提高大豆油水乳状液氧化稳定性的研究

为满足不同特殊人群的营养需求，可以设计不同的配方奶粉。富含不饱和脂肪酸的配方奶粉由于含有较高的不饱和脂肪酸油脂，容易出现脂肪氧化的质量问题。本文着重考察了配方粉在成粉前，引起乳状液的氧化的一些影响因素。结果表明，在有铁离了共存时，含花生四烯酸的大豆油水乳状液的脂肪氧化与铁离了成正相关，鏊合剂柠檬酸钠可以通过对铁离了的鏊合作用在起始阶段降低乳状液的氧化程度，抗氧化剂抗坏血酸棕榈酸酯抑制脂肪氧化主要体现在贮存后阶段。当二者联合应用时，在液体乳状液和固体粉状时都具有显著的抗氧化效果。     

Physicochemical Property and Oxidative Stability of Whey Protein Concentrate Multiple Nanoemulsion Containing Fish Oil

The objectives of this research were to produce whey protein concentrate (WPC) multiple nanoemulsion (MNE) and to study how whey protein concentration level and antioxidant type affected the physicochemical properties and oxidative stability of fish oil in MNE. The morphological and physicochemical characteristics of MNE were investigated by using transmission electron microscopy and particle size analyzer, respectively. The oxidative stability of fish oil in MNEs was assessed by measuring peroxide value (PV), p‐anisidine value, and volatile compounds. The spherical forms of emulsions with size ranging from 190 to 210 nm were observed indicating the successful production of MNE. Compared with free fish oil, fish oil in MNE exhibited lower PV, p‐anisidine value, and formation of maker of oxidation of fish oil indicating the oxidative stability of fish oil in MNE was enhanced. PV, p‐anisidine value, and makers of oxidation of fish oil were decreased with increased WPC concentration level. The combined use of Vitamin C and E in MNE resulted in a reduction in PV and p‐anisidine value, and development of maker of oxidation. In conclusion, WPC concentration level and antioxidant type are key factors affecting the droplet size of MNE and oxidative stability of fish oil.     

乳清蛋白肽美拉德反应产物的抗氧化活性与稳定性

以乳清蛋白碱性蛋白酶水解物为原料与葡萄糖发生美拉德反应,制备得到乳清蛋白肽美拉德反应产物（whey protein peptide Maillard reaction products,WPP-MRPs）,并研究其抗氧化活性以及温度、pH值、光照、金属离子和过氧化氢对其抗氧化活性的影响。结果表明,WPP-MRPs具有较强的总还原力、羟自由基（·OH）清除能力和2,2’-连氮基-双-（3-乙基苯并二氢噻唑啉-6-磺酸）二铵盐自由基（ABTS+·）清除能力,且抗氧化活性随着WPP-MRPs质量浓度的增加而加强。WPP-MRPs在90～100 ℃时具有较高的活性;在碱性环境中的抗氧化活性大于在中性及酸性环境中;室外自然光照射会降低WPP-MRPs抗氧化活性;金属离子Cu2+、Fe2+、Fe3+和氧化剂--过氧化氢能够显著降低WPP-MRPs的抗氧化活性。     

Oxidative Stability of Soybean and Sesame Oil Mixture during Frying of Flour Dough

ABSTRACT: Effects of roasted sesame seed oil on the oxidative stability of soybean oil during frying of flour dough at 160 °C were studied by determining fatty acid composition and conjugated dienoic acid (CDA), p -anisidine (PA), and free fatty acid (FFA) values. Concentration of sesame oil in frying oil was 0%, 10%, 20%, or 30% (v/v). Tocopherols and lignan compounds in the frying oil were also determined by high-performance liquid chromatography. As the number of fryings performed by the oil increased, linolenic acid content in frying oil decreased, and the decreasing rate was lower in frying oil containing sesame oil than in the oil containing no sesame oil. CDA and FFA values of frying oil increased during frying and their relative values to the initial value were lower in frying oil containing sesame oil than in the oil containing no sesame oil. This indicates that the addition of sesame oil improved thermooxidative stability of frying oil, possibly due to the presence of lignan compounds in sesame oil. Tocopherols and lignan compounds in frying oil decreased during frying. As the amount of sesame oil in frying oil increased, degradation of tocopherols increased and lignan compounds degradation decreased. Tocopherols were suggested to protect lignan compounds in sesame oil from decomposition during frying.     

