Effect of plant extracts on lipid oxidation during frozen storage of minced fish muscle

The aim of the study is to determine the effect of pomegranate seed extract (PSE) and grape seed extract (GSE) addition to chub mackerel minced muscle on lipid oxidation during frozen storage. Each extract was added to minced fish muscle at 2% concentration and then stored at ?18 °C for 3 months. The effect of plant dietary fibres to control lipid oxidation was compared with untreated samples (control). Formation of lipid hydroperoxides and thiobarbituric acid‐reactive substances (TBARS) was significantly inhibited by PSE and GSE addition when compared with control. Both extracts significantly retarded lipid oxidation according to the results of TBARS. A significant reduction of L* (lightness), a* (redness) and b* (yellowness) values was detected during frozen storage. GSE added samples had the highest redness and the lowest lightness and yellowness. However, samples with PSE showed the lowest redness and highest yellowness and h° (hue angle) values. The results from this study suggest GSE is a very effective inhibitor of primary and secondary oxidation products in minced fish muscle and have a potential as a natural antioxidant to control lipid oxidation during frozen storage of fatty fish.     

Inhibition effects of green tea and grape seed extracts on lipid oxidation in bonito fillets during frozen storage

The aim of this study was to investigate inhibition effects of green tea and grape seed extracts on lipid oxidation in bonito (Sarda sarda) fillets during frozen storage. Dried and powdered green tea and grape seed were extracted using ethanol. Extract solutions of 1 g 100 g^?1 were prepared using concentrated extracts and distilled water. Bonito fillets were divided into two groups. The first group was dipped into extract solutions and then frozen. The second group of fillets was glazed by extract solutions. Oxidation increased progressively through the storage period. 2‐Thiobarbituric acid and para‐anisidine values of samples treated with green tea and grape seed extracts remained at low levels. Both plant extracts displayed successful effects in delaying lipid oxidation compared to the control groups. The best results were obtained by extract treatment of fillets before freezing.     

抗氧化剂浸泡前处理对冻藏期大黄鱼脂质氧化的影响

目的 研究抗氧化剂浸泡前处理对冻藏期大黄鱼脂质氧化的影响。方法 以不同时期大黄鱼为原料,添加0.06%维生素E (vitamin E, VE)、0.06%海藻糖(trehalose, TRE)和0%、0.02%、0.04%、0.06%、0.08%的复配抗氧化剂(维生素E:海藻糖=1:1, V:V), VE为阳性对照,测定并评价大黄鱼油理化性质、色差、丙二醛、抗氧化活性。结果 抗氧化剂对不同贮藏期鱼油氧化性影响较大,其中复配抗氧化效果优于VE或TRE氧化性,贮藏期120d鱼油在0.06%复配抗氧化剂中酸价值为(1.99±0.09)mg/g,过氧化值为(22.47±0.47)meq/kg,丙二醛含量值为(0.49±0.04) mmol/mL。添加0.06%复配抗氧化剂能降低鱼油抗氧化性,减少鱼油氧化变质。7种不同比例抗氧化剂效果依次为:0.06%复配抗氧化剂>0.08%复配抗氧化剂>0.06%VE>0.04%复配抗氧化剂>0.02%复配抗氧化剂>0.06%TRE>0%复配抗氧化剂。结论 总体而言, 0.06%复配抗氧化剂的抗氧化性相对更优,有良好抑制活性...     

抹茶对贮藏期间薏仁米脂质氧化的影响

目的：利用天然物质抹茶延长薏仁米货架期。方法：以新鲜薏仁米为原料,经过不同剂量抹茶茶粉处理,测定贮藏期间薏仁米的水分含量、脂肪酸值、过氧化值、丙二醛含量等各项指标及菌落总数和脂质氧化关键酶的变化。结果：经不同剂量抹茶茶粉处理均会抑制薏仁米贮藏期间脂肪酸值、过氧化值、丙二醛含量以及脂肪酶和脂肪氧化酶活性的上升,减少水分的消耗及微生物的生长繁殖。抹茶对薏仁米的保藏效果存在一定程度的剂量依赖性,但添加质量分数为0.05%和0.08%的抹茶茶粉处理的保藏效果差异较小。贮藏4个月后,与自封袋组相比,添加质量分数为0.05%的抹茶茶粉处理组中薏仁米的脂肪酸值、过氧化值和丙二醛含量分别降低了31.60%,30.77%,44.83%,脂肪酶和脂肪氧化酶活性分别降低了23.05%,28.74%,且游离脂肪酸组成和含量与新鲜薏仁米更相似。结论：抹茶能有效抑制薏仁米贮藏期间脂质氧化,延长其货架期。     

