Antioxidant activity of sulphated polysaccharide conjugates from abalone (Haliotis discus hannai Ino)

The water-soluble sulphated polysaccharide conjugates were obtained from abalone viscera (Haliotis discus hannai Ino) by alkaline protease extraction followed by ethanol precipitation. Their antioxidant activities were evaluated in vitro by hydroxyl radicals scavenging activity, reducing power and metal chelating activity. Those various antioxidant activities were compared to standard antioxidants ascorbic acid and EDTA. The experimental results indicated that the crude extract having notable hydroxyl free radicals scavenging activity and moderate reducing power and chelating potency. The crude sulphated polysaccharide conjugates was enzymatically hydrolyzed by five commercially available proteases (trypsin, vernase, neutrase, pepsin and papain), and the resultant digests were tested for their antioxidant activities. Those proteolytic hydrolysates, although improving the hydroxyl radical scavenging activity in all cases except one, had lower reducing power and 3–15 times lower chelating ability than the native extract. Product derived from pepsin hydrolysate was fractionated by gel-filtration chromatography with sephadex G-100, giving two fractions containing sulphated polysaccharide conjugates termed ACP I and ACP II. The neutral monosaccharide composition of ACP I is rhamnose, fucose, xylose, mannose, galactose and glucose in a molar ratio of 1.00:45.14:4.00:5.36:33.18:2.15, with an average molecular weight of about 271 kDa. The neutral monosaccharide composition of ACP II is rhamnose, fucose, xylose, mannose, galactose and glucose in a molar ratio of 1.00:12.51:1.33:4.98:16.08:1.46, with an average molecular weight of about 6 kDa.     

鲍鱼不同部位肌肉的成分和热特性

测定了南日鲍不同部位肌肉的蛋白、多糖、脂质等基本成分,氨基酸组成和蛋白组分分布,并利用扫描电子显微镜(SEM)、傅立叶红外光谱分析仪(FTIR)和差示扫描量热仪(DSC)对它们的微观结构、二级结构和热特性进行分析。结果发现,鲍鱼肌肉水分含量从贝柱到裙边依次增加,而蛋白、多糖和脂肪含量却逐渐减小。贝柱肌肉部位氨基酸组成与过渡部位类似,而甘氨酸、脯氨酸和羟脯氨酸等具有胶原特征的氨基酸含量却比裙边部位低。电泳分析结果表明,贝柱和过渡部位肌肉蛋白主要由肌球蛋白重链、副肌球蛋白和肌动蛋白组成,裙边部位肌肉在150 kDa附近还出现胶原蛋白条带,但在任何部位肌肉中多糖均与副肌球蛋白和肌动蛋白结合。SEM图谱显示,鲍鱼肌肉组织纤维结构从贝柱到裙边逐渐变得致密。贝柱和过渡部位在FTIR中没有酰胺Ⅲ吸收峰,而裙边部位却出现酰胺Ⅲ吸收峰。而且,贝柱和过渡部位肌肉均在DSC曲线中出现1个放热峰和3个蛋白热转变的吸收峰,而裙边部位肌肉却只有1个胶原蛋白热转变的吸收峰。结果表明,鲍鱼贝柱和过渡部位肌肉的多糖含量比裙边高,纤维网络结构更疏松,成分更复杂。      

鲍鱼脏器多糖的抗氧化活性研究

采用酶法分别从雌、雄性皱纹盘鲍脏器中提取鲍鱼脏器粗多糖（AVP）。经Sephadex G-100凝胶过滤柱分离后,FAVP和MAVP各得到两个组分：FAVPⅠ,FAVPⅡ;MAVPⅠ,MAVPⅡ。它们清除羟自由基的EC50分别为1．38,0,99,1．51,1．19mg／mL,与对照Vc（EC50为1．23mg／mL）相比活性更强;其还原能力的A700,0.2分别为37．68,7．37,22．41,7.63mg／mL,与对照Vc（EC20为30．57μg／mL）相比弱很多;其络合能力则很弱。相关分析结果表明,鲍鱼脏器多糖具有一定的抗氧化能力。     

