Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/51125
標題: 不同保護劑對Lactococcus lactis ssp. cremoris CCRC 11067經冷凍、冷凍乾燥及真空乾燥後貯存安定性及產酸能力之影響
The Effect of Different Protectants on Storage Stability and Acidification Power of Lactococcus lactis ssp. cremoris CCRC 11067 after Freezing, Freeze-drying and Vaccum-drying
作者: 謝耀興
Uao-Shin, Shieh
關鍵字: 麥芽糊精
Lactococcus lactis ssp. cremoris
脫脂乳粉
碳酸鈣
冷凍乾燥及真空乾燥
真空貯藏及常壓貯藏
加速貯藏試驗
產酸能力
maltodextrin
nonfat dry milk solids
calcium carbonate
freeze-drying and vacuum-drying
vacuum storage amd atmospheric storage
accelerated storage test
acidification power
出版社: 食品科學系
摘要: 對菌體的保存效果來說,菌體的乾燥方式、貯存條件及保護劑的種類等條件,都會對其造成不同程度的影響。而在乳品工業上L. lactis ssp. cremoris是被廣泛使用的菌株,而菌數及產酸能力對此菌株的表現上來說是最基本重要的特質。因此本研究將分別以25%麥芽糊精、10%脫脂乳粉及0.5%碳酸鈣作為菌體的保護劑,並在經冷凍乾燥或真空乾燥後,分別於真空及常壓狀態下貯藏,然後進行加速貯藏試驗及產酸能力試驗,希望能以此找出對菌體具有最佳保護效果的保護劑及保存條件。 加速貯藏試驗所得的結果顯示,乾燥方式是以冷凍乾燥比真空乾燥好,保存方式真空貯藏比常壓貯藏好,保護劑之間則以10%脫脂乳粉最好。因此最佳的保護效果是以添加10%脫脂乳粉的樣品,在經過冷凍乾燥後以真空狀態貯藏時具有最佳的保存效果。而在冷凍、冷凍乾燥及真空乾燥後,樣品的產酸能力試驗的結果則是以添加25%麥芽糊精者最佳;但是三種處理後的菌數存活百分率卻是以添加10%的脫脂乳粉最佳。推測這是由於10%脫脂乳粉對菌數的保存雖然並非最佳,但在樣品的存活菌數中,其菌數受傷比例是三種保護劑中最低的。而在不同濃度脫脂乳粉的結果中,發現20%脫脂乳粉的保護劑其保護效果並不如添加15%時好,表示菌體的保護效果並不是隨著固形物濃度的增加而增加。推測這是由於濃度提高時,會造成樣品中水活性的下降,導致了菌體存活率的下降。
For the preservation of bacteria, there are many influential factors including drying methods, storage conditions, and kinds of protective agents used. The culture of L. lactis ssp. cremoris is extensively used for cheese manufacturing in dairy industry, and viability and acid production are the most important properties for it. In this research, accelerated storage test and acidification power test were used to study the most appropriate preservation conditions for L. lactis ssp. cremoris, and 25% maltodextrin (MD), 10% nonfat dry milk solids (NDFMS), and 0.5% calcium carbonate (CaCO3) were used as protective agents and samples were stored at vacuum or atmospheric conditions after freeze-drying and vacuum-drying respectively. Results of accelerated storage test showed that the preservation effect of freeze-drying was better than vacuum-drying, and that of vacuum storage was better than atmospheric storage. On the other hand, 10% NFDMS was the best protectant among those used. The best protective conditions for L. lactis ssp. cremoris in this research was the culture with 10% NFDMS that preserved at vacuum condition after freeze-drying. After freezing, freeze-drying or vacuum-drying, results showed that 25% maltodextrin possessed the highest residual viability than other protectants used. But in acidification power test, results showed that samples with 10% NFDMS had the best acidification power. This might be because the survival cells of samples with 10% NFDMS suffered the lowest injury than other samples. In the results using NFDMS of different total solids content, it was found that the protective effect of 20% NFDMS was worse than 15% NFDMS. It indicated that the protective effect did not increase with the increase of total solids content of protectants. This might be because high concentration of protectants would decrease the water activity of samples.
URI: http://hdl.handle.net/11455/51125
Appears in Collections:食品暨應用生物科技學系

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.