High-Temperature Natural Antioxidant Improves Soy Oil for Frying

ABSTRACT:  The objectives of this study were to determine the frying stability of soybean oil (SBO) treated with a natural citric acid-based antioxidant, EPT-OILShield™ able to withstand high temperatures and to establish the oxidative stability of food fried in the treated oil. Soybean oil with 0.05% and 0.5% EPT-OILShield and an untreated control SBO were used for intermittent batch frying of tortilla chips at 180 °C for up to 65 h. Oil frying stability was measured by free fatty acids (FFA) and total polar compounds (TPC). Chips were aged for up to 4 mo at 25 °C and evaluated for rancid flavor by a 15-member, trained, experienced analytical sensory panel and for hexanal content as an indicator of oxidation. Oil with 0.05% EPT-OILShield had significantly less FFA and TPC than the control. The effect of EPT-OILShield was apparently retained in aged chips because hexanal levels were significantly lower in chips fried in oil with 0.05% EPT-OILShield than in chips fried in the control. Tortilla chips fried in the control were rancid after 2 mo at 25 °C at sampling times evaluated from 25 to 65 h; however, chips fried in oil with 0.05% EPT-OILShield and used for 65 h were described as only slightly rancid after 4 mo. Gamma tocopherol levels were significantly higher in the chips fried in the oil with 0.05% EPT-OILShield than in the control, helping to inhibit oxidation in the tortilla chips during storage.     

浓香大豆油的开发及其氧化稳定性的研究

建立一种新型浓香大豆油(ASO)的生产方法。采用超临界萃取技术对焙烤后的大豆进行提取。通过感官评定对大豆焙烤工艺进行评估：在温度170℃条件下烘烤30min 时,焙烤出的大豆具有浓郁的香味。ASO 的萃取率随着大豆粉粒度的增加而提高,大豆粉的粒度为40～60 目时最佳。采用正交试验设计法对ASO 的萃取参数进行研究：萃取率随着温度的升高,先增大后减小,最佳萃取温度为50℃;萃取率随着压力的增大,先增大后减小,最佳萃取压力为25MPa;萃取率随着时间延长逐渐趋于最大值,确定萃取时间为2.5h。通过对氧化诱导期(IP 值)和抗氧化保护系数(Pf 值)的分析,探讨ASO 的氧化稳定性：ASO 和市售大豆油的IP 值分别为8.93、9.47,其他植物油均大于16;向ASO 中添加0.04% 的BHT、PG 分别能使其IP 值从8.93 提高到12.08、18.55,Pf 值分别达到1.353 和2.077,PG 对ASO 的抗氧化效果要明显优于BHT;在ASO 中单独添加0.01% 柠檬酸能使其Pf 值达到2.25,显示较强的抗氧化能力,复合添加0.01% 柠檬酸和0.04% PG 使其Pf 值达到4.14,显示很强的抗氧化能力。     

提取方法对大豆油脂体组成及氧化稳定性的影响

以大豆为原料,比较缓冲溶液法、水相法和酶法3种提取方法对大豆油脂体提取率、组成、脂肪酸组成、磷脂、生育酚、ζ-电势和粒径的影响,以及对大豆油脂体氧化稳定性的影响.试验结果表明,酶法提取大豆油脂体的提取率(19.74±0.14)％显著高于缓冲溶液法(12.76±0.14)％和水相法(6.67±0.32)％的提取率(P<0...     

利用微生物转谷氨酰胺酶回收大豆乳清废水

以大豆乳清废水为研究对象,以蛋白质含量为指标,通过单因素试验和正交实验研究了以微生物转谷氨酰胺酶(MTGase)对大豆乳清蛋白的聚合作用的条件,并对处理前后的大豆乳清废水中的蛋白质进行了分析.结果表明,微生物转谷氨酰胺酶对大豆乳清废水作用的最佳条件为:添加酶活为1 U/mL的酶6mL、反应时间1h、反应温度35℃pH ...     

