Determination of carnosine,anserine, homocarnosine,pentosidine and thiobarbituric acid reactive substances contents in meat from different animal species

The aim of this research was to determine the content of the histidinic antioxidants, advanced glycation end products (pentosidine) and thiobarbituric acid reactive substance (TBARS) in the meat from different animal species. Carnosine, anserine, homocarnosine and pentosidine were quantified by HPLC/MS, while TBARS was determined by photometric measurements. The total CRCs (carnosine + anserine + homocarnosine) content was in the increasing order: beef < rabbit < pork < horse < chicken < turkey. The analysis showed traces of pentosidine above the instrumental determination limits in all the meat samples, while the susceptibility of these meat to lipid oxidation decreased from beef to chicken, with the exception of turkey meat, which presented a high TBARS content towards even though its total CRCs was the highest. The structure of homocarnosine was elucidated by high resolving power multistage mass spectrometry.     

Ohmic cooking of whole turkey meat – Effect of rapid ohmic heating on selected product parameters

Intact turkey meat was cooked using low temperature long time (LTLT) and high temperature short time (HTST) protocols in a combined ohmic/convection system and compared to conventional (CONV) steam cooking. Both ohmic protocols gave a significantly lighter (p < 0.05) and a more uniform colour vs. CONV, while no significant differences (p ? 0.05) were found in texture profile analysis attributes between LTLT and CONV though HTST showed significantly higher attributes (p < 0.05). Cook loss was significantly (p < 0.05) different between treatments (25.2%, 27.9% and 31.3% for LTLT, CONV and HTST). Sensory studies largely confirmed these observations. Cook values (p < 0.05) were lowest for LTLT (4.0) followed by HTST (5.4) and control (8.5). Lipid oxidation and sulphur-flavour-compound development (measured over 7 days) were higher for conventional than ohmic treatments. Overall, these results demonstrate considerable industrial potential for ohmic heating, yielding high quality products with an 8–15-fold reduction in cooking time.     

Combined heat transfer and kinetic models to predict cooking loss during heat treatment of beef meat

A heat transfer model was used to simulate the temperature in 3 dimensions inside the meat. This model was combined with a first-order kinetic models to predict cooking losses. Identification of the parameters of the kinetic models and first validations were performed in a water bath. Afterwards, the performance of the combined model was determined in a fan-assisted oven under different air/steam conditions. Accurate knowledge of the heat transfer coefficient values and consideration of the retraction of the meat pieces are needed for the prediction of meat temperature. This is important since the temperature at the center of the product is often used to determine the cooking time. The combined model was also able to predict cooking losses from meat pieces of different sizes and subjected to different air/steam conditions. It was found that under the studied conditions, most of the water loss comes from the juice expelled by protein denaturation and contraction and not from evaporation.     

Stability of catalase and its potential role in lipid oxidation in meat

The activity of catalase in microbial growth-controlled and uncontrolled ground beef muscle (semimembranosus, SM) did not change (P>0.05) during 6-day storage at 4°C. Likewise, catalase activity in ground, beef SM and longissimus dorsi (LD), pork LD, and chicken breast (B) and thigh (T) muscles was not affected (P>0.05) by 2-month storage at −20°C, with or without mid-month thawing/refreezing. When sodium azide (a catalase inhibitor) was added to ground beef SM, lipid oxidation (as measured by peroxide values) during 4-day refrigeration was higher (P<0.05) in treated samples — 43 and 55% higher at day 2 and day 4, respectively — than in the controls. It was concluded that catalase would be stable during meat storage/distribution and contribute significantly to the antioxidative process in raw meat products.     

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.     

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.     