即食皱纹盘鲍腌制配方及食盐渗透规律

利用皱纹盘鲍生产即食食品,运用感官模糊综合评判法确定最佳腌制配方,并对腌制过程不同温度条件下食盐渗透规律进行了研究。正交实验结果表明,最佳腌制配方为食盐添加量5%,白糖添加量9%,味精添加量1%,食醋0.15%,此腌制配方所得即食皱纹盘鲍风味、质地、色泽均较好。按照最佳腌制配方,通过对不同温度下（30、40、50℃）腌制过程中食盐渗透量的数据进行拟合,得到相关方程,温度越高渗透速度常数越高;30、40、50℃渗透速度常数分别为0.6224、0.7431、0.8777;要得到食盐含量3.8%的鲍鱼,在最佳腌制配方的腌制溶液中的腌制条件为:30℃-3.78h、40℃-2.95h、50℃-1.99h。本研究为合理控制即食鲍鱼的加工时间及其扩大化工业生产提供一定的基础。      

A comparative of heavy metal contents and biochemical characteristics of Japanese (Haliotis discus) and Korean abalone (Haliotis discus hannai)

Heavy metal contents and biochemical characteristics of Japanese (J-abalone) and Korean abalone (K-abalone) were compared. Heavy metal contents of Jand K-abalone were less than the maximum levels in the Korea Food Code. There were significant differences in contents of crude protein and ash between J- and K-abalone (p<0.05). In fatty acid composition, K-abalone had 20:0, 22:1n-9, and 22:6n-3 but these fatty acids were not found in J-abalone. J-Abalone showed higher levels of 20:4n-6, and 22:5n-3 compared to K-abalone (p<0.05). The amino acid composition showed that J-abalone had significantly higher levels of aspartic acid, threonine, alanine, isoleucine, tyrosine, and arginine compared to Kabalone (p<0.05).     

鲍鱼内脏中天然牛磺酸的提取与检测

目的以皱纹盘鲍内脏为原料,优化高纯度牛磺酸的提取工艺,并建立用高压液相色谱检测牛磺酸纯度的方法。方法经水煮、乙醇抽提、蒸发浓缩、沉淀、活性炭处理、结晶等步骤,获得高纯度天然牛磺酸。用高压液相色谱检测牛磺酸纯度的方法为:色谱柱:Discovery C18;流动相:甲醇-0.05 mol/L乙酸钠缓冲液(pH 5.3)(v/v,50:50);流速:1 mL/min;检测波长:330 nm;柱温:室温。结果该提取工艺能从1 kg鲍鱼内脏中提取得到天然牛磺酸3.07 g。采用该检测方法,牛磺酸的出峰时间为6.037 min,在1~20μg/mL浓度范围内线性关系良好(R2=0.9999),最低检出限为0.03μg/mL,最低定量限为0.12μg/mL,样品测定的平均回收率为99.44%(RSD=0.25%),方法的精密度和稳定性好(RSD1%),用该方法检测提取得到的牛磺酸纯度为96.06%。采用红外光谱法(IR)对提取得到的鲍鱼内脏牛磺酸进一步作结构鉴定,发现它与标准品的红外特征吸收峰一致。结论获得了高纯度牛磺酸的提取工艺。本方法精密度和稳定性好,回收率高。     

皱纹盘鲍足肌热处理过程中品质变化的动力学初探

热处理一直是鲍鱼加工的关键工艺之一。以皱纹盘鲍足肌为样品,研究60、70、80、90、100℃下水浴加热640s的过程中,蒸煮损失、颜色和硬度随时间的动力学变化及规律。结果表明:蒸煮损失随时间和温度升高不同程度的递增,一段时间后趋于稳定,大部分蒸煮损失发生在80s内,遵循一级反应动力学改进模型;时间越长,温度越高,肉色越偏黄(b*),色变越大(ΔE),颜色变化遵循零级反应动力学模型;硬度随时间先急剧增大,再急剧减小,最后缓慢减小趋于稳定,温度越高,变化过程越迅速,遵循二级反应动力学模型。综合考量下,高温短时间的热处理有利于获得高品质的皱纹盘鲍。      

基于神经网络法优化即食皱纹盘鲍栅栏模式

以栅栏技术理论为指导,采用神经网络模型优化不同栅栏模式对即食鲍鱼（Haliotis discus hannai Ino）产品的防腐保鲜效果。通过研究几个栅栏因子（烘干后产品的水分活度（aw）、乳酸链球菌素（Nisin）、乳酸钠的添加量以及杀菌温度）组合得到的不同栅栏模式的防腐保鲜效果以及对产品品质的影响,以菌落总数及感官评分作为响应值建立神经网络模型并进行优化。结果表明：产品最适栅栏模式为：aw为0.92,Nisin、乳酸钠添加量分别为0.39 g/kg、1.6%,杀菌温度89 ℃,此栅栏模式防腐保鲜效果好,且能较好地保持产品的质地和风味。     

