冻藏时间对生、熟猪肉品质的影响

冷冻是猪肉常用贮藏手段,然而长期冻藏会对猪肉及其烹后品质产生较大影响。作者研究了-18 ℃不同冻藏时间（0、120、240、360 d）对猪肉加热前后营养品质、食用品质和贮藏特性的影响。结果表明：随着猪肉冻藏时间的延长,生、熟猪肉中水分质量分数、弹性和可溶性蛋白质质量分数显著降低（P<0.05）,游离氨基酸质量分数、POV值、TBARS质量分数均显著上升（P<0.05）,硬度、胶黏性、咀嚼性逐渐增加,电子鼻结果显示各组间风味具有显著差异（P<0.05）。表明猪肉品质随冻藏时间的延长而显著下降,且在冻藏120 d后,品质严重劣变,食用价值降低。     

Lipid Oxidation, Volatiles and Color Changes of Irradiated Pork Patties Affected by Antioxidants

Changes were measured in TBARS, color, and volatiles of irradiated (4.5 kGy) pork patties with antioxidants (sesamol, quercetin, rutin, BHT, and rosemary oleoresin) during 7 days storage at 4°C. Irradiation accelerated lipid oxidation of raw pork during storage. However, irradiation before cooking did not influence lipid oxidation of cooked pork during storage. Sesamol, quercetin, and BHT were effective in both irradiated raw and cooked pork during 7-days storage. Rosemary oleoresin and rutin were effective only in irradiated raw pork for 3 days. Hexanal, propanal and higher boiling components were well correlated (P < 0.01) with TBARS in cooked pork. Generation of volatiles was reduced by sesamol and quercetin, but the effects of antioxidants on color changes of raw pork patties were minor and inconsistent.     

Storage Stability of Vacuum Packaged Frozen Pork Sausage Containing Soy Protein Concentrate, Carrageenan or Antioxidants

Fresh pork sausage patties containing carrageenan, without or with soy protein and an antioxidant were packaged with or without vacuum. They were evaluated for sensory properties, visual color, thiobarbituric acid reactive substances (TBARS), and Hunter color ‘L’, ‘a’, ‘b’ values at 4-wk intervals during 16 wk frozen storage. Rosemary extract was as effective as butylated hydroxytoluene (BHT)/propyl gallate (PG)/citric acid (CA) in antioxidant properties, but patties with BHT/PG/CA showed less surface discoloration (P < 0.05). In fat-control (FC) products, antioxidants combined with vacuum packaging provided optimum protection against rancidity. With vacuum packaging (VP), reduced-fat products maintained acceptable quality (TBARS and sensory properties) during 16 wks frozen storage.     

天然抗氧化剂替代部分亚硝酸钠对乳化肠护色及抗氧化效果的影响

将迷迭香提取物、茶多酚、留兰香提取物、竹叶提取物及甘草提取物添加到乳化肠中,替代部分亚硝酸 钠,研究其对乳化肠色泽稳定性和抗氧化性的影响。结果表明：与空白对照组相比,天然抗氧化剂的添加促进了亚 硝酸钠的发色,延缓了乳化肠红度值（a*）的降低,降低了乳化肠的脂肪氧化程度。与0.010%的亚硝酸钠相比,竹 叶提取物的护色作用较强,且添加量为0.030%时乳化肠的a*最大;留兰香提取物与茶多酚的护色效果次之,添加量 分别为0.040%和0.024%时乳化肠的a*最大;迷迭香提取物与甘草提取物的护色效果最弱。与0.020%异抗坏血酸钠 相比,茶多酚与竹叶提取物的抗氧化活性较强,它们的添加量为0.030%时表现出较好的抗氧化活性;迷迭香提取物 与留兰香提取物的抗氧化效果次之,它们的添加量分别为0.030%和0.040%时具有较强的抗氧化活性;甘草提取物 的抗氧化活性最弱。天然抗氧化剂对乳化肠中脂肪氧化的抑制作用与其对色泽的保护作用有着良好的对应关系,整 体而言,竹叶提取物的护色及抗氧化效果最佳。     

Effect of Natural Antioxidants,Irradiation, and Cooking on Lipid Oxidation in Refrigerated,Salted Ground Beef Patties

Antioxidant effects of natural antioxidants in 73%‐lean ground beef patties during refrigeration were studied. Samples were subject to an antioxidant treatment (pomegranate extract, grape seed extract, butylated hydroxyanisole, or no treatment) and an irradiation treatment (0 or 1.5 kGy) before being evaluated for both uncooked and cooked indicators of lipid oxidation. Chemical evaluation of antioxidant activity were determined over 9 d through measurement of thiobarbituric reactive substances values. Physical evaluation of antioxidant activity was monitored by changes in physical color and sensory odor analysis on patties before and after cooking. Butylated hydroxyanisole extended the induction period of oxidation in all unirradiated beef patties better than the natural antioxidants. Panelists were able to distinguish a difference (in terms of oxidation attributes) between patty samples of different antioxidant and irradiation treatments while samples were uncooked, but unable to distinguish a difference between patties after cooking.     

