Sensory Evaluation of Ground Beef Stored in High-oxygen Modified Atmosphere Packaging

ABSTRACT: The quality of ground beef stored in high-oxygen modified atmosphere packaging (MAP) (80% O₂ and 20% CO₂) was evaluated and compared to controls stored in oxygen-impermeable chubs. Patties were formed from the stored ground meat at d 1, 6, and 10. Color, microbial load, thiobarbituric acid (TBA) number, and sensory acceptability were measured. Patties from both treatments bloomed to red with a* values > 16. Aerobic plate counts increased to 9 × 10⁵CFU/gby 10 d storage, but were not different (p < 0.05) between treatments. TBA number of high-oxygen samples increased to 2.1 after 10 d, compared to 0.8 for controls. The flavor of samples in high-oxygen were rated less desirable after 6 or 10 d.     

Sensory Evaluation of Irradiated Ground Beef Patties for the National School Lunch Program

ABSTRACT: The 2002 Farm Bill allows irradiated ground beef to be distributed in the Natl. School Lunch Program (NSLP). Sensory properties of irradiated ground beef specified for the NSLP were evaluated. Frozen ground beef patties with 15% fat content were either not irradiated or irradiated at doses of 1.35 and 3.0 kGy. Aroma, taste, aftertaste, and texture as well as overall liking of cooked patties after 0 and 6 mo of storage were evaluated using nontrained panels. Results showed that irradiation had no significant ( P > 0.05) effect on the ratings of any of the sensory attributes either at 0 or after 6 mo of storage. Average ratings of liking of aroma, taste, aftertaste, and overall were higher at 6 mo than at 0 mo.     

Effects of Carbon Monoxide Packaging on Color and Lipid Stability of Irradiated Ground Beef

ABSTRACT: The effects of packaging atmosphere (aerobic, vacuum, or modified atmosphere with carbon monoxide) on ground beef treated with ionizing radiation were investigated. Measurements of color (CIE L*, a*, b*), lipid oxidation (TBA value), and sensory quality were conducted during 28 d of storage at refrigerated (0 to 2°C) temperatures. Irradiation significantly ( p > 0.001) decreased color scores and increased TBA and off-odor scores. The MAP + CO treatments increased the L* and a* values ( p < 0.001), regardless of irradiation dose. The TBA values for MAP + CO-packaged samples were well below the levels considered "rancid" (about 1.0). In addition, sensory scores indicated minimal production of irradiation off-odors with MAP + CO packaging.     

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...     

冷却牛肉贮藏过程中的品质变化

分析冷却牛肉贮藏过程中各品质指标的变化,确定理化指标和微生物指标的相关性,为提高牛肉的品质提供依据。文中测定了4℃贮藏的冷却牛肉在0、2、4、6、8、10、12、14 d的菌落总数、嗜冷菌总数、pH值、挥发性盐基氮、失水率、色差值,确定了各指标随保存时间的变化规律及其相关性。结果表明:在贮藏过程中,pH值呈现先下降后上升的趋势;挥发性盐基氮呈上升趋势;系水力逐渐下降;肉色a值、DE(d ifference error)值不断降低。在品质变化的各指标中,微生物菌落总数、嗜冷菌总数与pH值呈正相关,且差异显著(P<0.05);菌落总数与系水力、a值呈负相关性,差异显著(P<0.05)。其中菌落总数与挥发性盐基氮、a值的相关性较大且极显著相关(P<0.01)。由此可知,微生物的活动能引起牛肉理化指标的变化,通过测定挥发性盐基氮和a值可以客观反映冷却牛肉的微生物污染状况。     

Addition of Antioxidant to Improve Quality and Sensory Characteristics of Irradiated Pork Patties

The effects of added antioxidants on the oxidative quality changes of irradiated pork patties were studied. Lipid oxidation (TBARS) was not a concern, even in aerobically packaged irradiated pork patties when antioxidants were added. Irradiation produced sulfur compounds, such as dimethyl sulfide and dimethyl disulfide, responsible for irradiation off‐odor. The addition of gallate + tocopherol or sesamol + tocopherol was effective in reducing the sulfur volatiles, but had no effect on the redness of irradiated raw pork patties. Aerobic packaging was highly effective in reducing sulfur volatiles and off‐odor from irradiated meat during storage. Antioxidants had little effect on the sensory characteristics and consumer acceptance of irradiated pork, and consumers did not consider the red color of irradiated raw pork as a quality defect.     

