Packaging Cooked Turkey Meat Patties while Hot Reduces Lipid Oxidation

Elimination of oxygen by “hot packaging” reduced the 2-thiobarbituric acid reactive substances (TBARS) value of meat patties by about 50% in control and myoglobin added, and between 30-40% in ferrous iron added turkey patties, as compared with “cold packaging.” The TBARS values of hot and cold vacuum packaged patties were significantly lower than those of loosely packaged patties after 1 wk refrigerated storage. Most lipid oxidation in meat patties occurred at day 0, and only small changes in TBARS values were observed after 1 wk storage. Although the prooxidants in meat were major factors in promotion of lipid oxidation of cooked meat, hot packaging minimized their effects.     

猪血浆蛋白水解物在熟肉糜中抗氧化效果研究

猪血浆蛋白碱性蛋白酶5 h水解物以0.5%、1.0%、1.5%、2.0%的添加量添加到熟肉糜中,并且与添加0.02%丁基羟基茴香醚(butylated hydroxyanisole,BHA)的熟肉糜进行比较。在4℃的冷藏过程中测定熟肉糜的红度值(a*值)、pH、硫代巴比妥酸值(TBARS值),并对感官指标进行评定。结果表明,添加猪血浆蛋白水解物的处理组在冷藏过程中能显著抑制脂肪的氧化,并能保持肉糜鲜红的色泽,其中以添加2.0%的水解物的效果最佳,但相比于BHA,效果要稍差。同时感官评定得出猪血浆蛋白水解物在颜色、降低脂肪氧化味等方面都具有较好的效果。     

Control of Lipid Oxidation in Cooked Ground Pork with Antioxidants and Dinitrosyl Ferrohemochrome

A number of antioxidants were added to ground meat prior to cooking to achieve oxidative stability. The 2-thiobarbituric acid (TBA) numbers of cooked-meat samples after storage for up to 35 days were determined. Of the antioxidants tested, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), t-butylhydro-quinone (TBHQ), trihydroxybutyrophenone (THBP), nordihydro-guaiaretic acid (NDGA), catechol, and ethoxyquin were effective at a level of 200 ppm giving TBA values of less than one. BHA, TBHQ, and ethoxyquin were equally effective at a level of 30 ppm. Ascorbyl acetal and ascorbyl palmitate retarded lipid oxidation effectively (TBA values of slightly over one after five weeks of storage). The cooked cured-meat pigment showed some antioxidant effect which increased with increasing concentration, and at 18–24 ppm was better than that of 200 ppm of α-tocopherol.     

Sensory Properties and Lipid Oxidation in Prerigor Processed Fresh Pork Sausage

Fresh pork sausage prepared from prerigor ground and salted meat had higher pH, lower cooking losses, higher juiciness scores, and less easily fragmented cooked patties than that prepared from post-rigor ground and salted meat. Sausage from prerigor ground-post-rigor salted meat was intermediate in these properties to prerigor ground and salted and postrigor ground and salted products. Prerigor grinding and salting reduced the rate of autoxidation (TBA number) during storage at 0°C contrasted to oxidation in sausage that was salted postrigor after either prerigor or postrigor grinding.     

Oxygen Availability Affects Prooxidant Catalyzed Lipid Oxidation of Cooked Turkey Patties

The catalytic effect of free ionic iron, hemoglobin and/or NaCI, and the effect of total lipid, class of lipid, and fatty acid composition on lipid oxidation of precooked refrigerated meat patties were highly significant only when oxygen was freely accessible to the patties during storage. With limited oxygen contact (cold vacuum-packaging) after cooking, the 2-thiobarbituric acid reactive substances (TBARS) values of patties were much lower than the values for patties with free oxygen contact (loose packaging) and did not increase substantially during storage. However, the TBARS values of cold packaged patties were higher (P<0.05) than those of hot packaged patties which had almost no oxygen contact after cooking. Elimination of oxygen during storage (hot or cold vacuum-packaging after cooking) resulted in prooxidants, fat content, fatty acid composition or the class of lipids having no effect on lipid oxidation.     

Lipid Oxidation in Cooked Turkey as Affected by Added Antioxidant Enzymes

Catalase (CAT) and glutathione peroxidase (GSH-Px) were added to turkey which had been cooked (80°C) to provide minimal activity of both enzymes, to determine their effects in development of lipid oxidation. CAT (100–500 U/g muscle) decreased the formation of thiobarbituric acid reactive substances (TBARS) 4–28% during 2 days of storage. GSH-Px (4.0 U/g muscle) decreased TBARS 8–11%. CAT (170 U/g muscle) and GSH-Px (1.3 U/g muscle) in combination decreased TBARS formation 7–14%. Reduced glutathione concentrations in the turkey were unaffected by cooking. These data suggest that heat inactivation of CAT and GSH-Px was not the only factor involved in heat-induced lipid oxidation reactions in turkey thigh muscle.     