液氮冻结温度对冻藏黄鳝脂质氧化和气味变化的影响

目的 探讨液氮冻结温度对冻藏黄鳝脂质氧化和气味变化的影响。方法 测定液氮冻结(?50、?80、?110℃)和?20℃冰柜冻结(对照)的冻藏黄鳝的脂质和游离脂肪酸(free fatty acids, FFAs)含量、过氧化值(peroxide value, POV)、硫代巴比妥酸反应物(thiobarbituric acid reactive substances, TBARs)、脂肪酸组成、挥发性气味物质, 并进行感官评价。结果 随着冻藏时间的延长, 整体上4种温度条件下黄鳝的脂质、单不饱和脂肪酸(monounsaturated fatty acids, MUFAs)和多不饱和脂肪酸(polyunsaturated fatty acids, PUFAs)含量显著下降(P<0.05), FFAs、POV、TBARs值及饱和脂肪酸(saturated fatty acids, SFAs)含量显著上升(P<0.05)。液氮冻结黄鳝的脂质、MUFAs、PUFAs含量和感官评分高于对照, ?80℃和?110℃液氮冻结黄鳝的FFAs、SFAs含量显著低于?50℃液氮冻结和对照(P<0.05); ?80℃和?110℃液氮冻结黄鳝的脂质氧化差异基本上不显著(P>0.05)。气相色谱-离子迁移谱法检测出25种挥发性气味物质。此外, 液氮冻结温度越低, 冻藏黄鳝的正己醛和正丙醛相对含量越低。结论 降低液氮冻结温度能够显著抑制冻藏黄鳝的脂质氧化和气味变化, 有效保护黄鳝的品质。     

Evaluation of lipid oxidation in horse mackerel patties covered with borage-containing film during frozen storage

Lipid oxidation of horse mackerel (Trachurus trachurus) patties covered with fish gelatin-based films containing a borage seed extract were evaluated, including commonly used analytical indexes (peroxide value, thiobarbituric acid reactive substances, polyene ratio), as well as determination of volatile compounds, quantitation of oxidized triacylglycerols and analysis by Fourier transform infrared (FTIR) spectroscopy, during 240 days of frozen storage and subsequent thawing and 4 days-chilling. Vacuum packaged-patties and control uncovered patties were also tested for comparative purposes. Methods applied to evaluate lipid oxidation in extracted lipids, i.e. peroxide value, quantitation of oxidized triacylglycerols and FTIR, clearly provided a better picture of the oxidation progress and led to similar conclusions. Film had protective effects on lipid oxidation of horse mackerel patties throughout frozen storage and particularly after thawing and chilled storage. Furthermore, when compared to vacuum packaging, film was found to be similarly effective until advanced stages of oxidation were reached and exerted enhanced protection once samples were thawed and exposed to air oxygen under chilling temperature; with the additional advantage of increasing the antioxidant capacity of muscle.     

Foaming capacity of fish minces during frozen storage

This work covers a year's study of the foaming capacity (FC) of minced muscle of three fish species—blue whiting (Micromesistius poutassou R). horse mackerel (Trachurus trachurus L), and mackerel (Scomber scombrus L)—caught in two different seasons (January and July) and stored at – 18°C. Periodic assays were performed to determine protein solubility, FC and dimethylamine formation. The results show that FC is initially inhibited by the presence of the species own lipids; however, during frozen storage this effect is attenuated and thus FC increases. The results corroborate the view that protein solubility is not an indispensible requisite for FC, and that mere dispersion of proteins is sufficient. However, FC is not diminished by changes in protein during frozen storage when this deficiency is offset by sufficient protein concentration. On the other hand, FC is clearly affected by the formaldehyde generated during frozen storage, so that beyond a certain level the aggregates formed as a result of formaldehyde formation are too large to disperse, and hence FC decreases drastically.     

Effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken meat

This study examined the effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken leg and breast meat. The meat was frozen at three different temperatures (−7, −12 and −18 °C) and then stored at −18 °C for up to 6 months. A significant effect of frozen storage duration on lipid oxidation was detected in leg and breast meat, whereas freezing temperature had no significant effect. In leg meat, freezing at −7 °C had a significant impact on protein oxidation, measured as the increase in carbonyl groups and the decrease in total sulphydryl groups, after 3 months of frozen storage. Lipid and protein oxidation appeared to occur simultaneously in chicken meat during frozen storage and was more intense in leg meat than in breast meat.     

Intensity of lipid oxidation and formation of cholesterol oxidation products during frozen storage of raw and cooked chicken

Raw and cooked chicken breasts were stored at ?18 °C for 3 months under aerobic and vacuum conditions, and the intensity of lipid oxidation and the formation of COP (cholesterol oxidation products) were studied. Raw samples showed low COP levels (4.60–7.40 µg g^?1 fat), TBARS (thiobarbituric acid reactive substances) levels (0.01–0.03 mg kg^?1) and peroxide values (not detected) under both aerobic and vacuum conditions. Cooked samples (grilled and roasted) showed TBARS levels of 0.36–0.99 mg kg^?1 in aerobic conditions and 0.21–0.70 mg kg^?1 in vacuum conditions, whilst peroxide levels reached 38–40 and 19–23 meq O₂ kg^?1 in samples stored under aerobic and vacuum conditions respectively. Total COP levels in grilled and roasted samples were 28.91 and 39.34 µg g^?1 fat in aerobic packaging and 4.90 and 20.24 µ g g^?1 fat in vacuum packaging respectively. Significant correlations were found between the lipid oxidation parameters and cholesterol oxidation indices. In general, TBARS were better correlated with total COP than with only 7‐ketocholesterol. Vacuum packaging was particularly efficient in slowing down the oxidation process during frozen storage of cooked samples. Copyright © 2004 Society of Chemical Industry     

冻藏对水产品脂质氧化影响研究进展

文章综述了水产品冻藏过程中脂质氧化的危害、影响脂质氧化的内源促氧化因子与外源促氧化因子,并总结了当前延缓脂质氧化的方法,如添加抗氧化剂、改进包装和新型技术的辅助等,指出既能控制冻藏过程中水产品脂质氧化,又能实现产业化推广的技术是水产品冻藏急需解决的问题。     

Effects of plant extracts on microbial growth, color change, and lipid oxidation in cooked beef

The effects of butylated hydroxyanisole/butylated hydroxytoluene (BHA/BHT), grape seed extract (ActiVin), pine bark extract (Pycnogenol), and oleoresin rosemary (Herbalox) on microbial growth, color change, and lipid oxidation were investigated in cooked ground beef. When compared to the control, 1.0% ActiVin and Pycnogenol) effectively reduced the numbers of Escherichia coli O157:H7 and Salmonella Typhimurium, and retarded the growth of Listeria monocytogenes and Aeromonas hydrophila. Pycnogenol resulted in reductions of 1.7, 2.0, 0.8, and 0.4 log CFU/g, respectively, in numbers of E. coli O157:H7, L. monocytogenes, S. Typhimurium, and A. hydrophila, respectively, after 9 days of refrigerated storage. The color of cooked beef treated with ActiVin was less light (L*), more red (a*), and less yellow (b*) than those treated with BHA/BHT, Pycnogenol, and Herbalox. ActiVin and Pycnogenol effectively retained the redness in cooked beef during storage. The control showed significantly higher thiobarbituric acid-reactive substances (TBARS) and hexanal content over storage. BHA/BHT, ActiVin, Pycnogenol, and Herbalox retarded the formation of TBARS by 75%, 92%, 94%, and 92%, respectively, after 9 days, and significantly lowered the hexanal content throughout the storage period. Results of this work show that ActiVin and Pycnogenol are promising additives for maintaining the quality and safety of cooked beef.     