Physical and Sensory Characteristics of Low Fat Ground Beef Patties

Ground beef patties with combinations of 0 and 10% added water and 0 and 0.25% added phosphate were compared with controls (22% fat and 0% added water and phosphate). Added water increased thaw and cooking losses but improved objective texture measurements and sensory panel ratings (P < 0.05). Added water and phosphate increased the percentage of water, decreased protein and did not affect fat. Added water and/or phosphate resulted in higher (P < 0.05) juiciness, tenderness and overall palatability scores. Low fat patties with added water were similar to 22% fat patties. Water and/or phosphate also improved sensory ratings for texture and flavor of 10% fat patties to equal those for 22% fat patties.     

电子束辐照对充氮包装冷鲜牛肉品质的影响

为探究电子束辐照对充氮包装冷鲜牛肉品质的影响,取6 头黄牛背最长肌,在高能电子加速器下辐照,4 ℃贮藏,评估不同辐照剂量和贮藏时间条件下微生物学、生物化学和感官特性的变化。辐照处理组和对照组相比,菌落总数显著下降,在贮藏第0天,处理组的菌落总数分别下降了0.766、1.801、2.673（lg（CFU/g））,差异显著（P＜0.05）;电子束辐照对牛肉样的贮藏损失、色泽、pH值、脂肪氧化并未产生显著性的影响,对TVB-N值的影响较小;但感官评价分析发现,随着辐照剂量的增加,色泽、气味、接受性得分下降。综合分析各品质指标,2.5 kGy左右的低剂量电子束辐照可以在杀灭微生物的同时,较好地确保牛肉品质,提高冷鲜牛肉的货架期。     

Microbiological, Sensory and Chemical Characteristics of Vacuum-Packaged Ground Beef Patties Treated with Salts of Organic Acids

Vacuum-packaged ground beef patties containing sodium lactate (NaL), sodium propionate (NaP), sodium acetate (NaA) and sodium citrate (NaC) at various levels and combinations were stored up to 28 days at 4°C. Addition of sodium lactate alone or in combination with sodium propionate increased shelf life of the patties by decreasing microbiological growth and decreasing negative flavor notes associated with lipid oxidation. Lean color also was improved by addition of sodium lactate alone or in combination with sodium propionate. Lipid oxidation by TBA was only slightly affected by treatment addition or storage.     

Storage Stability of Low-fat Ground Beef Made with Lower Value Cuts of Beef

Five combinations of low-fat ground beef treatments were prepared with lower value raw-materials: 90% lean cow trimmings, 50/50 Choice trimmings, 95% lean Choice trimmings, defatted clods and rounds, cow knuckles, and cow chucks. They were compared to a 20% fat control for quality attributes during 24 wk frozen (?20°C) storage. Control patties had greater (P<0.05) cooking loss, shear force, and connective tissue, and lower (P<0.05) juiciness scores than low-fat treatments. All low-fat pattie treatments were rated higher (P<0.05) in flavor intensity than control patties. Low-fat patties manufactured with a majority of lean cow trimmings had a greater color (pigment) and oxidative (lipid) stability.     

