超高压处理对小龙虾脱壳及虾仁性质影响的研究

为提高小龙虾人工脱壳效率及虾仁的品质,脱壳前对小龙虾采用超高压处理,通过对比不同处理条件下脱壳时间、虾仁得率和虾仁完整性等方面的差异,综合评价超高压处理对小龙虾脱壳及虾仁性质的影响。结果表明:超高压处理较传统手工脱壳能显著(p<0.05)缩短小龙虾脱壳时间、提高虾仁得肉率,最佳脱壳条件为300 MPa保压1 min,此条件下脱壳时间较未处理过的脱壳效率提高65.46%,较水煮脱壳工艺提高47.37%。另外,得到的虾肉完整性好,硬度有所增加、耐咀性变大、而弹性变化不明显。研究结果为超高压技术应用于小龙虾的脱壳提供了参考。      

冷冻处理的熟制虾肉在保鲜条件下的货架期

以熟制克氏原螯虾(Procambarus clarkia)虾肉为原料,分别进行缓慢冷冻和快速冷冻处理后,于4℃下贮藏,通过感官评价、理化指标和微生物指标的测定,研究冷冻处理的熟制虾肉的货架期和品质。研究发现:快速冷冻处理虾肉的品质优于缓慢冷冻处理,但两者的货架期均为5d,6d为可接受的限值,未经冷冻处理的虾肉货架期为2d。感官评分值与TVB-N,MDA含量和菌落总数均有极显著的负相关,R2均在-0.947以上(P<0.01)。快速冷冻组虾肉在贮藏期间失重率和pH值稳定。TVB-N和菌落总数有望作为评价熟制虾肉品质的化学指标,TVB-N值为30mg/100g和菌落总数为6logcfu/g可作为熟制虾肉可接受的限值。冷冻处理有效的延长了熟制虾肉在4℃贮藏条件的货架期,可作为一种处理手段应用于熟制水产品的保鲜。     

Considerations for the development of cost-effective cell culture media for cultivated meat production

Innovation in cultivated meat development has been rapidly accelerating in recent years because it holds the potential to help attenuate issues facing production of dietary protein for a growing world population. There are technical obstacles still hindering large-scale commercialization of cultivated meat, of which many are related to the media that are used to culture the muscle, fat, and connective tissue cells. While animal cell culture media has been used and refined for roughly a century, it has not been specifically designed with the requirements of cultivated meat in mind. Perhaps the most common industrial use of animal cell culture is currently the production of therapeutic monoclonal antibodies, which sell for orders of magnitude more than meat. Successful production of cultivated meat requires media that is food grade with minimal cost, can regulate large-scale cell proliferation and differentiation, has acceptable sensory qualities, and is animal ingredient-free. Much insight into strategies for achieving media formulations with these qualities can be obtained from knowledge of conventional culture media applications and from the metabolic pathways involved in myogenesis and protein synthesis. In addition, application of principles used to optimize media for large-scale microbial fermentation processes producing lower value commodity chemicals and food ingredients can also be instructive. As such, the present review shall provide an overview of the current understanding of cell culture media as it relates to cultivated meat.     

烟熏肉制品中多环芳烃的提取及检测分析

烟熏肉制品作为肉类加工制品的一大类,由于其独特的风味深受广大消费者的欢迎。但是,在烟熏肉中含有致癌的多环芳烃(PAHs),影响着人们的健康。主要从烟熏肉制品中多环芳烃(PAHs)的提取、检测方法对其进行综述,以实现多环芳烃的快速检测和达到寻找控制多环芳烃方法的目的。     