Plant extracts as natural antioxidants in meat and meat products

Antioxidants are used to minimize the oxidative changes in meat and meat products. Oxidative changes may have negative effects on the quality of meat and meat products, causing changes in their sensory and nutritional properties. Although synthetic antioxidants have already been used but in recent years, the demand for natural antioxidants has been increased mainly because of adverse effects of synthetic antioxidants. Thus most of the recent investigations have been directed towards the identification of natural antioxidants from various plant sources. Plant extracts have been prepared using different solvents and extraction methods. Grape seed, green tea, pine bark, rosemary, pomegranate, nettle and cinnamon have exhibited similar or better antioxidant properties compared to some synthetic ones. This review provides the recent information on plant extracts used as natural antioxidants in meat and meat products, specifically red meat.     

肉和肉制品中脂质氧化的研究进展

肉和肉制品在加工、贮藏和运输的过程中容易发生脂质氧化,影响肉制品的品质。脂质适度氧化可以促进肉制品的风味,但是脂质过度氧化还可能产生有毒有害物质,增加食用风险。脂质氧化反应产生的初级产物及次级产物化学性质不稳定,容易与肉中的其他成分(蛋白质、血红素、抗氧化添加剂等)发生反应从而影响肉制品的品质。因此,调控脂质氧化对肉及肉制品来说非常重要。本文主要综述了脂质的酶促氧化、自动氧化、脂质氧化与蛋白质氧化之间的关系。大量研究表明,脂质氧化过程复杂且受诸多因素和条件的影响,研究氧化过程及氧化机制对调控脂质氧化和提高食品品质的稳定性具有重要意义。     

Encapsulated phosphates reduce lipid oxidation in both ground chicken and ground beef during raw and cooked meat storage with some influence on color,pH, and cooking loss

Effects of encapsulated sodium tripolyphosphate (STP), sodium hexametaphosphate (HMP) and sodium pyrophosphate (SPP) on lipid oxidation in uncooked (0, 2, 24 h) and cooked (0, 1, 7 d) ground chicken and beef during storage were determined. Ten phosphate treatments included a control (no phosphate), three unencapsulated (u) at 0.5% and three encapsulated (e) phosphates (0.5%) each at a low (e-low) and high (e-high) coating level. Two heating rates (slow, fast) were investigated. Cooking loss (CL), pH, color, orthophosphate (OP), TBARS and lipid hydroperoxides (LPO) were determined. A fast heating and uSTP resulted in lower CL (p < 0.05). Orthophosphate increased with phosphate incorporation, slow heating and storage (p < 0.05). Encapsulated phosphates and increased coating level reduced OP (p < 0.05). Unencapsulated STP increased CIE a* and pH, whereas uSPP decreased CIE a* and pH (p < 0.05). Encapsulated phosphates and the greater coating level had no effect on the pH in cooked samples. Not increased coating level but encapsulated phosphates decreased lipid oxidation in cooked samples (p < 0.05).     

Effect of carnosine preblending on the quality of ground buffalo meat

A study was conducted on carnosine preblending at 0%, 0.5%, 1.0% and 1.5% levels with ground buffalo meat obtained from spent, adult, male Murrah buffalo carcasses, to identify the level of carnosine required for improving the quality of the meat during refrigerated storage at 4 ± 1 °C. It was observed that meat samples containing 1.0% and 1.5% carnosine significantly inhibited metmyoglobin formation and brown colour development. Carnosine also improved meat pH, and water-holding capacity and lowered cooking loss and 2-thiobarbituric acid-reacting substances (TBARS) values as compared to control sample. Carnosine also improved desired visual colour and odour, and gave higher LTCU ‘R’ and chroma of meat samples. Visual colour was inversely correlated with metmyoglobin, aerobic mesophiles and psychrotrophs plate count, and odour was inversely correlated with TBARS values. Use of 1.0% carnosine for preblending extended the shelf life of ground buffalo meat up to 8 days under refrigerated storage.     