Oxidative Stability of Frozen Pork Patties. Effect of Light and Added Salt

Salt (1%) and light effects on oxidative deterioration were followed during freezer storage (?18°C) in a display cabinet. Oxymyoglobin oxidation and lipid oxidation were strongly accelerated by added salt and more moderately by exposure to fluorescent light. The light-dependent lipid oxidation was prevented by using packaging material with incorporated UV-light absorber. However, a UV-light absorber only yielded partial protection against discoloration. The two oxidation processes showed similarities in progression. In contrast to color deterioration, lipid oxidation showed an initial lag period in agreement with previous indications that pigment oxidation was an initiator of lipid oxidation in beef during freezer storage.     

不同年龄延边黄牛牛肉在冻藏期间肉色与氧化稳定性的研究

选择1岁以下、1.5～3岁、5～6岁、9～10岁的延边黄牛牛肉作为4个实验组以研究年龄对延边黄牛牛肉品质的影响,在肉的冻藏期间进行表面肉色、pH值、高铁肌红蛋白含量、TBARS值的测定。结果表明:4个实验组中,1.5～3岁年龄组的高铁肌红蛋白含量及TBARS值最低,与5～6岁、9～10岁年龄组差异显著(P<0.05);1.5～3岁年龄组的表面肉色CIE值中a*、c*值最高(P<0.05),h值最低(P<0.05),肉色鲜艳,氧化稳定性高。     

石榴皮提取物对生猪肉饼品质的影响

研究石榴皮提取物的抗氧化性能及不同质量分数（0.01%、0.05%和0.10%）石榴皮提取物的添加对生猪肉 饼pH值、蒸煮损失、色差和冷藏过程中脂肪及蛋白氧化的影响。结果表明：石榴皮提取物富含多酚和黄酮,其总 抗氧化能力、自由基清除能力、Fe2＋螯合能力随石榴皮提取物质量分数增大而增强;石榴皮提取物的添加对生猪肉饼的 pH值和蒸煮损失率无显著影响,但对生猪肉饼的亮度值、红度值有一定的负面作用;石榴皮提取物能有效抑制生猪肉 饼冷藏过程中氢过氧化物、丙二醛及蛋白羰基生成,且质量分数越高抑制效果越好,整体效果优于丁基羟基茴香醚。     

石榴皮提取物对猪肉饼冷藏过程中脂肪氧化稳定性的影响

选用陕西省优势天然资源产物石榴皮提取物,测定其总酚及总黄酮含量,采用5 种方法对其抗氧化活性进行评价,并研究不同质量浓度石榴皮提取物的添加对猪肉饼冷藏过程中脂肪氧化稳定性的影响。结果表明：石榴皮提取物具有高效的2,2’-联氮双-（3-乙基苯并噻唑林-6-磺酸）二胺盐（2,2’-azinobis-（3-ethylbenzothi azoline-6-sulfonic acid）ammonium salt,ABTS）自由基（ABTS＋·）、?OH和1,1-二苯基-2-三硝基苯肼自由基清除能力以及一定的金属离子（Fe2＋）螯合能力;石榴皮提取物的添加（0.01%、0.05%和0.10%）能明显减缓猪肉饼冷藏过程中的脂肪氧化;总体来说,随着石榴皮提取物添加量的增加,其脂肪氧化抑制效果增强,且添加0.01%石榴皮提取物时的抑制效果与添加0.01%（以脂肪含量为基准）丁基羟基茴香醚相当。     

Natural Antioxidants Preserve the Lipid Oxidative Stability of Minimally Processed Avocado Purée

ABSTRACT: Lipid oxidation is one of the major phenomena that limit the shelf-life of avocado products. The effects of adding 100 ppma-tocopherol, 200 ppm ascorbic acid, and 200 ppm ethylenediaminetetraacetic acid (EDTA) on he stability of the lipidic fraction of minimally processed avocado purées were evaluated throughout storage. α tocopherol, followed by ascorbic acid, reduced oil rancidity processes during storage. Peroxide formation was minimal when a-tocopherol was added to avocado pulp, prolonging the induction stage of oils for at least 12 wk. When preserved in vacuum, iodine and specific extinction coefficient at 270 nm (k₂₇₀) values were more stable, with changes of 5.87 g I₂/100 g oil and 0.237, respectively, during 24 wk. On the other hand, EDTA was not shown to be effective in preserving the stability of the lipid fraction of avocado preserved by combined methods.     