Influence of skinning on lipid oxidation in different horizontal layers of herring (Clupea harengus) during frozen storage

This study was conducted to evaluate the effect of skinning and of compositional differences on the oxidative stability of various horizontal layers from herring (Clupea harengus) during frozen storage. Herring fillets, with and without skin, were stored at -18°C for 0, 3, 9, 16 and 28 weeks. After each storage period, the fillets were divided horizontally into three layers: ‘under skin’, ‘middle part’ and ‘inner part’. Each layer was then extracted for total lipids, in which peroxide value (PV), absorbance at 234 nm (A₂₃₄) and 268 nm (A₂₆₈) as well as lipid-soluble fluorescent oxidation products (FP) were measured. Prior to storage, the fat content, fatty acid pattern and α-tocopherol were also analysed. During storage of skinless fillets, the under skin layer increased most in PV, A₂₃₄, A₂₆₈ and FP (P<0·05), followed by the inner and middle parts. In fillets stored with skin, the high oxidation rate of the under skin layer lipids was suppressed, but this layer still gave rise to the highest responses. Firstly, these results point to the protective properties of the skin and, secondly, to the unfavourable composition of the under skin layer: a lot of dark muscle; the silver surface; the highest fat content and the lowest level of α-tocopherol. Concerning the fatty acid pattern in the three layers, the amount of C20: 5, C18:1 and C20:1 in the fat gradually decreased from the under skin layer towards the inner part of the fillet, whereas the opposite was true for C22: 6. © 1998 Society of Chemical Industry.     

蛋白质氧化对乌鳢在冻藏过程中保水性的影响

乌鳢是一种营养和经济价值都很高的鱼类,但在贮藏过程容易出现品质劣变的问题。本实验通过羟自由基氧化体系对乌鳢进行氧化后置于-4℃冻藏,研究了乌鳢肌肉保水性的相关变化。结果显示:乌鳢经羟自由基氧化后变化明显,在第10 d,氧化组（A组）的解冻失水率、加压失水率、蒸煮损失率比未氧化组（B组）分别高出7.51%、14.74%、10.65%;蛋白羰基含量、硫代巴比妥酸值（TBARS）、肌原纤维小片化指数（MFI）升高,肌原纤维裂解,保水性降低。在相关性分析中,氧化样品的肌原纤维蛋白结构变化中的羰基含量、TBARS、MFI均与解冻失水率、加压失水率、蒸煮损失率等保水性指标呈极显著相关（p<0.01）,且MFI与p H呈显著相关性（p<0.05）。结果表明,羟自由基氧化系统能使乌鳢肌肉肌原纤维遭到破坏,蛋白质氧化变性,导致其保水性降低。      

Effect of pre-soaking whole pelagic fish in a plant extract on sensory and biochemical changes during subsequent frozen storage

Plant extract treatments have largely shown a positive effect on inhibiting the quality loss during the frozen storage of minced and filleted fish products. In the present case, the effect of a plant extract on a whole fish product was checked. For it, whole fresh horse mackerel was soaked in a commercial extract solution during 60 min and then kept frozen up to 12 months at −20 °C. Sampling was carried out on the initial material and at months 1, 3, 5, 7, 9 and 12. Two parallel experiments consisting on untreated fish (Blank Control) and water treated fish (Water Control) were carried out in the same conditions. Lipid damage was measured by lipolysis development (free fatty acid formation), rancidity development (conjugated dienes (CDs), secondary oxidation compounds, fluorescent compounds and cholesterol oxides) and sensory (odour, firmness and colour) analyses. As a result of the previous plant extract treatment, better odour and colour scores were obtained that led to a larger shelf-life time (7 months) than in the two controls (5 months), according to the sensory analysis. Water treatment of fish (Water Control) also showed some better results in sensory (odour and colour) analysis than the Blank Control, that could be related to the elimination of some prooxidant molecules included in fish. Some biochemical indices (CDs and free fatty acids) also provided a damage inhibition (P<0.05) in the 9-12 months period as a result of the plant treatment and water treatment; however, fluorescence and cholesterol oxide detections did not show differences (P>0.05) when compared to the Blank Control. The present experiment provides promising results for soaking a pelagic whole fish in an aqueous plant extract as a previous step to its commercialization as a frozen product.     

The role of lipid oxidation on biscuit texture during storage

The role of lipid oxidation and humidity absorption on the shelf life of biscuits was analysed. Biscuits with low lipid and sugar content were prepared employing different oils, and texture changes that biscuits experience during storage were studied. Water activity, peroxide value, malonaldehyde content and colour were also determined at different storage times. The maximum peroxide level was between 1 and 1.5 mmol kg^?1 of oil, at 166 days of storage. Values of malonaldehyde were between 5.2 and 15.8 nmol g^?1 of dry sample. Water activity and peroxide value influence the biscuit texture (P ≤ 0.05). To study the effects of both factors simultaneously, a mathematical model was adjusted to the data. Results indicate that an increase in the peroxide level, even at low level of lipid oxidation, increases Young's modulus and leads to a harder biscuit, while the humidity absorption lowers the fracture stress and Young's modulus.     

