【作者】 孙健；

【导师】 徐幸莲； 周光宏；

【作者基本信息】 南京农业大学 ， 食品科学， 2011， 博士

【摘要】 亚麻籽胶是极具潜力的食品亲水胶体之一,主要含有木糖、阿拉伯糖、鼠李糖、岩藻糖、甘露糖、葡萄糖、半乳糖醛酸等。它在保水、乳化、抗淀粉老化方面显示了相当大的潜力。近年来,许多学者对亚麻籽胶的物理和化学功能特性显示了极大的兴趣。然而,相关研究大部分集中在非肉类产品。亲水胶体和肉类之间在保水、乳化、糊化和抗淀粉老化方面研究很少。所以,本研究的目的是对亚麻籽胶在肉品中保水、乳化、糊化和抗淀粉老化特性和应用进行更深入的了解,以期为亚麻籽胶在肉制品中的广泛应用提供一定的理论依据。具体研究包括以下七个部分：1亚麻籽胶对猪肌原纤维蛋白热诱导凝胶保水性的影响猪肌原纤维蛋白热诱导凝胶保水能力随着亚麻籽胶浓度增加而极显著的增加(P<0.001)。扫描电镜显示,蛋白质凝胶的保水能力是和凝胶的微观结构有关。T2驰豫时间分布分析揭示了添加亚麻籽胶显著的降低了猪肌原纤维蛋白中水的流动性(P<0.05)。傅立叶变换红外光谱分析表明添加亚麻籽胶增强了猪肌原纤维蛋白系统的静电吸引力。添加亚麻籽胶的猪肌原纤维蛋白热诱导凝胶保水能力的改善是浓度依赖型,添加亚麻籽胶实现了有一个较好的凝胶网络,较低的驰豫时间和较强的静电引力。2亚麻籽胶对猪油乳化稳定性的影响通过对乳化颗粒的大小、乳化活性、贮藏稳定性和显微结构的观察,对亚麻籽胶和猪油乳化稳定性进行了研究,其中猪油的变化浓度是6%、8%、10%w/W和亚麻籽胶的变化浓度是0.1%、0.3%、0.5%w/w,油和胶的比例是60-20。乳化液中亚麻籽胶含量较低时(0.1w/w％FG),液滴分子之间容易互相碰撞聚集桥联形成较大的粒径,容易分层,使乳化活性和稳定性下降；亚麻籽胶含量较高时(0.5w/w％FG),；由滴被亚麻籽胶完全覆盖,乳化颗粒分布均匀,乳化活性和稳定性较高。核磁共振被用来分析未经稀释的乳化液的基本特性,乳化液含有最高0.75%和最低0.25%的亚麻籽胶,经低场1H核磁共振分析表明,T2值越小表示对油分子的限制越多。低场’H、高场’H和13C核磁共振波谱中,猪油信号的线宽表示随着乳化液中亚麻籽胶浓度的不断增加,亚麻籽胶和猪油分子在界面上的相互作用越强。油分子各个基团高场’H核磁共振的响应值反映了油滴内部基团的不同空间位置。3亚麻籽胶对淀粉糊化特性的影响扫描量热仪(DSC)、红外分析(FT-IR)、X-射线衍射分析(XRD)和扫描电子显微镜(SEM)用来研究亚麻籽胶添加对淀粉糊化的影响。DSC结果表明,添加亚麻籽胶显著地提高了玉米淀粉的糊化起始温度和熔晶热焓值。红外分析表明,添加或未添加亚麻籽胶淀粉结构没有发生变化,在65℃时,亚麻籽胶和玉米淀粉之间没有发生明显的相互作用,在75℃时添加亚麻籽胶促进了淀粉分子结合水的能力增强。X-射线衍射分析显示,糊化前添加亚麻籽胶玉米淀粉相对结晶度没有太明显变化,糊化显著地降低了玉米淀粉的结晶度,同时也表明添加亚麻籽胶对玉米淀粉糊化有一定延迟作用。扫描电镜也直观地证明了亚麻籽胶延缓了玉米淀粉的糊化。4亚麻籽胶对淀粉老化特性的影响扫描量热仪(DSC)、核磁共振(NMR)、X-射线衍射分析(XRD)和扫描电子显微镜(SEM)用来研究亚麻籽胶添加对淀粉老化的影响。DSC结果表明,亚麻籽胶添加能明显降低储存7天、14天和21天玉米淀粉凝胶的最大回生度。核磁共振(NMR)T2值分布揭示了淀粉颗粒分子内和分子外两种水的不同分布情况,水的含量随着亚麻籽胶的增加而增加,DSC和NMR结果显示,随着淀粉凝胶水分含量的增加,由于淀粉分子浓度降低,淀粉分子之间的交联机会减少,因而老化程度逐步降低。同时,随着亚麻籽胶的添加,X-射线衍射结果也有相似的重结晶趋势,然而,X-射线衍射的灵敏度和DSC相比还是比较低的。扫描电子显微镜(SEM)结果也发现,添加的亚麻籽胶淀粉形成了更多多孔的结构,促进了淀粉凝胶保水能力的提高。5亚麻籽胶与其它亲水胶体在肉制品中的相互作用研究采用析因实验设计研究肉制品中亚麻籽胶、卡拉胶和黄原胶添加的相互作用。结果表明,添加亚麻籽胶显著地增强了猪肉肠在60℃下烘20min、40min、60min和80min的保水能力(P<0.01)。卡拉胶对猪肉肠在60℃下烘20min、40min勺保水能力无显著性的影响,亚麻籽胶与黄原胶对猪肉肠在60℃下烘20min、40min都有显著性交互作用(P<0.05)。保水能力上,从高到低依次为：亚麻籽胶、黄原胶、卡拉胶。亚麻籽胶对猪肉肠用乙醚浸提40min和60min的保油性有显著性的影响(P<0.05),黄原胶和卡拉胶对保油性没有显著性的影响。在保油能力上,从高到低依次为：亚麻籽胶、黄原胶、卡拉胶。6亚麻籽胶与非肉蛋白在肉制品中的相互作用研究采用析因实验设计研究肉制品中亚麻籽胶、大豆蛋白和酪蛋白添加的相互作用。亚麻籽胶添加对猪肉肠在60℃下烘20min的保水能力有极显著的影响(P<0.01),然而,亚麻籽胶对猪肉肠在60℃下烘40min的保水能力没有显著的影响(P>0.05)。酪蛋白的添加,对猪肉肠在60℃下烘20min和40min的保水能力有显著的影响(P<0.05)。保水能力上,从高到低依次为：酪蛋白、亚麻籽胶、大豆蛋白。亚麻籽胶的添加,显著地影响了用乙醚浸提20min、40min和60min猪肉肠的保油性(P<0.05),大豆蛋白和酪蛋白也有类似结果。大豆蛋白对猪肉肠用乙醚浸提60min的保油性有极显著性影响(P<0.01),并且,亚麻籽胶与大豆蛋白有显著的交互作用(P<0.05)。在保油能力上,大豆蛋白强于酪蛋白。7亚麻籽胶与黄原胶、大豆分离蛋白对肉制出品率和质构特性的影响利用三因素中心复合旋转试验设计的原理,研究各种添加物同时添加对出品率和质构特性的影响,其中亚麻籽胶浓度为0.1-0.5%；黄原胶浓度为0.2-0.6%；大豆蛋白浓度为1.0-4.0%。此外,采用响应曲面法研究了各种添加物在出品率和质构特性之间的相互作用。试验设计允许在各种参数中间评价各种潜在的交互作用和二次效应。实验结果表明：亚麻籽胶、黄原胶、大豆蛋白的添加均能显著性提高猪肉肠出品率,亚麻籽胶和大豆蛋白对出品率和粘着性有显著性交互作用；大豆蛋白的添加使得产品的硬度显著性增加；随着黄原胶和大豆蛋白的添加,猪肉肠的弹性不断下降,且二者之间有显著性交互作用；随着亚麻籽胶的添加,猪肉肠的凝聚性呈极显著性下降趋势,但是,随着黄原胶和大豆蛋白的添加,凝聚性不断增加,且二者之间有显著性交互作用；亚麻籽胶、黄原胶、大豆蛋白对猪肉肠的咀嚼性没有显著性影响。更多还原

