高效液相色谱法检测罗非鱼中丁香酚残留量

目的建立罗非鱼中丁香酚残留量的高效液相色谱分析方法。方法样品采用乙腈为提取溶剂,经超声提取、正己烷脱脂净化2次后,通过高效液相色谱技术检测,外标法定量。结果丁香酚在0.1~10.0 mg/L范围内具有良好的线性关系,相关系数为0.99998;5.00 g样品中丁香酚残留量的检出限为0.03 mg/kg,定量限为0.10 mg/kg;3个添加水平平均回收率为80.5%~101.2%,相对标准偏差为3.38%~5.39%。结论本方法具有操作简便、快速、准确的特点,适用于罗非鱼中丁香酚残留量批量检测。     

Preparation of selected spice microparticles and their potential application as nitrite scavenging agents in cured Tilapia muscle

The development of nitrite scavenging agents for application in curing products has attracted much attention. In this work, we developed eight types of spice microparticles (myrcia, aniseed, cinnamon, chili, Sichuan pepper, nutmeg, clove, and cumin) using a high-speed disintegrator method and explored their potential application as nitrite scavenging agents. The results demonstrate spice microparticles can efficiently reduce nitrite in sodium nitrite solutions (nitrite scavenging percentages: 36–100%) and high nitrite Tilapia muscle models (nitrite scavenging percentages: 11–42%). Moreover, the nitrite scavenging ability is dependent on spice types and spice microparticle sizes. These results suggest spice microparticles have another potential role (nitrite scavenging) besides flavor adding when they are applied in the curing process of fish and meat. This work can potentially expand the application of spice microparticles in food industry and provide useful information to understand the role of spice microparticles in cured fish, seafood and meats.     

Biochemical and gelling properties of tilapia surimi and protein recovered using an acid-alkaline process

The biochemical and gel properties of tilapia surimi prepared by a conventional washing method and protein isolated using alkaline-acid-aided processes were studied. Solubility and recovery of protein was found to be highest by using a conventional method, followed by an alkaline- and acid-aided process, respectively. Decreases in myoglobin and lipid contents were found in alkaline- or acid-aided process when compared to the conventional process (p < 0.05). The highest breaking force and deformation of kamaboko and modori gels was found in the gels prepared by the conventional washing method. Higher expressible water and whiteness were found in modori gels when compared to kamaboko gels. TCA-soluble peptide contents of conventional surimi gels were lower than those of acid- and alkaline-recovered protein gels. Degradation of myofibrillar protein was observed in acid-isolated protein. Microstructure of kamaboko gels showed more compact network than in modori gels in both conventional surimi and protein recovered using the pH-shift process.     

基于质构参数的低温保藏罗非鱼片品质评价方法

选取4℃、-7℃和-21℃保存的罗非鱼片,运用感官评定和TVB-N测量评价其品质变化,运用质构仪测量其各质构参数变化,所测结果绘制变化趋势曲线并用方程拟合建立模拟函数;运用SPSS13.0软件分析品质参数与质构参数之间的相关性;根据罗非鱼货架期,推测相关性较高的质构参数的腐败评价点。试验结果显示:冻罗非鱼片的弹性及内聚性变化与品质变化的相关性较大,估测相关腐败评价点分别为0.5828和0.1991,所测结果与实测值比较,误差在可接受范围内,因此该结果可以作为评价罗非鱼腐败的标准。     

罗非鱼的保鲜研究进展

罗非鱼肉质鲜嫩、细刺少,营养丰富,被公认为健康食品,并受到人们青睐.鱼肉腐败和货架期短是罗非鱼生产储藏中最大的问题,本文综述了目前国内外罗非鱼的现有保鲜技术,以便于更好地提高罗非鱼片的商业化生产.     

