Effect of Subprimal Fabrication and Packaging Methods on Palatability and Retail Caselife of Loin Steaks from Lean Beef

Eighty subprimals were fabricated from 20 pairs of beef strip loins from lean (fat thickness, 0.2-0.4 cm) US Standard and US Good carcasses. Three vacuum packaged (VP) and one dry aged treatments were randomly assigned to short loin sections of each carcass. Steaks from VP intact and VP not-reassembled subprimals were rated highest in overall appearance and eating quality. Dry aging reduced retail caselife, produced greater shrinkage and trim losses and lower overall satisfaction ratings by panelists. Precutting subprimals into steaks followed by VP aging tends to decrease retail caselife (especially if steaks are reassembled) and decrease juiciness and tenderness.     

Effect of Post-Cooking Storage Conditions on Shear-Force Values of Beef Steaks

One hundred twenty beef rib steaks were used to determine the effects of post-cooking storage for 2 or 4 hr at room temperature (22°C) or 4 or 24 hr at refrigerated temperature (2°C) on shear-force values of 1.3-cm cores. Steaks were cooked on an electric broiler to 40°C, turned over, cooked to 70°C and subjected to treatments. Neither time of storage nor temperature of storage affected appreciably shear-force values or variation of shear-force values within treatments. Valid shear-force values were obtained regardless of post-cooking storage conditions.     

Subcellular Distribution of Cholesterol within Muscle and Adipose Tissues of Beef Loin Steaks

Subcellular distribution of cholesterol (membrane versus storage components) within muscle and adipose tissue of raw and cooked beef longissimus steaks from three quality grades and three subcutaneous fat trim levels was determined. In muscle tissue, 60–80% of total cholesterol was located in the membrane component while the storage component contained 20–40%. In adipose tissue, the membrane fraction contained 8–12% of total cholesterol while the storage fraction contained 88–92%. Cooking caused a significant change in cholesterol distribution between membrane and storage sites of adipose tissue. Quality grade affected (P < 0.05) subcellular distribution of cholesterol within muscle tissue, while subcutaneous fat trim level affected (P < 0.05) cholesterol distribution within adipose tissue.     

Heating and Texture Profiles of Packaged Pasteurized Beef Loin Steaks from Precooked Roasts

Precooked beef loin steaks obtained from waterbath cooked roasts, were oasteurized usinge three different temoeratures (65° 85° and 100°C) and rimoved after reaching internal temperatures of 60°, 70° and 80°C. Temperatures of the steaks were monitored at three locations during heating and cooling. Steaks heated to internal temperatures close to the cooking water temperatures had the least differences in temperature between layers. Total cooking losses increased (P<0.05) as internal endpoint temperatures and pasteurization water temperature increased. Texture profiles of steaks cut from precooked roasts were similar to pasteurized steaks.     

Centralized Packaging of Beef Loin Steaks with Different Oxygen-Barrier Films: Microbiological Characteristics

Vacuum packaged beef strip loins (n = 72) were stored (2° 1°C) for either 0,12 or 24 days before fabrication; steaks were packaged and displayed (2°C or 7°C) up to 6 days in oxygen-permeable film or up to 30 days in vacuum packages (medium or high oxygen-barrier film). For steaks displayed in oxygen-permeable film, Pseudomonas spp. were a considerable (25–49%) or dominant (>50%) part of the microflora. The microflora of vacuum-packaged steaks from 0 day loins was dominated by a combination of hetero- and homofermentative Lactobacillus spp.; when vacuum-packaged steaks were from 12 and 24 day loins, the microflora was in most cases dominated by the heterofermentative Lactobacillus cellobiosus.     

