本文選題：谷粒態(tài)β-葡聚糖 + 存在形式��； 參考：《江南大學(xué)》2016年碩士論文

【摘要】：流行病學(xué)和臨床研究表明,全谷物燕麥的攝入會改善癌癥、心血管疾病和糖尿病的癥狀,而這其中的膳食纖維β-葡聚糖發(fā)揮了主要作用,β-葡聚糖是葡萄糖單體通過(1,3)-(1,4)-β-糖苷鍵連接起來的非淀粉多糖。目前,絕大部分研究都以提取純化的燕麥β-葡聚糖為研究對象,從其理化性質(zhì),比如粘度(分子量和濃度)來考慮其在降血糖,延緩淀粉消化等方面的功能,而以非提取的燕麥β-葡聚糖(保持β-葡聚糖在燕麥顆粒中原有的分布形式和存在狀態(tài),稱為‘谷粒態(tài)’β-葡聚糖)為研究對象的報(bào)道比較鮮見。因此,本課題探究了提取的β-葡聚糖和燕麥粉中谷粒態(tài)β-葡聚糖對餐后血糖影響的差異以及機(jī)理,同時(shí)以高脂膳食所喂養(yǎng)的C57BL/6J小鼠為模型,探究兩者對糖脂代謝影響的差異以及機(jī)理。本實(shí)驗(yàn)將燕麥粒磨粉、過篩,按照顆粒大小分級成了四種具有不同谷粒態(tài)β-葡聚糖含量的燕麥粉樣品,顆粒越大含越多的谷粒態(tài)β-葡聚糖和蛋白質(zhì),并且兩者的含量呈正相關(guān)。體外消化實(shí)驗(yàn)表明,燕麥粉中淀粉的消化速度隨著顆粒的減小而增大;胃蛋白酶和β-葡聚糖酶預(yù)處理燕麥粉后,提高了淀粉的水解速度,但外加β-葡聚糖于消化體系時(shí),對所提取純化淀粉的消化特性無顯著影響。燕麥粉糊化特性的研究表明糊化粘度值與顆粒大小呈正相關(guān),且β-葡聚糖酶預(yù)處理燕麥粉后,其糊化衰減值以及最終粘度也顯著下降。餐后血糖實(shí)驗(yàn)顯示,大顆粒燕麥粉的餐后血糖曲線峰值比小顆粒燕麥粉的峰值更低,同時(shí)添加等量提取的β-葡聚糖到小顆粒燕麥粉體系中,其餐后血糖曲線的峰值與大顆粒燕麥粉的血糖峰值仍存在顯著差異。推測燕麥粉中的蛋白質(zhì)、β-葡聚糖可能對淀粉形成了一種物理包裹結(jié)構(gòu),降低了消化酶與淀粉的接觸度,從而延緩了燕麥粉中淀粉的消化。采用高脂膳食喂養(yǎng)的C57BL/6J小鼠為模型,體內(nèi)實(shí)驗(yàn)結(jié)果顯示提取的β-葡聚糖和燕麥粉中谷粒態(tài)β-葡聚糖對小鼠的血糖、血脂、食欲調(diào)控都具有顯著影響。β-葡聚糖提高了小鼠肝臟中GK活性,促進(jìn)肝糖原合成;降低肝臟中G-6-Pase活性;降低了血液中TG和TC的含量以及OGTT曲線的GAUC;降低了GHbA1C含量。進(jìn)一步的實(shí)驗(yàn)顯示,β-葡聚糖可以促進(jìn)小腸糖異生作用,進(jìn)而提高胰島素的敏感性,抑制了促進(jìn)食欲的神經(jīng)肽NPY的分泌,同時(shí)提高了抑制食欲的神經(jīng)肽POMC的分泌。本文的創(chuàng)新點(diǎn)在于,從全谷物的角度出發(fā),探究了燕麥顆粒(粉)中谷粒態(tài)β-葡聚糖的存在形式和結(jié)構(gòu);開發(fā)了一種以物理加工為基礎(chǔ)的富集燕麥顆粒中β-葡聚糖的方法;并且首次從小腸糖異生的角度,探究了β-葡聚糖發(fā)揮有益生理功能可能的機(jī)理。
[Abstract]:Epidemiological and clinical studies have shown that whole-grain oats can improve symptoms of cancer, cardiovascular disease and diabetes. The dietary fiber 尾 -glucan plays a major role in this process. 尾 -glucan is a non-starch polysaccharide which is connected by a glucose monomer through the bond of 尾 -glucan and 尾 -glucan. At present, most of the studies focus on the extraction and purification of oat 尾 -glucan, and consider its function in lowering blood sugar and delaying starch digestion from its physical and chemical properties, such as viscosity (molecular weight and concentration). However, there are few reports on non-extracted oat 尾 -glucan (keeping the original distribution form and existing state of 尾 -glucan in oat granules, called 'grain state' 尾 -glucan). Therefore, the effects of 尾 -glucan and granulated 尾 -glucan on postprandial blood glucose in C57BL/6J mice fed with high fat diet were investigated. To explore the difference and mechanism of their effects on glucose and lipid metabolism. In this experiment, four kinds of oat flour samples with different grain 尾 -glucan content were classified into four kinds of oat flour samples with different grain size by grinding and sifting. The larger the grain size was, the more grain 尾 -glucan and protein were contained, and the two contents were positively correlated. In vitro digestion experiments showed that the digestion rate of starch in oat flour increased with the decrease of grain size, and that pepsin and 尾 -glucanase increased the hydrolysis rate of starch after pretreatment with pepsin and 尾 -glucanase, but when 尾 -glucan was added to the digestion system, There was no significant effect on the digestibility of the purified starch. The gelatinization properties of oat flour showed that the gelatinization viscosity was positively correlated with the particle size, and the gelatinization attenuation value and final viscosity of oat flour pretreated with 尾 -glucanase also decreased significantly. Postprandial blood glucose test showed that the peak of postprandial glucose curve of large granulated oat meal was lower than that of small granulated oat meal, and the same amount of 尾 -glucan was added to the small granulated oat meal system. There was still a significant difference between the peak of postprandial blood glucose curve and that of large granulated oat meal. It is speculated that the protein in oat meal, 尾 -glucan, may form a kind of physical encapsulation structure to starch, which reduces the contact degree between digestive enzyme and starch, thus delaying the digestion of starch in oat meal. C57BL/6J mice fed with high fat diet were used as the model. The results of in vivo experiments showed that the extracted 尾 -glucan and granulated 尾 -glucan in oat meal treated the blood glucose and blood lipid of mice. 尾 -glucan increased the activity of GK in liver of mice, promoted the synthesis of glycogen in liver, decreased the activity of G-6-Pase in liver, decreased the contents of TG and TC in blood and GAUCof OGTT curve, and decreased the content of GHbA1C. Further experiments showed that 尾 -glucan could promote the small intestinal glycosylation, thus increase insulin sensitivity, inhibit the secretion of appetite-promoting neuropeptide NPY, and increase the secretion of appetite-inhibiting neuropeptide POMC. The innovation of this paper is to explore the form and structure of 尾 -glucan in granulated oats from the point of view of whole grain, to develop a method of enriching 尾 -glucan in oat grains based on physical processing. From the point of view of small intestinal glycosylation, the possible mechanism of 尾-glucan's beneficial physiological function was explored for the first time.
【學(xué)位授予單位】：江南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：R151
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本文編號：1889276