Properties of Low-Fat Ground Beef Containing Potassium Lactate During Aerobic Refrigerated Storage

Low-fat patties containing water, carrageenan, encapsulated salt and hydrolyzed vegetable protein (carrageenan-based patties) with 0, 1, 2 or 3% potassium lactate were compared to low-fat all-beef patties with no additives. Carrageenan-based patties had enhanced (P<0.05) sensory properties (juiciness, tenderness, mealiness and beef flavor intensity) compared to all-beef patties. The bacterial populations of low-fat, carrageenan-based patties did not differ (P<0.05) from low-fat all-beef patties. Bacterial growth in low-fat, carrageenan-based patties was reduced through the use of 2 or 3% potassium lactate with no deleterious effects on the sensory properties of the low-fat, ground beef. However, low-fat, carrageenan-based patties underwent greater (P<0.5) discoloration and lipid oxidation during aerobic refrigerated storage than all-beef patties.     

Thawing Prior to Cooking Affects Sensory, Shear Force, and Cooking Properties of Beef Patties

Patties from 6 commercial formulations were cooked to 71°C from either the frozen state or after thawing for 24 to 27 h at 4 °C to eliminate the pink/red color exhibited when cooked to 71 °C from the frozen state. Thawed patties had shorter cooking times, higher cooking yields, and lower shear force peak load and peak energy values. Patties cooked from the thawed state increased in thickness during cooking, while patties cooked from the frozen state decreased in thickness during cooking. Thawing prior to cooking increased sensory evaluation scores except for patties made with carrageenan. Thawing not only eliminated the problem of pink/red color after cooking but also improved sensory, shear force, and cooking properties of beef patties.     

Effect of Low‐Dose Electron Beam Irradiation on Quality of Ground Beef Patties and Raw,Intact Carcass Muscle Pieces

The objectives of this study were to determine the effects of a low‐dose (≤1 kGy), low‐penetration electron beam on the sensory qualities of (1) raw muscle pieces of beef and (2) cooked ground beef patties. Outside flat, inside round, brisket and sirloin muscle pieces were used as models to demonstrate the effect of irradiation on raw beef odor and color, as evaluated by a trained panel. Ground beef patties were also evaluated by a trained panel for tenderness, juiciness, beef flavor, and aroma at 10%, 20%, and 30% levels of fat, containing 0% (control), 10%, 20%, 50%, and 100% irradiated meat. With whole muscle pieces, the color of controls appeared more red (P < 0.05) than irradiated muscles, however, both control and treatments showed a gradual deterioration in color over 14 d aerobic storage at 4 °C. Off‐aroma intensity of both control and treatments increased with storage time, but by day 14, the treated muscles showed significantly (P < 0.05) less off‐aroma than the controls, presumably as a result of a lower microbial load. It was found that a 1 kGy absorbed dose had minimal effects on the sensory properties of intact beef muscle pieces. Irradiation did not have a significant effect (P > 0.05) on any of the sensory attributes of the patties. Low‐dose irradiation of beef trim to formulate ground beef appears to be a viable alternative processing approach that does not affect product quality.     

Survival of Listeria monocytogenes, Yersinia enterocolitica and Escherichia coli O157:H7 and Quality Changes After Irradiation of Beef Steaks and Ground Beef

Beef steaks and ground beef were inoculated with Listeria monocytogenes, Yersinia enterocolitica, or Escherichia coli O157:H7. Samples were packaged in air or under vacuum and irradiated at low (0.60 to 0.80 kGy) or medium (1.5 to 2.0 kGy) doses, with each dose delivered at either a low (2.8 M/min conveyor speed) or high (6.9 M/min) dose rate. Medium-dose irradiation accompanied by 7°C storage resulted in no Y. enterocolitica or E. coli O157:H7 survivors being detected. There was no effect on survival of the pathogens by dose rate or storage atmosphere. No difference (P>0.05) was observed in meat pH or color, but TBA values increased after 7 days storage.     

