海带、鱿鱼复合海鲜营养酱的研制

本文介绍了一种以海带、鱿鱼为原料的复合海鲜营养酱的加工工艺,并对其工艺条件和质量指标进行了探讨。     

Purification and identification of novel antioxidant peptides from enzymatic hydrolysates of sardinelle (Sardinellaaurita) by-products proteins

In order to utilise sardinelle (Sardinellaaurita) protein by-products, which is normally discarded as industrial waste in the process of fish manufacturing, heads and viscera proteins were hydrolysed by different proteases to obtain antioxidative peptides. All hydrolysates showed different degrees of hydrolysis and varying degrees of antioxidant activities. Hydrolysate generated with crude enzyme extract from sardine (Sardinapilchardus) displayed high antioxidant activity, and the higher DPPH radical-scavenging activity (87 ± 2.1% at 2 mg/ml) was obtained with a degree of hydrolysis of 6%. This hydrolysate was fractionated by size exclusion chromatography on a Sephadex G-25 into eight major fractions (P₁–P₈). Fraction P₄, which exhibited the highest DPPH scavenging activity, was then fractionated by reversed-phase high performance liquid chromatography (RP-HPLC). Seven antioxidant peptides were isolated. The molecular masses and amino acids sequences of the purified peptides were determined using ESI-MS and ESI-MS/MS, respectively. Their structures were identified as Leu-His-Tyr, Leu-Ala-Arg-Leu, Gly-Gly-Glu, Gly-Ala-His, Gly-Ala-Trp-Ala, Pro-His-Tyr-Leu and Gly-Ala-Leu-Ala-Ala-His. The first peptide displayed the highest DPPH radical-scavenging activity (63 ± 1.57%; at 150 μg/ml) among these peptides.     

Dimethylamine, trimethylamine, and biogenic amine formation in high-pressure processed semidried squid (Todarodes pacificius) during refrigerated storage

The quality properties of semidried squid treated with high-pressure processing (HPP) were investigated during refrigerated storage. The vacuum-packed semidried squid samples were subjected to 500 MPa for 0 min (HPP-0), 5 min (HPP-5), and 10 min (HPP-10) by using a custom-made high-pressure processor and stored at a refrigerated temperature for 28 d. The populations of indigenous psychrotrophic and mesophilic bacteria were effectively reduced by approximately 1 and 2 log CFU/g at the HPP-10 treatment, respectively. Compared to the control, the bacterial counts in HPP-treated semidried squid samples were maintained at low levels throughout the storage period. The increase in the amounts of dimethylamine (DMA) and trimethylamine (TMA) was more pronounced at the unpressurized control than at the HPP treatments. The production of biogenic amines (BAs) varied with HPP treatment during refrigerated storage. Therefore, the application of HPP may provide a significant improvement in the safety and quality of semidried squid.     

Utilization of oryzacystatin for regulating the ripening of squid shiokara, a traditional Japanese salted and fermented seafood

Shiokara is a fermented seafood composed of sliced squid mantle muscle ripened with fresh squid liver. Preliminary sensory evaluation by using the ranking test revealed that the hardness of squid muscle in shiokara was reduced within 7 d of ripening. During the process of ripening, muscle proteins were digested by proteinases present in squid liver. The degradation of paramyosin and myosin heavy chain was observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The hardness of squid mantle muscle in shiokara was reduced with the degradation of paramyosin and myosin heavy chain. This degradation was mainly caused by E-64-sensitive cysteine proteinases. To control the hardness of shiokara, we used rice seed oryzacystatin, which suppresses proteolysis by papain-like cysteine proteinases. When oryzacystatin was added 4 d after the start of shiokara ripening, the muscle protein degradation stopped, without further muscle softening. These results show that oryzacystatin is useful to control the ripening of shiokara by regulating its hardness.     

微波能对杀虫效果及鱿鱼干品质的影响

通过不同的微波能量（微波功率与作用时间的调整）对苍蝇蛹、卵及幼虫、蝗虫卵进行处理,以研究微波对虫卵的杀灭效果及其对鱿鱼品质的影响。试验结果表明：在微波能量为110J／g以上时,苍蝇蛹、附着在鱿鱼表面的蝇卵及其幼虫、蝗虫卵的死亡率为100％,或当微波加热的温度超过500℃,虫卵的死亡率也达100％。研究同时表明：在同等能量输出的情况下,采用较小的输出功率和较长的作用时间其灭虫效果更好;对于温度的敏感性,幼虫最为敏感,其次是虫卵和蛹。比较微波处理之后的鱿鱼干品质,其感官特点、理化指标及贮藏性能未出现明显的变化或基本没有变化。     

鱿鱼内脏糖蛋白提取工艺及其免疫活性初步研究

本文分析了鱿鱼内脏的一般营养成分;探索了NaCl溶液提取鱿鱼内脏糖蛋白的工艺流程及工艺条件;并初步探讨了鱿鱼内脏糖蛋白对小鼠免疫功能的影响.结果表明:鱿鱼内脏中含有较高的蛋白质;提取的最佳工艺条件是:料液比为1:6、浸提时间为60 min、NaCl浓度为3%、浸提温度为80 ℃;该工艺所提取得糖蛋白具有一定的免疫活性.     

