Fat content has a significant impact on protein oxidation occurred during frozen storage of beef patties

This study examined the relationship between protein and lipid oxidation and the impairment of water holding capacity (WHC), colour and texture after frozen storage (20 weeks/−18 °C) and subsequent processing (cooking, chilled storage) of beef patties with increasing fat content (3, 20 and 35%). Various manifestations of protein oxidation were found to occur during frozen storage and processing of patties including, loss of tryptophan fluorescence, carbonylation and formation of Schiff bases structures (SB). Patties with higher fat content underwent the more intense protein oxidation as assessed by formation of protein carbonyls and SB, highlighting the timely interaction between proteins and oxidizing lipids. Protein oxidation occurred concomitantly with loss of WHC and discolouration of beef patties. Mechanisms and consequences of the chemical modifications induced by oxidative stress in meat proteins are thoroughly discussed.     

Evaluation of lipid oxidation in horse mackerel patties covered with borage-containing film during frozen storage

Lipid oxidation of horse mackerel (Trachurus trachurus) patties covered with fish gelatin-based films containing a borage seed extract were evaluated, including commonly used analytical indexes (peroxide value, thiobarbituric acid reactive substances, polyene ratio), as well as determination of volatile compounds, quantitation of oxidized triacylglycerols and analysis by Fourier transform infrared (FTIR) spectroscopy, during 240 days of frozen storage and subsequent thawing and 4 days-chilling. Vacuum packaged-patties and control uncovered patties were also tested for comparative purposes. Methods applied to evaluate lipid oxidation in extracted lipids, i.e. peroxide value, quantitation of oxidized triacylglycerols and FTIR, clearly provided a better picture of the oxidation progress and led to similar conclusions. Film had protective effects on lipid oxidation of horse mackerel patties throughout frozen storage and particularly after thawing and chilled storage. Furthermore, when compared to vacuum packaging, film was found to be similarly effective until advanced stages of oxidation were reached and exerted enhanced protection once samples were thawed and exposed to air oxygen under chilling temperature; with the additional advantage of increasing the antioxidant capacity of muscle.     

Effects of conjugated linoleic acid on color and lipid oxidation of beef patties during cold storage

The effects of conjugated linoleic acid (CLA) on color and lipid oxidation of beef patties were investigated. Ground beef was divided into three batches. The control patties were prepared with 90% lean meat and 10% tallow. The second treatment consisted of 90% lean meat with 9.5% tallow+0.5% CLA sources. The third treatment consisted of 90% lean meat with 8% tallow+2% CLA sources. The patties were wrap-packaged and then stored at 4° for 14 days. The CLA concentration significantly increased (P<0.05) by substituting CLA sources for fat. Storage of the patties did not alter the CLA concentration in beef patties. The treatment substituted with CLA sources had significantly lower TBARS (2-thiobarbituric acid-reactive substances) values (P<0.05) than the control. For oxymyoglobin contents and a* value, substituted CLA sources treatments had significantly higher values than the control. However, L* value significantly increased by substituting CLA sources for fat.     

Effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken meat

This study examined the effects of freezing temperature and duration of frozen storage on lipid and protein oxidation in chicken leg and breast meat. The meat was frozen at three different temperatures (−7, −12 and −18 °C) and then stored at −18 °C for up to 6 months. A significant effect of frozen storage duration on lipid oxidation was detected in leg and breast meat, whereas freezing temperature had no significant effect. In leg meat, freezing at −7 °C had a significant impact on protein oxidation, measured as the increase in carbonyl groups and the decrease in total sulphydryl groups, after 3 months of frozen storage. Lipid and protein oxidation appeared to occur simultaneously in chicken meat during frozen storage and was more intense in leg meat than in breast meat.     

