Potassium Lactate Effects on Low-Fat Fresh Pork Sausage Chubs During Simulated Retail Distribution

Typical pork sausage (25% fat) and low-fat (8% fat) sausage with or without 20% added water and 0.4% carrageenan were compared to identical treatments containing 3.0% potassium lactate. Microbial populations of low-fat treatments did not differ (P>0.05). However, typical sausages with lactate had lower psychrotrophic counts than typical sausage. Lactate delayed (P<0.05) pH decline in typical sausages but had no effect on low-fat sausages (P>0.05). Addition of water and carrageenan to commercially manufactured and distributed low-fat sausage had no deleterious effects on microbial, lipid or color stability.     

Effects of Rosemary Extract and Sodium Lactate on Quality of Vacuum-packaged Ground Ostrich Meat

ABSTRACT Vacuum‐packaged ground ostrich meat patties containing 2% sodium lactate (SL), 0.2% rosemary extract as oleoresin (RE), or their mixture (MIX) were evaluated and compared with control for their storage stability at 3 ± 1 °C in the dark by measuring pH, 2‐thiobarbituric acid‐reactive substance (TBARS) values, sample color (CIE L*, a*, b*, Hue and Chroma), and microbiological content. The pH values of ostrich patties, ranging from 6.03 to 6.13, were not affected by treatment (P < 0.05). At 9 d of storage, TBARS concentration for control samples containing no additives was 1.64 mg malonaldehyde/kg meat. Addition of RE to the ground ostrich meat inhibited lipid oxidation during storage at 3 ± 1 °C (P < 0.05). TBARS values of SL‐added samples were lower than control samples (P < 0.05); addition of SL also delayed the oxidation. It was found that RE had a protective effect on color, whereas addition of SL decreased CIE a* values (P < 0.05). SL, either alone or with RE, was effective in inhibiting total aerobic bacteria (TAB), coliforms, lactic acid bacteria (LAB), and Brochothrix thermosphacta in ostrich patties (P < 0.05) and provided a 2‐log reduction in microbial population during storage. In addition, RE did not have a significant effect on microbial growth at the concentration used in this study.     

Display, Packaging, and Meat Block Location Effects on Color and Lipid Oxidation of Frozen Lean Ground Beef

Ground beef chuck (15% fat) was packaged (500g) in vacuum bags, Saran Wrap^TM overwrapped with aluminum foil or polyvinyl chloride (PVC), exposed to retail display light (4°C) for 24 hr and then held frozen (?18°C) for 52 wk. Instrumental and visual color of PVC-packaged beef was affected most by display and by frozen storage. During frozen storage, as oxygen permeability of packaging material increased, TBA, visual brownness, and metmyoglobin increased while visual redness, acceptability, a* value, red color contributed by oxyrnyoglobin, and deoxymyoglobin decreased. Location on the meat block (exterior vs interior) affected (p<0.05) visual red and brown color, lightness, and acceptability, L*, a*, and b*, and TBA values.     

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。     

Low-Fat Fresh Pork Sausage Patty Stability in Refrigerated Storage with Potassiunn Lactate

Typical pork sausage patties (40% fat), low-fat (8%) control patties, and low-fat (8%) patties with 20% added water and 0.4% carrageenan were compared to identical treatments containing 2% potassium lactate. The lactate had no effect on percent discoloration or lean color during refrigerated aerobic storage. Sensory properties of pork sausage treatments were not affected by the lactate salt (P<0.05). Bacterial populations of low-fat pork sausage patties did not differ (P>0.05); however, the typical patties with 2% potassium lactate had lower (P<0.05) microbial numbers during refrigerated storage than typical fresh pork sausage. TBARS,‘L’,‘a’and‘b’values were unaffected by the potassium lactate (P>0.05).     

