共查询到17条相似文献,搜索用时 78 毫秒
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金华火腿生产过程中脂质氧化及脂肪氧合酶变化特点研究 总被引:4,自引:0,他引:4
60只重量为6.2~6.9kg的原料腿按传统工艺加工金华火腿.分别于原料腿、盐后、晒后、成熟中期、成熟结束、后熟-1和后熟-2七个工艺点随机取5只腿的股二头肌为样品,分析TBA值、羰基值、共轭二烯值及脂肪氧合酶活力的变化,同时用响应曲面法研究加工过程中主要因子对脂肪氧合酶活力的影响.结果显示TBA值在晒后达到最高,羰基值、共轭二烯值在盐后达到最高,在其它工艺步骤变化不明显.脂肪氧合酶活力从原料腿的8.00U/min·g蛋白上升到盐后的12.55U/min·g蛋白,之后不断下降,至后熟-2酶活为4.87U/min·g蛋白.温度、盐含量和硝酸盐含量是脂肪氧合酶活力的显著影响因子,且温度与盐和硝酸盐含量之间的交互作用对酶活产生显著影响.利用所得回归方程预测加工过程中的实际酶活在成熟中期达到最高,该酶活可解释20%左右的脂肪氧化水平,说明生产过程中脂肪氧合酶在脂肪氧化中不起主导作用,脂肪氧化以自动氧化为主. 相似文献
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脂质氧化诱导的大豆蛋白质聚集机理的研究 总被引:2,自引:0,他引:2
利用脂肪氧合酶、亚油酸和大豆分离蛋白构建的模拟体系,研究了脂质氧化诱导的大豆蛋白质聚集的机理。结果表明,在制备大豆分离蛋白的模拟体系中同时添加亚油酸和脂肪氧合酶会使样品的蛋白质氧化值与表面疏水性增加,巯基与二硫键的含量下降,说明脂肪氧合酶催化的脂质氧化可使大豆蛋白结构发生明显的改变。SDS-PAGE电泳表明大豆蛋白7S和11S的各个亚基均参与了反应,尤其是7S部分反应更为明显。HPLC凝胶色谱和激光光散射分析进一步证实反应后的大豆蛋白(RSPI4和5)形成了相对高分子质量和颗粒粒径较大的聚集体。现有的实验证据表明,高度聚集蛋白质的形成可能是通过包括二硫键在内的共价变联,以及诸如氢键、盐桥,尤其是疏水相互作用等的非共价相互作用,形成较大的聚集体。由脂肪氧合酶诱导的蛋白质一脂质相互作用模拟实验的结果说明。脂质氧化对大豆蛋白具有明显的影响;在大豆分离蛋白加工的过程中,控制脂肪氧合酶的活力或脂质的含量是非常重要的。 相似文献
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利用脂肪氧合酶催化亚油酸氧化的反应体系对花生分离蛋白进行不同程度的氧化修饰,通过研究不同亚油酸含量下花生分离蛋白的羰基值、游离巯基含量、粒径分布、表面疏水性、溶解度以及荧光光谱的变化规律,从而探讨氧化对花生分离蛋白结构的影响。结果表明:随着反应体系中底物亚油酸含量的增加,花生分离蛋白的羰基值先增加后略微下降,游离巯基含量下降,表面疏水性先增加后减小,说明氧化后花生分离蛋白的结构已经发生了改变。其粒径分布和溶解度的变化规律可以表征花生分离蛋白氧化聚集体的状态,同时其荧光峰位λmax的变化规律可反映花生分离蛋白三级结构的具体变化,表明脂肪氧合酶催化亚油酸氧化可以诱导花生分离蛋白分子发生聚集,使其结构发生显著变化。 相似文献
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本文通过跟踪传统咸肉加工过程中理化指标、脂肪氧合酶(Lipoxygenase,LOX)以及羟基十八碳二烯酸(HODEs)等的变化,研究LOX活性和HODEs含量、异构体构成的关系,并初步探讨咸肉加工中酶促和非酶促氧化模式演替规律。结果表明,咸肉加工过程中LOX活性呈现先升高后缓慢下降的趋势,HODEs的总量缓慢上升,13-HODEs/9-HODEs之比从1.31下降到1.13;LOX活性和13-HODEs/9-HODEs比值之间具有极显著正相关性(r=0.942,P<0.01);LOX作用下的酶促氧化在传统咸肉加工初期的脂质氧化中占有主导地位,随后其作用不断下降,在加工中、后期逐渐被自由基等诱导的自动氧化所取代。 相似文献
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鲈鱼风干成熟过程中脂质分解氧化规律 总被引:3,自引:0,他引:3
以鲈鱼(perch)为原料进行腌制风干成熟,通过分析测定加工过程中鲈鱼肌肉脂肪组成、脂肪酶及脂肪氧合酶(LOX)活力、硫代巴比妥酸值(TBARS)和过氧化值(POV)变化情况,探究其脂质分解氧化规律。结果表明:鲈鱼肌肉风干过程中总脂肪含量显著降低(P<0.05),中性脂质、磷脂含量在加工过程中显著下降(P<0.05),游离脂肪酸(FFA)含量显著上升(P<0.05),棕榈酸(C16:0)、硬脂酸(C18:0)、油酸(C18:1)、二十碳五烯酸(C20:5)和二十二碳六烯酸(C2 2:6)是FFA的主体成分;酸性脂肪酶、中性脂肪酶和磷脂酶活力在加工过程中总体上都呈显著下降趋势(P<0.05),且磷脂酶活力下降幅度最大,中性脂肪酶活力始终显著高于其他两种酶(P<0.05);而LOX活力持续下降,POV和TBARS值在整个加工过程中都呈现先增大后减小的变化趋势,说明风干成熟后期较高的温度能促进脂质氧化产物进一步分解,加速风味物质的形成。 相似文献
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大豆脂肪氧合酶研究进展 总被引:3,自引:0,他引:3
脂肪氧合酶(LOX)是影响食品风味和色泽最重要酶之一。该文介绍大豆脂肪氧合酶特性,探讨大豆脂肪氧合酶酶促反应特征和机理,概述大豆脂肪氧合酶对大豆性质影响,总结降低大豆脂肪氧合酶活性方法。 相似文献
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《食品与发酵工业》2017,(2):5-12
研究了不同麦芽品种的脂质氧化相关指标分布特点及性能差异,为优选麦芽,提高啤酒新鲜度提供依据。基于溶液模型,研究确定了单酚物质阿魏酸、儿茶酸、咖啡酸能抑制脂肪氧合酶(lipoxygenase,LOX)的催化作用,金属离子能促进LOX酶作用;随后测定啤酒厂6种常用麦芽品种的11项脂质氧化指标,方差分析显示,不同麦芽品种的反-2-壬烯醛(trans-2-nonenal,T2N)、壬烯醛潜力(nonenal potential,NP)、单酚、金属离子之间存在显著差异;判别分析显示,加麦Copeland、加麦Metcalfe和甘啤在脂质氧化指标上较接近;基于主成分分析,建立脂质氧化综合评价指标,优选出脂质氧化程度低的麦芽。 相似文献
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脂肪氧合酶催化亚油酸氧化与大豆蛋白相互作用的荧光光谱分析 总被引:1,自引:0,他引:1
利用低脂质含量大豆蛋白、脂肪氧合酶和亚油酸组成的三元体系,模拟大豆蛋白质制备过程,通过荧光光谱结合可溶性蛋白表面疏水性分析,研究了反应后大豆蛋白芳族氨基酸的氧化情况,结果证明,在LOX的催化作用下,LA过氧化所产生的氢过氧化物及其降解产物可与大豆蛋白作用,反应后大豆蛋白的荧光光谱最大激发波长在350nm,最大发射波长在440nm.LOX催化LA氧化与大豆蛋白的相互作用,在LRSP LA LOX模拟体系中产生荧光物质.该荧光物质部分可溶于氯仿-甲醇溶液的有机相中,其荧光光谱最大激发波长在350nm,最大发射波长在430nm,且荧光强度随着反应程度的增加而增强.伴随着荧光物质的形成,反应后大豆蛋白的可溶性蛋白的表面疏水性降低.使用抗氧化剂(BHT)可抑制荧光物质的产生和蛋白质疏水性的丧失. 相似文献
