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1.
为研究解冻鲐鱼背腹部鱼片在贮藏过程中的鲜度变化与脂肪氧化变化规律,分析了鱼片中挥发性盐基氮(TVB-N)、总脂肪、不饱和脂肪酸、酸价(AV)、过氧化值(POV)和硫代巴比妥酸值(TBARS)随贮藏时间的变化规律。结果表明:冰箱4℃解冻鲐鱼能很好保持鱼肉的鲜度和品质,TVB-N值在贮藏第(6~8)天时超出标准限量范围,表明开始腐败;总脂肪含量和不饱和脂肪酸随贮藏时间延长呈下降趋势;AV随贮藏时间延长呈逐渐升高趋势,在贮藏(6~14)d增长速度较快;POV先升高,在第(12~16)天期间达到最高,而后呈下降趋势;TBARS值随时间延长而增加,在贮藏第(10~12)天时,鱼肉已严重氧化,不能食用或加工利用。  相似文献   

2.
本文研究了沟帮子烧鸡冷藏过程中脂肪氧化和挥发性物质的变化规律。主要测定了烧鸡鸡腿肉和鸡胸肉的硫代巴比妥酸反应值(TBARS)、过氧化物值(POV)和p H值,采用固相微萃取-气相色谱-质谱联用法(SPME-GCMS)检测烧鸡中的挥发性物质,并对烧鸡进行感官评定。结果表明,随冷藏时间的增加,烧鸡鸡腿肉和鸡胸肉的TBARS值显著增加(P0.05),POV先上升后下降,p H值则先下降后上升,挥发性风味物质如醛类、醇类、酮类不断增多,刺激性气味增强,烧鸡最终呈现出软烂、粘手、异味等感官品质。随冷藏时间增加,沟帮子烧鸡脂肪氧化程度不断加深,其产物严重影响烧鸡的感官品质。  相似文献   

3.
厦门白姑鱼腌制加工过程中的脂肪酸变化分析   总被引:2,自引:0,他引:2  
探讨厦门白姑鱼(Argyrosomus amoyensis)腌制加工过程中的脂肪酸的变化,并结合脂肪氧化相关指标:过氧化值(peroxide value,POV)及硫代巴比妥酸反应物(thiobarbituric acid reactive substance,TBARS)值,确定脂肪氧化对脂肪酸组成的影响。从腌制加工的7个关键工序中取样,采用气相色谱-质谱联用法分析脂肪酸,同时考察POV及TBARS值。结果表明:厦门白姑鱼原料含26.41%的饱和脂肪酸(saturated fatty acids,SFA)、20.26%的单不饱和脂肪酸(monounsaturated fatty acids,MUFA)和53.33%的多不饱和脂肪酸(polyunsaturated fatty acids,PUFA),共24种,必需脂肪酸占12.49%,二十碳五烯酸(eicosapentaenoic acid,EPA)和二十二碳六烯酸(docosahexaenoic acid,DHA)占40.70%。在腌制加工中,SFA含量显著增加,MUFA含量和PUFA含量显著降低(P0.05)。POV和TBARS值都呈现了先增后减的趋势,分别在烘干1 d和3 d出现峰值。相关性分析表明,SFA与MUFA呈显著负相关(P0.05),与PUFA呈极显著负相关(P0.01),MUFA和PUFA没有相关性;SFA与POV和TBARS值呈现显著正相关(P0.05),而PUFA与POV和TBARS值分别呈显著(P0.05)和极显著负相关(P0.01)。因此,厦门白姑鱼脂肪酸种类多,含有丰富的不饱和脂肪酸,腌制加工过程对主要8种脂肪酸有显著影响,脂肪的氧化使SFA含量增加,同时使PUFA含量降低,PUFA更容易发生氧化。  相似文献   

4.
通过对即食风鹅加工过程中各工艺点肌肉及皮下脂肪的盐分含量、水分含量、POV值、羰基值和双烯值、TBARS值、酸价以及游离脂肪酸总量的测定,探究了即食风鹅加工过程中脂肪氧化的规律。结果表明:风干过程中皮下组织水分较肌肉散失速率快,盐分含量增加。肌肉水分含量与肌内脂肪的TBARS值呈显著负相关(p0.05),说明水分减少有利于脂肪氧化;风干阶段肌内脂肪的羰基值和双烯值较皮下脂肪波动大,肌内脂肪氧化程度比较大;蒸煮和灭菌工艺结束后TBARS值从风干结束后的0.27 mg/kg迅速增加到0.53 mg/kg,说明较高的温度促进了以丙二醛为代表的醛类物质的产生和游离脂肪酸的积累,从而加强了脂肪的水解和氧化程度。  相似文献   