【Abstract】 Flaxseed gum (FG), one of the most potential hydrocolloid gums, contains mainly xylose, rhamnose, galactose, glucose, arabinose, fucose and galacturonic acid. It has been shown that flaxseed gum has a potential in water holding capacity, emulsion and anti-retrogradation of starch. In recent years, FG has been intensitively focused on its physichemical properties, especially in non-meat products. However, few data are available on its application to meat products. The objective of the present study is to explore the effect of FG on water-holding capacity, emulsion, gelatinisation and anti-retrogradation of starch. The whole study includes the following seven parts:1 Effect of flaxseed gum on water holding capacity of heat-induced gel of porcine myofibrillar proteinsWater holding capacity of heat-induced gel of porcine myofibrillar proteins increased (P<0.001) as FG concentration increased. Scanning electron microscopy (SEM) showed that WHC of protein gel was related to its microstructure. Distributed analysis of the T2 relaxation revealed that addition of FG significantly decreased water mobility of porcine myofibrillar protein (P<0.05). The fourier transform infrared spectroscopy (FT-IR) analysis suggested that FG strengthened electrostatic attraction of PMP system. Flaxseed gum improved WHC of heat-induced gel of PMP, which is concentration-dependent, by a finer gel network, lower relaxation time and stronger electrostatic attraction.2 Effect of flaxseed gum on emulsifying stability of lard Emulsifying stability of lard was investigated at different concentrations of lard (6%, 8%,10% w/w oil) and FG (0.1,0.3,0.5% w/w) and their ratio (60 to 20). Particle size, emulsion ability, emulsion stability, the mobility of oil droplets and the oil/protein interaction at the interface were measured. At a low concentration (0.1% w/w), the presence of flaxseed gum caused the aggregation of oil droplets in an emulsion by the formation of cross-links, which resulted in larger particles and thus poor emulsion ability, and emulsion stability. At a high concentration (0.5% w/w), the emulsion droplets were fully covered by flaxseed gum and showed good particle stability, emulsion ability, and emulsion stability. NMR was used to characterize the undiluted emulsion systems. Lower T2 values (by low-field 1H NMR) in the emulsions containing both high (0.75% w/w) and low (0.25% w/w) amounts of flaxseed gum, indicated increasingly restricted mobility of lard. The line broadening in lard signals in the NMR spectra (low-field 1H, high-field 1H,13C) indicated increased interaction between lard molecules and flaxseed gum at the interface with increasing flaxseed gum concentration in emulsions. The values of resonances of the individual groups on lard molecules, obtained by high-field 1H NMR, reflected their different environments within the lard droplets.3 Influence of flaxseed gum on the gelatinisation of