市售壹号土猪肉理化品质及其熟制品感官特性分析

为了量化壹号土猪肉的特质性营养品质和加工性能,以三元猪肉作为对照,分析市售壹号土猪肉的营养物质含量和理化性质,并对其熟制品的感官特性进行分析。相较于三元猪肉,壹号土猪肉中含有较高的脂肪含量(p<0.05)、较低的水分含量(p<0.05)和相似的蛋白质含量(p>0.05)。壹号土猪肉具有较高的红度值(a*,p<0.05),较低的亮度值(L*,p<0.05)和黄度值(p>0.05)。壹号土猪肉具有较低的总抗氧化能力和较高的硫代巴比妥酸反应物值;壹号土猪肉p H值较高,其出品率也较高。汆制和煎制产品均具有明显的主体风味特征,煎制壹号土猪肉具有最高的酸味值,且在两种加工方式下,壹号土猪肉的酸味值较高;煎制产品的涩味值较汆制高,且壹号土猪肉的涩味值较三元猪肉低;煎制产品涩味回味值低于汆制产品,且壹号土猪肉的涩味回味值较三元猪肉低;煎制产品具有较高的鲜味回味值,且壹号土猪肉的鲜味回味值较高;煎制比汆制产品具有更高的咸味值(p<0.05),壹号土猪肉咸味值最高(p<0.05)。     

Conjugated Linoleic Acid Reduces Lipid Oxidation in Aerobically Stored, Cooked Ground Beef Patties

ABSTRACT: The effect of direct addition of conjugated linoleic acid (CLA) on lipid oxidation was studied. CLA and/or fat trim (4% by weight) were added to the lean trim (96%). Thiobarbituric acid reactive substances (TBARS) were determined on days 0, 3, and 7 for cooked or raw patties stored aerobically at 4 °C. Addition of CLA during the grinding process increased CLA isomers in both raw and cooked ground beef and decreased TBARS production ( P < 0.01). CLA caused a greater reduction in TBARS over storage time in cooked patties than in raw patties ( P= 0.006). The concentrations of 18:2n–6 and CLA isomers decreased with storage time. CLA increased 18:2n-6, whereas most fatty acids were decreased by the addition of CLA. CLA did not affect percentages of fat and moisture, cooking loss, or meat color (L*, a *, b *) ( P > 0.60).     

Lipid Oxidation in Cooked Pork as Affected by Vitamin E, Cooking and Storage Conditions

The individual and combined effects of muscle vitamin E level, cooking conditions (duration, temperature and rate) and packaging on lipid oxidation in refrigerated cooked pork were examined. Oxidative stability following cooking was higher in pork with a higher vitamin E level (p<0.01), cooked at a lower cooking temperature (p<0.01), cooked for a shorter time (p<0.01), cooked at a faster cooking rate (p<0.05) or stored in vacuum packs (p<0.01). Significant two-way and three-way interactions were observed between the effects of muscle vitamin E level, cooking conditions and packaging on lipid oxidation. Adopting more than one of these approaches to minimize lipid oxidation was more effective than adopting a single approach.     

Lipid Oxidation and Warmed-Over Aroma in Cooked Ground Pork from Swine Fed Increasing Levels of Iron

Fifteen crossbred feeder pigs were fed to market weight on corn-soy rations containing either 62, 131, or 209 ppm iron. After slaughter, pork was ground, cooked, and stored at 4°C for 12 days. Heavily fortifying swine rations with iron (≥200 ppm) increased nonheme iron (NHI) and thiobarbituric acid reactive substances (TBARS) in cooked, stored ground pork (GP) but did not increase warmed-over aroma (WOA) (p>0.05). NHI, TBARS, and WOA increased during storage. TBARS strongly correlated with WOA during storage (r=0.903) and with NHI (r=0.901).     

Photosensitized Lipid Peroxidation in Ground Pork and Turkey

The initiative role of singlet oxygen (¹O₂) in hydroperoxide production in ground pork and turkey was studied. Ground meats treated with or without various antioxidants and illumination (350 ft-c, 4°C) were monitored for lipid peroxidation by peroxide value (POV). Ground turkey breast meat developed higher (P < 0.01) POV during illumination than did thigh meat. In both pork and turkey, light exposure resulted in higher (P < 0.01) POV than samples kept in the dark. The prooxidant effect of light was reduced (P < 0.01) by a ¹O₂ quencher (2,2,6,6-tetramethy1-4-piperidone) in turkey meat, and by another ¹O₂ quencher (N,N,N′,N′-tetramethylethylene diamine, TMEDA), a free radical scavenger (butylated hydroxyanisole, BHA) and TMEDA + BHA in pork.     

