Sensory characteristics of meat cooked for prolonged times at low temperature

The present study evaluated the sensory characteristics of low temperature long time (LTLT) treated Semitendinosus from pork and beef and Pectoralis profundus from chicken. Semitendinosus and Pectoralis profundus muscles were heat treated at 53°C and 58°C for T_c + 6 h, T_c + 17 h, and T_c + 30 h (only Semitendinosus from pork and beef). T_c was the time for the samples to equalize with the temperature in the water bath. Tenderness increased with increasing heating temperature and time in pork and beef, but not in chicken. Juiciness decreased with increasing heating temperature and time in all species, and cooking loss increased with increasing temperature. A done appearance was developed with increasing heating time at 58 °C in pork and beef, while in chicken the done appearance was only affected by temperature. Flavor attributes were less affected by the LTLT treatment for all species.     

The physicochemical and microbiological characteristics of pork jerky in comparison to beef jerky

This study was carried out to compare the physicochemical and microbiological characteristics of beef and pork jerky, prepared from whole muscle of beef semimembranosus (BSM), pork semimembranosus (PSM), pork longissimus dorsi (PLD), and pork psoas major (PPM). The BSM and PSM jerky had higher moisture content, and PPM jerky had lower water activity than other jerky samples during 30 days of storage at 25 °C (P < 0.05). Pork jerky samples had higher lightness value than beef jerky, while PSM jerky had higher pH value than other jerky samples (P < 0.05). The shear force and TBARS values of PPM jerky were higher than those of other jerky samples (P < 0.05). Saturated fatty acid (SFA, %) was significantly higher in the BSM jerky than others, while unsaturated fatty acid (UFA, %) was significantly higher in the PSM and PLD than BSM and PPM jerky samples (P < 0.05). The PPM jerky showed a significant increase in UFA (%) during storage, and a significantly decrease in microbial count after storage of 30 days (P < 0.05).     

Predictive model for growth of Clostridium perfringens during cooling of cooked uncured meat and poultry

Comparison of Clostridium perfringens spore germination and outgrowth in cooked uncured products during cooling for different meat species is presented. Cooked, uncured product was inoculated with C. perfringens spores and vacuum packaged. For the isothermal experiments, all samples were incubated in a water bath stabilized at selected temperatures between 10 and 51 °C and sampled periodically. For dynamic experiments, the samples were cooled from 54.4 to 27 °C and subsequently from 27 to 4 °C for different time periods, designated as x and y hours, respectively. The growth models used were based on a model developed by Baranyi and Roberts (1994. A dynamic approach to predicting bacterial growth in food. Int. J. Food Micro. 23, 277-294), which incorporates a constant, referred to as the physiological state constant, q₀. The value of this constant captures the cells’ history before the cooling begins. To estimate specific growth rates, data from isothermal experiments were used, from which a secondary model was developed, based on a form of Ratkowsky’s 4-parameter equation. The estimated growth kinetics associated with pork and chicken were similar, but growth appeared to be slightly greater in beef; for beef, the maximum specific growth rates estimated from the Ratkowsky curve was about 2.7 log₁₀ cfu/h, while for the other two species, chicken and pork, the estimate was about 2.2 log₁₀ cfu/h. Physiological state constants were estimated by minimizing the mean square error of predictions of the log₁₀ of the relative increase versus the corresponding observed quantities for the dynamic experiments: for beef the estimate was 0.007, while those for pork and chicken the estimates were about 0.014 and 0.011, respectively. For a hypothetical 1.5 h cooling from 54 °C to 27° and 5 h to 4 °C, corresponding to USDA-FSIS cooling compliance guidelines, the predicted growth (log₁₀ of the relative increase) for each species was: 1.29 for beef; 1.07 for chicken and 0.95 log₁₀ for pork. However, it was noticed that for pork in particular, the model using the derived q₀ had a tendency to over-predict relative growth when the observed amount of relative growth was small, and under-predict the relative growth when the observed amount of relative growth was large. To provide more fail-safe estimate, rather than using the derived value of q₀, a value of 0.04 is recommended for pork.     

Phenolic acids composition and antioxidant activity of canola extracts in cooked beef,chicken and pork

Crude polyphenol extracts (15 or 100 mg gallic acid equivalents (GAE)/kg meat) from canola meal reduced the formation of 2-thiobarbituric acid-reactive substances (TBARS) in pre-cooked beef (66–92%), pork (43–75%) and chicken (36–70%). The canola extract contained sinapic (99.7%), ferulic (0.28%) and p-hydroxybenzoic acids (0.07%).     