maize starchDifferential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction(XRD) and scanning electron microscope(SEM) were used to investigate effect of flaxseed gum on the gelatinisation of maize starch. The DSC results showed that the addition of flaxseed gum to maize starch siginificantly increased the onset temperature and enthalpy of starch melting. The FT-IR spectra of the maize starch and maize starch-FG powders were very similar, indicating that the addition of FG did not change the chemical structure of maize starch. There was no interaction between flaxseed gum and maize starch at 65℃. However, FG can facilitate the combination of starch and water at 75℃. X-ray diffraction results showed that there was no significant change in relative crystallinity of maize starch before and after the addition of FG before gelatinization of maize starch, but relative crystallinity of maize starch was significantly decreased after gelatinization, which indicated that the addition of flaxseed gum delayed the maize starch gelatinization. Scanning electron microscopy confirmed it.4 Effect of flaxseed gum on the retrogradation of maize starchDSC, NMR, XRD and SEM were used to investigate effect of FG on the retrogradation of maize starch.The DSC results showed that the addition of FG siginificantly decreased maximum degree retrogradation (DR) of mazie starch gel at 7th, 14th and 21th day. NMR T2 distribution revealed two distinct water populations corresponding to intra-and extra-granular water, which significantly increased after FG was added. The results of DSC and NMR showed that with the increase in water content in maize starch gel, concentration of maize starchs was decreased and less cross-links were formed among starch molecules, and thus retrogradation degree was lower when FG was added to maize starch. However, recrystallization of maize starch could occur after FG addition under X-ray diffraction (XRD). However, the sensitivity of powder X-ray diffraction is relatively low compared with techniques with DSC which are able to detect even minor extents of recrystallization.Scanning electron microscopy showed that the addition of FG gum induced the formation of porous structure of maize starch, which increased the water holding capacity of starch gel.5 Interaction between Flaxseed Gum and other hydrocolloids in Meat ProductsFactorial design was applied to investigate the interaction among FG, carrageenan and xanthan gum, which are commonly added in meat products. Results indicated that the addition of FG had highly signifcant effect on water retention of sausage after drying for 20,40,60 and 80 min at 60℃(P<0.01). Carrageenan had no signifcant effect on water retention of sausage after drying for 20 and 40 min at 60℃(P>0.05). FG and xanthan gum had a signifcant interaction on water retention of