本文選題：乳脂肪球 + 加工處理��； 參考：《江南大學(xué)》2017年博士論文

【摘要】：乳是哺乳動(dòng)物新生兒的主要營(yíng)養(yǎng)來源。其中的脂肪以脂肪球的形式存在,外圍由獨(dú)特機(jī)制分泌的三層膜包裹。本文圍繞乳脂肪球(MFG)的脂質(zhì)組成及結(jié)構(gòu)特點(diǎn),研究對(duì)比了三種哺乳動(dòng)物(牛、羊和人)MFG的脂質(zhì)組成和微觀結(jié)構(gòu)及不同加工處理對(duì)牛乳MFG脂質(zhì)組成和微觀結(jié)構(gòu)的影響。在此基礎(chǔ)上通過模擬體外消化進(jìn)一步研究它們?cè)趮雰杭俺扇梭w內(nèi)的消化特點(diǎn)及其對(duì)細(xì)菌與HT-29細(xì)胞的粘附及侵染作用,為開發(fā)合適的母乳替代品提供理論依據(jù)。主要研究?jī)?nèi)容包括:首先,應(yīng)用色譜分析及顯微檢測(cè)手段全面分析了牛乳、羊乳和人乳MFG的脂質(zhì)組成、理化性質(zhì)和微觀結(jié)構(gòu)。結(jié)果表明:牛乳和羊乳含有較高比例的飽和脂肪酸(60%),而人乳中的飽和脂肪酸比例40%,且人乳中C18:2的含量大約是牛乳和羊乳的7倍以上。人乳中膽固醇的含量比牛乳和羊乳高約20%。牛乳與羊乳和人乳相比,含有更多的短、中鏈的甘油三酯。牛乳和羊乳中最主要的磷脂為磷脂酰膽堿(PC),分別占總磷脂組分的33.1%和31.6%。而人乳中最主要的磷脂則為鞘磷脂(SM)占29.28%。牛乳和羊乳中的磷脂酰乙醇胺(PE)、SM和磷脂酰肌醇(PI)含有的脂肪酸組成類似。人乳中的PE、磷脂酰絲氨酸(PS)和PC中含有的不飽和脂肪酸(40%)比牛乳和羊乳高。羊乳MFG的平均粒徑最小,Z-電位的值也最低。從激光共聚焦顯微圖片可知,液態(tài)有序區(qū)(Lo)的形狀和大小也與物種有關(guān)。牛乳MFG中主要為圓形,羊乳中大部分形狀不規(guī)則,而人乳中則以圓形和不規(guī)則形共存。由拉曼共聚焦光譜圖可知,人乳和牛乳MFG的不飽和度隨著MFG粒徑的增大而降低,而羊乳中則是中等大小的MFG的不飽和度最高。人乳中類胡蘿卜素的峰強(qiáng)度比羊乳和牛乳高,且隨著粒徑的減小而增強(qiáng)。其次,對(duì)比研究了乳粉生產(chǎn)過程對(duì)MFG微觀結(jié)構(gòu)及組成的影響。結(jié)果表明:除總脂肪酸的組成沒有明顯改變外,磷脂、膽固醇和磷脂脂肪酸的組成都發(fā)生了變化。牛乳MFG經(jīng)巴氏殺菌后,磷脂的含量和分布相對(duì)穩(wěn)定。均質(zhì)對(duì)PE、PS和SM的含量影響最大。噴霧干燥之后PE的含量由28%降低到22%。膽固醇的含量也隨著巴氏殺菌和均質(zhì)處理而降低。巴氏殺菌后的乳脂肪球膜(MFGM)依然呈圓環(huán)狀包裹在MFG外圍,但是熒光環(huán)結(jié)構(gòu)較松散。均質(zhì)和噴霧干燥之后MFGM結(jié)構(gòu)完全破壞,熒光探針呈點(diǎn)狀分布。經(jīng)過真空冷凍干燥和噴霧干燥這兩種不同的干燥處理后,MFG的粒徑變大,但其MFGM結(jié)構(gòu)依然保持完整。這兩種不同的干燥處理對(duì)磷脂及膽固醇的含量影響較大,我們推測(cè)脂肪球的Lo區(qū)更容易受低溫干燥的影響,而液態(tài)無序(Ld)區(qū)更容易受高溫干燥的影響。然后,通過體外實(shí)驗(yàn)?zāi)M研究不同動(dòng)物MFG在嬰兒及成人胃腸道的消化特點(diǎn)。結(jié)果表明:三種哺乳動(dòng)物MFG在嬰兒體外消化過程中的水解速率為:羊牛人。牛、羊和人乳MFG消化后的脂解產(chǎn)物中,游離脂肪酸(FFA)分別占總脂肪的76.06%、60.72%和68.89%。牛乳和羊乳比人乳產(chǎn)生更多的短、中鏈脂肪酸和飽和脂肪酸。牛乳和人乳消化產(chǎn)物中膽固醇的含量比未消化時(shí)增加了將近0.5倍,而羊乳則無明顯差異。三種哺乳動(dòng)物MFG中的磷脂主要是PE、PC和SM發(fā)生了水解,且PE的水解程度最高。由激光共聚焦顯微圖像可知,牛乳和羊乳經(jīng)過30 min胃消化后,MFG的粒徑減小,一部分MFG聚集在一起,之后相互融合形成大MFG。而人乳MFG的粒徑則一直呈減小趨勢(shì)。牛乳和羊乳MFG在成人體外腸消化前10 min內(nèi),沒有出現(xiàn)之前文獻(xiàn)報(bào)道的延滯期,水解速度很快,脂解產(chǎn)物的比例有明顯區(qū)別。但是產(chǎn)生的FFA的組成及含量除了C10:0和C14:0并無顯著差異。消化產(chǎn)物中膽固醇的含量比嬰兒體外消化產(chǎn)物中高,分別為424mg/100g和387 mg/100g。成人體外消化過程中也主要是PE、PC和SM發(fā)生了水解,且PE的水解程度最高。激光共聚焦顯微圖像顯示,在成人體外胃消化過程中MFG大量的聚集幾乎不發(fā)生消化,MFGM的結(jié)構(gòu)依然保持完整。經(jīng)過腸液消化后,可以看到由消化產(chǎn)物與未消化的TAG及蛋白形成中間有空洞的脂肪顆粒。不同加工處理的MFG在嬰兒體外胃消化時(shí),生乳和巴氏殺菌乳的延滯期要比均質(zhì)乳和噴霧干燥乳的長(zhǎng)。噴霧干燥之后的乳,脂解速度明顯快于其它三種乳。嬰兒體外腸消化過程中,生乳、均質(zhì)乳及噴霧干燥乳的脂解速率沒有顯著差異,而巴氏殺菌乳的消化速率最低。均質(zhì)乳和噴霧干燥乳中未水解的TAG最高,分別占16%和21%。均質(zhì)和噴霧干燥處理也影響了消化產(chǎn)物中膽固醇的含量,與生乳和巴氏殺菌乳相比約減少10%。巴氏殺菌、均質(zhì)和噴霧干燥都增加了PC的水解度。四種不同加工處理的MFG經(jīng)過嬰兒體外胃消化1 h后,都有部分MFG發(fā)生聚集,尤其是均質(zhì)乳和噴霧干燥乳。經(jīng)過腸消化后進(jìn)一步形成更小粒徑的MFG,其中噴霧干燥乳消化后仍然有一部分大的脂肪液滴存在。隨著消化的進(jìn)行MFGM的環(huán)狀熒光結(jié)構(gòu)都消失了,整個(gè)顆粒都被磷脂探針Rh-DOPE染成了紅色。生乳、巴氏殺菌乳、均質(zhì)乳及噴霧干燥乳在成人體外腸消化的前10 min,脂解速率分別達(dá)到23、16.8、21.6和20.4μmol/m L乳。巴氏殺菌乳中未水解的TAG最高,占10.86%。加工處理對(duì)釋放的FFA的種類和含量無影響,但是對(duì)水解產(chǎn)物MAG的脂肪酸組成卻有明顯的區(qū)別。成人體外胃腸道消化后與嬰兒相比增加了消化產(chǎn)物中膽固醇的含量。不同加工處理的MFG在成人胃中容易發(fā)生聚集。牛乳和巴氏殺菌乳MFG在成人體外胃消化1 h后,依然能檢測(cè)到MFGM的環(huán)狀熒光。經(jīng)過2 h腸消化后,環(huán)狀的熒光環(huán)消失后膜磷脂被膽鹽取代,MFG被胰脂肪酶進(jìn)一步分解為小的顆粒。但是巴氏殺菌乳中依然有一些聚集的大微粒存在。最后,研究了不同MFG對(duì)細(xì)菌與HT-29細(xì)胞的粘附及侵染作用。結(jié)果表明:不同動(dòng)物(牛、羊和人)的MFG都會(huì)促進(jìn)益生菌(德氏乳桿菌保加利亞亞種、嗜酸乳桿菌、嬰兒雙岐桿菌和長(zhǎng)雙歧桿菌嬰兒亞種)與HT-29細(xì)胞的粘附。羊乳MFG對(duì)長(zhǎng)雙歧桿菌有良好的促粘附的作用。人乳MFG對(duì)嬰兒雙歧桿菌表現(xiàn)出較高的促粘附作用。人乳MFG對(duì)于德氏乳桿菌保加利亞亞種的促粘附作用最小,不及牛乳MFG和羊乳MFG。并且羊乳MFG比牛乳和人乳MFG對(duì)四種益生菌都表現(xiàn)出較高的促粘附作用。這三種哺乳動(dòng)物MFG都對(duì)致病菌(沙門氏菌、阪崎腸桿菌和大腸桿菌)與HT-29細(xì)胞的粘附有抑制作用,但是羊乳MFG對(duì)這三種致病菌的抑制效果明顯優(yōu)于牛MFG,人乳MFG對(duì)大腸桿菌的抑制作用最強(qiáng)。經(jīng)過加工處理后的MFG對(duì)益生菌和致病菌粘附到HT-29細(xì)胞的數(shù)量有不同程度的影響。除巴氏殺菌外,加工處理的程度越大,益生菌與HT-29細(xì)胞粘附的數(shù)量越少,對(duì)致病菌的抑制程度越低。
