【摘要】：酪蛋白膠束粉(Micellar casein concentrate,MCC)是采用膜分離技術(shù)生產(chǎn)的蛋白產(chǎn)品。與傳統(tǒng)酸沉或酶凝法生產(chǎn)的酪蛋白相比,MCC保留了酪蛋白的天然膠束結(jié)構(gòu),表現(xiàn)出優(yōu)異的溶解性、起泡性和風(fēng)味等特性,用于蛋白飲料、冰激凌、干酪、酸奶、糕點及功能食品等,應(yīng)用前景廣闊。為早日實現(xiàn)MCC國內(nèi)工業(yè)化生產(chǎn),本文研究了MCC的膜分離生產(chǎn)工藝、噴霧干燥溫度對MCC功能特性和微觀結(jié)構(gòu)的影響和超聲對MCC功能特性及微觀結(jié)構(gòu)的影響。本文選用200 nm陶瓷膜對脫脂乳中乳清蛋白、乳糖、灰分和鈣進(jìn)行脫除。結(jié)果表明:膜通量維持在20 Lm-2h-1,累計脫除率方面,乳糖的脫除率為85.81%,x-乳白蛋白(α-Lactalbumin, α-La)的脫除率為 79.27%, β-乳球蛋白(β-Lactoglobulin, β-Lg)的脫除率為71.64%,灰分的脫除率為62.16%,鈣的脫除率為35.64%。稀釋過濾完畢,膜的純水通量衰減89.27%,經(jīng)質(zhì)量分?jǐn)?shù)為2%氫氧化鈉和0.5%的硝酸溶液清洗后,膜通量恢復(fù)99.07%,膜通量得到很好的恢復(fù)。開展了噴霧干燥溫度對MCC功能特性和微觀結(jié)構(gòu)的影響。設(shè)定不同的進(jìn)出口溫度130℃/65℃,160℃/78℃, 180℃/90℃對酪蛋白截留液進(jìn)行噴霧干燥處理,研究結(jié)果表明,噴霧干燥溫度為130℃/65℃時,MCC分子表面平整,微觀結(jié)構(gòu)完整;當(dāng)溫度上升至180℃/90℃時,MCC表面變得粗糙,并且伴有凹陷。隨著噴霧溫度的上升,MCC的粒徑D50從14.13μm降低到10.47μm,溶解度從84.14%降低到60.44%,水分含量從4.07%降低到3.20%, MCC粉末的流動性指數(shù)從4.16減小到1.27。探索了超聲對MCC功能特性和微觀結(jié)構(gòu)的影響。微濾生產(chǎn)的酪蛋白截留液經(jīng)超聲處理(超聲功率600 W、超聲時間0 min、0.5 min、1 min、2 min、5 min)后噴霧干燥,得到經(jīng)超聲改性的MCC。結(jié)果表明,隨著超聲時間的延長MCC溶液的電導(dǎo)率從454.00 μS.cm-1增加到460.67μS.cm-1,溶解性從84.14%增加到91.03%,疏水作用力從166.32增加到336.96。從傅里葉紅外光譜可以得出,α-螺旋從26.39%減少至22.82%, β-轉(zhuǎn)角從20.30%減少至13.94,而β-折疊從31.19%增加到34.56%,自由卷積從22.11 %增加到27.22%。從電泳的結(jié)果可知,蛋白的一級結(jié)構(gòu)沒有發(fā)生明顯變化。電鏡的結(jié)果表明蛋白的微觀結(jié)構(gòu)發(fā)生變化,粒徑明顯變小。在MCC粉體性質(zhì)方面,隨著超聲時間的延長,粉末壓縮性顯著降低,流動指數(shù)(Flow index,ffc)從4.11減小到1.67,基本流動能(Bais flowabilityenergy,BFE)在超聲處理0.5 min達(dá)到最小值709.31 mJ;特殊流動能(Specific energy,SE)在超聲 1 min 達(dá)到最大值 15.90 mJ/g。本研究通過膜技術(shù)將酪蛋白從脫脂乳中分離,為MCC的工業(yè)化生產(chǎn)提供了參考。為生產(chǎn)出品質(zhì)更優(yōu)的MCC,從噴霧干燥工藝和超聲改性兩個方面進(jìn)行工藝優(yōu)化,改善了 MCC的功能特性,促進(jìn)了 MCC在食品工業(yè)中的應(yīng)用。
[Abstract]:Casein micellar powder (Micellar casein concentrate,MCC) is a protein product produced by membrane separation technology. Compared with the casein produced by traditional acid precipitation or enzyme coagulation method, MCC retains the natural micellar structure of casein and shows excellent solubility, foaming and flavor. It is used in protein drinks, ice cream, cheese, yoghurt, pastries and functional foods. In order to realize the domestic industrial production of MCC at an early date, the membrane separation process of MCC, the effect of spray drying temperature on the functional characteristics and microstructure of MCC and the effect of ultrasound on the functional characteristics and microstructure of MCC were studied in this paper. In this paper, 200 nm ceramic membrane was used to remove whey protein, lactose, ash and calcium from skim milk. The results showed that the membrane flux was maintained at the cumulative removal rate of 20 Lm-2h-1, the removal rate of lactose was 85.81%, the removal rate of x-Lactalbumin, 偽-La was 79.27%, the removal rate of 尾-Lactoglobulin, 尾-Lg was 71.64%, the removal rate of ash was 62.16%, and the removal rate of calcium was 35.64%. After dilution and filtration, the pure water flux of the membrane decreased by 89.27%. After cleaning with 2% sodium hydroxide and 0.5% nitric acid solution, the membrane flux recovered 99.07% and the membrane flux recovered very well. The effect of spray drying temperature on the functional characteristics and microstructure of MCC was carried out. The casein interception solution was sprayed at different inlet and outlet temperatures of 130 鈩，

本文編號：2497768