Combination effect of sodium lactate and irradiation on color,lactic acid bacteria,lipid oxidation and residual nitrite in Chinese sausages during storage at 25 °C

Chinese sausages, with the addition of 0 or 2% sodium lactate, were vacuum‐packaged and stored overnight at 4°C. Refrigerated sausages were gamma‐irradiated at 0, 3 or 5 kGy absorbed dose. Meat samples were stored at 25°C for up to 30 days. Color, lactic acid bacteria, pH, lipid oxidation and residual nitrite were determined during storage. Irradiated samples were reduced in redness as a result of irradiation and storage time. Irradiation at 5 kGy alone or in combination with 2% sodium lactate and irradiation at 3 kGy could completely inhibit lactic acid bacterial growth. Thiobarbituric acid reactive substances (TBARS) values decreased as the pH values of samples increased. Sodium lactate decreased TBARS values of all samples and protected against a decrease of residual nitrite during storage. Irradiation reduced residual nitrite in Chinese sausage, and residual nitrite decreased with increased time. Copyright © 2004 Society of Chemical Industry     

响应曲面法优化影响清真牛肉香肠感官品质和保质期的超高压工艺参数

利用响应曲面法,对影响清真牛肉香肠感官品质、脂肪氧化和保质期的超高压参数进行了试验优化设计,建立了各响应值的二次多项式数学模型,验证了模型的有效性.结果表明:在处理压力200～600MPa、保压时间5～25min、处理温度20～60℃的模型区间内,此3者均为影响感官品质和保质期的显著影响因子,显著顺序为处理压力＞保压时间＞处理温度,并得出超高压处理清真牛肉香肠感官品质和保质期的最优工艺参数:压力473.59MPa,时间14.94min、温度20℃.在此条件下清真牛肉香肠的硬度2785g、弹性0.6711、内聚力0.2871、咀嚼度673.8、硫代巴比妥酸还原值0.6888mg/100g,感官评价16.16,保质期26.34d.     

Extension of the Retail Display Life of Fresh Beef Packaged in Modified Atmosphere by Varying Lighting Conditions

ABSTRACT: The effect of lighting conditions (darkness and either a standard supermarket fluorescent, a low-UV, color-balanced lamp, and the supermarket fluorescent with a UV filter) on the retail display life of fresh beef steaks packaged in a modified atmosphere was studied. Lighting without UV radiation led to a significant delay of meat spoilage, as assessed by surface color (a* and MetMb percentage), lipid oxidation (TBARS value), bacterial counts and sensory evaluation (discoloration and odor). Shelf life of fresh meat was extended from 12 to 22 to 28 d, similar to that of display in the darkness, by using either the low UV lamp or the fluorescent with a UV filter.     

桑椹多酚对广式腊肠贮藏过程中脂质降解和氧化特性的调控作用

脂质氧化和水解是形成腊肠特征风味的重要途径,但过度氧化会造成腊肠品质的劣变。桑椹多酚是一类天然抗氧化剂,被证实可以有效缓解腊肠储藏过程中的氧化反应,然而其通过调控腊肠脂质氧化和水解来改变腊肠风味的相关机制还鲜有研究报道。鉴于此,该研究将桑椹多酚提取物（1 g/kg）加入到肉糜中,制成广式腊肠,跟踪28 d的储藏过程中腊肠的脂质氧化代谢产物（共轭二烯、共轭三烯、TBARS和己醛）以及脂肪酸（中性脂肪酸、游离脂肪酸和磷脂）的组成变化。研究发现,桑椹多酚主要通过抑制脂质次级代谢产物（己醛和丙二醛）来延缓腊肠的脂质氧化。经过28 d的储藏期后,桑椹腊肠中己醛与丙二醛的含量较对照组分别下降63.10%与28.05%。此外,储藏过程中桑椹多酚还可以有效抑制腊肠储藏过程中游离脂肪酸、磷脂的释放。经过28 d的储藏期后,与对照组相比,桑椹腊肠的游离脂肪酸含量下降了9.59%。同时,桑椹多酚还可以减少风味物质中醛类物质的产生和积累。综上所述,桑椹多酚主要通过延缓腊肠储藏过程中脂质的降解及次级氧化过程来调控产品的风味。     

茶多酚对鸵鸟肉脂肪氧化及色泽稳定性的影响

研究了茶多酚(TP)对真空包装、于(4±1)℃条件下冷藏的鸵鸟肉脂肪氧化及色泽稳定性的影响。结果显示:茶多酚能显著抑制鸵鸟肉中脂肪的氧化;添加200 mg/kg(T200)、400 mg/kg(T400)的茶多酚可抑制鸵鸟肉中高铁肌红蛋白的形成,,并提高鸵鸟肉的总色素含量和色度值(a*),表明茶多酚不仅能抑制鸵鸟肉的脂肪氧化而且对鸵鸟肉的色泽具有一定的保护作用。     

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.     