Efficacies of soy sauce and wine base marinades for controlling spoilage of raw beef

Fresh beef slices were marinated by immersion in marinades based on soy sauce without (SB) or with lactic acid (SBLA) or red wine base without (WB) or with 0.5% v/v oregano essential oil (WBO). For control samples (immersed in saline), a mean increase of 0.9log CFU/cm² in total viable counts (TVCs) occurred during the 24 h treatment. During marination with WB and SB, mean TVC decreased by 0.7 and 0.3log CFU/cm², respectively. The mean decrease in TVC for samples marinated in WBO or SBLA was 1.2log CFU/cm². Subsequent storage of beef resulted in a rapid increase of TVC in control samples, to ≥9.5log CFU/cm² after 8 days at 5 °C or 3 days at 15 °C. Significant (P < 0.05) microbial growth occurred in marinated samples stored at 5 °C. During storage at 15 °C TVC increased in only WB samples but the final numbers of 5.9log CFU/cm² were significantly lower (P < 0.05) than the numbers in the control. Results similar to those for TVC were observed for Pseudomonas spp. All marinades also gave meat with significant lower TBARS values than the controls. There were no significant differences (P > 0.05) in the toughness of the marinated samples compared to the control, except for SBLA samples which had significantly higher (P < 0.05) shear force values. Marination with soy sauce or red wine marinades can evidently control microbial spoilage and oxidation of meat.     

Tenderization and fragmentation of myofibrillar proteins in bovine longissimus dorsi muscle using proteolytic extract from Sarcodon aspratus

The objective of this study was to examine the Sarcodon aspratus extract including protease how to affect tenderness of the bovine longissimus dorsi muscle. In addition, we investigated myofibrillar protein fragmentation, particularly in myosin, and its influence on meat tenderness. Beef loin chunks were marinated with 0.5 g/100 g, 1 g/100 g, and 2 g/100 g powdered S. aspratus extract, 0.2 g/100 mL papain, and distilled water (control), respectively. Although tenderness of meat is increased by adding S. aspratus extract, differences in meat quality traits, such as muscle pH and meat color, were small and not considered to have practical importance between the control and enzyme-treated samples. Furthermore, the S. aspratus extract influenced the myofibril fragmentation index (MFI) as well as protein solubility. The changes in MFI and protein solubility were due to the myofibrillar protein degradation. Through Western blotting, we found that the S. aspratus extract, as well as papain, caused fragmentation of the myosin heavy chain, but the mushroom extract induced more fragmentations of myofibrillar proteins, and caused more tender meat.     

Effects of nutritional level on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs

The study was designed to investigate the effects of nutritional level (control diet (CD), 14.19% crude protein, 13.81 MJ of DE/kg; low nutritional level diet (LND), 11.08% crude protein, 12.55 MJ of DE/kg) on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs. The LND treatment increased drip loss (P < 0.05), had a trend to increase intramuscular fat (IMF) content (P = 0.09), decreased Warner–Bratzler shear force (WBSF) of pork (P < 0.05), improved mRNA level of μ-calpain (P < 0.05) in skeletal muscle, but had no effect on gene expression of calpastatin, compared with the CD treatment. These data suggest that a moderately reduced energy and protein diet increased pork tenderness and intramuscular fat. The increase in tenderness by LND treatment may be partly due to increased gene expression of μ-calpain in muscle.     

Phytochemical and Antimicrobial Evaluation of Aqueous and Organic Extracts of Calotropis procera Ait Leaf and Latex

The aqueous and ethanol extract of Calotropis procera leaf and latex were investigated. The leaves and latex from the plant were tested for antimicrobial activities. The bioactive constituents extracted from the leaf and latex were tested against pathogenic organisms (Eschericia coli, Salmonella typhi, Bacillius subtilis, Candida albicans, Aspergillus niger) using the Agar well diffusion method. The ethanolic latex extract showed significant activity against all the test organisms. The results revealed that ethanol is a more effective extractive solvent for antimicrobial activity of leaf and latex of C. procera. The ethanol extract of the latex gave the widest zone of inhibition (21 mm) against B. subtilis. All the extracts inhibit the growth of all the organisms except B. subtilis of which the aqueous extract has no effect. The Minimum Inhibitory Concentration (MIC) for the latex extract was between 3 and 7.5 mg/ml for bacteria, and 5.0 to 7.0 mg/ ml for fungi. For the leaf extract the MIC for bacteria was between 5.0 and 10.5 mg/ml and 11 and 15 mg/ml for fungi. The results also showed an increase in antimicrobial activity with increase in temperature. This study therefore revealed that C. procera latex extract demonstrated strong and better inhibitory activity on the test organisms than the leaf extract. These findings therefore provide an explanation for the traditional medicinal use of C. procera extracts.     

