包装方式对牛排贮藏期间微生物数量和演替的影响

为研究包装方式对牛排贮藏期间的品质、微生物数量和演替的影响,牛排分别采用50％O2气调包装(50％O2+30％CO2+20％N2)和真空包装在0～4℃下贮藏21 d,并检测贮藏期间pH值、肉色、微生物数量和微生物多样性.结果表明:50％O2气调包装组比真空包装具有更好的护色效果;贮藏21 d时,与真空包装组相比,气调包...     

Aging and Enhancement Effects on Quality Characteristics of Beef Strip Steaks

ABSTRACT: Strip loins were removed 48 h postmortem from beef sides ( n = 20 pairs) to assess the effects of enhancement before or after aging on quality attributes of beef strip steaks. Strip loins were enhanced to 108% of original weight to contain 0.4% alkaline phosphate, 0.3% salt, 0.1% natural flavoring (on a final weight basis), and added water for comparison with non-enhanced samples. Regardless of when enhancement occurred relative to aging, enhanced samples were more tender, juicy, and salty than their non-enhanced counterparts. Enhanced samples were lighter, less red and less yellow, and had lower L *, a *, and b * values than non-enhanced samples; however, they generally had lower hue angles indicating that their color was closer to the true red axis of the color scale. Samples enhanced before aging achieved maximum tenderness after 14 d, whereas those enhanced after aging experienced no tenderness changes. Warner- Bratzler shear values were lower and pH values were higher in enhanced steaks than in controls.     

Carbon Monoxide in Modified Atmosphere Packaging Affects Color, Shelf Life, and Microorganisms of Beef Steaks and Ground Beef

ABSTRACT— Color and microbiology of steaks and ground beef stored in 0.4% CO, 30% CO2, and 69.6% N2 (but removed from the modified atmosphere before display) were compared with product displayed immediately after packaging in polyvinyl chloride film (only atmospheric oxygen). Storage of ground beef, loineye, inside round, and tenderloin steaks for up to 35 d in 0.4% CO resulted in typical initial bloomed color. Compared with product exposed to only oxygen, storage of ground beef and loineye steaks in 0.4% CO decreased color stability, whereas color life increased for tenderloin and inside semimembranosus muscles. No steaks having acceptable color had spoilage levels of microbes (≥log 7). Thus, carboxymyoglobin formed from 0.4% CO did not mask microbial spoilage.     

不同包装方式对土豆烧牛肉菜肴中牛肉贮藏品质的影响

本试验主要对比了免拆膜包装、真空包装和托盘包装对土豆烧牛肉菜肴中牛肉的菌落总数、色值、水分活度、水分含量、硬度、弹性等指标来阐述不同包装方式对土豆烧牛肉菜肴中牛肉贮藏品质的影响。结果表明,随着储藏时间延长,三种包装方式样品的菌落总数逐渐升高,其中贮藏4~11 d时,菌落总数上升最快,储存到21 d后,真空包装样品的菌落总数达到4.68 lg(CFU/g),免拆膜包装达到5.04 lg(CFU/g),菌落总数超标托盘包装样品已腐败;贮藏后期真空包装的土豆烧牛肉菜肴中牛肉的水分含量和水分活度分别达到50.25%和0.97,均高于免拆膜包装和托盘包装;真空包装的感官评分值为8.18,显著高于其他两种包装(P<0.05)。三种包装方式的pH在6.04~6.14之间,且无显著性差异(P>0.05);真空包装的色值、硬度、弹性等食用品质指标均优于免拆膜包装和托盘包装。由此可知,真空包装的土豆烧牛肉中牛肉的食用品质最好且可以长时间保存,免拆膜包装方式操作简单,但其包装效果不及真空包装,但明显优于托盘包装,这为土豆烧牛肉菜肴的工业化生产提供了可靠的理论依据。     

气调包装对牛肉保鲜效果的影响

冷却牛肉的嫩化及保鲜问题在一定程度上制约了冷却牛肉的普及和发展,气调包装是一种通过调节和控制食品所处环境中气体组成的保鲜方法,并在一定时间内保持相对稳定,以抑制或延缓产品的变质过程,从而达到延长保鲜期和提高保鲜效果的目的。本实验以牛肉为包装对象,通过研究5种不同透气性包装材料在气调包装(45%氧气+30%二氧化碳+25%氮气)气体比例的充气包装方式下,每天对牛肉菌落总数、酸碱值、挥发性盐基氮值、色泽、包装袋内气体含量的变化和剪切力进行测定分析。结果表明:以聚丙烯-聚乙烯-聚对苯二甲酸乙二醇酯的气调包装材料效果最佳。     