贮藏条件对猪肉糜氧化效应的影响

将肥瘦比为1:1的猪糜于-18、-24、-40℃三种条件下贮藏,每10d取样一次,通过测定酸价（AV）、过氧化值（POV）和硫代巴比妥酸（TBARS）值,研究贮藏温度、贮藏时间对猪肉糜氧化效应的影响。结果表明,贮藏时间和温度显著影响肉糜的氧化进程（p<0.05）,随贮藏时间的延长,酸价整体呈先上升后下降的趋势,而过氧化值、硫代巴比妥酸值整体呈上升趋势;贮藏温度越低,肉糜的AV值、POV值和TBARS值也越低,且变化缓慢。缩短贮藏时间和降低贮藏温度有利于控制肉糜脂肪氧化,研究表明,贮藏时间小于20d时效果最佳,30d时脂肪水解与氧化达到了动态平衡;-40℃贮藏效果最好,但从节能等角度综合考虑,-24℃更适合作为肉糜长期贮藏的温度。      

抗氧化剂处理对微冻贮藏泥鳅品质及脂肪氧化的影响

研究丁香提取物、油菜粉提取物、植酸、VE及2,6-二叔丁基对甲苯酚(BHT)处理对微冻(-2.5℃)贮藏泥鳅品质及脂肪氧化的影响。结果显示,不同处理组泥鳅的感官综合得分逐渐降低;pH值先下降后上升;汁液流失率呈增加趋势;剪切力不断降低(P0.05);挥发性盐基氮(TVB-N)值呈增加趋势,且所有处理组在24d时均小于最大限量(20mg/100g),处于可接受范围;硫代巴比妥酸值(TBARS)、过氧化值(POV)均呈上升趋势(P0.05);饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)含量整体升高,多不饱和脂肪酸(PUFA)含量相对下降。以上所有处理组的变化趋势均优于对照组。综合上述分析,对照组在微冻条件下的货架期为8～12d,而添加抗氧化剂组货架期均达到20～24d,其中植酸、BHT以及VE抗氧化能力更强,能够更有效地抑制不饱和脂肪酸氧化,维持样品的食用品质和加工性能。     

Effects of dietary soybean oil on lipid and protein oxidation in pork patties during chill storage

The effect of dietary soybean oil on lipid and protein oxidation in low and high fat pork patties made from quadriceps femoris during chill storage in a high oxygen atmosphere packaging (80% O(2)/20% CO(2)) in the dark for 7 days was investigated. Pigs were fed either a standard diet or a diet added 2% soybean oil. After slaughter high fat pork patties were prepared for both feeding regimes by addition of back fat from pigs fed the same diet whereas low fat pork patties were prepared without addition of back fat. The 2% soybean diet increased the amount of unsaturated fat in the pork. Secondary lipid oxidation products determined as thiobarbituric acid reactive substances (TBARS) were found to increase in the pork patties with increased unsaturated fat. Increased unsaturated fat in the pork patties had no effect on protein oxidation determined as free protein thiol content and protein carbonyl content. A small, but significant increase in protein oxidation was found in the high fat pork patties independent on dietary fat. In conclusion, protein oxidation is unaffected by dietary fat in pork patties during chill storage for periods normally used in retail trade, and lipid and protein oxidation are not coupled under these conditions.     

Emulsifying capacity of fish mince from several species during frozen storage

Abstract : As a functional property of protein, emulsifying capacity (EC) is of great technological interest. This article examines EC in fish mince from three species differing in fat content and in the pattern of deterioration during frozen storage—blue whiting (Micromesistius poutassou R), horse mackerel (Trachurus trachurus L) and mackerel (Scomber scombrus L)—caught during two seasons of the year in which physiological behaviour is expected to be different (winter and summer). EC and protein solubility were determined periodically. The results indicate the existence of a direct relationship between the fat content of the species used and its EC. Furthermore, in the species studied EC was independent of protein solubility and the amount of protein in the medium, both of which decline as a result of the formation of aggregates during frozen storage. This is not therefore a suitable method for determining protein quality during frozen storage.