低钠盐酱牛肉贮藏品质的变化

本试验以冷鲜牛肉为原料,使用NaCl、MgCl₂、KCl、乳酸钾和酵母提取物按照不同比例配制成的复合低钠盐加工酱牛肉,以2% NaCl加工的酱牛肉为对照组,研究低钠盐酱牛肉于0~4℃下贮藏第1、3、5、7、9 d时菌落总数、质构(硬度、弹性、咀嚼性)、蒸煮损失率、色差(L^*值和a^*值)及感官品质的变化。结果表明:复合低钠盐配比为1.0% NaCl、0.3% KCl、0.3% MgCl₂、0.4%乳酸钾、1.0%酵母提取物时加工酱牛肉,第7 d时菌落总数在国标允许范围内;硬度、弹性、咀嚼性以及蒸煮损失率均与对照组无显著差异(P>0.05);a^*值与对照组差异不显著(P>0.05),且优于对照组;口感及弹性评分与对照组最接近(P>0.05),色泽、组织状态及总体可接受性均与对照组无显著差异(P>0.05)。用此配比低钠盐加工的酱牛肉能达到传统钠盐酱牛肉相同的品质,并使钠盐含量降低50%,为消费者提供一种更加健康的肉制品。     

Effects of Ascorbic Acid and Antioxidants on the Color of Irradiated Ground Beef

Irradiation significantly decreased the redness of ground beef (P < 0.05), and the visible color of beef changed from a bright red to a green/brown, depending on the age of meat. Addition of ascorbic acid (0.1%, wt/ wt) in ground beef prior to irradiation prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. Ground beef with added ascorbic acid had significantly lower oxidation‐reduction potential than the control (P < 0.05), and the low oxidation‐reduction potential of meat helped maintain the heme pigments in reduced form. Sesamol +α‐tocopherol had no effect in stabilizing color of irradiated beef.     

Sensory and Microbial Quality of Irradiated Crab Meat Products

Low dose gamma irradiation has proved effective in reducing pathogenic and spoilage microorganisms in a variety of seafood products. However, little information is available on the effect of irradiation on the sensory quality and consumer acceptance of such products. We compared microbial and sensory quality of irradiated (2 kGy or less) crab products (white lump, claw, and fingers) through 14-days of ice-storage. Irradiation effectively reduced spoilage bacteria extending shelf-life by more than 3 days beyond control samples. During storage, fresh crab odor and flavor were similar for treated and control samples, while off-flavors and odors developed more rapidly in controls. Overall acceptability scores for irradiated crab samples were higher than for control samples throughout 14-days ice storage.     

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。     

TBA Values, Sensory Characteristics, and Volatiles in Ground Pork During Long-term Frozen Storage: Effects of Packaging

Ground pork (30% fat) was packaged in vacuum bags (V), polyvinyl chloride film (P), Saran Wrap?(S), aluminum foil (A), or Saran?-aluminum foil combination (SA) and frozen at - 17°C for 13, 26, and 39 wk. Samples were analyzed for TBA value and pH. Volatiles were steam distilled, volatilized at 60°C, and 1 mL samples of headspace gas was analyzed using gas chromatography and mass spectrometry. Spectra for individual peaks on the total ion chromatograms were identified with spectra from known standards. Ground pork (cooked to 75°C) was evaluated by a trained sensory panel for flavor and texture. Rancid and acid odor and flavor scores and TBA values increased over time regardless of packaging treatment; however, V-packaged pork had lower scores and P-packaged had higher scores at all time periods than did that in other materials. Eighteen volatiles were identified and quantified using GC/MS; 3-hydroxy-2-butanone had the highest correlation coefficients with TBA value, odor, and flavor scores.     

Antioxidative Activity of Maillard Reaction Products in Cooked Ground Beef, Sensory and TBA Values

Maillard reaction products (MRPs) obtained by autoclaving egg albumin acid hydrolysate and glucose for 1 hr were added to ground beef which was cooked and stored at 4°C for 8 days. The antioxidative activity of MRPs was investigated by a trained sensory panel and the TBA test. The panel evaluated samples for loss of desirable cooked beef notes and generation of off-flavors, such as cardboard and painty. With added 1% MRPs, painty aroma and flavor scores were low and did not (p > 0.05) change over time. The coefficients of determination were high (r²= 0.92 to 0.77, p < 0.0001) between aroma and flavor scores for any two similar attributes. The TBA values decreased by 17% with the addition of 0.5% MRP and by 39% with 1% MRP over time.