Shelf‐Life Extension of Chill‐Stored Beef Longissimus Steaks Packaged under Modified Atmospheres with 50% O2 and 40% CO2

This study was conducted to compare the shelf‐life of beef steaks stored in different packaging conditions: overwrapped (OW) packaging and 2 modified atmosphere packaging systems (MAP): 80% O₂ MAP (80% O₂/20% CO₂) and 50% O₂ MAP (50% O₂/40% CO₂/10% N₂). Steaks were stored at 2 °C for 20 d. Headspace gas composition, microbial counts, color stability, pH, purge loss, and lipid oxidation were monitored. Among the packaging types, 50% O₂ MAP was superior to OW packaging and 80% O₂ MAP in delaying bacterial growth and extending shelf‐life to 20 d. 50% O₂ MAP also gave steaks an acceptable color during storage. No significant differences were observed in color stability of steaks packaged in both 50% O₂ MAP and 80% O₂ MAP. This study reveals 50% O₂ MAP is a realistic alternative to preserve beef steaks efficiently.     

Headspace Volume and Percentage of Carbon Monoxide Affects Carboxymyoglobin Layer Development of Modified Atmosphere Packaged Beef Steaks

ABSTRACT:  Carboxymyoglobin (COMb) development of beef  Longissimus lumborum  as related to molecular CO availability and package headspace volume was evaluated. Steaks from six pairs of USDA Select strip loins were packaged in modified atmosphere packages with 0.2%, 0.4%, or 0.8% CO and 30% CO₂ and balanced with N₂ to obtain meat-to-gas ratios of 0.4, 0.7, and 1.1, and CO molar concentrations of 0.07, 0.10, and 0.20 mMol. Steak redness (CIE  a *), COMb layer thickness, percentage of CO in the headspace, visual display color, and bloom intensity scores were evaluated 4 and 7 d after packaging. Greater concentration of CO in a smaller headspace resulted in a thicker COMb layer compared with lesser concentration of CO in a larger headspace, regardless of moles CO available. The combined effects of concentration of CO and headspace volume had a greater impact on COMb development than millimoles of CO in the package headspace. Package headspace can be reduced and the concentration of CO can be increased without detriment to fresh beef color or consumer safety.     

2005年真空包装机产品质量国家监督抽查结果的分析

本文通过对2005年真空包装机产品的产品质量抽查的数据进行分类分析,总结出目前我国真空包装机行业存在的共性问题,供行业有关人士参考。     

Internal Premature Browning in Cooked Steaks from Enhanced Beef Round Muscles Packaged in High-oxygen and Ultra-low Oxygen Modified Atmospheres

ABSTRACT: Beef round muscles were injection-enhanced to 6%, packaged in high-oxygen (HiOx) or ultra-low oxygen (LoOx) modified atmospheres, stored 7 d and displayed 2 d (HiOx) or stored 16 d and displayed 1 d (LoOx) at 0 °C, and cooked to 71.1 °C. Raw internal color for steaks in HiOx was lighter, redder, more yellow and saturated, and had more oxymyoglobin and less deoxymyoglobin than steaks in LoOx ( P < 0.0001). Cooked internal color of steaks from HiOx appeared prematurely brown and was darker, less red, yellow, and saturated, and had more denatured myoglobin than steaks from LoOx ( P < 0.0001). This study presents conclusive evidence that modified-atmosphere packaging influences internal cooked color development of beef steaks.     

不同贮藏条件下牛肉的理化性质及感官品质的对比分析

为分析牛肉在不同包装方式与贮藏温度下理化性质及感官品质的变化,该试验将牛肉背最长肌分别采用空气包装(air-packaging,AP)、真空包装(vacuum packaging,VP)和气调包装(modified atmosphere packaging,MAP),其中MAP包括两种气体比例:MAP1为78.8％O2...     

Irradiated Ground Beef: Sensory And Quality Changes During Storage Under Various Packaging Conditions

Ground beef patties (irradiated with 2 kGy and nonirradiated) were packaged using oxygen permeable (polyolefin) or oxygen impermeable material (polyethylene). Samples were irradiated in air and stored in air; irradiated under vacuum and stored under vacuum; or irradiated under vacuum and stored in air. Changes in flavor, texture, juiciness or aftertaste were evaluated after either 1 or 7 days storage at 25°C prior to cooking. Irradiated "Vac/Air" samples were more tender, irradiated "Vac" samples were more moist, and irradiated "Air" samples had the least aftertaste. A 3 log₁₀ reduction in total aerobic counts was detected immediately after irradiation. No difference in lipid oxidation was found within the first week of storage, regardless of packaging atmosphere. Shelf life of ground beef patties was extended 55 days at 4°C.     