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,气调包装组菌落总数、乳酸菌数和假单胞菌数降低;两种包装的微生物多样性均随时间延长呈现先升高后降低的趋势,且真空包装牛排比50% O2气调包装牛排具有更复杂的微生物多样性;牛排的初始微生物主要由不动杆菌属、苍白杆菌属、栖热菌属和金黄杆菌属组成,随着贮藏时间的延长,肉食杆菌属逐渐成为真空包装牛排的优势菌群,而环丝菌属、沙雷氏菌属和乳杆菌属则成为50% O2气调包装牛排的优势菌群;贮藏7～14 d是牛排中微生物种类产生变化的关键时间点;相比于真空包装牛排,50% O2气调包装牛排中的微生物群落具有更低的糖代谢和更高的蛋白质代谢能力。本研究结果明确了不同贮藏方法下牛排的品质变化和微生物的演替规律,为定向抑制牛排中的微生物、延长产品货架期提供了参考。     

Centralized Packaging of Beef Loin Steaks with Different Oxygen-Barrier Films: Physical and Sensory Characteristics

Vacuum packaged beef strip loins (n = 72) were stored (2 ° 1°C) for either 0, 12 or 24 days before fabrication; steaks were packaged and displayed (2°C or 7°C) up to 6 days in oxygen-permeable film or up to 30 days in vacuum packages (medium or high oxygen-barrier film). Steaks displayed at 2°C, rather than 7°C, tended to have higher overall appearance scores especially when steaks were from 12 or 24 day subprimals. Overall palatability of vacuum packaged steaks was unacceptable after 10–15 days of display. Vacuum packaged steaks can be displayed for 10 days if: (1) steaks are from relatively fresh subprimals, (2) steaks are vacuum packaged with high oxygen-barrier film, and (3) steaks are displayed at 2°C. Although visual scores for vacuum packaged steaks were acceptable for 20–30 days, off-odors and off-flavors were limiting factors in determining shelf-life.     

Effect of Chloride Salts and Antioxidants on Sensory and Storage Traits of Restructured Beef Steaks

The effects of antioxidants (0.01 or 0.02% of total fat), salt level (0.375 or 0.750%) and salt type (NaCl, KCl or a 65% NaCl + 35% KCl combination) in a 2 × 2 × 3 factorial arrangement on the quality of restructured beef steaks were determined. Meat blends with 0.02% antioxidant had lower thiobarbituric acid (TBA) values than those with 0.01% after 85 to 155 days of frozen storage. Steaks with no salt (pooled across antioxidant levels) had lower TBA values than steaks with any salt type after 85 days storage or either level of salt after 155 days storage. Steaks with either level of added salt resulted in higher ratings for juiciness, saltiness and overall palatability than steaks with no added salt. Juiciness, flavor desirability, saltiness and overall palatability ratings generally were higher for restructured steaks made with NaCl or NaCl + KCl compared to those made with KCl. KCl at 35% of total salt could serve as a NaCl substitute in restructured beef steaks.     

O_3处理对草莓果贮藏品质的影响

以草莓果 (丰香 )为试材 ,经O3 处理 3～ 6min后 ,在 (2 0± 1)℃下贮藏 4d ,探讨O3 处理对草莓果贮藏品质的影响。结果表明 ,O3 处理 3min有利于降低草莓果呼吸强度和腐烂率 ,减少可溶性固形物、有机酸和抗坏血酸含量损失 ;花青素含量随草莓的硬度降低而增加。     

Dry and Wet Aging Effects on Palatability Attributes of Beef Loin and Rib Steaks from Three Quality Grades

Twenty Prime and 20 Choice IMPS 107 ribs, and 20 Prime, 20 Choice and 20 Select IMPS 179 short-cut strip loins were equally divided between dry aging and wet aging treatments. Steaks and Toasts, aged for 21 days, were evaluated by trained and consumer panels for sensory attributes. Some statistically significant palatability differences were observed due to treatment, grade and cut of loin and rib steaks by the trained panel, but no statistical differences in palatability attributes of loin steaks were detected by consumer panelists. A major difference between aging treatments, however, was the greater shrink and trim loss associated with dry aging.     