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The stability and effectiveness of Tinuvin 326TM, a UV absorber, dispersed within the regrind layer of coextruded, multilayered, polypropylene-based containers to protect packaged, bleached soybean oil from photooxidation was investigated. The level of Tinuvin 326 in the containers was determined by using high pressure liquid chromatography (HPLC) and UV spectrophotometric methods. No loss of Tinuvin 326 from the containers was observed over a 42-day storage period at 21 and 35°C, respectively. The migration of Tinuvin 326 from the containers to the oil stored at 35°C was greater than at 21°C. Migration levels at both temperatures, however, were too low to notably reduce Tinuvin 326 levels in the containers. Bleached oil in containers with 0.3% Tinuvin 326 underwent less photooxidation than oil in containers with no Tinuvin 326 when exposed to fluorescent light at 21 and 35°C for 35 days. 相似文献
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An Overview on Nondestructive Spectroscopic Techniques for Lipid and Lipid Oxidation Analysis in Fish and Fish Products
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Jun‐Li Xu Cecilia Riccioli Da‐Wen Sun 《Comprehensive Reviews in Food Science and Food Safety》2015,14(4):466-477
Due to the high content of polyunsaturated fatty acids, fish lipids are readily susceptible to oxidation, which leads to serious food deterioration during storage. However, it remains a major challenging task to develop proper and effective assessment of lipid oxidation because the process is complicated and relies on the type of the oxidation agents, lipid substrate, and the environmental factors. This fact, in association with the limitations of traditional methods, which are normally burdensome, time‐consuming, and destructive, highlights the great necessity of developing and spreading the use of convenient, cost‐effective, and noninvasive alternative methods, such as spectroscopic techniques. As spectroscopic techniques have provided interesting and promising results in the area of fish quality and safety inspection, the goal of this review is to give an overview of research advances in the application of various spectroscopic techniques, namely infrared (IR) spectroscopy, Raman spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and hyperspectral imaging (HSI), for constituent analysis of fish lipids and for oxidation evaluations. These spectroscopic techniques are described in terms of their basic principles and application advantages. Meanwhile, some perspectives on the current situation and future trends are also presented. 相似文献
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Francisco J. Hidalgo 《Critical reviews in food science and nutrition》2016,56(8):1242-1252
Differently to amino acid degradations produced by carbohydrate-derived reactive carbonyls, amino acid degradations produced by lipid oxidation products are lesser known in spite of being lipid oxidation a major source of reactive carbonyls in food. This article analyzes the conversion of amino acids into Strecker aldehydes, α-keto acids, and amines produced by lipid-derived free radicals and carbonyl compounds, as well as the role of lipid oxidation products on the reactions suffered by these compounds: the formation of Strecker aldehydes and other aldehydes from α-keto acids; the formation of Strecker aldehydes and olefins from amines; the formation of shorter aldehydes from Strecker aldehydes; and the addition reactions suffered by the olefins produced from the amines. The relationships among all these reactions and the effect of reaction conditions on them are discussed. This knowledge should contribute to better control food processing in order to favor the formation of desirable beneficial compounds and to inhibit the production of compounds with deleterious properties. 相似文献