The Effects of Marination and Cooking Regimes on the Waterbinding Properties and Tenderness of Beef and Bison Top Round Roasts

ABSTRACT: The combined effect of marination and different cooking regimes on the cooking yield and palat-ability of bison and beef top round roasts was investigated. Semimembranosus (SM) muscles from beef and bison top rounds were injected with a marinade to achieve 20% extension by weight and 0.5% sodium chloride and 0.3% sodium tripolyphosphate levels and then subdivided into 4 roasts and cooked by following 4 cooking regimes: cooking at a constant temperature of 75°C (control; C); similar to the control treatment except that roasts were held at an internal temperature of 55°C for 45 min (Hold45) or 90 min (Hold90) prior to final cooking at 75°C; initial cooking at 55°C with a 5°C increase in oven temperature every hour (Step-up) until the 71°C internal temperature was achieved. Cooking yield, expressible moisture, purge, and shear force of processed roasts were determined. Marination by injection improved the yield and tenderness of beef and bison SM roasts. The cooking yield for injected samples (78%) was significantly (P < 0.05) higher compared with noninjected controls (68%). Injected SM roasts from bison had lower cooking losses than those from beef, whereas control samples from these 2 species did not differ in their cooking yields. Injected beef SM was more tender than bison SM; however, marination significantly reduced the shear force values of SM roasts for both species (i.e., shear force values of 82 N in control samples was reduced to 63 N in injected ones). The cooking regimes, Hold45, Hold90, and Step-up (which allowed a longer time at 55 to 60°C), gave products with lower ( P < 0.05) shear force values than those of the controls. Based on the cooking yield and time involved, the Hold 45 treatment performed the best.     

酱牛肉气调和真空包装保鲜效果比较研究

为了改进酱牛肉的保鲜效果并延长其货架期,以真空包装为参照,探讨气调包装（5% O2＋70% CO2＋ 25% N2）对酱牛肉的保鲜效果。以细菌总数、硫代巴比妥酸反应物（TBARS）值、总挥发性盐基氮含量、pH值、 色差、风味为评价指标,比较酱牛肉真空和气调两种包装方式保鲜效果的差异。结果表明：在10 ℃贮藏18 d后,气 调包装组和真空包装对照组相比,其细菌总数降低2 个数量级,TBARS值降低了38.7%,挥发性盐基氮含量降低了 66.8%,且通过电子鼻主成分分析能将两种包装方式完全分开。表明气调包装更有利于酱牛肉的保鲜,可有效提高 其品质稳定性,并延长产品的货架期。     

Color and Its Stability in Restructured Beef Steaks during Frozen Storage: Effects of Various Binders

Color and its stability were evaluated in restructured steaks made with various binders (calcium alginate, crude myosin extract, whey protein concentrate, wheat gluten, soy isolate or surimi) vs controls (intact ribeye muscle, restructured steaks with no additives or with NaCl and sodium tripolyphosphate). Steaks made with various binders showed similar effects on initial surface metmyoglobin concentration and sensory color attributes, except steaks made with calcium alginate or soy isolate protein. During 12-wk frozen storage, steaks made with various binders (except soy protein isolate) had similar color stabilities.     

不同包装与贮藏条件对两种低盐腌制罗非鱼片的品质影响

为了开发低盐罗非鱼（Oreochromis mossambicus）深加工产品,延长其货架期,以本实验室开发的低盐腌制罗非鱼片、复合低盐腌制罗非鱼片为对象,通过普通包装（对照）、真空包装和气调包装,测定鱼片在4 ℃（冷藏）和－3 ℃（微冻）贮藏过程中汁液流失率、感官评分、pH值、硫代巴比妥酸反应物（thiobarbituric acid reactive substances,TBARS）值、挥发性盐基氮（total volatile base-nitrogen,TVB-N）含量、菌落总数等指标,分析不同包装方式和不同贮藏条件下的品质变化规律。结果表明：不同包装方式的两种低盐腌制罗非鱼片在4 ℃和－3 ℃贮藏过程的感官评分随贮藏时间延长逐渐下降,pH值呈现先降低后升高的趋势,而汁液流失率、TBARS值、TVB-N含量、菌落总数均随着贮藏时间的延长呈现上升的趋势。综合各项指标的变化规律,复合低盐组罗非鱼片比低盐组罗非鱼片在贮藏过程中能更好地维持品质,气调包装的鱼片品质优于真空包装和普通包装。在4 ℃贮藏时,气调包装的两种低盐腌制罗非鱼片货架期均为12 d,比普通包装和真空包装分别延长8 d和4 d;在－3 ℃贮藏时,气调包装组的货架期均达到43 d,比普通包装组和真空包装组分别延长25、10 d。两种低盐腌制罗非鱼片采用气调包装、－3 ℃贮藏可明显保持产品的品质和延长货架期,这为罗非鱼低盐深加工产品的开发生产提供技术支持。     