The combined effect of antioxidants and modified atmosphere packaging on protein and lipid oxidation in beef patties during chill storage

Effect of rosemary extract and ascorbate/citrate (1:1) in combination with modified atmosphere packaging (100% N(2), 80% O(2)/20% N(2)) on protein and lipid oxidation in minced beef patties during storage in the dark for up to 6 days at 4°C was investigated. A high level of oxygen in the packaging atmosphere was found to increase both lipid and protein oxidation during storage as evaluated by TBARS analysis of secondary lipid oxidation products and by 2,4-dinitrophenylhydrazine derivatization of protein carbonyls. Both antioxidant systems tested were found to inhibit lipid oxidation but not protein oxidation. In contrast, ascorbate/citrate was found to promote protein oxidation. Rosemary extract was found to regenerate or protect α-tocopherol whereas the packaging atmospheres had no effect on α-tocopherol stability. In high oxygen atmospheres both antioxidants protected the fresh red meat colour with ascorbate/citrate being more efficient than the rosemary extract, whereas no effect of antioxidant on meat colour was found in beef patties stored in 100% nitrogen.     

Honey inhibits lipid oxidation in ready-to-eat ground beef patties

Our objective was to evaluate the antioxidant capabilities of clover (CH) and wildflower honeys (WH) in delaying lipid oxidation in cooked and reheated ground beef patties stored in refrigerated and frozen states. CH and WH (5%, 10%, or 15% w/w) were each mixed separately into ground beef chuck (18% fat) and formed into 30 g patties mixed with 1% salt (w/w). A control (CON) with no honey and a control with sodium tripolyphosphate (STP; 0.25% w/w) were used for comparison. Patties were cooked to 71 °C, overwrapped with oxygen-permeable PVC film and either stored refrigerated (4 °C) for 12 days or frozen (−18 °C) for 45 days. Cook yield, pH and water activity were measured on day 0. On designated sampling days, patties were reheated to 71 °C. Thiobarbituric acid-reactive substances (TBARS) and lipid hydroperoxides (LOOH) were measured spectrophotometrically to assess lipid oxidation. TBARS and LOOH of ready-to-eat (RTE) ground beef patties containing either CH or WH were lower (P < 0.01) than CON patties following storage; however, STP patties had lower TBARS values than honey-containing patties (P < 0.01). WH and CH at 15% were equally effective in suppressing LOOH compared to STP in refrigerated and frozen patties. All honey concentrations improved cook yield, with 10% WH being more effective than STP. Both CH and WH delayed lipid oxidation in RTE ground beef patties stored at 4 °C and −18 °C, with WH decreasing LOOH formation in refrigerated patties as effectively as STP. Honey may be a natural alternative to phosphates to delay lipid oxidation.     

Inhibition of protein and lipid oxidation by rapeseed, camelina and soy meal in cooked pork meat patties

In this study protein-containing by-products of deoiling processes rich in phenolics were applied to meat to be used as potential food ingredients in developing meat products with antioxidant effect. The effect of rapeseed meal (Brassica rapa L.), camelina meal (Camelina sativa), soy meal and soy flour (from soybean, Glycene max L.), in inhibiting oxidation of lipids and proteins was tested in cooked pork meat patties. A commercial CO₂ extract from rosemary (Rosmarinus officinalis) was used as a reference material alone and in combination with the other plant materials. The cooked pork meat with added plant materials was oxidized for 10 days at 5 °C under light. The oxidation was followed by measuring the formation of hexanal, pentanal and propanal by headspace gas chromatography and the formation of protein carbonyls by converting them to 2,4-dinitrophenylhydrazones (DNPH). Rapeseed meal (0.5 and 0.7 g/100 g meat) and camelina meal (0.7 g/100 g meat) as such and their combination (addition of 0.5 g/100 g) with rosemary extract (0.04 g/100 g) were effective antioxidants toward both protein and lipid oxidation while soy meal and flour were effective only in combination with rosemary extract.     

Avocado by-products as inhibitors of color deterioration and lipid and protein oxidation in raw porcine patties subjected to chilled storage

Processing of avocados generates an important amount of by-products such as peels and seeds that are rich in bioactive substances with proven radical suppressing activities. The objective of this study was to evaluate the effectiveness of peel and seed extracts from two avocado varieties-'Hass' and 'Fuerte'-as inhibitors of lipid and protein oxidation and color deterioration of raw porcine patties during chilled storage (4 °C/15 days). Avocado extracts significantly (p<0.05) reduced the loss of redness and the increase of lightness during storage of porcine patties. 'Fuerte' extracts were more efficient at inhibiting discoloration of chilled patties than 'Hass' extracts. Patties treated with avocado extracts had significantly lower amounts of TBA-RS than control ones throughout the storage. 'Hass' avocado extracts significantly inhibited the formation of protein carbonyls in chilled patties at day 15. The present results highlight the potential usage of extracts from avocado by-products as ingredients for the production of muscle foods with enhanced quality traits.     

