热变性法提纯猪血SOD最适条件研究

采用热变性法,研究不同的温度和不同的处理时间对提纯猪血中SOD的影响.结果表明,随着温度的升高和处理时间的延长,酶活性和杂蛋白均呈下降趋势.提纯猪血SOD的最适热变性温度为55 ℃,变性时间为15 min.     

壳蛋保鲜与液蛋杀菌技术研究进展

本文综述了国内外有壳蛋保鲜、贮藏和液蛋杀菌方面的研究,并探讨在蛋液杀菌处理过程中不同的处理方式对蛋液品质的影响,以期为蛋品保鲜研究和推进工业化生产提供参考.     

鸡蛋储藏时间对蛋清液起泡性的影响研究

研究通过监测不同温度(25℃、4℃)储藏鸡蛋蛋液pH值、起泡性和泡沫稳定性随时间的变化,分析储藏时间对蛋清液起泡性的影响。结果显示:鲜蛋于常温25℃条件下放置29 d,全蛋液p H值先由6.8升至7.7后逐渐降低,蛋清液起泡性随储藏时间的延长先升高后降低,起泡性初始值为107.8%,储藏25 d后达到421.2%,之后逐渐降低;4℃下储藏的样品起泡性变化规律与常温相似,储藏17 d后达到270.9%。研究表明:在使用鸡蛋生产焙烤食品时,选用4℃储藏2周或25℃储藏1周的鸡蛋较好。     

驴乳和牛乳蛋白热稳定性的研究

通过对驴乳和牛乳采取4种不同的热处理研究,比较了不同的加热方法对驴乳和牛乳中蛋白质稳定性的影响。结果发现,驴乳的乳清蛋白在60℃已经完全变性,驴乳酪蛋白的变性温度介于90~100℃,变性温度比较窄,而牛乳的酪蛋白的变性温度比较高。研究表明,驴乳乳清蛋白的变性温度低于60℃,驴乳中的α-乳白蛋白相对较多,而β-乳球蛋白较少,牛乳则相反。相比较而言,驴乳的酪蛋白和乳清蛋白的变性率较高,而牛乳的热稳定性更好。说明控制温度和时间可获得不同变性程度乳制品。     

不同涂膜材料对鸡蛋保鲜品质影响的研究

试验选取2%壳聚糖和1%聚乙烯醇的混合溶液、聚偏二氯乙烯PVDC乳液、白矿油分别对鸡蛋进行涂膜。在室温(25℃左右)下贮藏7周,测定鸡蛋的哈夫单位、蛋白高度以及蛋液的p H、水分含量、蛋白质含量、脂肪含量等指标。结果显示:经白矿油涂膜的鸡蛋,随着贮藏期延长其哈夫单位、蛋白高度、水分含量均高于同时期其他组,并且涂白矿油的鸡蛋蛋液p H变化较小。表明本试验中,白矿油对鸡蛋的保鲜效果优于2%壳聚糖和1%聚乙烯醇的混合溶液、PVDC乳液。     

豌豆水浸液对高原引种绿玛瑙番茄萌发特性的影响

为了为高原引种绿玛瑙番茄提供理论指导,试验采用重复处理的方法,研究20℃温度条件下经不同浓度Na Cl处理过的豌豆水浸液对绿玛瑙番茄种子萌发特性的影响。结果表明:不同浓度的豌豆水浸液对绿玛瑙番茄种子萌发的影响不同,随着浓度的增加抑制作用增强;其中用0.5%豌豆水浸液处理绿玛瑙番茄种子的发芽率最高,为95.56%,与纯化水处理的发芽率接近,而且此处理的变异系数较小。说明0.5%豌豆水浸液能够促进绿玛瑙番茄的萌发。     