5.
本文以乌鳢(Ophicephalus argus)为研究对象,研究了冷藏(4±1)℃条件下分别以0.5%、1.0%、1.5%的食盐腌制对乌鳢鱼肉品质变化规律的影响,通过感官评分、p H、色泽、嫩度、蒸煮损失、汁液损失、盐溶蛋白、硫代巴比妥酸值(TBARS)、挥发性盐基氮(TVB-N)等指标,探究了不同浓度食盐对生鲜及腌制鱼肉贮藏品质的影响。结果表明:随贮藏时间的延长感官分值逐渐降低,对照组(0%食盐组)于第8 d就已失去食用价值,而T_3组(1.5%食盐组)在第12 d时仍可食用。在贮藏过程中,盐溶蛋白呈下降趋势;p H呈现波动性变化;蒸煮损失总体呈下降趋势。此外,TBARS值、汁液损失率、挥发性盐基氮含量在贮藏期间呈增长趋势。研究表明,T_3组(1.5%食盐组)在一定程度上减缓冷藏过程中乌鳢鱼片的品质变化,但会降低肌肉保水性、促进脂肪的氧化。  相似文献   

6.
旨在明确草鱼和鲢鱼鱼片冷藏过程中生物胺的动态变化规律以及其特征生物胺变化差异,测定分析了4℃贮藏条件下草鱼和鲢鱼片pH、挥发性盐基氮(TVB-N)、菌落总数(TVC)、感官评价以及生物胺含量的动态变化。结果表明,随着贮藏时间的延长,TVB-N、TVC呈明显上升趋势;草鱼和鲢鱼鱼片冷藏过程中苯乙胺、腐胺、酪胺及8种生物胺总量变化明显,且草鱼和鲢鱼鱼片中各生物胺显著变化的时间点分别为第10天和第8天。草鱼和鲢鱼片生物胺含量的差异变化主要发生在腐败后期,在贮藏第12天,草鱼、鲢鱼片间腐胺和酪胺含量差异显著(P0.05),其含量分别为(23.39±0.40),(44.46±1.88)mg/kg和(25.01±1.85),(50.84±1.50)mg/kg。经相关性分析显示,苯乙胺、腐胺、酪胺与草鱼片品质指标间显著相关(P0.05),可作为草鱼品质的监测指标;苯乙胺、腐胺、酪胺、尸胺与鲢鱼片品质指标间显著相关(P0.05),可作为鲢鱼片品质的评价指标。且冷藏期间草鱼和鲢鱼鱼片关键腐败时间点的酪胺和8种总生物胺的含量分别相近,可作为草鱼和鲢鱼片品质评价的共同指标。  相似文献   

7.
不同温度条件下鱼油氧化的动态变化   总被引:2,自引:0,他引:2  
鱼油是水产饲料重要的脂肪源,但由于其富含多不饱和脂肪酸而极易氧化。系统研究了不同氧化温度下,鱼油过氧化值(POV)、酸值(AV)、碘值(IV)、羰基值(CV)和硫代巴比妥酸反应物(TBARS)随氧化时间的变化规律。结果表明:在各氧化温度下,鱼油的POV、AV、CV和TBARS均随氧化时间的延长而显著升高(P<0.05);IV随氧化时间的延长而显著降低(P<0.05)。在各氧化温度下,鱼油的POV和AV随氧化时间的延长均呈二次曲线变化;IV和CV随氧化时间的延长均呈线性变化;而TBARS随氧化时间的延长呈幂回归变化。  相似文献   