Antioxidant activity of black currant (Ribes nigrum L.) extract and its inhibitory effect on lipid and protein oxidation of pork patties during chilled storage

This experiment was conducted to assess the antioxidant efficacy of black currant (Ribes nigrum L.) extract (BCE) in raw pork patties during chilled storage. The extracting conditions of frozen BCE including ethanol concentrations (0-100%) and extracting times (0.25-12h) were studied. BCE extracted with 40% ethanol for 2h had the highest anthocyanin content, the strongest radical scavenging activities as well as the second strongest reducing power. BCE was condensed and added to pork patties at 5, 10 or 20 g/kg. Compared with the control, BCE treatments significantly decreased the thiobarbituric acid-reactive substance values and carbonyls formation and reduced the sulfhydryl loss of pork patties in a dose-dependent manner (P<0.05), which showed that the BCE significantly inhibited lipid and protein oxidation. The BCE-treated patties showed significantly higher redness (P<0.05) than the control. The findings demonstrated strong potential for BCE as a natural antioxidant in meat and meat products.     

Effect of white grape extract and modified atmosphere packaging on lipid and protein oxidation in chill stored beef patties

The oxidative stability of beef patties added 500 ppm white grape extract (WGE), packed in four different modified atmospheres (MAP) with varying oxygen and carbon dioxide levels (70% or 0% O₂, 30% or 0% CO₂, balanced with N₂ in all four combinations) and stored for up to 9 days (4 °C) was evaluated by a sensory panel, formation of TBARS, formation of protein carbonyl, appearance of myosin cross-links, and thiol loss. Formation of secondary lipid oxidation products, as detected by TBARS, and the rancidity, as perceived by sensory analysis, were inhibited in WGE beef patties independent of MAP compared to control beef patties. The protein carbonyl formation was also reduced in WGE beef patties, but no significant effects were observed in relation to different MAP. Loss of thiol groups in control beef patties was consistent with the formation of myosin cross-linkages. In the presence of WGE, thiol groups decreased faster but showed less myosin cross-link formation compared to control beef patties, indicating that WGE interacts with the thiol groups of the myofibrillar proteins, and thus reduces the cross-link formation in beef patties stored in high-oxygen MA.     

Effect of frozen storage conditions (temperature and length of storage) on microbiological and sensory quality of rustic crossbred beef at different states of ageing

The effect of frozen storage conditions on meat from 36 Morucha × Charolais crossbred yearlings was studied. Slices of M. Longissimus thoracis were randomly assigned to groups arising from the combination of experimental factors. These factors were: ageing extent (3 and 10 days), length of frozen storage (0, 30, 75 and 90 days) and temperature (−20 and −80 °C). Regarding microbiological counts, although values were acceptable in all cases, longer storage time and longer previous ageing extent provided higher phychrotrophic bacteria counts. As frozen storage period increased, colorimetric parameters L^∗, a^∗ and C^∗ decreased, but H^∗ increased. Regarding Warner–Braztler shear force and tenderness values, an interaction (p < 0.05) between frozen storage and post-mortem ageing resulted from larger differences between frozen storage periods at shorter ageing periods than those at longer ageing periods. Frozen storage for 90 days resulted in a reduction in water holding capacity, without differences in juiciness. No effect of freezing temperature was observed in any of the parameters studied.     