苜蓿粒复合灌肠的研制

选取大豆组织蛋白、苜蓿粒、变性淀粉三因素进行响应曲面（Response Surface Methodology, RSM）试验设计，研究了不同添加量对苜蓿粒灌肠出品率和质构特性的影响，并优化了添加量。结果显示，产品的出品率为97%～121%；灌肠的黏着性受苜蓿粒和大豆组织蛋白的影响(P<0.05)，大豆组织蛋白和变性淀粉的二次模型形式对黏着性产生影响 (P<0.01)；苜蓿粒和变性淀粉都与大豆组织蛋白交互作用于灌肠的黏着性 (P<0.01)；灌肠的凝聚性受大豆组织蛋白的影响(P<0.05)；优化后的最佳添加量为苜蓿粒8%、大豆组织蛋白3%、淀粉2%。     

食盐添加量对鸡肉糜热性质及流变性的影响

利用食盐对鸡胸肉进行腌渍处理,以食盐添加量0%为空白对照组,比较不同食盐添加量下鸡肉糜的蒸煮损失、质构特性、热性质及流变特性。结果表明,食盐添加量对鸡肉的质构特性、蒸煮损失、热性质及流变性影响显著。蒸煮损失随食盐添加量的增加呈先降低后升高趋势,食盐添加量在0%~3%范围内的鸡肉具有较强保水能力。剪切力值与食盐添加量呈正相关,显示食盐可一定程度增加蛋白结合性能,保证鸡肉更佳的质构特性。腌渍后鸡肉蛋白变性温度较对照样明显降低(P0.05),显示鸡肉蛋白经腌渍处理后对热处理温度更为敏感。不同食盐添加量鸡肉蛋白流变曲线变化明显,存储模量随食盐添加量增幅明显(P0.05),显示食盐具有加速蛋白变性与增加凝胶强度的作用。     

液蛋生产技术与应用

1 液蛋 液蛋是指液体鲜蛋,是禽蛋经打蛋去壳,将蛋液经一定处理后包装冷藏(或冷冻),代替鲜蛋消费的产品.     

不同处理方式对苹果渣中苹果多酚含量的影响

为了研究苹果渣中苹果多酚在处理过程中的稳定性,试验以苹果渣为原料分别进行青贮和不同温度及时间的烘干处理,采用改进的微波提取和福林-酚法测定苹果渣中总酚、可溶性糖和可溶性蛋白的含量。结果表明:青贮方法对苹果多酚的含量影响较小,可以最大限度地保存果渣中的苹果多酚;烘干处理对苹果多酚有显著影响(P<0.05),随着烘干温度的升高,苹果多酚的含量先降低后升高,65℃时含量最低;烘干时间对苹果多酚的含量也有较大影响,随着时间的延长,苹果多酚的含量也表现为先降低后升高的变化特点,24h苹果多酚的含量最低。加热温度及时间对可溶性糖和可溶性蛋白的含量也有一定影响。研究发现了不同条件下苹果多酚的变化规律,为苹果渣的适当处理和贮存提供了理论依据。     

电场处理对羊柴种子萌发及幼苗生长的影响

用不同强度的匀强电场作用羊柴种子一定时间，实验测定电场对幼苗发芽率、含水量和根系的影响。多重比较结果表明：不同电场强度对羊柴种子萌发生长的影响程度不同，用恰当电场处理羊柴种子可以提高种子发芽率、幼苗生长和根系发达程度。     

Evaluation of nutrient content,physicochemical and functional properties of desalted duck egg white by ultrafiltration as desalination

In this study, the effects of ultrafiltration technique on the desalination efficiency, nutrient content, physicochemical properties, functional properties, texture profile, and microstructure of salted duck egg white were evaluated. The results showed that ultrafiltration can remove 92.93% salt from salted duck egg white (SDEW) and final salt% of desalted duck egg white (DDEW) was 0.65%. The analysis of nutrient content and amino acid of SDEW and desalted duck egg white powder (DDEWP) sample was significantly lower than those of fresh duck egg white (FDEW). Although emulsifying capacity of SDEW, DDEW, and DDEWP exhibited significantly lower than that of FDEW, an excellent foaming ability was found in those samples. Moreover, the texture profiles (gel strength, hardness and elasticity) of SDEW, DDEW, and DDEWP samples presented lower value than FDEW. The observation of microstructure, DDEWP possessed smooth surface of protein globules with deep hole liked donuts and distribution of a few of salt crystals. While salted duck egg white powder (SDEWP) had a raisin‐like surface formation with salt formed cubic crystals. Overall, both liquid and dried material of desalted duck egg could be used as a good ingredient in baking food due to their excellent foaming capacity.     