8.
真空包装烟熏火腿切片贮藏品质动态变化研究   总被引:1,自引:0,他引:1  
对不同温度贮藏条件下真空包装烟熏火腿切片的品质变化进行动态跟踪,分析产品在4℃、10℃、20℃条件下贮藏,其感官、pH值、TVB-N值、TBARS值、蛋白、脂肪及水分含量的动态变化。结果表明:产品在贮藏过程中,pH值呈下降趋势,TVB-N值和蛋白含量呈上升趋势,脂肪、水分含量及TBARS值变化不明显。贮藏温度对产品质量和货架期影响显著,低温可以延长产品的货架期。根据感官品质判断产品的货架期,4~10℃贮藏货架期为21 d,20℃贮藏货架期为14d。  相似文献   

9.
氧化是限制许多食品保质期的最重要因素之一。为了调查藤茶提取物(vine tea extract,VTE)对素肉丸在冷藏期间脂质氧化和蛋白质氧化的抗氧化活性,按素肉丸质量添加0.1%、0.3%VTE到素肉丸中,并与空白对照和0.01%二丁基羟基甲苯(butylatedhydroxytoluene,BHT)(阳性对照)进行比较,通过对比冷藏期间各组素肉丸的理化性质、过氧化值(peroxide value,POV)、硫代巴比妥酸反应产物(thiobarbituric acid reactive substances,TBARS)值、羰基和巯基含量来评估VTE对素肉丸脂质和蛋白质氧化的影响。结果表明:与空白对照相比,VTE可以有效保持素肉丸的水分含量、亮度及弹性(P0.05);能显著抑制POV和TBARS值的增加(P0.05),并以剂量依赖方式抑制羰基化合物的形成(P0.05),且这种抑制作用高于BHT。以上表明一定剂量的VTE可以显著抑制素肉丸在冷藏期间的脂质氧化和蛋白质氧化,为VTE作为仿肉产品的天然抗氧化剂提供了理论依据。  相似文献   

10.
电子鼻在秋刀鱼鲜度评定中的应用   总被引:3,自引:0,他引:3       下载免费PDF全文
为建立秋刀鱼鲜度快速评定方法,研究了秋刀鱼于4℃条件下感官评分、TVB-N、TBARS、细菌总数以及电子鼻检测信号的变化情况。结果表明,秋刀鱼在冷藏过程中感官评分呈下降趋势,贮藏前期气味劣化是总评分降低的主导因素;TVB-N值在贮藏前期变化较小,第5 d开始呈显著增加(p0.05),11 d时接近0.30 mg/g的界限值;TBARS含量在贮藏过程中迅速增加;细菌总数的变化与TVB-N值的变化趋势较为一致,第11 d时接近7.0 Log10 CFU/g的界限值。综合感官、生化和微生物指标,秋刀鱼在4±1℃条件下一级鲜度可保持3 d,二级鲜度可保持至第7 d,货架期为9~11 d。冷藏过程中秋刀鱼样品在PCA的二维图形上倾向于聚类分布,且特征区域没有重叠,电子鼻可以很好的表征秋刀鱼的鲜度变化,同时与感官评分、生化指标以及微生物指标指示的鲜度等级基本一致。研究结果将为秋刀鱼鲜度的快速评定提供技术参考。  相似文献   

11.
Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.  相似文献   

12.
An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.  相似文献   

13.
The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.  相似文献   

14.
The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.  相似文献   

15.
A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.  相似文献   

16.
17.
Capillary electrophoresis (CE) and polarized light microscopy (PLM) were utilized in the detection of the adulteration of locust bean gum with guar gum. For CE analyses, standards of locust bean and guar gums were extracted with 30% CH3CN, removing the residual proteins from the gum matrix. A 8.75 mM NaH2PO4-20.6 mM Na2B4O7 buffer, pH 9, was used to separate these proteins and to identify marker proteins that were present in the guar gum. These markers did not co-migrate with components in the extracts of mechanically processed locust bean gum, and are used as indicators of adulteration. Using PLM with toluidine blue and iodine staining techniques, unadulterated locust bean gum samples were distinguished from mixed samples through the differential staining of components in locust bean versus guar and tara gums. These experiments in the use of CE and PLM provide orthogonal and complementary methods for the verification of 'true' positives and the elimination of 'false' positives.  相似文献   

18.
BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H2O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.  相似文献   

19.
An investigation is described in which various polyfunctional compounds were applied to wool in attempts to stabilize the temporary improvements in wrinkle-recovery brought about by ‘annealing’. Several reactive systems involving formaldehyde were found to produce the desired permanently improved wrinkle-recovery.  相似文献   

20.
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