The effects of ascorbic acid, taurine, carnosine and rosemary powder on colour and lipid stability of beef patties packaged in modified atmosphere

This research was aimed at evaluating the inhibition of oxidative changes of beef patties packaged in modified atmosphere (70% O₂+20% CO₂+10% N₂) by natural antioxidants: ascorbic acid (500 ppm), taurine (50 mM), carnosine (50 mM), rosemary powder (1000 ppm) and their combinations with the first. Beef patties stored at 2±1°C for 20 days were evaluated for colour (L*, a*, b*, C* and H*), TBARS, metmyoglobin formation (% of total myoglobin), psychrotrophic microbial counts and sensory odour and discolouration. Rosemary, either alone or with ascorbic acid, was highly effective in inhibiting both metmyoglobin formation and lipid oxidation; sensory analysis was in agreement with these results. Ascorbic acid, ascorbic acid+taurine and ascorbic acid+carnosine treatments showed a limited inhibitory effect of myoglobin oxidation, while carnosine and carnosine+ascorbic acid were effective in inhibiting lipid oxidation. Taurine alone failed to exert any antioxidant effect. Principal components analysis confirmed these results.     

青梅添加量对牛肉饼贮藏品质的影响

以未添加抗氧化剂和添加0.02%二丁基羟基甲苯(butylated hydroxytoluene,BHT)的牛肉饼作对比,研究添加5%,10%,15%,20%青梅(Prunus mume,PM)对-18℃冻藏10d的牛肉饼脂肪氧化、蛋白质氧化、抑菌能力及品质特性的影响。结果表明:与对照组相比,10%,15%,20%PM试验组的TBARS值显著降低(P0.05),且20%PM试验组的抗脂肪氧化效果与添加0.02%BHT效果相当;所有PM试验组在4d后TVB-N值显著低于对照组(P0.05),而20%PM试验组在贮藏期间的TVB-N值与添加0.02%BHT无显著差异(P0.05);10%,15%,20%PM试验组在贮藏期间具有显著的抑菌效果(P0.05),且20%PM试验组4d后的抑菌能力与添加0.02%BHT的相当;此外,添加青梅能显著增加牛肉饼总酚含量,降低pH值、红色度,增大黄色度(P0.05),并能提升肉饼的多汁性,降低油腻感,改善感官特性。     

Effects of dietary soybean oil on lipid and protein oxidation in pork patties during chill storage

The effect of dietary soybean oil on lipid and protein oxidation in low and high fat pork patties made from quadriceps femoris during chill storage in a high oxygen atmosphere packaging (80% O(2)/20% CO(2)) in the dark for 7 days was investigated. Pigs were fed either a standard diet or a diet added 2% soybean oil. After slaughter high fat pork patties were prepared for both feeding regimes by addition of back fat from pigs fed the same diet whereas low fat pork patties were prepared without addition of back fat. The 2% soybean diet increased the amount of unsaturated fat in the pork. Secondary lipid oxidation products determined as thiobarbituric acid reactive substances (TBARS) were found to increase in the pork patties with increased unsaturated fat. Increased unsaturated fat in the pork patties had no effect on protein oxidation determined as free protein thiol content and protein carbonyl content. A small, but significant increase in protein oxidation was found in the high fat pork patties independent on dietary fat. In conclusion, protein oxidation is unaffected by dietary fat in pork patties during chill storage for periods normally used in retail trade, and lipid and protein oxidation are not coupled under these conditions.     

Characteristics of restructured beef steak with different proportions of walnut during frozen storage

Physicochemical (thawing loss, cooking loss, surface shrinkage, texture, colour and lipid oxidation) and sensory properties of restructured beef steak with different levels of added walnut (0%, 10% and 20%) were determined at various times during frozen storage up to 128 days. Cooking loss (CL), Kramer shear force (KSF) and binding strength (BS) of restructured beef decreased (P<0.05) as the proportion of walnut increased. Walnut enhanced (P<0.05) lightness and yellowness and reduced (P<0.05) redness. Frozen storage did not affect (P>0.05) CL, KSF and BS of restructured beef steak. Redness decreased (P<0.05) over storage for all samples. Lipid oxidation of restructured beef steak containing walnut was not a limiting factor for frozen stability of meat products. Frozen storage had no effect (P>0.05) on the sensory quality of restructured beef steak.     

