disadvantages, such as the flow of nutrients, using traditional methods. Loss, destruction of structure and texture, high cost of operation, and longer drying time. Therefore, in order to preserve nutrients in sweet potatoes and some other physical and chemical properties, osmotic dehydration is very promising. Ultrasound is a new and efficient technology that can not affect the environment at the same time, and can be widely used in food. During the process of production, such as auxiliary extraction, hydrolysis, degassing, freezing and emulsification, ultrasonic can effectively strengthen mass transfer, shorten processing time, reduce the use of raw materials as much as possible while increasing the yield of the product. This paper involves three kinds of experimental methods applied to sweet potato processing, including ultrasonic assisted distilled water soaking (UD) sweet potato samples No ultrasonic osmotic dehydration (OD) and ultrasonic assisted osmotic dehydration (UOD). The first part of the experiment includes the following purposes: first, to determine and optimize the technical parameters of ultrasonic assisted osmotic sweet potato dehydration (UOD) processing, and to further determine the effect of ultrasonic pretreatment on the mass transfer dynamics and diffusion coefficient during the process of osmotic dehydration of sweet potato; The effects of ultrasonic pretreatment on the texture, color, structure, carotenoid and vitamin C content of the sweet potato samples with osmotic dehydration were investigated. The second part of the experiment focused on the frying experiment of sweet potato samples after the pretreatment, including the following purposes: To explore the possibility of reducing the oil content in sweet potato by ultrasonic pretreatment. The effect of ultrasonic pretreatment on the structure, texture and color dynamics of deep fried sweet potato was determined, and the effects of ultrasonic pretreatment on sensory and nutritional content of sweet potato (carotenoid and vitamin C) were investigated. The ultrasonic assisted sweet potato osmotic dehydration was optimized. In the process, the ultrasonic frequency is 20-50 kHz and the ultrasonic pretreatment time is 10-30 min. At the same time, the concentration of sucrose is 20-60% (w/v) at the temperature of 30oC. The diameter range of the ultrasonic probe is between 1-3cm. The response parameters are represented by the dewater, the solids increment and the material reduction. When the wave frequency is from 20-35khz, the amount of dehydration and material weight decrease, and then decreases with the increase of frequency (35-50khz). The ultrasonic frequency, the pretreatment time and the sucrose concentration have been proved to have an important effect on the dewatering. The pretreatment time and the concentration of sucrose have also been proved to have an important effect on the reduction of material. The optimum parameters are the ultrasonic frequency 33.93khz, the ultrasonic treatment time 30min, the sucrose solution concentration 35.69% (w/v). Under the optimal processing conditions, the dehydration amount and the material reduction reach the maximum value of 21.62% and 17.23% respectively, and the solids increment reaches the minimum, 4.40%. shows that low frequency ultrasound is beneficial to the osmotic dehydration of sweet potato, but also reduces the use of sucrose when the sweet potato is permeated and dehydrated. The ultrasonic pretreatment has a certain influence on the mass transfer kinetics, structure, carotenoid and vitamin C in the osmotic dehydration of sweet potato. In this experiment, the diameter of the ultrasonic probe is 2cm and the frequency is 28K Hz, the maximum power is 300W. at room temperature (30oC). The ultrasonic pretreatment time is 20,30,45 and 60min. used to determine the kinetic parameters respectively. The fitting correlation coefficient of the model is 0.92-0.98, the square value is less than 0.6, the root mean square error is less than 0.9 and the average relative deviation is less than 10%, which shows that the model can be highly matched with the experimental data. Compared with distilled water ultrasound (UD) and non ultrasonic osmotic dehydration (OD), ultrasonic assisted osmotic dehydration preconditioning (UOD) obviously has higher mass transfer coefficient (0.0690/min; 0.0456/min), higher dehydration balance (33.11%) and solid increment (6.5487%), and better sample structure. Compared to UD and UOD, OD treated samples contain the highest Carotenoid retention. However, ultrasound has been shown to increase the retention of vitamin C in samples with UD and UOD pretreatment. Further research on how ultrasound pretreatment affects the diffusion coefficient, texture and color of sweet potatoes after osmotic dehydration. The peri were 2.89 * 10-10-4.95 * 10-10 and 1.17 x 10-10-1.67 x 10-10m~2s~ (-1) respectively. The moisture diffusion rate of the samples treated by UOD was significantly higher than that of (P0.05) after OD (32.82%) and UD (41.62%) treatment. Meanwhile, the texture of the samples treated by UOD also changed to the maximum degree. The result of the soft 92.47%. results compared to the untreated sample was further indicated. The brightness (l*) of the samples treated with UD and the red color (a*) decreased, while the yellow color (b*) and the color concentration (c*) of the sweet potato samples treated by UOD increased at the same time. The sweet potato samples showed the maximum total chromatic aberration (delta E) after UOD treatment. HO) for 66.24o, the range of average chromaticity values of sweet potato samples treated by UD, OD and UOD is the kinetic model of the reaction of 2,4,6,8 and 10 min. 1 at the temperature of the pre treated sweet potato at the oil temperature of 130150170 degrees centigrade, respectively, for 64.49-71.9o, 63.41-72.62o and 54.68-61.39o., respectively, and the water loss and oil absorption of the samples during the process. The mass transfer rate was highly matched (R2 range between 0.82-0.98). The samples of sweet potato treated by UOD and OD were proved to have the lowest water content, while the oil content of the sweet potato samples treated by UD was lowest at oil temperature 150 and 170 C, and the K value of all pretreated samples was higher than that of 65.11 and 71.47%. at 150 and 170 degrees centigrade respectively. The results showed that ultrasonic pretreatment could effectively reduce the oil content of the samples during deep frying. The texture, color, structure, carotenoids and vitamin C content and sensory evaluation of the fried sweet potato with ultrasonic pretreatment were experimentally investigated. Some samples of sweet potato were respectively under 130150170 oil temperature. The texture and color change of 2,4,6,8 and 10 min were studied. Other samples were fried 6 min under the oil temperature of 150oC. The changes of the structure, carotenoid and vitamin C content and sensory evaluation were studied. The results showed that the maximum standardized F value of the sweet potato samples treated by UD was not significant compared to the untreated samples. The change of sex (P0.05); while the UOD and OD pre treated sweet potato samples have significant changes (P0.05), and the hardening rate of the sweet potato samples is much higher than that of the untreated samples. In particular, the samples treated by UOD have more advantages, such as high brightness, low red color, moderate yellow color, and small total color difference. The quality of sweet potato samples. The ground and color dynamics were temperature dependent. In this experiment, the activation energy was used to show that the carotenoids content of the samples treated by OD had significant changes (P0.05), but the samples treated with UOD and UD had no significant difference compared with the control group (P0.05). The changes of vitamin C content and carotenoids The results further showed that compared with the control group, the samples treated by UD only contained only very little oil, or no oil residue after the frying, which confirmed the results of the previous experiments, and the amount of oil pretreated by UD was lower than that of other methods and treated samples. Sensory analysis also showed that the samples were untreated. There is no significant difference between the samples and the samples treated by ultrasound. It is obvious from the above situation that the ultrasonic pretreatment can be well applied to the process of industrial osmosis dehydration and sweet potato frying, which can effectively improve the drying degree of sweet potato and reduce the oil absorption of the products during the frying process.
【学位授予单位】：江苏大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TS215
，
本文编号：2174594
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