乳酸钙对牛肉糜色泽稳定性的影响

为研究乳酸钙对牛肉糜色泽稳定性的影响,将牛背最长肌绞碎成肉糜,分别添加0.1%、0.3%、0.5%的乳酸钙溶液,研究在(4±1)℃的冷藏条件下,肉糜肉色稳定性、色素含量、脂肪氧化及高铁肌红蛋白还原酶活性随时间的变化。结果表明：在7d的贮藏期内,添加不同质量分数乳酸钙均可有效抑制高铁肌红蛋白的生成和脂肪氧化的发生,并显著提高高铁肌红蛋白还原酶活性和肉色稳定性,但会使肉糜L*值显著降低(P＜0.05)。其中0.3%的乳酸钙对稳定肉色有显著作用,护色效果明显。     

乳酸盐对冷却牦牛肉色泽稳定性及高铁肌红蛋白还原的影响

以牦牛背最长肌为实验材料,通过向牦牛肉糜中添加三种不同种类的乳酸盐(乳酸钙,Ca L;乳酸钾,KL;乳酸钠,Na L)和不同浓度的Ca L(0.1%、0.3%、0.5%),研究了在(4±1)℃冷藏条件下乳酸盐对牦牛肉肉色稳定性和高铁肌红蛋白还原系统的影响。结果表明:经过7 d的贮藏,0.3%的乳酸盐可以抑制牦牛肉糜a*值的下降,但会使肉色变暗;可显著抑制牦牛肉贮藏过程中MbO_2的氧化(p0.05),抑制Met Mb含量的上升,提高MRA,且Ca L处理组的效果最显著(p0.05)。添加不同质量分数的Ca L后,0.3%Ca L处理组的a*值上升速度显著高于其他3组(p0.05),但会使肉糜L*值降低;不同浓度的Ca L均可抑制牦牛肉贮藏过程中Mb O2的氧化(p0.05)和Met Mb的生成(p0.05),并显著提高MRA(p0.05)和肉色稳定性,其中添加0.3%的Ca L对稳定和保持肉色的作用最明显。     

高良姜精油微胶囊的制备及其对猪肉糜的保鲜效果

采用复凝聚法制备得到高良姜精油微胶囊并将其应用于猪肉糜的保鲜,研究不同质量分数微胶囊添加量对肉糜在10 d冷藏期间菌落总数、脂肪氧化程度(TBA值)和高铁肌红蛋白(Met Mb)含量的影响。结果表明:以壳聚糖和海藻酸钠为壁材制备的高良姜精油微胶囊能缓慢释放精油,对大肠杆菌、金黄色葡萄球菌和酵母菌有良好的抑菌效果。用于肉糜保鲜,与对照组相比,所有处理组均能抑制肉糜微生物生长,降低其TBA值和MetMb含量。其中,添加质量分数0.1%和0.2%微胶囊对肉糜有较好的保鲜作用且效果接近,而0.05%微胶囊保鲜效果不明显。结论:添加0.1%高良姜精油微胶囊可以提高肉糜品质,延长肉糜冷藏的货架期。     

乳清分离蛋白水解物对猪肉糜抗氧化作用的研究

研究乳清分离蛋白(WPI)的碱性蛋白酶(alcalase)水解物的抗氧化能力,并将其应用于生肉糜中研究其抗氧化效果。实验分为6组,第1组为对照组,第2组加入2.0%的WPI未水解物,第3～5组中分别加入1.0%、1.5%、2.0%的水解物冻干粉(5h),第6组中加入0.02%的BHA,在冷藏过程中测定肉糜的红度值(a*)、硫代巴比妥酸值(TBARS)值、pH值、高铁肌红蛋白(MetMb)含量,并对产品的感官指标进行评定。结果表明,在贮藏7d内,与对照组相比,添加WPI水解物处理组能够显著抑制生肉糜脂肪的氧化(P<0.05),其中2%WPI水解物处理组效果最明显,能显著降低TBARS值、增加肉糜的红度值(a*)(P<0.05),且其高铁肌红蛋白(MetMb)含量仅为对照组的79%,与添加BHA处理组的水平相当。同时,WPI水解物处理组抑制脂肪的氧化效果比WPI未水解组好。因此,WPI水解物可以有效的抑制食物中脂肪氧化,且其抗氧化效果与水解物的使用量相关。     

