Acid, bile, and heat tolerance of free and microencapsulated probiotic bacteria
Acid, bile, and heat tolerance of free and microencapsulated probiotic bacteria
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DOI：
10.1111/j.1750-3841.2007.00565.x
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发表时间：
2007-11-01
影响因子：
3.9
通讯作者：
Shah, N. P.
中科院分区：
文献类型：
--
作者：
Ding, W. K.;Shah, N. P.
对8株益生菌，包括鼠李糖乳杆菌、长双歧杆菌、L.唾液腺L. [医]植物嗜酸乳杆菌L. paracasei，B.乳酸菌B1-04型和B型。乳酸菌Bi-07的耐酸性、耐胆汁性和耐热性。在藻酸盐基质中的微胶囊化用于提高细菌在酸和胆汁中以及短暂暴露于热中的存活。游离益生菌生物体用作对照。在2小时的孵育期内使用MRS肉汤中的HCl测试益生菌生物体的耐酸性。胆汁耐受性测试使用2种类型的胆汁盐，牛胆汁酸和牛磺胆酸，在8小时的孵育期。通过将益生菌生物体暴露于65摄氏度长达1小时来测试耐热性。结果表明，微囊化益生菌在含HCl的MRS中的存活率显著高于游离益生菌（P < 0.05）。当游离益生菌暴露于牛胆汁时，活力降低6.51-log CFU/mL，而微胶囊化菌株仅损失3.36-log CFU/mL。在热处理30分钟时，微囊化益生菌存活，平均损失仅为4.17-log CFU/mL，而游离益生菌的损失为6.74-log CFU/mL。然而，加热1小时后，游离和微胶囊化益生菌菌株的活力均显示出类似的损失。当暴露于酸性条件、胆盐和温和的热处理时，总体微胶囊化改善了益生菌的存活。
Eight strains of probiotic bacteria, including Lactobacillus rhamnosus, Bifidobacterium longum, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, B. lactis type B1-04, and B. lactis type Bi-07, were studied for their acid, bile, and heat tolerance. Microencapsulation in alginate matrix was used to enhance survival the bacteria in acid and bile as well as a brief exposure to heat. Free probiotic organisms were used as a control. The acid tolerance of probiotic organisms was tested using HCl in MRS broth over a 2-h incubation period. Bile tolerance was tested using 2 types of bile salts, oxgall and taurocholic acid, over an 8-h incubation period. Heat tolerance was tested by exposing the probiotic organisms to 65 degrees C for up to 1 h. Results indicated microencapsulated probiotic bacteria survived better (P < 0.05) than free probiotic bacteria in MRS containing HCl. When free probiotic bacteria were exposed to oxgall, viability was reduced by 6.51-log CFU/mL, whereas only 3.36-log CFU/mL was lost in microencapsulated strains. At 30 min of heat treatment, microencapsulated probiotic bacteria survived with an average loss of only 4.17-log CFU/mL, compared to 6.74-log CFU/mL loss with free probiotic bacteria. However, after 1 h of heating both free and microencapsulated probiotic strains showed similar losses in viability. Overall microencapsulation improved the survival of probiotic bacteria when exposed to acidic conditions, bile salts, and mild heat treatment.