小龙虾虾壳酶解液制备及其在小龙虾丸加工中的应用

目的:提高小龙虾虾丸风味特性与营养价值,丰富小龙虾加工产品的多样性。方法:以小龙虾虾壳为原料制备酶解液,通过单因素和正交试验优化确定复合酶法制备小龙虾虾壳酶解液工艺,并对添加有酶解液冻干粉及虾肉的小龙虾“全虾丸”进行营养品质分析。结果:小龙虾虾壳酶解液最佳制备工艺条件为1 g虾壳粉中添加0.5 mL乳酸,60℃预处理40 min,复合蛋白酶(m_{木瓜蛋白酶}∶m_{风味蛋白酶}为3∶1)添加量为5%(质量分数),酶解温度60℃,酶解时间4 h,料液比1∶100 (g/mL),酶解液中蛋白提取率为64.69%。酶解液冻干粉重金属含量均符合水产品重金属限量标准,且含有钙、镁、铁、硒等人体所需常量及微量元素;其成分分析显示,酶解液冻干粉有一定营养价值,在一定程度上可增加食品的鲜香风味,且符合安全标准。小龙虾虾丸的营养和质构分析表明,全虾丸蛋白质含量高,富含多种氨基酸,营养全面,风味独特,黏弹性及咀嚼性良好。结论:添加了虾壳酶解液冻干粉及虾肉的小龙虾虾丸有一定的营养价值,丰富了小龙虾即食产品种类,提高了小龙虾利用率。     

龙虾下脚料中虾油的提取工艺和性质研究

采用单因素实验和响应面优化实验对龙虾下脚料中虾油的提取工艺进行研究,并对其脂肪酸组成和氧化稳定性进行了分析。结果表明:虾油提取的适宜工艺条件为78.88%乙醇、液料比(mL∶g)6.65∶1、提取温度40℃、提取时间1h、提取2次。采用逐步回归拟合,获得虾油提取率的预测模型如下:提取率/%=10.73+0.12A+0.65B-0.072C-0.43A2-0.56B2+0.027C2-0.31AB+0.012AC-0.033BC,预测最大提取率为11.04%,实测值为10.96%。通过对精炼虾油的脂肪酸分析,共检出14种脂肪酸,以总脂肪酸含量为基数,其中不饱和脂肪酸占47.98%,饱和脂肪酸占52.02%,必需脂肪酸占17.26%。EPA和DHA含量占多不饱和脂肪酸含量的7.35%,顺式脂肪酸含量占不饱和脂肪酸含量高达95.65%,说明此虾油具有很好营养价值。氧化稳定性研究表明,虾油的诱导时间为0.86 h。     

Influence of gender and spawning on thermal stability and proteolytic degradation of proteins in Australian red claw crayfish (Cherax quadricarinatus) muscle stored at 2 °C

Thermal stability and proteolytic degradation of male (M), nonspawning female (F) and spawning female (SF) red claw crayfish (Cherax quadricarinatus) muscle proteins during refrigerated storage (2 °C) were investigated. The thermal transition temperatures (T_max) of myosin and actin remained relatively constant during storage, but their enthalpies of denaturation (ΔH) increased, especially in SF samples. SF muscle proteins were more heat‐stable (greater T_max and ΔH values, P < 0.05) than M and F muscle proteins. Protein degradation occurred in all muscle groups, more rapidly in M and F muscles than in SF muscle. The diminishments of a 69‐kDa component and troponin‐I and the appearance of a 55‐kDa polypeptide represented the most salient proteolytic changes. The results suggested that the spawning status was a more significant factor than gender in affecting the quality of red claw muscle proteins and their changes during refrigerated storage.     

Influence of Gender and Spawning on Meat Quality of Australian Red Claw Crayfish (Cherax quadricarinatus) Stored at 2 °C

ABSTRACT:  Shell-on tails of male (M), nonspawning female (F), and spawning female (SF) Australian red claw crayfish ( Cherax quadricarinatus ) ( n = 270) were aerobically stored at 2 °C up to 10 d to monitor meat quality changes under a retail condition. Percentage protein of SF muscle was higher ( P < 0.05) and moisture and ash content lower ( P < 0.05) than those of M and F muscles. The pH of muscle changed during storage, with SF generally having a lower value than M or F ( P < 0.05). Lipid oxidation increased during the 1st 5 d and no significant difference existed between the 3 muscle groups. Cooking yield of SF (91.72%) at 10 d was significantly lower than that of M (96.25%) or F (97.81%), and its muscle shear force was also higher ( P < 0.05) than M at 0, 3, 5, and 7 d and than F at 5 and 7 d. Sensory panel results (cooked meat tenderness, juiciness) were significantly correlated with instrumental results (shear force, cooking yield), with SF showing a lower meat tenderness, juiciness, and overall acceptability than M and F samples.     