美拉德反应对乳清分离蛋白及其水解物抗氧化性的影响

以乳清分离蛋白及其蛋白水解物为原料分别与半乳糖发生美拉德反应,研究两者美拉德反应的褐变程度、接枝度及产物荧光光谱的变化,同时以乳清分离蛋白和蛋白水解物作对照,研究两者美拉德反应产物的抗氧化性。结果表明:乳清分离蛋白及其水解物美拉德反应的褐变程度、接枝度及产物的抗氧化性均在4 h达到最大。其中,乳清分离蛋白及其水解物与半乳糖美拉德反应的褐变程度和接枝度最大值分别为1.114、18.431%和1.413、28.273%;两者美拉德反应产物的还原力、2,2’-联氨-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基清除能力和1,1-二苯基-2-三硝基苯肼自由基清除能力分别为0.605、46.29%、61.77%和0.923、69.81%、78.43%,均显著高于对照组(P0.05)。同时,内源荧光光谱发现,美拉德反应改变了乳清分离蛋白及其水解物的构象,使二者的结构更加松散。     

大豆乳清的开发研究进展

综述了大豆乳清综合利用的研究开发现状,并展望大豆乳清在国内的开发前景。大豆乳清中生理活性物质的提取包括蛋白质、低聚糖、异黄酮、皂甙等,提取大豆乳清中具有功能特性和生物特性的食品配料,是目前的研究热点,主要是用在食品工业和饲料工业中。     

不同贮存条件下大豆油氧化指标的比较

对四个等级的大豆油在不同存放条件下的过氧化值、羰基价、茴香胺值等氧化指标的变化规律进行了研究。结果表明:在阳光直射条件下,随着贮存时间的延长,不同等级的大豆油被氧化的程度明显不同,贮存样品以过氧化值、羰基价、茴香胺值等氧化指标的上升速度排列:大豆一级油＞大豆二级油＞大豆三级油＞大豆四级油。而在其它贮存条件下,不同等级的大豆油被氧化的程度差别不明显。     

Antioxidant Activity of Whey in a Salmon Oil Emulsion

The antioxidant capabilities of whey in a Tween 20^TM‐stabilized salmon emulsion were investigated. Whey fractions inhibited formation of thiobarbituric acid reactive substances (TBARS) and lipid peroxides in a 10 % salmon oil emulsion in the order of whey > high‐molecular‐weight (HMW) fraction > low‐molecular‐weight fraction. Heating the HMW fraction exposed sulfhydryls, with optimum exposure at 80 °C. Heating the HMW fraction above 80 °C increased antioxidant activity. The HMW fraction of whey (80 °C) alone, α‐tocopherol (40 ppm) alone, and their combination inhibited TBARS 59,19 and 86%, respectively, at 21 d of storage. Sulfhydryls oxidized before a‐tocopherol, suggesting that sulfhydryls are the primary antioxidant. Results indicate that whey proteins could be useful antioxidants in food emulsions.     

鱼油氧化稳定性的研究（Ⅱ）

鱼油氧化稳定性的研究（Ⅱ）烟台大学脂类研究实验室（２６４００５）曹国锋，翁新楚（接上期）２鱼油的保有和抗氧化２．１鱼油的保存由于鱼油极易氧化，所以其保存显得尤为重要。油脂保存中常用的方法和措施有避光、避热、低温贮存、真空贮存、充氮贮存、使用除氧剂、添...     

碳源对益生菌发酵黄浆水抗氧化和抑菌活性的影响

本文研究了乳糖和蔗糖及其添加量对嗜酸乳杆菌和鼠李糖乳杆菌发酵豆腐黄浆水产酸能力、抗氧化能力和抑菌能力的影响,研究结果表明,添加蔗糖能够提高乳酸菌的产酸能力,其中添加5%的蔗糖发酵24 h时,嗜酸乳杆菌和鼠李糖乳杆菌发酵黄浆水的酸度值分别为95.80 oT和93.68 oT;添加蔗糖也可以增强嗜酸乳杆菌和鼠李糖乳杆菌发酵黄浆水的抗氧化能力,其中添加5%的蔗糖发酵48 h后效果最好,还原力分别为2.57和2.47 mM生育酚/mL样品、清除ABTS自由基分别为37.69和37.98 mM生育酚/mL样品、螯合二价铁离子的能力分别为75.69%和78.70%,菌种之间没有显著性差异;此外,发酵24 h的黄浆水可以抑制金黄色葡萄球菌和大肠杆菌的生长,但对蜡样芽孢杆菌没有抑制效果,其中嗜酸乳杆菌发酵的黄浆水抑菌能力更强,添加1%的蔗糖后发酵黄浆水的抑菌能力稍有增强。     

Oxidative Stability of Anhydrous Milkfat Microencapsulated in Whey Proteins

The chemical stability was studied on anhydrous milkfat (AMF) encapsulated in whey protein isolate (WPI) and WPI combined with lactose (1:1 w/w WPI/L). AMF-containing microcapsules, as well as bulk milkfat, were stored at 20°C with light, 40°C without light, and 50°C with and without light for up to 12 mo. Milkfat oxidation was monitored by oxygen uptake in headspace and hexanal accumulation. In all cases, AMF oxidation was significantly limited by microencapsulation in WPI or WPI/L. Whey proteins are effective microencapsulating agents.     

