【摘要】： 雙歧桿菌和嗜酸乳桿菌是人體的微生態(tài)調(diào)節(jié)劑。研究發(fā)現(xiàn),要想獲得預(yù)期的保健效果,一般來(lái)說(shuō),食品中活菌體的數(shù)量不少于10~6cfu/mL左右或日攝入量在10~8cfu左右,只有這樣才能補(bǔ)償益生菌在人的胃、腸中數(shù)量的下降。然而,由于益生菌的自身生長(zhǎng)特性及周圍環(huán)境因素的影響,導(dǎo)致進(jìn)入市場(chǎng)的產(chǎn)品中活菌含量較低。因此,如何提高產(chǎn)品中益生菌活菌數(shù)已成為商業(yè)的重點(diǎn)研究課題。通過(guò)實(shí)驗(yàn),篩選出黏附性高、對(duì)人體胃腸環(huán)境耐受性強(qiáng)的雙歧桿菌和嗜酸乳桿菌各一株,對(duì)其凍干保護(hù)劑進(jìn)行了優(yōu)化,并對(duì)凍干粉儲(chǔ)存穩(wěn)定性進(jìn)行測(cè)試。將兩種菌的凍干粉等量混合后獨(dú)立包裝,與酶解法制得的低乳糖乳粉共同飲用,起到緩解乳糖不耐癥和微生態(tài)調(diào)節(jié)的雙重保護(hù)作用。 供試雙歧桿菌5株,分別來(lái)源于國(guó)內(nèi)三種益生菌藥品及健康嬰兒糞便;供試嗜酸乳桿菌5株,2株來(lái)源于國(guó)內(nèi)二種益生菌藥品,2株來(lái)源于本實(shí)驗(yàn)室保藏,1株購(gòu)于黑龍江應(yīng)用微生物研究所。分別對(duì)篩選到的不同菌株進(jìn)行個(gè)體形態(tài),菌落形態(tài)及其生理生化鑒定,確認(rèn)分別屬于雙歧桿菌屬和乳酸菌屬。通過(guò)用激光共聚焦顯微鏡觀察供試菌對(duì)結(jié)腸癌細(xì)胞COCA-Ⅱ的黏附性、分別通過(guò)耐酸和耐膽汁鹽試驗(yàn),篩選出指標(biāo)較高的雙歧桿菌3株和嗜酸乳桿菌2株。通過(guò)模擬胃液和模擬腸液進(jìn)行復(fù)篩,分別篩選出高耐受性菌各1株,分別命名為雙歧桿菌L-1、嗜酸乳桿菌La-5。L-1對(duì)COCA-Ⅱ的黏附數(shù)為:16.6±2.1黏附菌數(shù)/細(xì)胞;在pH3.0模擬胃液中作用120min后的存活率為72%;在膽汁鹽濃度為0.2%的模擬腸液中,L-1 24h后其活菌數(shù)仍大于10~6cfu/mL。La-5對(duì)COCA-Ⅱ數(shù)為18.8±2.4黏附菌數(shù)/細(xì)胞;在pH2.5模擬胃液中作用3h后,其活菌數(shù)仍大于10~7cfu/mL;膽汁鹽濃度為0.2%的模擬腸液時(shí),La-5 3h后其活菌數(shù)仍大于10~6cfu/mL。 應(yīng)用單因素試驗(yàn),析因試驗(yàn)和響應(yīng)面分析法等數(shù)學(xué)統(tǒng)計(jì)方法,分別對(duì)L-1和La-5凍干保護(hù)劑進(jìn)行優(yōu)化,試驗(yàn)得出L-1凍干保護(hù)劑的最佳配方為:海藻糖18%、甘油6%、維生素C 0.1%、明膠0.1%,雙歧桿菌的凍干粉凍干保護(hù)率可達(dá)86.7%;嗜酸乳桿菌La-5凍干保護(hù)劑的最佳配方為:海藻糖19%,甘油6%,MnSO_40.1%,明膠0.1%,嗜酸乳桿菌菌的凍干粉凍干保護(hù)率可達(dá)96.8%,經(jīng)驗(yàn)證均與模型預(yù)測(cè)基本相符。 經(jīng)過(guò)儲(chǔ)藏穩(wěn)定性試驗(yàn)得出,L-1與La-5凍干粉經(jīng)過(guò)密封包裝,儲(chǔ)存60天后,在20℃(即常溫)儲(chǔ)存條件下,L-1凍干粉活菌數(shù)僅下降0.68個(gè)對(duì)數(shù)點(diǎn),為10~(9.32)cfu/g。La-5凍干粉活菌數(shù)只0.15個(gè)對(duì)數(shù)點(diǎn),為10~(10.85)cfu/g;在37℃儲(chǔ)存條件下,L-1凍干粉活菌數(shù)下降1.31個(gè)對(duì)數(shù)點(diǎn),為10~(8.69)cfu/ g。La-5凍干粉活菌數(shù)下降0.25個(gè)對(duì)數(shù)點(diǎn),為10~(10.75)cfu/g。 以新鮮牛奶為原料,采用中溫乳糖酶水解制得低乳糖奶粉。應(yīng)用單因素試驗(yàn)和均勻試驗(yàn),確定各因素對(duì)奶粉褐變程度的影響。結(jié)果表明,影響褐變程度的因素依次為:水解的溫度㧐水解的pH值㧐褐變抑制劑添加時(shí)間㧐褐變抑制劑的用量。最佳工藝條件為:乳糖酶添加量為0.15U/kg,水解的溫度39℃,水解的pH值為6.6,復(fù)合褐變抑制劑(BHA:VE=1:1)添加量為0.1%,添加時(shí)間為水解前20min。該條件下制備的低乳糖奶粉乳糖水解率能夠達(dá)70%,白度達(dá)到87.2。將兩種菌的凍干粉等量混合用4層復(fù)合材料包裝成2g獨(dú)立包裝。添加到低乳糖乳粉,凍干粉的添加量為1袋/10g。
[Abstract]:Bifidobacterium and Lactobacillus acidophilus are microecological regulators of the human body. Studies have found that to achieve the desired health effects, generally speaking, the number of living organisms in food is not less than 10-6 cfu/mL or the daily intake is about 10-8 cfu. Only in this way can the decrease of probiotics in the stomach and intestines be compensated. How to increase the viability of probiotic bacteria in products has become an important research topic in commerce. Bifidobacterium and Lactobacillus acidophilus strains with high adhesion and strong tolerance to human gastrointestinal environment were screened out through experiments. The freeze-drying protectant was optimized and the storage stability of the freeze-drying powder was tested. The freeze-drying powder of the two bacteria was packaged independently and drinked together with the low-lactose milk powder produced by enzymatic hydrolysis to alleviate lactose intolerance and regulate microecology.
