响应面法优化中碳链脂肪酸甘油三酯微胶囊制备配方的研究

中碳链脂肪酸甘油三酯具有降低体重、调节脂代谢、缓解疲劳等功效,其常温下为液态,为方便其在食品领域应用,以乳清蛋白、菊粉为壁材,采用喷雾干燥的方法制备中碳链脂肪酸甘油三酯微胶囊。通过单因素实验,考察复配壁材比例、壁材添加量、芯壁比、乳化剂添加量、复配乳化剂比例对中碳链脂肪酸甘油三酯微胶囊包埋率的影响,采用Box-Behnken设计响应面实验优化中碳链脂肪酸甘油三酯微胶囊的制备配方,并测定制备的中碳链脂肪酸甘油三酯微胶囊基本理化性质。结果表明：中碳链脂肪酸甘油三酯微胶囊最佳制备配方为乳清蛋白：菊粉3∶1(w/w)、乳化剂添加量0.4 g/100 mL、芯壁比1∶1(w/w)、复配壁材（乳清蛋白和菊粉）添加量14 g/100 mL、复配乳化剂（单甘酯∶羧甲基纤维素钠）1∶1(w/w),在此条件下制备的中碳链脂肪酸甘油三酯微胶囊包埋率可达95%,具有良好流动性、分散性及溶解性,粒径分布均匀,平均粒径为4.43μm。     

Crystal morphology of mixtures of tripalmitin and butterfat

Blends of butterfat and tripalmitin are of interest for use as moisture barriers in edible films. Tripalmitin was blended with butterfat in the ratios 100:0, 90:10, 80:20, and so on through to 10:90 and 0:100. Crystal morphologies of squash and smear preparations were determined by polarizing light microscopy. Samples were stored at 19–22°C and re-examined after 6 d and after 30 d. Morphology was strongly dependent on composition and the presence of a coverslip. Morphology was less dependent on polymorphic form and age. Barrier properties depend more strongly on morphology than on polymorphic form.     

超临界CO_2酶法合成低热量三酰甘油工艺条件的优化

研究了在超临界CO2状态下酶法酯化合成长短链脂肪酸三酰甘油的工艺条件,选用脂肪酶Lipozyme RM IM,以酯化率为参考指标,通过单因素试验考察反应压力、反应温度、反应时间、体系水分添加量、酶用量和底物物质的量比对酯化率的影响,再通过响应面对工艺条件进行优化,结果:反应压力11 MPa、反应温度56℃、反应时间15 h、体系水分添加量2.5%、酶用量4%、底物物质的量比3∶1。在此最佳工艺条件下进行酯交换试验,测得产品的酯化率为65.3%,且此法制得的三酰甘油热量值较普通葵花油降低了大约50%。     

High-performance liquid chromatography of the triacylglycerols ofVernonia galamensis andCrepis alpina seed oils

The triacylglycerols ofVernonia galamensis andCrepis alpina seed oils were characterized because these oils have high concentrations of vernolic (cis-12,13-epoxy-cis-9-octadecenoic) and crepenynic (cis-9-octadecen-12-ynoic) acids, respectively. The triacylglycerols were separated from other components of crude oils by solid-phase extraction, followed by resolution and quantitation of the individual triacylglycerols by reversed-phase high-performance liquid chromatography with an acetonitrile/methylene chloride gradient and flame-ionization detection. Isolated triacylglycerols were characterized by proton and carbon nuclear magnetic resonance and by capillary gas chromatography of their fatty acid methyl esters. The locations of the fatty acids on the glycerol moieties in the oils were obtained by lipolysis. TheVernonia galamensis oil contained 50% trivernoloyl and 21% divernoloyllinoleoyl glycerols along with 20% triacylglycerols with one vernolic and two other fatty acids. TheCrepis alpina oil contained 36% tricrepenynoyl and 33% dicrepenynoyllinoleoyl glycerols, 17% triacylglycerols with two crepenynic and one other fatty acid and 7% triacylglycerols with one crepenynic acid and two other fatty acids. Vernolic acid was found at both the 1(3)- and 2-glycerol carbons but was more abundant at the 1,(3)-position in theVernonia galamensis oil. Crepenynic acid was found at both glycerol carbon positions but was more abundant at the 2-position in theCrepis alpina oil. Visiting scientist from Technical Research Institute, Snow Brand Milk Company, Ltd., Saitana, Japan.     

Solid fat content determination using ultrasonic velocity measurements

The ultrasonic group velocity has been measured through 0–20% mass fraction samples of tristearin, tripalmitin, trilaurin and 1-oleodipalmitin suspended in paraffin oil at 25°C and 1 MHz. For tristearin, tripalmitin and trilaurin there is an increase of about 3.1 m/sec per 1% increase in insoluble triglyceride in suspension. For trilaurin and 1-oleodipalmitin there is a slight decrease in velocity with increasing soluble triglyceride. The technique may, therefore, prove useful for determination of solubilities of triglycerides in suspension, as well as for determining solid fat contents. For the tristearin/paraffin oil suspensions there is a good correlation between the solid content added and that predicted by a theoretical formula available in the literature (correlation = 0.998 for twenty samples). The reproducibility of the solid fat content determination is 0.2%, the accuracy is about 0.6%. The technique is easily automated, cheap, accurate, rapid and non-intrusive and should, therefore, prove useful both as an in-line quality control monitoring device and as a new instrumental technique for research applications.