肌肽对牛肉糜肉色及脂肪氧化的影响

在牛背最长肌中添加肌肽(C9H14N4O3),研究在4±1℃冷藏条件下,不同浓度(0.05%、0.1%、0.5%、1.0%)肌肽对牛肉肉糜高铁肌红蛋白(MetMb)还原酶活性、色素含量、脂肪氧化及肉色稳定性的影响。结果表明:在7d的贮藏期内,添加不同浓度肌肽均可有效抑制肉糜MetMb含量上升、提高高铁肌红蛋白还原酶活性,并与无添加组有显著性差异(p<0.05)。0.1%、0.5%浓度肌肽对抑制脂肪氧化、稳定肉色有显著作用,护色效果较理想。      

施钾量对不同生态区烤烟生长和钾肥利用率的影响

为研究不同生态区施钾量与烤烟生长和钾肥利用率的关系,以不施钾（CK）为对照,分别在气候和土壤差异明显的山东即墨和云南罗平开展了3个钾水平（即墨,T1 123.75 kg/hm²、T2 247.50 kg/hm²、T3 371.25 kg/hm²;罗平,T1 67.50 kg/hm²、T2 135.00 kg/hm²、T3 202.50 kg/hm²）的田间试验。结果表明：（1）施钾肥显著提高即墨烤烟茎、叶的生物量和总生物量,仅显著提高罗平烤烟烟叶生物量;T1、T2和T3显著提高烟叶生物量,即墨分别为7.62%、29.4%和31.5%,罗平分别为12.4%、19.5%和13.1%。（2）施钾肥显著提高即墨烟叶钾积累量和钾总积累量,T3效果最显著;显著提高罗平烤烟钾总积累量,T2效果最显著。（3）即墨施钾量与烤烟烟叶产量、烟叶钾含量和钾总积累量之间呈极显著正相关,而罗平则符合一元二次方程曲线;罗平T2对应施钾量下,烟叶产量、烟叶钾含量和钾总积累量与最大值（6579 kg/hm²、2.19%、230 kg/hm²）接近。（4）T2处理,即墨烟叶含钾量>3%,钾肥表观利用率（RE）和钾肥农学效率（AE）最高,分别为27.8%和2.50 kg/kg,钾肥偏生产力（PEP）降低,土壤钾素盈余显著;罗平RE高达45.3%,AE和PEP较高,分别为8.05 kg/kg和49.3 kg/kg,土壤钾素亏缺显著。综上,T2处理在提高即墨和罗平烟叶产质量和钾肥利用率以及平衡土壤钾素方面效果显著,可推荐为两地烤烟生产的适宜施钾量。     

服装陈列设计中色彩和面料的搭配

介绍了服装色彩及面料在服装卖场陈列设计中的功能作用,详述了服装陈列设计中色彩和面料的搭配方式,以及实际操作中的各种影响因素。     

抗氧化剂对早餐肠高压后脂肪氧化的影响

为探究抗氧化剂对早餐肠高压后脂肪氧化的影响,在低温鸡肉早餐肠中添加0.05%的乙二胺四乙酸二钠(Na2EDTA)或维生素E(VE),与无添加抗氧化剂组作对比,然后进行不同强度的超高压处理(HPP,400、600MPa,20min),检测各组样品在4℃下贮藏28d各脂肪氧化指标的变化。结果表明:4℃随着贮藏时间延长,早餐肠的不饱和脂肪酸(UFA)比例逐渐减小,POV和TBA值逐渐增大。贮藏前期,脂肪氧化以一级氧化为主;后期二级氧化占主导作用。抗氧化剂Na2EDTA和VE都能在高压下提高脂肪的稳定性,且前者的抗氧化效果更佳。     