Myoglobin Oxidative State Affects Internal Cooked Color Development in Ground Beef Patties

Ground beef patties known to develop a normal (NRM) or premature brown (PMB) color when cooked to 55°C received no treatment or were reduced or oxidized before cooking. Internal raw appearances were red/ purplish-red for NRM, purplish-red/red for reduced, and brown for PMB and oxidized groups. Cooked colors of NRM-no treatment and reduced, and PMB-reduced were more red (P <0.05) than those of NRM-oxidized and PMB-no treatment and oxidized. Cooked colors of PMB-reduced and NRM-no treatment were similar (P>0.05), and those of NRM-oxidized and PMB-no treatment were similar (P>0.05). Oxidized pigment produced a PMB color, whereas reducing conditions produced NRM cooked color.     

脂溶性天然抗氧化剂对甲鱼油稳定性的影响

为探究三种脂溶性天然抗氧化剂(脂溶性茶多酚(LTP)、维生素E(V_E)、脂溶性迷迭香提取物(LRO))对甲鱼油稳定性的影响,以甲鱼油为原料,采用Schaal加速氧化法,添加不同浓度梯度(0.02%、0.04%、0.06%、0.08%)的LTP、V_E、LRO,定期测定甲鱼油的酸价(AV)、过氧化值(POV)及挥发性成分,确定最佳的抗氧化剂添加量;并在最佳添加量条件下,比较三种抗氧化剂对甲鱼油AV、POV、脂肪酸含量的差异。结果表明,LTP、LRO、V_E能有效减缓甲鱼油的氧化速率,当其添加量分别为0.06%、0.04%、0.08%时,随贮藏时间增加,甲鱼油中AV、POV增长速率最慢,且具有强烈鱼腥味等不良气味的壬醛、己醛、1-戊烯-3-醇及表征油脂氧化酸败程度的乙酸、丁酸的峰面积变化最小。对比三种抗氧化剂对甲鱼油中脂肪酸组成的作用效果,发现0.04% LRO的抗氧化性最强,0.06% LTP次之,0.08% V_E最弱。本实验结果对抗氧化剂的选择、提高贮藏稳定性及延长货架期提供理论参考,对促进甲鱼加工过程中内脏和脂肪块的综合利用有工业化指导意义。     

富含麦角硫因的金针菇提取物对冷冻猪肉糜品质的影响

基于蘑菇中含有麦角硫因等天然抗氧化物质,选取金针菇作为原料,利用醇提取法获得富含麦角硫因的金针菇提取物,将其添加到猪肉糜中(6 g/kg),冷冻贮藏12周后,通过测定脂肪氧化、蛋白质氧化、核苷酸和感官评价等指标来评价金针菇提取物对冷冻肉糜品质的影响.结果表明,金针菇提取物的麦角硫因含量为15.29 mg/g.在冷冻贮藏...     

天然抗氧化剂对玉米油稳定性的影响

分别将生育酚、β-胡萝卜素和迷迭香提取物天然抗氧化剂添加到纯化后的玉米油中,采用schaal烘箱加速氧化法,对比纯化玉米油,研究天然抗氧化剂对玉米油稳定性的影响,建立氧化反应动力学方程。结果表明,3?种抗氧化剂抗氧化能力为迷迭香提取物＞β-胡萝卜素＞生育酚。当每100 g玉米油添加天然抗氧化剂0.02?g时,玉米油添加生育酚、β-胡萝卜素和迷迭香提取物后的动力学模型分别为、和,而纯化玉米油的动力学模型为,并推测出纯化玉米油与添加过3?种天然抗氧化剂后,一级玉米油的货架期分别为15、19、24、27?个月。所以以迷迭香提取物为抗氧化剂添加到玉米油中,可明显提高玉米油的货架期。     

Cooked Color in High pH Beef Patties as Related to Fat Content and Cooking from the Frozen or Thawed State

Beef patties were processed from high pH (>6.0) beef to contain 5, 10, 15, 20 or 25% fat. Patties were cooked to 71°C from the frozen or thawed state before evaluating color. Neither fat content nor state of patties when cooked exerted any major influence on color, but linear effects (p<0.01) in association with increased fat content included higher L* values and hue angles and lower a* values (15.2% reduction). Higher values for L*, b* (but not for 5% fat patties), and hue angles were observed for patties cooked thawed rather than frozen. The use of high pH beef lessened the effects of increased fat and cooking from the thawed state on increased brown color in cooked patties.     