[Abstract]:Milk is the main source of nutrition in mammal newborns. The fat in the form of fatty balls and three layers of membrane secreted by unique mechanisms. The lipid composition and microstructure of the three mammals (cattle, sheep and people) and the different processing places of the lipid composition and structure of the milk fat balls (MFG) are studied and compared in this paper. The lipid composition and structure characteristics of the milk fat balls (MFG) are compared with the three mammals. The effects of the lipid composition and microstructure of milk MFG were studied. On this basis, the digestive characteristics and the adhesion and infection of bacteria to HT-29 cells in infants and adults were further studied by simulated digestion in vitro, and the theoretical basis for the development of appropriate breast milk substitutes was provided. The lipid composition, physicochemical properties and microstructure of milk, goat milk and human milk MFG were analyzed by spectral analysis and microscopic examination. The results showed that milk and goat milk contain a high proportion of saturated fatty acids (60%), and the proportion of saturated fatty acids in human milk is 40%, and the content of C18:2 in human milk is about 7 times more than that of milk and sheep milk. The content of cholesterol is higher than milk and goat milk about 20%. milk and goat milk and human milk. It contains more short, middle chain triglycerides. The main phosphatidylcholine (PC) in milk and goat milk is 33.1% and 31.6%. of the total phosphatidylcholine, and the most important phosphatide in human milk is sphingomyelin (SM) in 29.28%. milk and goat milk. Phosphatidylethanolamine (PE), SM and phosphatidylinositol (PI) contain a similar composition of fatty acids. PE, phosphatidylserine (PS) and PC in human milk are higher than milk and goat milk. The average particle size of the goat milk MFG is the smallest and the Z- potential is the lowest. The shape of the liquid ordered region (Lo) is known from the laser confocal microscope picture. And the size is also related to species. The main shape of the milk MFG is round, most of the shape of the goat milk is irregular, and the human milk coexists with round and irregular shape. The Raman confocal spectrogram shows that the unsaturation of human milk and milk MFG decreases with the increase of the MFG size, while the middle size MFG is the highest unsaturation in the goat milk. The peak intensity of carotenoids in milk was higher than that of goat milk and milk, and increased with the decrease of particle size. Secondly, the effects of the milk powder production process on the microstructure and composition of MFG were compared. The results showed that the composition of the phospholipid, cholesterol and phospholipid fatty acids in Chengdu had changed in addition to the composition of the total fatty acid. After pasteurization, the content and distribution of phospholipids were relatively stable. Homogenization had the greatest influence on the content of PE, PS and SM. After the