【摘要】：共軛亞油酸(CLA)具有優(yōu)越的生理功能,在藥物、食品、生物等領(lǐng)域具有廣闊的應(yīng)用前景。然而,CLA水溶性差,在含水體系中的利用率及生物利用度有限、易被空氣氧化變質(zhì)。本課題以蠟質(zhì)玉米淀粉為原料,經(jīng)異淀粉酶脫支處理后得到直鏈糊精;再以直鏈糊精為包合載體,優(yōu)化水-乙醇法制備了直鏈糊精-CLA復(fù)合物,提高了CLA的水溶性、氧化穩(wěn)定性,實(shí)現(xiàn)了CLA在小腸內(nèi)的控制釋放。主要的研究結(jié)果如下:采用3,5-二硝基水楊酸(DNS)比色法考察不同溫度、p H值、異淀粉酶添加量、反應(yīng)時(shí)間對(duì)蠟質(zhì)玉米淀粉脫支效果的影響。結(jié)果表明:p H值3.5,異淀粉酶用量7.5 U/g淀粉,溫度40℃,反應(yīng)時(shí)間12 h時(shí),蠟質(zhì)玉米淀粉的脫支效果最佳。脫支得到的直鏈糊精鏈長(zhǎng)分布由高效體積排阻色譜法(HPSEC)分析表明蠟質(zhì)玉米淀粉的脫支程度完全,直鏈糊精的聚合度(DP)為6~150。通過比較復(fù)合物的產(chǎn)率、CLA復(fù)合率及結(jié)晶度考察不同的復(fù)合條件對(duì)直鏈糊精-CLA復(fù)合物復(fù)合效果的影響,以確定最佳的復(fù)合物制備工藝條件。結(jié)果顯示復(fù)合溫度、直鏈糊精濃度對(duì)產(chǎn)率的影響較為顯著;溫度、溶解CLA的乙醇用量及保溫時(shí)間對(duì)復(fù)合率有一定的影響;而除了保溫時(shí)間,其他的復(fù)合條件都對(duì)復(fù)合物的結(jié)晶結(jié)構(gòu)產(chǎn)生顯著的影響。最優(yōu)的復(fù)合條件為糊精溶液濃度1%,直鏈糊精與CLA的質(zhì)量比12:1,用于溶解CLA的乙醇用量1 m L,復(fù)合溫度30℃,攪拌保溫2 h。復(fù)合物的形成由差示掃描量熱法(DSC)、X-射線衍射(X-RD)、熱重分析(TGA)、紅外光譜(IR)進(jìn)行驗(yàn)證并用掃描電鏡(SEM)觀察復(fù)合物的微觀結(jié)構(gòu)。結(jié)果表明:CLA與直鏈糊精發(fā)生了絡(luò)合,形成的復(fù)合物為VⅡ型結(jié)構(gòu),結(jié)晶熔融峰峰值溫度為83.4℃。復(fù)合物呈薄片狀,表面光滑,但具有輕微程度的裂紋。對(duì)復(fù)合物的氧化穩(wěn)定性、控制釋放性、粒徑大小分布及溶解度等理化特性進(jìn)行了研究,并探究了超聲波對(duì)復(fù)合物粒徑大小和儲(chǔ)存穩(wěn)定性的影響。結(jié)果表明,直鏈糊精-CLA復(fù)合物具有良好的氧化穩(wěn)定性。復(fù)合物在模擬的胃環(huán)境下穩(wěn)定性高;在模擬的小腸環(huán)境下,復(fù)合物中直鏈糊精的水解程度隨酶解時(shí)間的增加而增大,12 h可達(dá)89.5%;而隨著直鏈糊精的水解,CLA的釋放百分比也逐漸增大,12 h可達(dá)34%,表明直鏈糊精-CLA復(fù)合物可作為傳遞體系在小腸中緩慢釋放CLA。未經(jīng)超聲波處理的復(fù)合物懸浮液平均粒徑為708 nm,粒徑分布較寬,儲(chǔ)存1天后出現(xiàn)沉淀;而經(jīng)超聲波處理7 min的平均粒徑約為324 nm,且分布變窄,儲(chǔ)存3天后有少量沉淀;表明超聲波處理一定時(shí)間既可以降低粒子的平均粒徑,又可以改善懸浮液的儲(chǔ)存穩(wěn)定性。室溫下直鏈糊精-CLA復(fù)合物具有較好的溶解度,為62.64%,且隨著溫度的升高而增大,在90℃可達(dá)91.05%;在室溫25℃,p H5的酸性溶液中,復(fù)合物的溶解度很低,而在偏中性溶液中溶解度較高;表明直鏈糊精作為包埋壁材,可以提高復(fù)合物的溶解度,但不適于加入p H5的酸性溶液中。最后,通過HPSEC分析參與復(fù)合物形成的直鏈糊精的鏈長(zhǎng)分布,結(jié)果顯示包合在復(fù)合物中的直鏈糊精鏈長(zhǎng)DP在26~150左右,表明DP26的直鏈糊精不能包埋CLA形成復(fù)合物。
[Abstract]:The common linoleic acid (CLA) has excellent physiological function, and has wide application prospect in the fields of medicine, food, and biology. However, the water-solubility of CLA is limited, and the utilization rate and bioavailability in the aqueous system are limited, and it is easy to be oxidized by air. in that invention, the waxy corn starch is taken as a raw material, and the amylose is obtain through the debranching treatment of the isoamylase, the linear dextrin is used as the inclusion carrier, the water-ethanol method is optimized to prepare the linear dextrin-CLA compound, the water solubility and the oxidation stability of the CLA are improved, And the control release of CLA in the small intestine is realized. The main results are as follows:3,5-dinitrosalicylic acid (DNS) colorimetric method is used to study the effect of different temperature, p-H, isoamylase addition and reaction time on the debranching of waxy corn starch. The results showed that the debranching of waxy corn starch was the best when the content of p H was 3.5, the amount of isoamylase was 7.5 U/ g, the temperature was 40 鈩，

本文編號(hào)：2481738