PSE(白肌)、RFN(正常)、DFD(黑干)3种质量猪肉冷藏期间的肉色稳定性

比较了PSE(白肌)、RFN(正常)、DFD(黑干)3种质量猪肉冷藏期间的肉色稳定性。宰后24h直接切块取样的3种质量猪肉(背最长肌)于(2±1)℃下避光透氧包装[O2透过率=2.06×10-3mL/(m2.h.Pa)]冷藏6d,采用色度计法测定了样品表面L*(亮度)值、a*(红色度)值、b*(黄色度)值、hueangle(色调角)值。从上述指标的变化研究了3种质量猪肉表面的肉色稳定性。3种质量猪肉表面肉色稳定性顺序为:DFD>RFN>PSE;a*值下降、hueangle值上升可反映肉色稳定性变差。     

Oxidative Stability of Cooked Comminuted Lean Pork as Affected by Alkali and Alkali-Earth Halides

Lipid oxidation of comminuted lean pork containing alkali or alkali-earth metals (at 100 or 200 meq/kg sample) was monitored over a 7-day storage at 4°C using the 2-thiobarbituric acid-reactive substances (TBARS) test. For samples exhibiting an antioxidative effect, further studies were carried out to determine their content of volatiles. Fluorides and iodides of alkali metals inhibited lipid oxidation in meat model systems as reflected in TBARS values and hexanal contents. A high correlation (r = 0.9263) existed between hexanal contents and TBARS values of treated meat. Chloride and bromide salts of alkali and alkali-earth metals exhibited a slight prooxidative influence on lipid oxidation. Fluorides of alkali-earth metals did not exhibit antioxidant activity, presumably due to an ion-pairing mechanism, while their iodide analogues retained antioxidative activity.     

Freeze/thaw Stability of Cooked Pork Sausages as Affected by Salt, Phosphate, pH, and Carrageenan

The effects of κ, ι, or λ carrageenan (CGN), sodium tripolyphosphate (STPP), chloride salts, and meat pH on the freeze/thaw stability of cooked pork sausages were investigated. STPP decreased thaw drip (TD) and increased hardness for all treatments regardless of type of salt or CGN. KCI did not affect the texture of control samples in the presence of STPP, but decreased the functionality of κ- and ι-CGN. Increased meat pH increased the hardness and decreased thaw drip for all CGN treatments, except for λ-CGN, which remained unchanged. k- and ι- CGN increased moisture retention of sausages prepared from low-pH meat.     

迷迭香提取物对真空包装熟猪肉饼抗氧化和抑菌效果的影响

以真空包装熟猪肉饼为试材,探讨不同质量分数迷迭香提取物的抗氧化、抑菌能力及其对肉饼品质的影响。将0.03%、0.06%和0.09%的迷迭香提取物分别添加到肉饼中,对肉饼在10 d冷藏期间的硫代巴比妥酸（thiobarbituricacid reactive substance,TBARS）值、菌落总数、挥发性盐基氮（total volatile basic nitrogen,TVB-N）含量、pH值、红度值（a*）和质构进行测定,并与0.02%二丁基羟基甲苯（butylated hydroxytoluene,BHT）进行比较。结果表明：添加迷迭香提取物的各处理组抗脂肪氧化能力高于空白对照组（P＜0.05）,迷迭香提取物添加量为0.09%的处理组在前7 d的冷藏过程中抑菌能力显著高于空白对照组（P＜0.05）。添加迷迭香提取物的各处理组TVB-N含量在冷藏4 d后显著低于空白对照组,而pH值在整个冷藏过程中均显著低于空白对照组（P＜0.05）。在冷藏1 d后,添加0.09%迷迭香提取物的肉饼a*值与空白对照组相比显著上升,而在冷藏7、10 d后,添加迷迭香提取物的各处理组a*值均显著升高（P＜0.05）。此外,添加迷迭香提取物的各处理组咀嚼性在冷藏4、7、10 d后显著升高,硬度在冷藏1、10 d后显著升高,迷迭香提取物添加量为0.09%的肉饼在冷藏4、7 d后硬度也显著提升（P＜0.05）。可见,迷迭香提取物能有效抑制真空包装熟猪肉饼的脂肪氧化及微生物生长,并且能在一定程度上改善其颜色和质构。     

出口冻猪肉过氧化值检测方法的探讨

本课题选用 30～ 60℃沸程的石油醚提取脂肪 ,研究了不同提取时间和温度对检测结果的影响 ,探讨了出口冻猪肉过氧化值检测方法的基本操作条件 ,确定了合格出口冻猪肉贮存期过氧化值的临界值指标为 <4.2 meq/kg。