笼养与平养蛋鸭蛋品质测定与相关性分析

试验旨在比较笼养和平养方式对不同品种蛋鸭蛋品质的影响,以期为评价不同饲养方式下的鸭蛋品质提供参考依据。随机选取40周龄笼养和平养的金定鸭（青壳蛋）和山麻鸭（白壳蛋）鸭蛋各30枚于产后24 h内进行蛋品质测定。结果表明,同一品种笼养蛋鸭蛋重极显著大于平养蛋鸭蛋重（P<0.01）,蛋重与蛋壳重、蛋白重和蛋黄重之间均存在极显著正相关（P<0.01）,但不同类型鸭蛋的蛋黄重之间差异不显著（P>0.05）。青壳蛋的蛋壳强度显著高于白壳蛋（P<0.05）,笼养青壳蛋的蛋壳强度亦高于平养青壳蛋（P<0.05）。蛋的比重与蛋壳厚度呈极显著正相关（0.503,P<0.01）,与蛋壳强度的相关系数亦达到0.536（P<0.01）。4种类型鸭蛋的哈氏单位均达到72以上。虽然蛋白重与蛋黄重之间呈极显著正相关（P<0.01）,但蛋白重与蛋黄比率之间却呈极显著的负相关（P<0.01）。蛋的比重与蛋黄重和蛋黄比率之间亦存在显著负相关（P<0.05）。以上结果表明,就蛋品质而言,蛋鸭养殖以采用笼养模式、选择青壳蛋鸭品种为宜。     

蛋壳颜色和蛋壳强度与蛋各部位钙含量的关系

本文旨在研究新扬州鸡蛋壳颜色和蛋壳强度与蛋各部位钙含量的关系.方法采用QC-SPA蛋壳强度测定仪、蛋壳颜色测定仪及相关仪器测定相同日龄新扬州鸡鸡蛋的蛋壳强度及蛋壳颜色,用乙二胺四乙酸二钠(EDTA)络合滴定快速测钙法,测定不同颜色鸡蛋的不同部位的钙含量.研究结果表明:随着蛋壳颜色加深,蛋壳和蛋白中钙含量增大,但蛋壳强度随之减小;当蛋壳强度为4000～4500g/cm<'2>时,鸡蛋各部位的钙含量均最大.     

Determination and Correlation Analysis on the Egg Quality of Egg-laying Ducks Reared in Cages and on Floor

The purpose of this test was to evaluate the egg quality from two breeds of ducks reared in cages and on floor.30 eggs were chosen from each type of eggs,which were from Jinding (green shell) and Shan Partridge ducks (white shell)at 40 weeks-old reared in cages and on floor for egg quality evaluation.The results showed that the egg weight of caged duck was extremely significantly larger than the floor duck (P<0.01) in the same breed,there were very significant positive correlations between the egg weight and eggshell weight,egg-white weight and egg yolk weight (P<0.01),but no significant difference among the egg yolk weights of different types of ducks (P>0.05).The shell strength of green egg was obviously higher than that of white shell eggs (P<0.05),and the shell strength of green egg from caged ducks was higher than that of the green egg ducks on floor.The correlation coefficients of the egg specific gravity and eggshell thickness,the specific gravity and eggshell strength were 0.503 (P<0.01) and 0.536 (P<0.01) respectively.Haugh units of four types of ducks all reached 72 or more.Although there was significant positive correlation between egg-white weight and egg yolk weight (P<0.01),significant negative correlation was existed between egg-white weight and egg yolk ratio (P<0.01).There were significant negative correlations between egg specific gravity and egg yolk weight (P<0.05) and egg yolk ratio (P<0.05).In conclusion,the mode of cage feeding and the breed with green shell were appropriate choices in laying-egg duck production for high egg quality.     