sausage after drying for 20and 40 min at 60℃(P<0.05). FG, xanthan gum, carrageenan showed different water holding capacity, from high to low in order. FG had signifcant effect on oil retention of sausage after dipping into diethyl ether for 40 and 60 min (P<0.05) but rather not for xanthan gum and carrageenan. The oil holding capacity in order from high to low is flaxseed gum, xanthan gum, carrageenan.6 Interaction between Flaxseed Gum and non-meat proteins in Meat ProductsFactorial design was applied to investigate the interaction among FG, SPI and casein, which were also commonly added in meat product. The addition of FG had highly signifcant effect on water retention of sausage after drying for 20 min at 60℃(p<0.01) However, the addition of FG did not affect water retention of sausage after drying for 40 min at 60℃(P>0.05). The addition of casein also affected water retention of sausage after drying for 20 and 40 min at 60℃(P<0.01).The order for water holding capacity was casein,FG, SPI from high to low. The addition of FG had signifcant effect on oil retention of sausage after dipping into diethyl ether for 20,40 and 60 min (P<0.05) as did the addition of SPI and casein. The addition of SPI showed highly signifcant influence on oil retention of sausage after dipping into diethyl ether for 60 min (P<0.01) and there was signifcant interaction between FG and SPI on water retention of sausage after drying for 60 min at 60℃(P<0.05).The oil holding capacity of SPI is higher than that of casein.7 Effects of flaxseed gum, xanthan gum and soy protein on yield and textural properties of pork sausageA three-factor Central composite rotatable design was adopted for studying the simultaneous effects of processing variables such as FG (0.1-0.5%), xanthan gum (0.2-0.6%) and SPI (1.0-4.0%) on yield and textural properties of pork sausage. In addition, the ridge analysis was conducted to find the interactions of processing variables, i.e., yield and the texture profile analysis (TPA) parameters. Experimental design allowed for evaluation of potential interactive and quadratic effects between these variables. It was found that the addition of FG, xanthan gum and SPI increased the yield (p<0.05) as the amount of FG, xanthan gum and SPI increased. FG and SPI had interactive effect on yield and adhesiveness. There was signifcant increase on hardness of sausage with increasing SPI. The springiness of sausage decreased with increasing amount of xanthan gum and SPI, and there was signifcant interaction between xanthan gum and SPI. The cohesiveness of sausage significantly decreased with the increasing amount of FG, but increased with the increasing amounts of xanthan gum and SPI. There was signifcant interaction between xanthan gum and SPI on cohesiveness of sausage. Neither of FG, xanthan gum and SPI affected chewiness.更多还原