spray drying, the content of PE decreased from 28% to 22%. cholesterol and decreased with pasteurization and homogenization. After pasteurization, the milk fat globule membrane (MFGM) remained round and round in the periphery of MFG, but the fluorescent ring was in the ring. The structure was looser. After homogenization and spray drying, the structure of MFGM was completely destroyed and the fluorescent probe was distributed in a spot. After two different drying processes, vacuum freeze drying and spray drying, the particle size of MFG became larger, but the structure of MFGM remained intact. These two different drying treatments had great influence on the content of phospholipid and cholesterol. We speculate that the Lo region of the fat ball is more susceptible to low temperature drying, and the liquid disorder (Ld) region is more susceptible to the effect of high temperature drying. Then, the digestive characteristics of different animals MFG in the gastrointestinal tract of infants and adults are studied by experiments in vitro. The results show that the hydrolysis rate of three kinds of mammalian MFG in the process of infant digestion is: sheep The free fatty acid (FFA) accounted for 76.06% of the total fat, 60.72% and 68.89%. milk and goat milk produced more short, medium chain fatty acid and saturated fatty acid than human milk. The content of cholesterol in cow milk and human milk digestion products increased by nearly 0.5 times than that of undigested, and the sheep milk was less obvious than that of the MFG. The phospholipids in the three mammalian MFG were mainly PE, PC and SM, and the hydrolysis of PE was the highest. By laser confocal microscopy, the milk and goat milk were digested by 30 min, the particle size of MFG decreased and some MFG gathered together and then formed a large MFG. and the size of the human milk MFG decreased. The trend. Milk and goat milk MFG in 10 min before the digestion of human intestines, there is no prior period of delay reported in the literature, the rate of hydrolysis is very fast, and the proportion of the hydrolysate products is distinct. But the composition and content of the produced FFA have no significant difference between C10:0 and C14:0. The content of cholesterol in the digestive products is more than in the digestive products of the baby's in vitro. High, PE, PC and SM were hydrolyzed mainly in the process of 424mg/100g and 387 mg/100g. in vitro digestion, and the hydrolysis degree of PE was the highest. The laser confocal microscopic image showed that in the digestive process of the adult stomach, a large number of MFG gathered almost without digestion, and the structure of MFGM remained intact. After digestion of the intestine, it could be obtained. It is found that there are hollow fat particles between the digestive products and the undigested TAG and protein formation. The delay period of the raw milk and pasteurized milk is longer than that of the homogenized milk and the spray dry milk during the digestion of the baby's stomach in vitro. The milk after spray drying is faster than the other three kinds of milk. During the process, there was no significant difference in the lipo rate of raw milk, homogeneous milk and spray drying milk, but the digestion rate of pasteurized milk was the lowest. The highest TAG in homogeneous milk and spray