热处理对袋装草莓果保鲜效果的影响

研究了袋装草莓果经 40℃热处理后在室温 ( 2 2± 2 )℃贮藏过程中呼吸强度和化学成分的变化。结果表明 ,热处理可降低草莓果贮藏期间的腐烂率和减少抗坏血酸、还原糖和有机酸含量的损失。以热处理 3 0min的效果最明显 ,且对草莓呼吸的刺激作用最小     

Effects of Flake Size on Textural and Cooking Properties of Restructured Beef and Pork Steaks

Flaked and formed beef and pork steaks were manufactured using eleven different Comitrol cutting heads selected to give a wide range in flake size. Data from texture profile panel, Instron and cooking studies were collected. As flake size increased, visually detected fi-brousness, first bite hardness, cohesiveness of the chewed mass, number of chews required for swallowing, amount of connective tissue detected by sensory panel and shear force all increased, while uniformity of the chewed mass decreased. Textural properties in beef and pork steaks were affected in a similar manner by flake size. Thickness of the flake particle was as important as width of the flake particle in affecting texture.     

Lipid Characteristics in Fresh and Broiled Loin and Round Steaks from Concentrate Fed and Pasture Grazed Steers

Broiling of loin and round steaks from concentrate-fed and pasture-grazed steers had no significant effects upon levels of intramuscular triglycerides or cholesterol when expressed on a freeze-dry basis. Broiling did cause increases in phospholipids and free fatty acids. Broiling did not influence fatty acid compositions of triglycerides, polar lipids and free fatty acids. Loin steaks contained more triglycerides and free fatty acids and less phospholipids and cholesterol than round steaks. Increases in intramuscular triglycerides were not accompanied by increases in cholesterol or phospholipids. Polyunsaturated/ saturated acid ratios and levels of linolenic acid, an n-3 acid, were highest in steaks from steers that had grazed pastures.     

National Consumer Retail Beef Study: Palatability Evaluations of Beef Loin Steaks that Differed in Marbling

Top loin steaks from strip loins selected from 700 beef carcasses representing seven degrees of marbling (Slightly Abundant through Traces) were randomly assigned to untrained consumers (n = 180 per city) in San Francisco, Philadelphia and Kansas City. Statistical analyses revealed a significant marbling level x city interaction. As marbling level decreased from Slightly Abundant to Traces, consumers in San Francisco and Kansas City gave consistently high ratings that were only slightly reduced as marbling was decreased. Consumers in Philadelphia rated steaks with high marbling the same as those from the other cities, but ratings were sharply reduced as marbling decreased. Separate markets might need to be identified to more effectively reflect differences in consumers’ tastes among and within geographic areas of the United States.     

Influence of Feeding Regimen on the Sensory Qualities and Fatty Acid Contents of Beef Steaks

Longissimus dorsi (loin) and gluteus medius (rump) muscles were obtained from twenty carcasses (ten grain-fed and ten forage-fed). A trained sensory panel rated longissimus dorsi steaks from grain-fed animals significantly (p < 0.05) more tender and more flavorsome than those from forage-fed animals. Fatty acid profiles indicated some significant differences due to feeding regimen. Forage-fed beef had a higher proportion of omega-3 polyunsaturated fatty acids than grain-fed beef.     

贮藏、加工、烹调对十字花科蔬菜中硫苷物质含量的影响

十字花科芸薹属蔬菜在日常生活中极为普遍,其含有丰富的硫代葡萄糖苷物质。本文综述了不同贮藏条件、加工方法、烹调方式对不同种类十字花科蔬菜中的硫代葡萄糖苷物质的影响。     

烹饪方式对重组鱼排质构及体外模拟消化的影响

研究水煮、汽蒸、微波、油炸4种烹饪方式对重组鱼排质构及体外模拟消化的影响,重组鱼排的质构及体外模拟消化率与处理方式存在一定的关系.结果 表明:烹饪方式和谷氨酰胺转氨酶均不同程度地影响重组鱼排的硬度、弹性、胶黏性和咀嚼性,其中添加谷氨酰胺转氨酶的样品除内聚性外各质构参数均呈增加趋势.此外,烹饪方式和酶均影响重组鱼排的体外...