托盘和真空包装对冷却猪肉中MetMb还原活性的影响

在冷却肉的贮藏过程中,其肌红蛋白(Mb)被氧化为高铁肌红蛋白(MetMb),导致了冷却肉的褐变。研究了托盘包装和真空包装条件下,冷却肉自身的还原系统活性变化规律及其对肉色稳定性的影响。在2周的贮藏期内,真空与托盘包装冷却肉糜肌浆蛋白粗提液的还原活性持续下降;但真空包装组MetMb还原酶粗提液还原活力第1天到第14天活性差异不显著,托盘包装组前后差异显著。真空包装组在贮藏期间MetMb含量持续下降,但托盘包装组MetMb含量则持续上升,说明无氧条件有利于MetMb的还原。托盘包装组TBA在贮藏期间持续上生,但真空包装组TBA变化不明显。结果表明,托盘包装不利于冷却肉自身MetMb还原能力的维持,而真空包装的无氧环境,有利于MetMb的还原和肉色的保持。     

不同包装冷却肉在贮藏过程中高铁肌红蛋白还原系统活性变化

在冷却肉的贮藏过程中,其肌红蛋白(Mb)被氧化为高铁肌红蛋白(MetMb),导致了冷却肉的褐变。研究了CO气调包装和真空包装条件下,冷却肉自身的还原系统活性变化规律及其对肉色稳定性的影响。结果表明:CO-MAP的包装护色效果最好,但是对MetMb含量下降和脂肪氧化没有明显作用;在19d的贮藏期内,肌肉中MetMb还原酶活力稳中有升,在其作用下,肉中MetMb含量不断下降,从第9天开始保持平稳,MetMb维持在较低的水平。结果表明,肌肉中MetMb的含量不仅与还原酶系统的活力有关,还与肌肉中自身的电子传递体NADH的含量有关。同时对肌肉中脂肪氧化程度变化的研究表明,TBA值与MetMb含量的变化趋势有一定的相关性。     

琥珀酸钠和线粒体共同作用对牛肉高铁肌红蛋白含量的影响

高铁肌红蛋白(MetMb)的形成是造成肉色褐变的主要原因 MetMb的还原对于保持肉色鲜红非常重要.本文提取了牛心中的线粒体,研究了在高活性线粒体中,琥珀酸钠对MetMb相对百分含量的影响.结果表明:随着pH增加,MetMb相对百分含量显著下降.在不同线粒体浓度下,随着贮藏时间的延长,MetMb的含量先下降而后又上升.琥珀酸钠含量不变,线粒体浓度越高,MetMb含量越低,而线粒体浓度不变,琥珀酸钠浓度在16mmol/L和24mmol/L时,被还原的Metbh的百分比显著多于其他组     

注射水和氯化钙溶液对宰后猪肉肉色及其稳定性的影响

目的：探讨注射水和氯化钙溶液对宰后冷藏期间猪背最长肌肉色及其稳定性的影响。方法：猪背最长肌于宰后1.5h注射肉质量分数5%的水和200mmol/L氯化钙溶液,分别测定其冷藏期间肉色a*值、总色素含量、高铁肌红蛋白(MetMb)相对百分含量、MetMb还原酶活性等指标。结果：注射氯化钙溶液能降低肉中a*值、总色素含量、MetMb还原酶活性和乳酸脱氢酶-B(LDH-B)活性,增加MetMb相对百分含量和丙二醛(MDA)含量。注水能降低肉中总色素含量和MetMb还原酶活性,增加MetMb相对百分含量。结论：注射水和氯化钙溶液均能降低宰后冷藏期间猪背最长肌中总色素含量,增加MetMb相对百分含量,从而加快猪背最长肌的褪色,不利于其冷藏期间新鲜肉色的维持。     