Effect of α-Tocopherol, β-Carotene, and Sodium Tripolyphosphate on Lipid Oxidation of Refrigerated, Cooked Ground Turkey and Ground Pork

ABSTRACT α-Tocopherol and β-carotene at 0.03% levels and sodium tripolyphosphate (STP) at 0.2% and 0.3% levels, alone and in combination, were added to ground turkey and ground pork. Hexanal was measured after cooking and storage at 4 °C for 2, 4, or 6 d. α-Tocopherol alone significantly reduced hexanal of stored, cooked, turkey but had no effect in pork. STP was more effective than α-tocopherol and a combination of α-tocopherol with STP resulted in enhanced antioxidant activity. Hexanal of pork with 0.03%α-tocopherol plus 0.3% STP did not increase significantly during storage, and that of turkey increased only slightly. β-Carotene and salt (1% NaCl) had no effect on hexanal.     

Changes in Sensory Quality of Sterile Cantaloupe Dice Stored in Controlled Atmospheres

Diced cantaloupe flesh that was microbiologically sterile was prepared to study the physiological deterioration of fruit when stored under a range of controlled atmospheres at 4.5°C. Sterile fruit pieces were prepared by boiling whole melons for 3 min, then dicing aseptically. Storage atmospheres were in continuous flow and contained from 0 to 26% CO₂ and 3.5 to 17% O₂. Sensory assessments were carried out by a highly trained panel at 14 day intervals. Acceptable product up to 28 days was obtained for three treatments: 6% CO₂ and 6% O₂, 9.5% CO₂ and 3.5% O₂, and 15% CO₂ and 6% O₂. Overall treatment with 0, 19.5 or 26% CO₂ (irrespective of O₂ concentration) caused significant deterioration in sensory characteristics.     

Rosemary Extracts as Inhibitors of Lipid Oxidation and Color Change in Cooked Turkey Products During Refrigerated Storage

ABSTRACT: Water-soluble rosemary extracts were evaluated for their inhibitory effects on lipid oxidation and color change in cooked turkey products during storage. Changes were measured in thiobarbituric acid-reactive substances, hexanal production and color of the cooked turkey samples containing 0, 100, 250 and 500 ppm water-soluble rosemary extracts, at storage day 0, 1, 2, 3, 5, 7, 10, and 13. The rosemary extracts showed significant protection of lipid oxidation and color change in cooked turkey. Higher levels of water-soluble rosemary extracts were more effective in delaying quality loss in cooked turkey at all tested storage times.     

Physical and Sensory Characteristics of Fresh Pork Leg Roasts Cooked at Low Temperatures

The effects of oven temperatures of 82, 93, 121 and 163°C were studied using 31 fresh pork leg roasts cooked to 74°C in oven bags. Warmed-over-flavor (WOF) was measured by sensory analysis after holding 3 hr at 68°C and after holding 24 hr at 2°C and then reheating to 68°C prior to serving. Roasts cooked at 82 and 93°C tended to have less WOF after refrigeration and reheating than roasts cooked at 121 and 163°C. Roasts cooked at 93°C had fewer aerobic mesophilic bacteria than those cooked at 121 and 163°C. In general, objective and sensory perception measurements indicated that roasts cooked at 82 and 93°C were of higher quality.     

Sensory and Chemical Characteristics of Fresh Pork Roasts Cooked to Different Endpoint Temperatures

Pork roasts cooked to various endpoint temperatures were evaluated by sensory and chemical analyses. Increased endpoint temperatures were associated with increased cooking losses; decreased juiciness, pink color, and metallic flavor; increased graininess, brown color, and pork flavor. Increased endpoint temperatures also led to a concentration of lipid, protein and certain fatty acids. Cholesterol levels were not significantly influenced by endpoint temperature. Lipid content was decreased by removal of external fat before cooking. To minimize pink color in some muscles and maximize other sensory characteristics and yield of cooked meat, at least 71.1°C and no more than 76.6°C is recommended as the endpoint temperature for fresh pork roasts.     

Survival and Growth of Listeria monocytogenes and Yersinia enterocolitica in Pork Chops Packaged under Modified Gas Atmospheres

Listeria monocytogenes Scott A, serotype 4b, and Yersinia enterocolitica from vacuum-packaged pork were inoculated onto fresh pork chops. Survival and growth were determined in different atmospheres at 4 °C during 35-days. Atmospheres were gas mixtures [20/0/80, 40/ 0/60, and 40/10/50 (CO₂/O₂/N₂)], vacuum and air. In air L. monocytogenes and Y. enterocolitica grew slower than psychrotrophic spoilage flora. In gas atmospheres, Y. enterocolitica grew at the same rate as psychrotrophic spoilage flora and L. monocytogenes grew more slowly. When 10% O₂ was included in the 40% CO₂ mixture, growth was reduced. Vacuum packaging was no more effective than gas mixtures in retarding growth. Modified atmospheres provide an environment in the package that would allow growth of Y. enterocolitica and potentially compromise safety of meat products.