Five strains of Bifidobacterium were isolated from three domestic probiotics and healthy infant feces, five strains of Lactobacillus acidophilus, two from two domestic probiotics, two from our laboratory and one from Heilongjiang Institute of Applied Microbiology. The adherence of the tested bacteria to COCA-II was observed by laser confocal microscopy. Three strains of Bifidobacterium and two strains of Lactobacillus acidophilus were screened out by acid-and bile-salt-tolerant tests. The two strains were fed into simulated gastric juice and simulated intestinal juice. After re-screening, one strain of highly tolerant bacteria was screened and named as Bifidobacterium L-1, Lactobacillus acidophilus L-5.L-1 adhering to COCA-II was 16.6+2.1 adherent bacteria/cells, the survival rate was 72% after 120 minutes in simulated gastric juice at pH 3.0, and the number of viable bacteria was still greater than 10-6 cfu/m after 24 hours in simulated intestinal juice with bile salt concentration of 0.2%. L.La-5 still had more viable bacteria than 10-7 cfu/mL after 3 hours of exposure to simulated gastric juice at pH 2.5, and more viable bacteria than 10-6 cfu/mL after 53 hours of exposure to simulated intestinal juice with bile salt concentration of 0.2%.
L-1 and La-5 freeze-drying protectants were optimized by single factor test, factorial test and response surface analysis. The optimum formula of L-1 freeze-drying protectant was obtained as follows: trehalose 18%, glycerol 6%, vitamin C 0.1%, gelatin 0.1%, Bifidobacterium freeze-drying protectant rate 86.7%; Lactobacillus acidophilus La-5 freeze-drying protectant. The optimum formulation of the protectant was trehalose 19%, glycerol 6%, MnSO_40.1%, gelatin 0.1%, and the freeze-drying protective rate of Lactobacillus acidophilus powder was 96.8%. The experimental results showed that the protective rate was basically consistent with the model prediction.
The results of storage stability test showed that the viable bacteria count of L-1 and La-5 freeze-dried powder decreased by 0.68 logarithm points after 60 days storage at 20 C (normal temperature), and the viable bacteria count of L-1 freeze-dried powder was only 0.15 logarithm points of 10_ (9.32) cfu/g. La-5 freeze-dried powder and 10_ (10.85) cfu/g under 37 C storage condition. 1.31 logarithmic points, 10 ~ (8.69) CFU / g.La-5 lyophilized powder viable bacteria count decreased by 0.25 logarithmic points, 10 ~ (10.75) CFU / g.
Low lactose milk powder was prepared from fresh milk by hydrolysis of lactase at medium temperature.The effects of various factors on browning degree of milk powder were determined by single factor test and uniform test.The results showed that the factors influencing browning degree were: hydrolysis temperature? PH value of hydrolysis? Adding time of browning inhibitor? Dosage of browning inhibitor. The technological conditions were as follows: the addition of lactase was 0.15U/kg, the hydrolysis temperature was 39 C, the hydrolysis pH was 6.6, the addition of compound browning inhibitor (BHA:VE=1:1) was 0.1%, and the addition time was 20 minutes before hydrolysis. The material was packaged into 2G independent packaging. The addition of low lactose milk powder to freeze-dried powder was 1 bags of /10g..
【學(xué)位授予單位】：黑龍江八一農(nóng)墾大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2008
【分類號(hào)】：R371

【引證文獻(xiàn)】

相關(guān)期刊論文 前2條

1 劉延國(guó);張琳;馮香安;李杰;;益生菌在消化道中的抑菌作用[J];中國(guó)飼料;2011年16期

2 陳琳;彭虹旎;孔垂斌;王增元;呂左航;甄麗;;幾株飼用益生菌對(duì)體外模擬胃腸道環(huán)境的抗逆性評(píng)估[J];中國(guó)微生態(tài)學(xué)雜志;2010年08期

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本文編號(hào)：2176102