蛋清粉凝胶性与凝胶稳定性的研究

研究蛋清粉在贮藏期间所成凝胶的质构、持水性以及微观结构的变化。结果显示,蛋清粉的凝胶硬度、弹性、粘结性、持水性分别为346g/cm2、0.905、0.382、52.00%,25℃下贮藏180d后,蛋清粉的凝胶硬度与粘结性较贮藏初期并无显著性变化(P>0.05),而凝胶弹性与持水性与贮藏初期相比差异性显著(P<0.05)。蛋清粉的溶解性随贮藏时间的延长呈下降趋势,但降幅很小,25℃下贮藏180d时与贮藏初期相比无显著性差异(P=0.154)。500倍扫描电镜(SEM)下观察蛋清粉所成凝胶,其结构空隙很大,分布疏松,随贮藏时间的延长无明显变化。研究结果表明,贮藏时间与温度对蛋清粉的溶解性影响很小,而对蛋清粉的凝胶性影响较大,含水量是影响蛋清粉凝胶稳定性的重要因素。     

日粮添加甜菜碱对夏季高温蛋鸡生产性能、蛋品质及血液理化特征的影响

本研究旨在评估夏季高温时日粮添加甜菜碱对蛋鸡生产性能、蛋品质及骨骼和血液理化特性的影响.试验将480只产蛋性能一致的罗曼粉壳蛋鸡随机分为2组,每组240只,每组10个重复(24只/重复).对照组饲喂基础试验日粮,处理组蛋鸡饲喂基础试验日粮+150?mg/kg甜菜碱,试验为期8周.结果:日粮添加150?mg/kg甜菜碱对...     

Study of enrofloxacin and flumequine residues depletion in eggs of laying hens after oral administration

Two groups of laying hens (each n=12) were administered 10 mg/kg enrofloxacin (ENRO) (group A) or 26.6 mg/kg flumequine (FLU) (group B) by gastric catheter daily for five consecutive days. A third group (n=6) was untreated controls. Eggs were collected from day one of treatment and up to 30 days after withdrawal of the drug. Egg white and yolk from each egg were separated, and ENRO, its metabolite ciprofloxacin (CIP) and FLU residues were analysed by a high-performance liquid chromatography method with fluorescence detection. The sum of ENRO and CIP was detectable in egg white on the first day of treatment in high-level concentrations (2007.7 μg/kg) and remained steady during administration. In egg yolk, residues were detectable at day one in lower concentrations (324.4 μg/kg), increasing to the end of treatment. After treatment, these residues decreased and were detectable up to day 8 in egg white, and day 10 in yolk. FLU residues during drug administration in white were detectable in high concentrations from day one to five (6788.4-6525.9 μg/kg), and in yolk, concentrations were lower during administration (629.6-853.9 μg/kg). After drug withdrawal, FLU residues remained longer in egg white (30 days) than in yolk (26 days). For both drugs, differences of concentrations between matrices were significant.     

不同品种、不同周龄鸡蛋营养成分比较研究

本试验选用北京油鸡、白来航、海兰褐3个品种,每个品种随机挑选17或19周龄(北京油鸡)、42周龄、70周龄母鸡收集鸡蛋进行蛋黄营养成分的测定。结果表明:不同品种3个产蛋时期的蛋黄比例、蛋白比例、蛋黄维生素E含量都有极显著差异(P<0.01)。其中白来航、海兰褐在不同产蛋时期的蛋黄、蛋白比例呈现相同的变化趋势,即蛋黄比例为70周龄蛋最高,蛋白比例为初产蛋最高。3个品种不同产蛋时期维生素E含量变化亦势趋相同,初产蛋最高。3个品种42周龄蛋中的必需氨基酸比例显著高于其他2个时间点(P<0.01)。商业品种与中国地方鸡种所产蛋在蛋黄、蛋白比例、维生素B2变化趋势迥异,无统一规律可循。