超聲波預(yù)處理對甘薯（IPOMEA BATATAS）滲透脫水及油炸的影響研究
發(fā)布時間：2018-08-09 15:57
【摘要】：甘薯是一種含有極其豐富營養(yǎng)物質(zhì)的農(nóng)作物,例如淀粉、纖維、類胡蘿卜素、維生素C和礦物質(zhì)。食用甘薯對健康有很多益處,例如增強(qiáng)視力、提高免疫力、降低血糖指數(shù),同時甘薯還具有抗氧化和抗炎作用。中國是最大的甘薯生產(chǎn)國,而美國是最大的甘薯出口國。甘薯的食用方式各種各樣,例如蒸煮、油炸、焙烤、甘薯泥、甘薯面條等。因?yàn)楦适硪赘瘮〉男再|(zhì),在收割之后甘薯一般經(jīng)過干燥處理便可貯藏較長時間。使用傳統(tǒng)方法對甘薯進(jìn)行干燥存在一些弊端,例如營養(yǎng)物質(zhì)的流失、結(jié)構(gòu)和質(zhì)地的破壞、操作費(fèi)用昂貴以及干燥所需時間較長等。因此,為了保存甘薯中的營養(yǎng)物質(zhì)和一些其他理化性質(zhì),滲透式脫水方法很有發(fā)展前景。超聲波是一種簡便有效而且同時不會影響到環(huán)境的新型技術(shù),可以廣泛應(yīng)用到食品生產(chǎn)加工過程中,例如輔助提取、水解、脫氣、凍結(jié)及乳化過程。超聲波可以有效地強(qiáng)化傳質(zhì)、縮短加工時間,在盡可能減少原料使用的同時提高產(chǎn)品的產(chǎn)率。本文涉及三種應(yīng)用于甘薯加工的試驗(yàn)方法,包括超聲波輔助蒸餾水浸泡(UD)甘薯樣品,無超聲滲透脫水(OD)以及超聲波輔助滲透脫水(UOD)。實(shí)驗(yàn)的第一部分包括如下目的:首先確定和優(yōu)化超聲輔助滲透甘薯脫水(UOD)加工過程的技術(shù)參數(shù);進(jìn)一步確定在甘薯滲透脫水過程中超聲波預(yù)處理對傳質(zhì)動力學(xué)和擴(kuò)散系數(shù)的影響;探討超聲波預(yù)處理對滲透脫水的甘薯樣品的質(zhì)地、顏色、結(jié)構(gòu)、類胡蘿卜素和維生素C含量的影響。實(shí)驗(yàn)的第二部分著重研究對經(jīng)過上述預(yù)處理之后的甘薯樣品進(jìn)行油炸實(shí)驗(yàn),包括如下目的:探討超聲預(yù)處理減少油炸甘薯中含油率的可能性;探討經(jīng)過預(yù)處理的甘薯樣品在深度油炸時的傳質(zhì)動力學(xué);確定超聲預(yù)處理對油炸甘薯的結(jié)構(gòu)、質(zhì)地及顏色動力學(xué)的影響;探討超聲預(yù)處理對油炸甘薯的感官和營養(yǎng)含量(類胡蘿卜素和維生素C)的影響。在優(yōu)化超聲波輔助甘薯滲透脫水的過程中,超聲波頻率為20-50 kHz,超聲波預(yù)處理時間為10-30 min,同時在30oC的處理溫度下,蔗糖的濃度為20-60%(w/v)。根據(jù)實(shí)驗(yàn)需求不同超聲探頭的直徑范圍在1-3cm之間。響應(yīng)參數(shù)由脫水量、固形物增量以及物料減少量來表示。結(jié)果表明,當(dāng)超聲波頻率從20-35khz時,脫水量和物料減重量均增加,隨后隨著頻率的繼續(xù)增加(35-50khz)而減少。超聲波頻率、預(yù)處理時間和蔗糖濃度均被證明對脫水量有很重要的影響,預(yù)處理時間和蔗糖濃度同時也被證明對物料減少量有重要影響。對于固形物增量而言,只有蔗糖濃度對其有顯著性影響。經(jīng)過優(yōu)化,獲得的最佳參數(shù)為:超聲頻率33.93khz、超聲處理時間30min、蔗糖溶液濃度35.69%(w/v)。在該最優(yōu)加工條件下,脫水量和物料減少量達(dá)到最大值,分別為21.62%和17.23%;固形物增量達(dá)到最小,為4.40%。這說明低頻率超聲波有利于甘薯的滲透脫水,同時也減少了甘薯滲透脫水時蔗糖的使用量。超聲預(yù)處理對甘薯滲透脫水的傳質(zhì)動力學(xué)、結(jié)構(gòu)、類胡蘿卜素和維生素c的含量有一定的影響。在本實(shí)驗(yàn)中,超聲探頭的直徑為2cm、頻率為28khz、最大功率為300w。在室溫下(30oc),超聲預(yù)處理時間分別為20、30、45和60min。用阿蘇阿拉模型用來確定動力學(xué)參數(shù)。所建模型的擬合相關(guān)系數(shù)為0.92-0.98、卡方值小于0.6、均方根誤差小于0.9、平均相對偏差小于10%,說明該模型能與實(shí)驗(yàn)數(shù)據(jù)高度匹配。相比蒸餾水超聲(ud)和無超聲滲透脫水(od),采用超聲輔助滲透脫水預(yù)處理(uod)明顯具有較高的傳質(zhì)系數(shù)(0.0690/min;0.0456/min),較高的脫水平衡值(33.11%)和固形物增量(6.5487%),及較好的樣品結(jié)構(gòu)。相比ud和uod,經(jīng)過od處理的樣品含有最高的類胡蘿卜素保留量。