Effects of the flaxseed oil on the fatty acid composition of tilapia heads

The objective of this study was to evaluate the effects of adding flaxseed oil (FO) to feed on the incorporation of n‐3 PUFA in tilapia heads. Tilapia were given diets with increasing levels of FO (0.00, 1.25, 2.50, 3.75 and 5.00% for treatments A, B, C, D and E, respectively), as a source of LNA for 150 days. The proximate composition of the heads indicated high nutritional value and 40 FA (fatty acids) common to all treatments were identified in total lipids. Intake of LNA caused storage of LNA and sequential desaturation‐elongation to eicosapentaenoic acid (EPA) and DHA. With increasing levels of FO in the diet, the content of LNA in tilapia heads increased (1.7 and 14.0% for diets A and E, respectively), as well as the contents of EPA (0.1 and 0.9% for diets A and E, respectively) and DHA (0.5 and 1.8% for diets A and E, respectively). Adding FO to tilapia feed markedly increased the total content of n‐3 PUFA (3.0 and 21.1% for diets A and E, respectively), decreased the total content of n‐6 PUFA (41.3 and 24.9% for diets A and E, respectively), and consequently resulted in a decrease in the n‐6/n‐3 ratio (13.8 and 1.2 for diets A and E, respectively). Therefore, feeding tilapia with FO is a good way of valorizing this part of the fish by creating a valuable nutritional food source.     

罗非鱼冷藏期间新鲜度变化及控制的研究

研究了罗非鱼冷藏期间新鲜度的变化及保鲜剂对其的影响,结果表明,在罗非鱼冷藏过程中,随着感官质量的下降,鱼体组织中组胺、三甲胺、氨基态氮含量增加。组胺和三甲胺的含量与鱼体新鲜程度之间呈显著的负相关关系。0～2℃冷藏罗非鱼的感官一级鲜度和感官二级鲜度的临界组胺含量分别为:(6.0±1.53)μg/g FW和(20.4±3.28)μg/g FW。用3种复合保鲜剂处理均能降低鱼体组织中组胺、三甲胺、氨基态氮的增加,延缓感官质量的下降。与对照相比,在3个保鲜处理中,保鲜效果以复合保鲜剂C最好。     

Thermal inactivation of Escherichia coli O157:H7 and Salmonella on catfish and tilapia

Thermal inactivation kinetics of individual cocktails of Escherichia coli O157:H7, or of Salmonella meat isolates or seafood isolates were determined in catfish and tilapia. Determinations were done at 55, 60 and 65 °C using a circulating-water bath and calculated using linear regression analysis. Salmonella seafood and meat isolates D-10 values on the finfish were the same and ranged from 425 to 450, 27.1 to 51.4, 2.04-3.8 s (z = 4.3 °C) at 55, 60 and 65 °C, respectively. The E. coli O157:H7 D-10 values ranged from 422 to 564, 45.2 to 55.5 and 3.3-4.2 s (z = 4.3 °C) at 55, 60 and 65° C, respectively. The only statistical difference (P ≤ 0.05) was found when comparing the D-10 values for E. coli O157:H7 at 55 °C on catfish and tilapia. The other D-10 values for the Salmonella at all temperatures and E. coli O157:H7 at 60 and 65 °C on the catfish or tilapia showed no statistical difference. D-10 values for the catfish and tilapia were significantly lower than the reported values in other food systems, but the z-values were within the literature reported range. These D-10 values can be used to determine cooking parameters of finfish.     

双酶水解罗非鱼碎肉制备蛋白胨的工艺研究

以冷冻罗非鱼片加工过程的碎鱼肉为原料,选用AS.1398中性蛋白酶和木瓜蛋白酶同步水解罗非鱼碎肉制备蛋白胨。通过响应面中心组合设计试验,得到罗非鱼碎肉酶解条件的优化数学回归方程。此模型在实验范围内能较准确预测蛋白胨得率。通过贡献率法计算表明,在实验范围内各因子对蛋白胨得率作用的大小依次为加酶量>酶解时间>酶解温度;利用岭嵴分析可知,酶解罗非鱼碎肉制备蛋白胨的最适工艺条件为:温度为56.5℃,时间为4.7 h,加酶量为1174.0 U/g。