光照条件对冷却猪肉MetMb还原活性及色泽稳定性的影响

冷却肉中的肌红蛋白很容易受到光的作用而发生褪色,导致颜色劣变.本文采用猪冷却肉为原料,在相同光照强度(40～ 80Lux)下,研究不同波长光照对冷却猪肉肉糜中MetMb还原酶活性及肉色稳定性的影响.结果表明:不论托盘包装还是真空包装,避光与其他光照条件(紫光、绿光、红光、白光)对肉的色泽影响差异显著(P<0.05);真空包装有利于保持肉中MetMb还原酶活性.     

琥珀酸钠对牛肉糜色泽及高铁肌红蛋白含量的影响

在牛肉糜中加入0、4、6、8mmol/L的琥珀酸,研究其对牛肉糜pH、颜色、Mb和MetMb含量、TBARS的影响,以揭示琥珀酸-琥珀酸脱氢酶体系在MetMb还原中的作用.结果显示:琥珀酸添加对牛肉糜pH没有影响,低浓度琥珀酸(4～6mmol/L)可提高红度值和Mb含量,降低MetMb含量,但对肉的脂肪氧化没有抑制作用.     

喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响

研究喷雾冷冻干燥对葛仙米藻胆蛋白抗氧化特性的影响,并与冷冻干燥技术进行比较。主要测定ABTS+ ·、铁还原抗氧化能力(FRAP)、对羟自由基( ·OH)清除作用和H2O2诱导的脂质过氧化的抑制作用,结果发现,喷雾冷冻干燥(SFD)对葛仙米藻胆蛋白的抗氧化特性有一定的影响,在基于电子转移和氢原子转移的抗氧化测定方法中,SFD与冷冻干燥(FD)制备的样品差异不明显,但在基于活性氧自由基清除的测定方法中,SFD显著优于FD。表明SFD非常适合于高活性成分的干燥。     

Antioxidative activity of carnosine in gamma irradiated ground beef and beef patties

The activity of carnosine as a natural antioxidant in gamma irradiated ground beef and beef patties was studied. Samples of ground beef, in the absence and presence of 0.5% or 1.0% carnosine, as well as raw and cooked beef patties prepared with 1.5% salt (NaCl), in the absence and presence of 0.5% or 1.0% carnosine, were gamma irradiated at doses of 0, 2, and 4 kGy. The extent of oxidation in irradiated and non-irradiated samples of ground beef and raw beef patties was then determined during refrigerated (4 ± 1 °C) and frozen (−18 °C) storage, while determined for cooked beef patties during refrigerated storage only. Moreover, the determination of metmyoglobin (MetMb) accumulation and sensory evaluation for the visual color were carried out for samples of ground beef and raw patties. The results indicated that salt or salt and cooking accelerated the oxidative processes and significantly increased the peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) in the prepared non-irradiated samples. However, salt slowed down the accumulation of MetMb in raw patties. Irradiation treatments and storage in the absence of carnosine significantly (P < 0.05) increased the PV and TBARS in samples, at higher rates in salted or salted and cooked beef. Moreover, irradiation and storage significantly (P < 0.05) increased the formation of MetMb in ground beef and raw patties in the absence of carnosine. Addition of carnosine significantly (P < 0.05) reduced the oxidative processes and MetMb formation (proportionally to the used concentration) in samples post-irradiation and during storage. Furthermore, carnosine exerted significant efficacy in maintaining an acceptable visual red color post-irradiation and during storage of ground beef and raw patties. These results demonstrate that carnosine can be successfully used as a natural antioxidant to increase the oxidative stability in gamma irradiated raw and cooked meat products.     