dried milk, 16% and 21%. homogenization and spray drying, were also affected by the content of cholesterol in the digestive products, compared with the milk and pasteurized milk. Reducing 10%. pasteurization, homogenization and spray drying increased the degree of hydrolysis of PC. Four different processed MFG had a partial aggregation of MFG after the digestion of the stomach for 1 h in the baby's stomach, especially the homogenized milk and spray dry milk. After digestion, the MFG was further formed with a smaller particle size, and there was still one after the spray drying milk was digested. The large fat droplets exist. As the cyclic fluorescent structure of MFGM disappears, the whole particle is dyed red by the phospholipid probe Rh-DOPE. Raw milk, pasteurized milk, homogenized milk and spray dry milk are in the first 10 min of the digestive tract of human intestines, the rate of lipid is 23,16.8,21.6 and 20.4 mu mol/m L milk. Pasteurized milk The unhydrolyzed TAG was the highest, which accounted for no effect on the type and content of FFA released by 10.86%. processing, but there was a distinct difference in the fatty acid composition of the hydrolysate MAG. The content of cholesterol in the digestive products was increased after the digestive tract digestion in adults. The MFG in the adult stomach was easy to accumulate in the adult stomach. Milk and pasteurized milk MFG can still detect the ring fluorescence of MFGM after digestion of the stomach of adults in vitro for 1 h. After digestion of 2 h intestines, the ring phospholipid is replaced by the bile salt and MFG is further decomposed into small particles by the pancreatic lipase. However, there are some large particles in the pasteurized milk. Finally, the study is done. The adhesion and infection effect of different MFG on bacteria and HT-29 cells showed that the MFG of different animals (cattle, sheep and human) would promote the adhesion of probiotics (Lactobacillus bulgaricus subspecies, Lactobacillus acidophilus, Bifidobacterium infantile and Bifidobacterium infantile subspecies) with HT-29 cells. Goat milk MFG has good adhesion to bifidobacteria. Human milk MFG showed higher adhesion to Bifidobacterium infantile. Human milk MFG had the smallest adhesion to the Bulgarian subspecies of Lactobacillus Deshi, less milk MFG and goat milk MFG., and the goat milk MFG showed higher adhesion to four probiotics than milk and MFG of human milk. These three mammalian MFG were both induced by MFG. The bacteria (Salmonella, sakazakibacillus sakazakybacilli and Escherichia coli) inhibited the adhesion of HT-29 cells, but the inhibitory effect of goat milk MFG on these three pathogenic bacteria was obviously better than that of bovine MFG, and the inhibitory effect of human milk MFG on Escherichia coli was the strongest. The number of probiotics and pathogenic bacteria adhered to HT-29 cells after processing MFG was different. In addition to pasteurization, the greater the degree of processing, the less the probiotics adhered to HT-29 cells, and the lower the degree of inhibition to pathogenic bacteria.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：TS252.1

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 巫慶華,龔廣予;巴氏殺菌牛乳和UHT牛乳的差別[J];乳業(yè)科學(xué)與技術(shù);2003年04期

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本文編號(hào)：2035459