鹰嘴豆膳食纤维的提取及其对午餐肉品质的影响

鹰嘴豆豆渣是鹰嘴豆加工后的下脚料,大部分被用作饲料、肥料或被废弃,造成严重的资源浪费。鹰嘴豆豆渣中含有较多的水不溶性膳食纤维,故采用酸、碱结合的化学法对鹰嘴豆豆渣进行处理,通过正交试验设计得到鹰嘴豆水不溶性膳食纤维的最佳提取工艺:碱用量5 mL/g,碱处理时间70 min,碱处理温度80℃,酸用量2 mL/g,酸处理时间80 min。研究鹰嘴豆膳食纤维的添加对午餐肉中亚硝酸盐含量的降低作用。结果表明:添加了1.0%鹰嘴豆水不溶性膳食纤维的午餐肉中亚硝酸盐含量显著降低。     

Microbiological and physicochemical properties of red claw crayfish (Cherax quadricarinatus) stored in different package systems at 2 degrees C

ABSTRACT:  This study compared 3 package systems for their influence on the stability of shell-on red claw crayfish tail meat stored at 2 °C for 14 d. Modified atmosphere packaging (MAP, with 80% CO₂/10% O₂/10% N₂) suppressed ( P < 0.05) the growth of aerobic bacteria and coliforms when compared with aerobic packaging using polyvinylchloride (PVCP) and vacuum packaging (VP). MAP and VP tended to retard lipid oxidation, inhibited Ca-ATPase activity change, but produced more intense protein denatuation when compared with PVCP. The MAP packaging enhanced proteolysis and resulted in more ( P < 0.05) cooking losses and a higher ( P < 0.05) shear force than VP and PVCP for samples stored for 6 and 14 d ( P < 0.05). Sensory panel results were in general agreement with the physicochemical changes, suggesting that the specific package systems had a significant impact on the quality of refrigerated red claw crayfish raw meat.     

Determination of antibiotics in meat samples using analytical methodologies: A review

Antibiotics are widely used to prevent or treat some diseases in human and veterinary medicine and also as animal growth promoters. The presence of these compounds in foods derived from food-producing animals can be a risk for human health. Consequently, regulatory agencies have set maximum residue limits for antibiotics in food samples. Therefore, the development of novel methodologies for its determination in food samples is required. Specifically, the analysis and quantification of these substances in meat tissues is a challenge for the analytical chemistry research community. This is due to the complexity of the matrix and the low detection limits required by the regulatory agencies. In this sense, a comprehensive review on the development of new sample preparation treatments involving extraction, cleanup, and enrichment steps of antibiotics in meat samples in combination with sensitive and sophisticated determination techniques that have been carry out in the last years is necessary. Therefore, the aim of this work is to summarize the published methodologies for the determination of antibiotics from 2016 until the beginning of the second semester of 2020. The first part of this review includes an introduction about antibiotic families, followed by sample preparation and determination techniques applied to the different families. Finally, a detailed discussion of the current trends and the future possible perspectives in this field are also included.     