Evaluation of the antioxidant ability of hydrazine-purified and untreated commercial carnosine in beef patties

The aim of this research was to reevaluate the inhibition of oxidative changes in beef patties packaged in modified atmosphere (70% O(2)+20% CO(2)+10% N(2)) by carnosine (50 mM). The need for reevaluation was because it had been postulated that hydrazine present as contaminant in commercial carnosine could contribute to the antioxidant activity. Beef patties with either commercial or purified hydrazine-free carnosine were stored at 2±1?°C for 20 days and evaluated for colour (a* and H*), TBARS, metmyoglobin formation (% of total surface myoglobin), psychrotrophic microbial counts and sensory odour. Results indicated that both forms of carnosine effectively inhibited lipid oxidation and color changes in beef patties throughout storage, showing no significant differences (P>0.05) between them. It was concluded that the antioxidant effect was brought about by the carnosine molecule and not by hydrazine.     

洋葱皮乙醇提取物对冷却牛肉颜色、脂质和蛋白质氧化稳定性的影响

将牛肉切片在3种浓度（0.5 %、1.0%、2.0%）的洋葱皮乙醇提取物（Ethanol Extract of Onion Skin,EEOS）溶液中浸渍后在4 ℃条件下冷藏12 d,并与空白对照组和添加了抗坏血酸（ascorbic acid,V_C）的处理组进行比较,分析EEOS对牛肉在冷藏期间的颜色褐变、脂肪和蛋白质氧化以及腐败程度的影响。结果表明:EEOS总酚含量较高,具有很强的自由基清除活性;添加EEOS可延缓牛肉pH上升,提高颜色稳定性,减少高铁肌红蛋白的生成,同时延缓脂肪和蛋白的氧化进程。2% EEOS有效降低了牛肉样品硫代巴比妥酸反应物（Thiobarbituric acid reactive substances,TBARS）和蛋白质羰基含量,与空白对照组相比分别降低56.9%和17.6%。此外,2% EEOS还可显著降低挥发性盐基氮（Total Volatile Basic Nitrogen,TVB-N）的含量（P<0.05）。因此,添加2% EEOS可抑制牛肉冷藏期间的颜色褐变和脂肪、蛋白质的氧化,可在牛肉冷藏保鲜中作为天然抗氧化剂。     

产酸丙酸杆菌发酵甘油提取物对冷藏调理猪肉饼品质的影响

以未添加抗氧化剂的调理猪肉饼作为对照,研究不同添加量的产酸丙酸杆菌发酵提取物（fermented extract of Propionibacterium acidipropionici,FEPA）对4 ℃冷藏调理猪肉饼品质的影响。将0.2%（以猪瘦肉质量计,下同）、0.3%、0.4%和0.5%的FEPA分别添加到调理猪肉饼中,测定其在1、4、7、10 d冷藏期间的pH值、色泽（L*、a*、b*值）、质量损失率、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARS）值、菌落总数和质构变化。结果表明：添加FEPA可显著提高调理猪肉饼冷藏期间的a*值（P＜0.05）,有利于猪肉饼色泽的改善,并能显著降低猪肉饼的咀嚼性、质量损失率、菌落总数（P＜0.05）,显著抑制蛋白和脂肪氧化（P＜0.05）;其中添加0.5%的FEPA可显著降低猪肉饼的硬度（P＜0.05）,且其抑制蛋白、脂肪氧化和抗菌效果最佳,因此在所有处理组中,0.5%的FEPA对调理猪肉饼的品质有较优的改善作用。     

