Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/51218
標題: 間歇性遠紅外線加熱應用於乳酸菌控低溫真空乾燥及冷凍乾燥的探討:Ⅱ. Lactobacillus acidophilus BCRC 10695
The Application of Intermittent Far-Infrared Radiation Heating on the Freeze-Drying and Controlled Low-Temperature Vacuum Drying of Lactic Acid Bacteria: II . Lactobacillus acidophilus BCRC 10695
作者: 楊純華
Yang, Chun-Hua
關鍵字: far-infrared radiation;遠紅外線;freeze-drying;controlled low-temperature vacuum drying;intermittent heating;L. acidophilus;冷凍乾燥;控低溫真空乾燥;間歇性加熱;L. acidophilus
出版社: 食品暨應用生物科技學系
摘要: 
Lactobacillus acidophilus對於人體生理具有多項保健功效,在市售乾燥食品中常有添加,為人們常食用的生活補給品。冷凍乾燥為一種普遍使用於菌種保存的方法,但是乾燥所需時間過長及能量消耗過大是其主要的缺點,而控低溫真空乾燥是將乾燥樣品保持在非凍結的低溫狀態下進行真空乾燥,樣品可以避免凍結之傷害,不但可得到類似於冷凍乾燥操作之高品質產品而且乾燥時間可以縮短很多。但是在乾燥狀態下,菌株的存活率及貯存安定性並不佳,加以傳統所採用的冷凍乾燥方法成本高且需時長,因此若能改善乾燥操作,縮短乾燥所需時間,而且同時具有良好的乾燥處理後之菌株活性及貯存安定性,為主要探討的目的,且遠紅外線輻射加熱具有傳熱效率高、裝置簡單、操作方便、成本低廉等優點,常被應用於乾燥操作。此外間歇性的遠紅外線輻射加熱方式,可以縮短乾燥所需時間,改善產品品質,在乾燥條件的控制上亦常被考慮。
本研究將遠紅外線輻射加熱(T = 40°C;α = 0, 0.25, 0.5, 0.75, 1.0)應用於冷凍乾燥及控低溫真空乾燥操作,來對L. acidophilus進行乾燥處理,並探討乾燥後之存活率及貯存安定性,同時比較不同遠紅外線輻射加熱處理條件及不同乾燥處理對菌體的影響,了解這些作用與存活率、活性等之間的關係,並進一步探討乾燥方法對於細胞膜脂肪酸組成與細胞內蛋白質之影響。
結果顯示,遠紅外線的使用能有效縮短乾燥時間,此外,L. acidophilus相較於控制組(α = 0.0),在控低溫真空乾燥乾燥處理後以α = 0.5具有最高的存活率,而在冷凍乾燥的部份,遠紅外線的使用,皆有提升存活率的效果,在FD(-30°C)及FD(-60°C)都以α = 0.25可提升最多的存活率。貯藏實驗方面,L. acidophilus於低溫貯藏下,乾燥菌株具有較高的貯藏安定性。產酸能力以控低溫真空乾燥的效果較佳,同樣發現以α = 0.5的處理較佳。在蛋白質分析的結果可以發現無新的胞內蛋白質的生成,但可以發現不同的乾燥處理及間歇值,其胞內蛋白的濃度有所不同;脂肪酸組成分析結果可以發現,C16:0經過冷凍後其含量有上昇之情形。
綜合以上結果可以發現,於不同的乾燥過程中,若能配合適當的間歇值之運用,除了能有效的縮短乾燥時間外,並能得到高品質的L. acidophilus菌粉產品,其中控低溫真空乾燥以α = 0.5具有最佳的活性及存活率,而冷凍乾燥皆以α = 0.25最好。

Lactobacillus acidophilus possesses lots of important physiological functions beneficial to human health and numerous dried products which containing it is now popular for use as dietary adjuncts for humans and animals. Freeze-drying(FD) is a popular method used in the culture preservation of microorganisms. However, it possesses the major defects of lengthy drying time. Controlled low-temperature vacuum drying(CLTVD) is a method to dehydrate products as cold as possible without freezing. Freezing damage could be avoided and high quality products as those produced by FD might be manufactured. Besides, the lengthy drying time as well as large amount of energy used for freeze drying could be reduced. On the other hand, the FD method traditionally used is also slow and needs high cost. Therefore, competitiveness could be enhanced by means of the improvement of the drying operation, such as reduction in drying time, enhancement of the viability and storage stability after drying, etc. Far-infrared radiation possesses many advantages, such as high thermal transmission, simple design, easy operation, and low cost, etc., and is frequently used in dehydration operation. Besides, intermittent heating is also often used in far-infrared heating in order to reduce drying time and improve product quality.
The objectives of this study are to employ far-infrared radiation heating(T = 40°C;α = 0, 0.25, 0.5, 0.75, 1.0) in the FD and CLTVD of L. acidophilus in order to ameliorate the survival, activity, and storage stability of dried cell cultures. Besides, the effects of different far-infrared radiation heating conditions on the fatty acid index changes of the dried cells membrane and intracellular protein composition were investigated.
The application of far-infrared radiation could shorten the most drying time. Results indicated that L. acidophilus had the greatest survival after far-infrared radiation heating α = 0.5 in the CLTVD and far-infrared radiation heating α = 0.25 in the FD. The sensitivity of FD(-30°C, α = 0.25; -60°C, α = 0.5) and CLTVD(α = 0.25)with far-infrared radiation heating L. acidophilus was lower than without far-infrared radiation heating. During storage, L. acidophilus stored at lower temperatures possessed higher survival. The acidification power test demonstrated that better value obtained was CLTVD with far-infrared radiation in α = 1.0 and α = 0.5. In SDS-page analysis, no new intracellular protein was found but different intracellular protein contents were found after in various drying methods. In the fatty acid composition analysis, CLTVD had the lower C16:0 content content and freezing was increased C16:0 content.
The application of intermittent far-infrared radiation heating α = 0.5 in the CLTVD、α = 0.25 in the FD will shorten drying time and had the greatest survival.
URI: http://hdl.handle.net/11455/51218
Appears in Collections:食品暨應用生物科技學系

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