Comparison of spice-derived antioxidants and metal chelators on fresh beef color stability

Effects of Type I antioxidants eugenol and rosmarinic acid were compared to those of Type II antioxidants milk mineral (MM), sodium tripolyphosphpate (STPP), and phytate in raw ground beef held for 14 days at 4 °C in oxygen-permeable polyvinylchloride. Meat color stability was measured as % oxymyoglobin, Hunter a∗ value, chroma, and hue angle. Significant correlations (P < 0.0001) were observed between all color measurement methods. By day 14, STPP-treated patties lost more red color (P < 0.05 for a∗ and hue angle) and had higher thiobarbituric acid values than other treatments. By day 14, MM was as effective as eugenol and rosmarinate at preventing oxymyoglobin oxidation (72, 76, and 71% retained, respectively) and red color loss as measured by a∗ (9.2, 9.4, and 10.9), hue angle (58.4, 56.2, and 53.5), and chroma (17, 17, and 18), but was unable to inhibit microbial growth as effectively as the spice-derived antioxidants.     

辐照对肉品微生物及牛羊肉品质的影响

研究了不同温度、不同包装形式下辐照处理对牛羊肉货架期和营养品质的影响。结果表明,产品经真空包装后,2~4.0KGy低温辐照,产品贮藏在2±1℃环境下,牛羊肉的货架期可达到60d。     

Effect of different cooking methods on lipid oxidation and formation of volatile compounds in foal meat

The influence of four different cooking methods (roasting, grilling, microwaving and frying) on cooking loss, lipid oxidation and volatile profile of foal meat was studied. Cooking loss were significantly (P < 0.001) affected by thermal treatment, being higher (32.5%) after microwaving and lower after grilling (22.5%) and frying (23.8%). As expected, all the cooking methods increased TBARs content, since high temperature during cooking causes increased oxidation in foal steaks, this increase was significantly (P < 0.001) higher when foal steaks were microwaved or roasted.     

Assessment of the influence of diet on lamb meat oxidation

The effect of pasture- or concentrate-diet on colour stability, lipid oxidation and protein oxidation was measured in lamb meat (M. longissimus dorsi) during refrigerated storage of 7 days under gas permeable film. Lipid and protein oxidation increased rapidly with storage time while evolution of colour parameters exhibited a biphasic curve. Diet had an important effect on lipid oxidation where animals fed concentrate showed higher thiobarbituric reactive substance (TBARS) levels than animals fed pasture-diet. However the nature of diet did not affect protein oxidation or colour parameters of meat. In parallel anti-oxidant status of meat was estimated by measurement of vitamin E content and anti-oxidant enzyme activities while pro-oxidant status was evaluated by haeminic iron, polyunsaturated fatty acid (PUFAs) and glycogen content of muscle. Statistical analysis was performed in order to relate oxidation parameters to pro- and anti-oxidant status of muscle.     

Suitability of the TBA method for assessing lipid oxidation in a meat system with added phenolic-rich materials

Numerous protocols and modifications of the thiobarbituric acid (TBA) test are available in the literature. The present paper compares the effectiveness of different TBA tests in minimizing the interferences caused by the addition of phenolic-rich materials (wild fruits) as antioxidants in cooked burger patties. The aqueous acid extraction procedure (EM) and a modified distilation TBA method (DM) were tested with different conditions of incubation – boiling (B) vs. room temperature (RT) – for monitoring lipid oxidation in cooked burger patties during refrigerated storage. DM-B and DM-RT were more suitable than EM procedures for assessing TBA-reactive substances (TBA-RS) in meat samples containing compounds such as anthocyanins, with similar spectral properties than that of the TBA–malondialdehyde (MDA) adduct. Additionally, interferences caused by browning development during incubation were avoided by DM procedures or by performing RT incubations. Correlations between TBA-RS numbers and hexanal contents in cooked pork burger patties were calculated in order to corroborate the suitability of the tested TBA procedures. The DM-RT procedure showed the highest correlation with hexanal content (R² = 0.90; p < 0.001).     