Effects of pyruvate on lipid oxidation and ground beef color

Our overall objective was to better understand the effects of added pyruvate on enhanced beef color stability. The 2 possible mechanisms assessed were the role of pyruvate in lipid oxidation and direct interaction between pyruvate and beef myoglobin. Microsomes were incubated with pyruvate at pH 5.6, 25 °C, and lipid oxidation was measured hourly for 3 h. Bovine oxymyoglobin at pH 5.6 was incubated with pyruvate and used to quantify both redox stability (metmyoglobin formation) and pyruvate-myoglobin adduction using mass spectrometry analysis. Surface color and lipid oxidation were measured on ground beef patties stored for 6 d in polyvinyl chloride over-wrap (PVC) or high oxygen. Addition of pyruvate to microsomes decreased lipid oxidation compared with controls (P < 0.05). Conversely, no effect on myoglobin was observed (no changes in redox stability and no peaks corresponding to pyruvate were observed; P > 0.05). However, pyruvate increased color stability and decreased lipid oxidation of ground beef patties packaged in PVC and high oxygen. Pyruvate decreased nitric oxide metmyoglobin-reducing capacity and oxygen consumption of patties compared with controls (P < 0.05). This research suggests that pyruvate may improve beef color stability primarily through its antioxidant effect on lipids. Practical Application: Discoloration of meat often results in significant revenue loss. This study suggests that pyruvate can improve the color stability of patties packaged in high oxygen and PVC primarily through its antioxidant effect on lipids.     

Effect of carnosine, salt and dietary vitamin E on the oxidative stability of chicken meat

The effect of carnosine on lipid and cholesterol oxidation in salted chicken thigh meat and its relationship to dietary α-tocopherol supplementation was examined. Broilers (Cobb 500) were fed diets with a basal (30 mg kg(-1)) or supplemental (200 mg kg(-1)) level of α-tocopheryl acetate for 6 weeks. Thigh meat patties were prepared with carnosine (1.5%), salt (1%) or salt plus carnosine. Salt accelerated lipid and cholesterol oxidation following cooking and refrigerated storage. However, carnosine inhibited lipid and cholesterol oxidation in salted patties. Dietary α-tocopherol supplementation also reduced the extent of lipid and cholesterol oxidation in salted patties. The combination of carnosine and dietary α-tocopherol resulted in the greatest lipid and cholesterol stability in salted meat.     

Evaluation of the antioxidant activities and nutritional properties of ten edible plant extracts and their application to fresh ground beef

In this study, we assessed the antioxidant efficacy and nutritional value of 10 leafy edible plants and evaluated their potential as natural antioxidants for meat preservation. We measured total phenolic content, 2,2-diphenyl-1-picryl-hydrazil (DPPH) radical scavenging activity, and vitamin C, chlorophyll, and carotenoid contents of 70% ethanol and water extracts of the edible plants. Based on these results, we investigated the effects of butterbur and broccoli extracts on lipid oxidation in ground beef patties. Plant extracts and butylated hydroxytoluene (BHT) were individually added to patties at both 0.1% and 0.5% (w/w) concentrations. Thiobarbituric acid reactive substance (TBARS) values and color parameters were tested periodically during 12 days of refrigerated storage. TBARS levels were significantly lower (p ≤ 0.05) in the samples containing plant extracts or BHT than the non-treated control. In addition, the beef patties formulated with the selected plant extracts showed significantly (p ≤ 0.05) better color stability than those without antioxidants. These results indicate that edible plant extracts are promising sources of natural antioxidants and can potentially be used as functional preservatives in meat products.     

Effect of Cooking Method and Ethanolic Tocopherol on Oxidative Stability and Quality of Beef Patties During Refrigerated Storage (Oxidative Stability of Cooked Patties)

ABSTRACT: Incorporation of δ-tocopherol using an ethanolic carrier to control lipid oxidation in impingement and ohmic cooked beef patties was evaluated, and quality characteristics were determined. Ethanolic δ-tocopherol delayed oxidative deterioration of cooked beef patties in both cooking methods. Ohmic cooked samples developed significantly higher ( P < 0.05) thiobarbituric acid-reactive substances (TBARS) than impingement-cooked samples. Formation of TBARS significantly ( P < 0.05) increased with storage time in both cooking treatments. Cooking method significantly ( P < 0.05) influenced color and textural attributes of beef patties. Samples cooked by ohmic heater were lighter, displaying significantly ( P < 0.05) larger L * color values. Additionally, ohmic samples were harder, chewier, and more cohesive ( P < 0.05) than samples cooked with an impingement oven. Exogenous addition of ethanolic tocopherol can delay lipid oxidation and improve quality of cooked meat products.