不同分子质量鲍鱼外套膜酶解物抗氧化活性研究

研究鲍鱼外套膜酶解物(AMH)及其不同分子质量组分的抗氧化活性。采用中性蛋白酶水解鲍鱼外套膜制得AMH,通过超滤得到分子质量分别为小于1kDa和1～3,3～5,5～10kDa的4种酶解物组分;考察AMH和不同分子质量组分的体外抗氧化活性。结果表明:AMH清除DPPH自由基、OH自由基和亚铁离子螯合能力的IC50值分别为11.76,12.07,4.04mg/mL;经过超滤分离后,其抗氧化活性明显增强,且1～3kDa分子质量范围组分的清除DPPH自由基和OH自由基能力最强,3～5kDa分子质量范围组分的亚铁离子螯合能力最强。     

不同溶剂对皱纹盘鲍内脏脂质的提取及其组分对比分析

采用氯仿/甲醇、正己烷、环己烷/乙酸乙酯等五种不同提取溶剂对皱纹盘鲍内脏粗脂肪以及磷脂进行提取,分析其对油脂和磷脂得率的影响,并采用气相色谱-质谱法(GC-MS)对油脂脂肪酸成分进行分析。结果表明,以正己烷/乙酸乙酯(3:1,V/V)为提取剂效果最佳,粗脂肪和磷脂得率分别达14.87±0.69%和11.48±0.71%。五种不同溶剂对粗脂肪和磷脂的提取得率、脂肪酸组成及含量之间存在一定的差异,所得粗脂肪中饱和脂肪酸有4~7种,占28.72%~31.71%,单不饱和脂肪酸有5~6种,占30.02%~38.98%,多不饱和脂肪酸8~12种,占25.62%~31.32%,其中ω-3脂肪酸约占4.96%~7.83%;环己烷/乙酸乙酯提取的多不饱和脂肪酸种类最多,达12种,占总量的30.82%,其中ω-3系列（亚麻酸,二十碳五烯酸,二十二碳五烯酸）占7.71%。综合考虑萃取剂性质以及油脂的得率和脂肪酸营养利用价值选用环己烷/乙酸乙酯作为提取鲍鱼内脏鱼油的最佳溶剂。     

杂交鲍Haliotis discus hannai × Haliots discus discus体内食源性脂肪酸的标志分异

本文研究了底播增殖的杂交鲍的内脏团、肌肉和消化腺内的得到公认的几种食源性脂肪酸标志的分布特征,可为杂交鲍的长期食源的判别提供依据。同等大小的杂交鲍,其内脏团、消化腺和肌肉内的硅藻脂肪酸标志(∑C16/∑C18和C20:5n-3)之间无显著无差异;消化腺内的绿藻脂肪酸标志(C18:2n-6+C18:3n-3)显著高于肌肉中的(p5%);肌肉中的褐藻脂肪酸标志(C20:4n-6)显著低于肌肉内的(p5%);异养细菌脂肪酸标志(C18:1n-7/C18:1n-9)在同等大小的杂交鲍内脏团、消化腺和肌肉中无差异。内脏团脂肪酸标志受性腺发育的影响;肌肉内脂肪酸含量较低;消化腺中脂肪酸组成的季节变化由食物的季节变化所致且总脂含量较高。从影响脂肪酸组成的因素及测试方法的灵敏度来看,消化腺用于脂肪酸标志法判断杂交鲍的长期食源更适宜。     

Antioxidant and anticancer effects of extracts from fermented Haliotis discus hannai with Cordyceps militaris mycelia

Food Science and Biotechnology - In this study, Haliotis discus hannai (H. discus hannai) was fermented using Cordyceps militaris (C. militaris) and was investigated for the improvement of its...     