Effect of varying salt and fat levels on the sensory quality of beef patties

The interactive effects of varying levels of salt and fat on the sensory and physiochemical properties of beef patties were investigated. Twenty beef patties with varying levels of fat (30% 40% 50% 60% w/w) and salt (0.5%, 0.75% 1.0% 1.25% 1.5% w/w) were manufactured. All samples were assessed instrumentally for colour, moisture, fat, cooking loss and texture profile analysis. Sensory consumer evaluation was conducted using 25 consumers. The consumers rated each coded product, in duplicate, in terms of colour, texture, tenderness, juiciness, salt, taste, meat flavour, off flavour and overall acceptability. The data indicate that the most consumer acceptable beef patty was that containing 40% fat with a salt level of 1%. This is a 20% decrease in fat and a 50% decrease in salt levels when compared to commercial patties available in Ireland and the UK.     

Thiol oxidation and protein cross-link formation during chill storage of pork patties added essential oil of oregano,rosemary, or garlic

The effect of two levels (0.05% and 0.4%) of essential oil of rosemary, oregano, or garlic on protein oxidation in pork patties was studied during storage under modified atmosphere (MAP: 70% O₂: 20% CO₂: 10% N₂) or under aerobic conditions (AE) at 4 °C. The oxidative stability of the meat proteins was evaluated as loss of thiols for up to 9 days of storage, and as formation of myosin cross-links analyzed by SDS-PAGE after 12 days of storage. Protein thiols were lost during storage to yield myosin disulfide cross-links. Essential oils of rosemary and oregano were found to retard the loss of thiols otherwise resulting in myosin cross-links. Garlic essential oil, on the contrary, was found to promote protein oxidation, as seen by an extreme loss in thiol groups, and elevated myosin cross-link formation compared to control.     

Protein oxidation in emulsified cooked burger patties with added fruit extracts: Influence on colour and texture deterioration during chill storage

The influence of protein oxidation, as measured by the dinitrophenylhydrazine (DNPH) method, on colour and texture changes during chill storage (2 °C, 12 days) of cooked burger patties was studied. Extracts from arbutus-berries (Arbutus unedoL., AU), common hawthorns (Crataegus monogynaL., CM), dog roses (Rosa caninaL., RC) and elm-leaf blackberries (Rubus ulmifoliusSchott., RU) were prepared, added to burger patties (3% of total weight) and evaluated as inhibitors of protein oxidation and colour and texture changes. Negative (no added extract, C) and positive control (added quercetin; 230 mg/kg, Q) groups were also considered. The significant increase of protein carbonyls during chill storage of control burger patties reflect the intense oxidative degradation of the muscle proteins. Concomitantly, an intense loss of redness and increase of hardness was found to take place in burger patties throughout refrigerated storage. Most fruit extracts as well as Q significantly reduced the formation of protein carbonyls and inhibited colour and texture deterioration during chill storage. Likely mechanisms through which protein oxidation could play a major role on colour and texture changes during chill storage of burger patties are discussed. Amongst the extracts, RC was most suitable for use as a functional ingredient in processed meats since it enhanced oxidative stability, colour and texture properties of burger patties with no apparent drawbacks.     

Functional stability of frozen normal and high pH beef

The functional properties of whole, diced or minced high and normal pH beef were determined after 0, 1, 2, 3 and 7 month’s storage. There was no interaction between pH, degree of comminution and storage time for most of the attributes measured. Regardless of storage time or comminution method, high pH meat had significantly (P < 0.001) higher sarcoplasmic protein solubility, water holding capacity, cooked batter torsion stress and strain, yield and emulsion stability than normal pH meat. Normal pH meat had significantly (P < 0.01) higher myofibrillar protein solubility and hue angle than high pH meat. Water holding capacity significantly (P < 0.01) decreased and hue angle increased with the increase in the degree of comminution. Protein solubility in raw meat and the cooked batter stress, strain, yield and emulsion stability of both high and normal pH meat deteriorated with time. However, this deterioration was faster in the normal pH meat compared to high pH meat except for total and myofibrillar protein solubility. Within the parameters of the present study, it is concluded that frozen high pH meat possesses superior functional attributes compared to normal pH meat regardless of the degree of comminution or storage time.