基于HPLC-AFS技术研究南极磷虾油对大鼠脏器中砷形态分布的影响

目的:建立动物组织脏器中砷形态的分析方法,探讨摄食南极磷虾油尤其是砷甜菜碱对大鼠脏器中砷形态分布的影响。方法:雄性Wistar大鼠随机分为大豆油对照组(7 d组、30 d组)、南极磷虾油组(7 d组、30 d组)、添加100 mg/kg砷甜菜碱的南极磷虾油组(7 d组、30 d组),每组5只,灌胃剂量2.625 g油/kg·bw,喂养7 d或30 d后,剥离肝脏、肾脏。采用建立的高效液相色谱-原子荧光光谱法,经Hamilton PRPx-100色谱柱分离,磷酸二氢铵缓冲液洗脱,对脏器中砷甜菜碱(AsB)、二甲基砷酸(DMA)、一甲基砷酸(MMA)、亚砷酸盐(AsⅢ)和砷酸盐(AsⅤ)的含量进行测定。结果:大鼠脏器中五种砷形态的检出限为0.35~0.50 μg/L,定量限为1.0~2.0 μg/L,加标回收率为80.2%~113.0%,RSD为1.34%~3.97%,方法线性良好,R2>0.999。采用该方法测得,大鼠肝脏和肾脏中主要砷形态为AsB和DMA。与对照组相比,大鼠摄食磷虾油和砷甜菜碱磷虾油7或30 d后,脏器中总砷、AsB、AsⅢ、DMA、MMA和AsⅤ含量均无显著性变化。结论:摄食南极磷虾油后,大鼠肝脏和肾脏中不会出现砷蓄积现象。南极磷虾油及其砷甜菜碱不会对大鼠脏器中砷形态含量以及各砷形态之间的转化产生显著影响。本研究可为南极磷虾油食用安全性的科学认识及其应用领域拓展提供理论支撑。     

不同梯度有机硒饲粮对羔羊肉及内脏组织硒沉积的影响

采用随机区组设计,选择滩羊与小尾寒羊杂交羔羊64 只,随机分为4 组,分别制备有机硒含量0.14（1组）、0.96（2组）、1.41（3组）、1.92 mg/d（4组）的饲粮。正式期60 d,每隔10 d随机选择参试羔羊2 只屠宰后,采集其代表性肌肉及内脏样品进行硒含量分析。结果表明：不同梯度有机硒添加量及日龄对羔羊肌肉及其内脏组织硒沉积量有显著影响,各实验组分别饲喂其有机硒添加剂日粮10 d,羔羊背肌、股肌及其内脏组织硒沉积量即可达到DB 61/T 556—2012《富硒食品与其相关产品硒含量标准》的标准;实验2组、3组和4组分别饲喂其有机硒日粮20～30 d,羔羊背肌和股肌硒沉积量即可达到DBS 42/002—2014《富有机硒食品硒含量要求》的标准。     

栉孔扇贝内脏、裙边油中脂肪酸组成分析

采用索氏提取法对栉孔扇贝内脏和裙边中的油脂进行提取,用气相色谱对其油的脂肪酸组成进行分析测定.结果表明:扇贝内脏油脂含量远远高于扇贝裙边,扇贝内脏油脂含量占70℃烘干样品的14％以上;扇贝内脏和裙边油中不饱和脂肪酸分别为68.10％和55.29％,尤其是(EPA+DHA)含量高,内脏油为44.12％,裙边油为39.77％;扇贝内脏油中(EPA+DHA)含量高于目前报道的各种鱼油的( EPA+ DHA)含量(12％～42％).从扇贝内脏中提取油脂将有较大的市场潜力.     

鱿鱼下脚料水解物的制备及降血压抑制肽研究

通过对鱿鱼肝脏蛋白水解液中抑制肽的研究,为鱿鱼及其下脚料水解物的高效利用奠定了理论基础。采用酶解技术和凝胶过滤分离等技术进行研究。实验得出:胃蛋白酶为鱿鱼肝脏蛋白水解的最佳酶类,同时以水解度和ACE抑制活性为指标,得出胃蛋白酶水解的最佳条件:在36℃条件下酶解22h,酶与底物的质量比2%,底物浓度2.5%。经过上述条件处理后的水解液经超滤处理(分子量为20ku)后,用Sephadex G-50进行分离,洗脱得到等5个峰值,其中组分B的ACE抑制活性最高,其半抑制浓度(IC50)达到1.80mg/mL。