但是超聲被證明在ud和uod預(yù)處理樣品時可以提高樣品中維生素c的保留量。對超聲預(yù)處理如何影響滲透脫水之后甘薯的擴(kuò)散系數(shù)、質(zhì)地和顏色進(jìn)行了進(jìn)一步的研究。在所有的預(yù)處理中,水分含量和溶質(zhì)的擴(kuò)散系數(shù)的范圍分別為2.89×10-10-4.95×10-10和1.17×10-10-1.67×10-10m~2s~(-1)。經(jīng)過uod處理后的樣品的水分?jǐn)U散率明顯高于(p0.05)經(jīng)過od(32.82%)和ud(41.62%)處理。同時經(jīng)uod處理的樣品質(zhì)地也發(fā)生了最大程度的改變,相比未處理的樣品松軟了92.47%。結(jié)果進(jìn)一步表明,經(jīng)過ud處理的甘薯樣品其亮度(l*)增加而紅色色度(a*)減小;而經(jīng)過uod處理的甘薯樣品其黃色色度(b*)和顏色濃度(c*)同時增加。甘薯樣品經(jīng)過uod處理顯示出最大的總色差(Δe)。結(jié)果進(jìn)一步表明,未經(jīng)過任何預(yù)處理的甘薯樣品的平均色度值(ho)為66.24o,而經(jīng)過UD、OD和UOD處理過的甘薯樣品平均色度值的范圍分別為為64.49-71.9o,63.41-72.62o和54.68-61.39o。經(jīng)過預(yù)處理的甘薯樣品分別在130、150、170℃的油溫下油炸2、4、6、8和10 min。一級反應(yīng)的動力學(xué)模型與該過程中樣品的水分損失和油量吸收的傳質(zhì)速率高度匹配(R2范圍在0.82-0.98之間)。經(jīng)過UOD及OD預(yù)處理的甘薯樣品被證明水分含量最低,而經(jīng)過UD處理的甘薯樣品的含油量在油溫150和170℃時最低,分別為65.11和71.47%。在150和170℃時,所有經(jīng)過預(yù)處理的樣品的k值均高于未經(jīng)過與處理的樣品。因此,該結(jié)果表明,超聲波預(yù)處理在深度油炸中可以有效地降低樣品含油量。實(shí)驗(yàn)探討了超聲波預(yù)處理對油炸甘薯的質(zhì)地、顏色、結(jié)構(gòu)、類胡蘿卜素和維生素C的含量、感官評定的影響。部分甘薯樣品在130、150、170 的油溫下分別油炸2、4、6、8和10 min,研究其質(zhì)地和顏色的變化情況;其他樣品在150oC的油溫下油炸6 min,研究其結(jié)構(gòu)、類胡蘿卜素和維生素C的含量及感官評定的變化情況。結(jié)果表明,相比未經(jīng)過預(yù)處理的樣品,經(jīng)過UD處理的甘薯樣品的最大標(biāo)準(zhǔn)化F值無顯著性的變化(p0.05);而經(jīng)過UOD及OD預(yù)處理的甘薯樣品有顯著性的變化(p0.05),同時甘薯樣品的硬化速度也遠(yuǎn)遠(yuǎn)高于未處理的樣品。尤其是經(jīng)過UOD處理的樣品相比其他更有優(yōu)勢,例如亮度高、紅色色度低、黃色色度適中、總色差小。甘薯樣品的質(zhì)地及顏色動力學(xué)呈溫度依賴性,在本實(shí)驗(yàn)中用活化能來表示。經(jīng)過OD處理的甘薯樣品相比未處理樣品的類胡蘿卜素含量有顯著性的變化(p0.05),而經(jīng)過UOD和UD處理的樣品較對照組無顯著性差異(p0.05)。維生素C含量的變化情況與類胡蘿卜素大致類似。結(jié)果進(jìn)一步表明,相比對照組,UD處理的樣品在油炸之后其結(jié)構(gòu)中僅僅只含有極少油量,或者沒有油殘留。這也證實(shí)了以前實(shí)驗(yàn)的結(jié)果,經(jīng)過UD預(yù)處理的樣品含油量要低于其他方法與處理的樣品。感官分析還表明了未經(jīng)處理的樣品和超聲預(yù)處理的樣品之間并沒有顯著性的差異。從上述情況中可以明顯看出超聲波預(yù)處理可以很好地應(yīng)用于工業(yè)滲透脫水和甘薯油炸的生產(chǎn)過程,可以有效地提高甘薯的干燥程度并能減少油炸過程中產(chǎn)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.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TS215
，
本文編號：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.
【學(xué)位授予單位】：江蘇大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2017
【分類號】：TS215
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本文編號：2174594
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