Comparative studies on lipid oxidation of organic model sausage without nitrite produced with the addition of native or autoclaved mustard seed and acid whey

The objective of this work was to evaluate the influence of the addition of native and autoclaved mustard seed (AMS) with combination of acid whey (AW) on the stability of organic model sausages during 30 days of vacuum storage by measuring primary and secondary products of lipid oxidation, the changes in the fatty acid composition, oxidation–reduction potential and antioxidant capacity. Briefly, the addition of AW (5%) with combination of AMS (1%) significantly increased the capacity of sausages to capture the radical cations 2,2‐azinobis(3‐ethyl‐benzothiazoline)‐6‐sulphonate at 1 day of storage which suggests that autoclaved mustard possessed significantly higher amount of phenolic acids compared with native mustard. The salted samples with mustard seed addition characterised by lower oxidation–reduction potential values (264.5–302.1 mV) during the whole storage period compared with control‐cured sample (307.3–330.5 mV). Results of conjugated dienes (CD) measurements indicated that salted meat product samples with mustard seed addition were characterised by significantly lower CD concentration (1.12–1.90 μmol mg^?1 meat product) compared with control‐cured sample (1.86–2.55 μmol mg^?1 meat product). The AW and mustard seed added to uncured sausage were able to protect polyunsaturated fatty acids against the oxidation comparable to nitrite.     

中式香肠加工及贮藏中脂肪氧化对其品质特性的影响

通过对中式香肠加工贮藏过程中包装、温度、光照以及抗氧化剂的不同处理,建立中式香肠的氧化模型,并对脂肪氧化的相关性进行分析。结果表明：以酸价(AV)、过氧化值(POV)、硫代巴比氨酸反应物(TBARS)为氧化指标,经过不同方式处理的3组中式香肠氧化程度不同;贮藏过程中脂肪中磷脂和游离脂肪酸的变化显著,且与氧化程度显著相关。     

低钾胁迫下钙调素拮抗剂对烟草幼苗钾积累的影响

为探讨低钾胁迫下钙调素（CaM）拮抗剂对植株幼苗钾积累的影响及其生理机制,采用室内水培法,以烟草品种K326为试验材料,设置2个钾水平和2种钙调素拮抗剂（氯丙嗪和三氟拉嗪）处理,分别测定叶片钙离子及钙调素含量、植株各部位钾含量、根系钾离子吸收相关基因的相对表达量、植株生理特征。结果表明,与常钾水平相比,低钾胁迫下植株各部位钾含量、叶片抗氧化酶活性、叶绿素含量及光合特性指标（除水汽压饱和亏外）明显降低。其中,植株地上部及根系钾含量分别显著降低了23.80%和55.50%,根系中NKT2、NtKC1和NtHAK1基因的相对表达量分别增加了4.05、2.98和12.74倍。2个钾水平下,施加钙调素拮抗剂后,植株各部位钾含量、抗氧化酶活性、叶绿素含量及光合特性6项指标（除水汽压饱和亏外）明显降低。低钾胁迫下,与未添加钙调素拮抗剂相比,钙调素拮抗剂处理的叶片钙调素含量、植株各部位钾含量、根系钾吸收相关基因表达量、叶绿素总含量及光合特性6项指标（除水汽压饱和亏外）显著降低,其中植株地上部及根系钾含量平均降低了23.69%和60.00%,根系中NKT2、NtKC1和NtHAK1基因的相对表达量平均降低了82.84%、94.18%和52.44%。低钾胁迫下添加钙调素拮抗剂会抑制钙调素含量,阻碍Ca²⁺-CaM复合体的形成,影响信号传导,导致叶片抗氧化酶活性及光合作用降低,根系中K⁺吸收相关基因的表达量减少,抑制植株K⁺吸收和积累。