Solution Enhancement and Post-enhancement Storage Effects on the Quality, Sensory, and Retail Display Characteristics of Beef Triceps Brachii Muscles

Beef triceps brachii muscles (6 d postmortem; n= 15; muscle sections n= 45) were sectioned into 3rds and allocated to 1 of 3 treatments. The treatments were untreated (CNT), or injected at a 12% pump rate with either tap water‐only (H₂O) or a solution comprising tetrasodium pyrophosphate and sodium chloride (TSPP/ NaCl) at 0.4% and 1.0% target final product weight concentrations, respectively. Each muscle (comprising all 3 treatments) was then allocated to 2, 14, or 28 d of vacuum‐packaged 1°C storage. Purge losses during storage were greatest (P < 0.05) for H₂O muscles and least (P < 0.05) for TSPP/NaCl muscles. Purge losses also increased (P < 0.05) from 2 d to 14 d of storage. Steaks enhanced with TSPP/NaCl had less (P < 0.05) free water and lower (P < 0.05) cooking losses than either CNT or H₂O steaks. Storage duration did not affect (P > 0.05) Warner‐Bratzler shear force (WBS) or sensory tenderness, but juiciness decreased (P < 0.05) with increased storage duration. While storage duration did not impact (P > 0.05) instrumental color characteristics, aerobic plate counts generally increased during storage. The TSPP/NaCl steaks had lower (P < 0.05) WBS values and improved (P < 0.05) sensory tenderness and juiciness characteristics compared with CNT or H₂O steaks. While CNT steaks had greater (P < 0.05) L* values (lightness) than TSPP/NaCl steaks, TSPP/NaCl steaks had similar (P > 0.05) oxymyoglobin proportions (630/580 nm) and a* values (redness) as CNT steaks. These results suggest enhancement with TSPP/NaCl can improve triceps brachii yield and palatability characteristics. Increased post‐enhancement storage did not impact or worsened palatability while increasing purge losses, suggesting general deleterious effects of increased postmortem storage for this muscle.     

包装机械行业产品质量现状分析及展望

本文通过对半自动捆扎机、真空包装机产品的国家质量监督抽查的数据进行分类分析,总结出目前我国包装机械行业存在的共性问题,供行业有关人士参考。     

不同包装条件对米糠贮藏稳定性的影响

米糠资源营养丰富,具有很高的开发利用价值,但其贮藏稳定性差导致品质迅速下降。本实验以米糠为研究对象,分析自然贮藏条件下采用PE、PE/PA及编织袋包装的米糠在常压密封、真空密封条件下主要品质指标变化。结果发现：贮藏30d后,PE/PA/真空组水分含量下降0.99%,粗脂肪含量下降3.74%,脂肪酸值升高77.7mg KOH/100g,而对照组相应指标分别为PE/PA/真空组的3.6、2、5.33倍;PE/PA/真空组VE、γ-谷维素含量分别下降了0.4mg/100g、0.01%,对照组降幅分别是PE/PA/真空组的2.78倍和6倍;菌落总数PE/PA/真空组由初期的2.82×108CFU/g减少到0.3×107CFU/g,性状保持良好,具有米糠特有的香味,而对照组菌落总数增加到1.8×1010CFU/g,且出现明显的霉味,颜色变深,结块严重。结果表明不同包装对提高米糠贮藏稳定性效果依次为：PE/PA/真空＞PE/PA/常压＞PE/真空＞PE/常压＞编织袋＞对照,各样品结果呈显著差异(P＜0.05)。采用PE/PA真空包装贮藏能有效提高米糠贮藏期品质稳定性。     

Microflora and Color of Ground Beef in Gas Exchange Modified Atmosphere Packaging with Abusive Display Temperatures

Gas exchange modified atmosphere packaging (GEMAP) with display gas of 80% O²:20% CO₂ retarded microbial growth and improved color stability of ground beef patties compared with vacuum packaging (VP) followed by air‐permeable polyvinylchloride (PVC) overwrapping during 3 d of retail display. Predominant microorganisms for GEMAP were Pseudomonas, Yersinia, Aeromonas, and Enterobacter and for VP‐PVC were Pseudomonas, Brochothrix, Aeromonas, Enterobacter, Moraxella, and Lactobacillus. Lower levels of pathogens were isolated in GEMAP samples with 7 °C than 15 °C display temperature. Patties were darker (lower L*) with those with 15 °C than with 7 °C display and redder (higher a*) in GEMAP than VP‐PVC. Good manufacturing practices should be followed with MAP meat to reduce the risk of pathogenic microbial growth.