南北方养殖不同规格皱纹盘鲍营养成分和呈味物质分析

目的 系统探究养殖模式和规格对鲍营养和呈味成分的影响。方法 选取全年北方养殖、南北接力养殖和全年南方养殖3种模式下小规格、中规格皱纹盘鲍(Haliotis discus hannai), 分别对其基本性状指标(总重、足肌重和壳长等)、营养成分(基本营养成分、脂肪酸和氨基酸)和呈味物质(游离氨基酸、核苷酸、有机酸和甜菜碱)进行测定和分析。结果 小规格南北接力养殖和全年南方养殖皱纹盘鲍足肌重(17.85±0.57 g)、蛋白质(67.55±5.01 g/100 g)、呈味物质[等效鲜味浓度(equivalent umami concentration, EUC)(2.06±0.02)、腺苷酸(71.04±8.15 g/100 g)和琥珀酸(8.16±0.76 g/100 g)]含量均高于小规格全年北方养殖皱纹盘鲍(P<0.05), 但小规格全年北方养殖皱纹盘鲍必需氨基酸总量(20.12±0.62 g/100 g)(P<0.05)和必需氨基酸指数(65.73)高于南北接力和全年南方养殖皱纹盘鲍; 中规格全年北方养殖皱纹盘鲍EUC值(1.63±0.05)显著高于(P<0.05)中规格南北接力养殖鲍, 但营养方面反之。3种来源的中规格皱纹盘鲍营养成分含量均高于小规格皱纹盘鲍; 除全年北方养殖鲍外, 小规格皱纹盘鲍呈味物质含量均高于中规格鲍。结论 不同养殖模式、规格皱纹盘鲍营养成分和呈味品质均有差异, 全年南方养殖和南北接力养殖鲍营养品质均优于全年北方养殖鲍, 但全年北方养殖鲍呈味品质优于南北接力鲍(小规格除外); 同一来源中规格鲍营养优于小规格鲍, 但小规格鲍呈味品质均优于中规格鲍(全年北方养殖鲍除外)。本研究结果将为皱纹盘鲍养殖、消费、加工及其营养品质评价提供有力数据支撑。     

Gelling properties of myofibrillar protein from abalone (Haliotis Discus Hannai Ino) muscle

Texture of muscle food is dependent on the gelation properties of myofibrillar protein. Defining the performance of myofibrillar protein during gelation is beneficial for maintaining quality and developing muscle food. The myofibrillar protein from abalone muscle (AMP) was extracted and the gel-forming ability was investigated. The lowest protein solubility of AMP in distilled water was obtained at pH 5.5, but shifted to a lower pH value by ionic strength. The breaking force and deformation of AMP gel formed at pH 7.0 were 48.00 g and 27.70 mm, respectively, but they could not be detected at pH 5.0 and pH 5.5 due to the low gel-forming ability. Scanning electron microscopy data showed that a coarse and disorder gel containing clusters of agglomerates was observed at pH 5.0 and pH 5.5, but gradual compact network structure was observed in the gel formed at increasing pH. The glass transition temperature (Tg) of AMP gel formed at pH 5.5 was higher than that of AMP, and the Tg of AMP gel was increased with increasing the pH of gel-forming solution. It was found that the unfolding of tertiary structure of AMP at pH 7.0 was easier than that at pH 5.5 through the result of infrared spectra. We therefore conclude that both the solubility and gel-forming ability of AMP are pH dependent.     

Effect of thermal treatment on the texture and microstructure of abalone muscle (Haliotis discus)

The texture and microstructure of edible abalone meats were studied during heat treatments from 50 to 100°C for 60 min. No increase in extractable soluble collagen content was observed below 80°C, but a 9-fold increase was observed at 100°C. SDS-PAGE showed that extractable myosin heavy chains and paramyosin contents reduced significantly at 80°C, and disappeared completely at 100°C. The shear force increased slowly from 50 to 70°C, but relaxed back to the initial level at 100°C. Rapid reduction of hardness was observed at 50°C, minimum hardness was obtained at 100°C. Springness, cohesiveness, chewiness, and resilience were enhanced to maximum levels at 70, 90, 70, and 90°C, respectively. Optical micrographs and transmission electron microscope showed a significant increase of intermyofibrillar gaps at 90°C and broken fibers at 100°C. Results suggested that 80°C might be a suitable temperature to produce ready-to-eat abalone products.     

重组鲍鱼肌肉脯氨酰内肽酶的性质研究

为研究皱纹盘鲍(Haliotis discus hannai)中脯氨酰内肽酶(Prolyl endopeptidase,Hdh-PEP)的酶学特性与结构特性,利用基因工程技术重组并在大肠杆菌中高效表达了皱纹盘鲍PEP.原核表达的Hdh-PEP分子量为85kDa,在pH2～6、温度20～60℃条件下,Hdh-PEP的表面...