Effects of Sesame Oil Addition to Soybean Oil During Frying on the Lipid Oxidative Stability and Antioxidants Contents of the Fried Products During Storage in the Dark

ABSTRACT: Effects of sesame oil addition to soybean oil during frying on the lipid oxidative stability and antioxidants contents of fried products during storage in the dark were studied. Flour dough pieces (2 cm × 2 cm × 0.1 cm) were fried at 160 °C for 1 min in sesame oil-added soybean oil. Concentrations of sesame oil in the frying oil were 0%, 10%, and 20% by volume. Fried products were put into a glass bottle, and the bottles were tightly sealed and stored at 60 °C in the dark for 18 d. Lipid oxidation of fried products was determined by fatty acid composition changes and conjugated dienoic acid (CDA) and p -anisidine (PA) values. Tocopherols and lignan compounds in the fried products were determined by high-performance liquid chromatography. Relative content of linolenic acid decreased, and CDA and PA values increased during storage of the fried products in the dark. Fatty acid composition change and CDA and PA values during storage were lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil. The results clearly showed that addition of roasted sesame oil to soybean oil at 10% and 20% during frying decreased the lipid oxidation of fried products during storage in the dark for 18 d by extension of induction period and decrease in decomposition of oxidized lipids. Fried products contained 134 to 267 ppm tocopherols and 0 to 148 ppm lignans before storage; however, their contents decreased during storage in the dark. Lignan compounds were more stable than tocopherols, and the rate of tocopherols degradation was lower in the products fried in sesame oil-added soybean oil than in the products fried in soybean oil without sesame oil, which could be because of protection of tocopherols from degradation by lignan compounds.     

Droplet Size and Coalescence Stability of Whey Protein Stabilized Milkfat Peanut Oil Emulsions

Droplet diameter and the polydispersity of droplet size tended to decrease with increased proportion of peanut oil. Macromolecular additives affected droplet size. Xanthan gum or sodium carboxymethyl-cellulose (Na-CMC) produced smaller droplets than the controls, but the average diameter was independent of the composition of the dispersed phase. At 50°C the coalescence stability of these emulsions qualitatively correlated with the initial droplet diameter. Xanthan gum and Na-CMC, despite increasing continuous phase viscosity, gave lower stability than controls, primarily the result of flocculation of droplets due to depletion of the highly hydrophilic macromolecule from the intervening region between approaching droplets. At 25°C, stability increased as solid butter oil content of the dispersed phase increased.     

压榨花椒籽仁油的制备及其氧化稳定性

以大红袍花椒籽为原料,油脂去除率为指标,采用碱液去除花椒籽表皮油脂,优化其工艺;以去除了表皮油脂的花椒籽为原料,采用螺旋压榨法制取花椒籽仁油;以过氧化值为指标,研究花椒籽仁油在不同温度、光线、空气和抗氧化剂条件下存放的氧化稳定性。结果表明:工艺条件优化后花椒籽表皮油脂去除率达93.85%,压榨花椒籽仁油出油率为20.2%;温度、光线和空气均可加速花椒籽仁油的氧化反应,且温度>光线>空气;特丁基对苯二酚(TBHQ)、VE和芝麻酚3种抗氧剂均能明显提高花椒籽仁油的稳定性,在相同剂量条件下,TBHQ的效果最好。     

Oxidative Stability of Whey Protein-stabilized Oil-in-water Emulsions at pH 3: Potential ω-3 Fatty Acid Delivery Systems (Part B)

ABSTRACT: Consumption of omega-3 (ω-3) fatty acids is beneficial for human health. Incorporation of ω-3 fatty acids into functional foods is limited by their high susceptibility to oxidative degradation. Oil-in-water emulsions may be a more effective method to deliver ω-3 fatty acids into functional foods. Protein-stabilized oil-in-water emulsions at pH values below the isoelectric point of the protein produce cationic emulsion droplets that decrease the oxidation of lipids by decreasing iron-lipid interactions. This research showed that whey protein isolate (WPI)-stabilized algal oil emulsions at pH 3.0 had good physical and oxidative stability after pasteurization. Addition of ethylenediaminetetraacetic acid