Effect of method of cooking on identification of heat processed beef using polymerase chain reaction (PCR) technique

Effects of various cooking methods including boiling, roasting, pressure cooking, and pan frying on species determination of beef by PCR was studied. The meat was cooked by boiling at 97.5°C for 140, 200 or 230min, by roasting at 200°C for 80, 120, or 150min or by autoclaving at 120°C for 30, 60, or 90min. The beef sample was pan fried until the meat was acceptable for sensory attributes (45min, meat temperature 115°C, fat temp 173°C) and further cooked until unacceptable. DNA was extracted from samples taken after cooking and a 271bp fragment of the mitochondrial DNA was amplified by PCR. The results indicated that with the exception of pan frying for 80min, beef was determined in all meat samples including the broth and sauce of the roasted meat.     

Effects of chestnut tannins on carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbits

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P < 0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P < 0.01), palmitoleic acid (C16:1 cis-9; P < 0.05) and pentadecanoic acid (C15:0; P < 0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P < 0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P < 0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n − 6/n − 3 ratios among the groups.     

Influence of chestnut tannins on welfare, carcass characteristics, meat quality, and lipid oxidation in rabbits under high ambient temperature

A study was conducted to evaluate the influence of chestnut tannins (CT) on welfare, carcass characteristics, meat quality, and lipid oxidation in rabbits under high ambient temperature. Rabbits in one group were raised at 20 °C and fed with basal diet (N) and other three groups (33 °C) were fed basal diet with 0 (C), 5 (CT5), and 10 g (CT10) of CT/kg of diet. Compared with the C group, rabbits in CT10 had higher pH₂₄ and lower cooking loss and thiobarbituric acid reacting substance values at 0, 30, and 60 min of forced oxidation. Rabbits in C group had higher cortisol levels, creatine kinase activities, white blood cell counts, neutrophil percentage, neutrophil:lymphocyte ratio and lower T₃, T₄ levels, lymphocyte percentage than N and CT10 groups. Supplementation of CT seemed to have a positive effect on growth performance, welfare, and meat quality of rabbits under high ambient temperature.     

Grape seed extract as antioxidant in cooked, cold stored turkey meat

Efficiency of four concentrations of grape seed extract (0.0, 0.4, 0.8, and 1.6 g/kg) in retarding oxidative rancidity was tested with cooked turkey breast meat. Development in lipid oxidation during 13 days of refrigerated storage was evaluated by means of thiobarbituric acid-reactive substances (TBARS) and volatile compound formation. Hexanal, pentanal, octanal, 2-octenal, 1-octen-3-ol, 2-octen-1-ol, and 1-penten-3-ol showed high correlations (r>0.95) with TBARS values and could, therefore, serve as markers for the oxidation process in the cooked turkey breast meat. Supplementation of grape seed extract prior to cooking significantly improved oxidative stability of minced turkey meat during heat treatment and storage. The ability of grape seed extract to prevent lipid oxidation was concentration-dependent. Vacuum-packaging considerably improved oxidative stability of meat regardless of the low concentration of grape seed extract used. It appears that grape seed extract could be very effective in inhibiting lipid oxidation of cooked turkey meat during chill-storage.     

Temperature of frozen storage affects the nature and consequences of protein oxidation in beef patties

The effect of three frozen storage temperatures (− 8, − 18 and − 80 °C) on protein oxidation in beef patties was studied through the analysis of novel oxidation markers. Additionally, the connection between lipid and protein oxidation and the impact of the latter on particular quality traits (water holding capacity, color and texture) of subsequently processed beef patties (cooking/cold-stored) were investigated. Protein oxidation was measured as the loss of tryptophan fluorescence and formation of diverse lysine oxidation products (α-aminoadipic semialdehyde, α-aminoadipic acid and Schiff bases). Lipid oxidation was assessed by levels of thiobarbituric acid reactive substances and hexanal. A significant effect of storage temperature on protein oxidation was detected. Frozen storage increased the susceptibility of meat proteins to undergo further oxidation during processing. Timely interactions were found between lipid and protein oxidation. Plausible mechanisms by which oxidative damage to proteins may have an impact in particular quality traits are thoroughly discussed.