小龙虾壳中虾青素的提取纯化工艺研究

目的优化纯化粗提品中虾青素的工艺,提高游离虾青素含量和提取率。方法以碳酸钠水溶液洗涤虾青素粗提品为去除杂质的最佳方法。结果洗涤条件是碳酸钠洗涤浓度0.025 g/mL,温度25℃,时间6 min,以虾青素的提取量和杂质沉淀量评价提取纯化工艺,提取量为375μg/g,杂质沉淀量为199μg/g。结论此法提高了虾青素的提取量,减少了杂质含量。     

Extraction and characterisation of telopeptide-poor collagen from porcine lung

The aim of the investigation was to develop optimum extraction conditions of telopeptide-poor collagen from porcine lung (TPCPL). Chemical composition, histological properties of porcine lung, removal efficiency of haemoglobin by different solvents and effects of pepsin solubilisation time on TPCPL properties were evaluated. Histological observation of lung tissue revealed collagen coexists with elastin. Treatment with 0.1 M Tris–HCl/5% Triton X-100 (pH 8.2) for 12 h exhibited the highest efficiency for removal of haemoglobin. The maximal yield of TPCPL reached 6.702 g/kg by pepsin solubilisation for 72 h. SDS–PAGE indicated that type I collagen was a major component of TPCPL; FTIR spectra of all TPCPL were similar to commercial porcine collagen and absent from denatured product (gelatin) and TPCPL 72 exhibited the lowest denaturation temperature (36.4 °C) and maximum enzymatic sensitivity. Finally, the optimum pepsin solubilisation of TPCPL was controlled at 4 °C for 48 h for better structural integrity and acceptable yield.     

繁缕叶蛋白提取工艺研究

以鲜繁缕为材料,采用酸化和加热相结合的方法,研究了提取繁缕叶蛋白的最佳工艺条件。在考虑料液比、滤布层数、加热温度和加热时间等单因素对叶蛋白提取率影响的基础上,进行了正交试验,最终确定叶蛋白最佳提取工艺条件为：料液比1:5、5 层滤布过滤、加热到75℃并在此温度下持续11min,繁缕叶蛋白的提取率为52.08%,得率为27.17%。     

大体积肉中DNA提取方法的优化

目的优化一种从大体积肉类中提取DNA的方法。方法从大组织肉上多点取样,用组织粉碎机打碎,称取10 g肉加入90 m L PBS缓冲液和450μL蛋白酶K,60℃消化至澄清后,混匀,取200μL消化液用试剂盒进行DNA提取;再与常规试剂盒方法提取的DNA在同条件进行实时荧光PCR及琼脂糖凝胶电泳验证。结果 2种方法提取DNA的Ct值差异在0.5个循环以内,无显著性差异(P0.05);电泳结果显示,2种方法所扩增的为同一产物。结论该方法取样具有代表性,可适用于大体积肉类掺假检测或动物源性成分检测中的DNA提取。     

酶法提取克氏原螯虾头和虾壳的中蛋白质

采用蛋白酶法对克氏原螯虾头和虾壳中蛋白质的提取工艺进行研究。单因素试验和正交试验结果表明:虾头和虾壳中蛋白质提取的最优工艺条件为木瓜蛋白酶与风味蛋白酶按1:1.5混合作为复合蛋白酶,酶解温度为50℃、酶解时间为3h、蛋白酶用量为1.0%、pH6.5、料液比为1:10,该条件下蛋白质提取率为54.22%。     

牦牛肉组织蛋白酶L提取工艺的优化

为了获得提取牦牛肉中组织蛋白酶L的最佳工艺参数,首先采用Plackett-Burman试验对影响酶活力的7个因素进行筛选,发现浸提缓冲液pH值、L-Cys浓度及(NH4)2SO4饱和度3个因素显著影响酶活力。基于该3个因素的最陡爬坡试验、中心组合设计及响应面分析结果表明:3个因素对酶活力的影响大小依次为浸提缓冲液pH值>(NH4)2SO4饱和度>L-Cys;最佳提取工艺为:浸提缓冲液pH值5.68、L-Cys浓度为6.48 mmol/L、(NH4)2SO4饱和度为76.63%。在此条件下,酶活力最高为13.98 U/mg。试验结果与模型预测值吻合良好,说明所建模型切实可行,为进一步研究牦牛肉组织蛋白酶L的提取工艺提供理论依据。