Meat species identification and Halal authentication using PCR analysis of raw and cooked traditional Turkish foods

The method performance characteristics of commercially available PCR kits for animal species identification were established. Comminuted meat products containing different levels of pork were prepared from authentic beef, chicken, and turkey. These meat products were analysed in the raw state and after cooking for 20 min at 200 °C. For both raw and cooked meats, the PCR kit could correctly identify the animal species and could reliably detect the addition of pork at a level below 0.1%. A survey of 42 Turkish processed meat products such as soudjouk, salami, sausage, meatball, cured spiced beef and doner kebap was conducted. Thirty-six samples were negative for the presence of pork (< 0.1%) and four were found to be correctly labelled as containing pork. However, one sausage sample was labelled as containing 5% beef, but beef DNA was not detected and a meatball sample labelled as 100% beef was found to contain chicken. Another turkey meatball sample was predominantly chicken.     

Effects of high pressure/thermal treatment on lipid oxidation in beef and chicken muscle

Lipid oxidation was studied in beef and chicken muscle after high pressure treatment (0.1–800 MPa) at different temperatures (20–70 °C) for 20 min, prior to storage at 4 °C for 7 days. Pressure treatment of beef samples at room temperature led to increases in TBARS values after 7 days storage at 4 °C; however, the increases were more marked after treatment at pressures ?400 MPa (at least fivefold) than after treatment at lower pressures (less than threefold). Similar results were found in those samples treated at 40 °C, but at 60 °C and 70 °C pressure had little additional effect on the oxidative stability of the muscle. Pressure treatments of 600 MPa and 800 MPa, at all temperatures, induced increased rates of lipid oxidation in chicken muscle, but, in general, chicken muscle was more stable than beef to pressure, and the catalytic effect of pressure was still seen at the higher temperatures of 50 °C, 60 °C and 70 °C. The addition of 1% Na₂EDTA decreased TBARS values of the beef muscle during storage and inhibited the increased rates of lipid oxidation induced by pressure. The inhibition by vitamin E (0.05% w/w) and BHT (0.02% w/w), either alone or in combination, were less marked than seen with Na₂EDTA, suggesting that transition metal ions released from insoluble complexes are of major importance in catalysing lipid oxidation in pressure-treated muscle foods.     

Changes in Muscovy duck breast muscle marinated with ginger extract

The effects of ginger extract (GE) marination on the changes in Muscovy duck breast muscle were evaluated. Pectoralis muscles were excised from the carcasses of male Muscovy ducks and marinated for 14 days in GE at 5 °C. Samples were taken at the end of 0, 1, 3, 7 and 14 days of the marination. The results showed that the pH was higher (p < 0.05) in the GE-marinated samples than in control samples and that TBARS values were lower (p < 0.05) in the GE-marinated samples. The SDS–PAGE and western blot results indicated that titin, myosin heavy chain, desmin and α-actinin degraded more rapidly in the GE-marinated samples than in the control samples and that 32- and 30-kDa troponin-T degradation components were also generated in the GE-marinated samples. Our results suggest that GE marination could not only retard lipid oxidation, but also enhance the proteolysis of Muscovy duck breast muscle.     

Effect of marinating time and low pH on marinade performance and sensory acceptability of poultry meat

The effects of marinating time (30, 60, 120 and 180 min) and acidic marinade pH (3.0, 3.2, 3.4, 3.6, 3.8, 4.0 and 4.2) on the instrumental and sensory properties of cooked Chinese-style marinated chicken were investigated. With increasing marinating time up to 180 min, a significant (P < 0.05) increase in surface redness (a∗ value) and the dark pink sensory attribute was observed, along with a corresponding decrease in lightness (L∗ value) and colour penetration. Increased marinating times of 120–180 min were found to produce more acceptable end products with increased scores for colour, aroma and flavour attributes. Marinade uptake was greater at higher marinade pH levels of 3.8, 4.0 and 4.2, with the highest marinade uptake (3.34%) recorded at pH 4.0. As changes to core meat pH were not observed, the effect of marinating time (up to 180 min) and marinade pH on the instrumental and sensory properties of Chinese-style marinated chicken were located principally at the surface of samples. Consumers considered surface colour as contributing to acceptability of marinated chicken to a greater degree compared to colour penetration.     

Inhibition of melanosis formation in Pacific white shrimp by the extract of lead (Leucaena leucocephala) seed

Lead (Leucaena leucocephala) seed extract was prepared using distilled water as a medium. An extraction yield of 26.16 g/100 g of seed was obtained after extraction at room temperature for 12 h. Total phenolic and mimosine contents in the lead seed extract powder (LSEP) were 17.4 g GAE/100 g and 8.8 g/100 g, respectively. LSEP at different concentrations (0.05%, 0.1%, 0.25%, 0.5%, and 1%, w/v) showed inhibitory activity towards polyphenoloxidase (PPO) of Pacific white shrimp in a dose dependent manner. When the whole Pacific white shrimp were treated with 0.25% and 0.5% (w/v) LSEP, the shrimp treated with 0.5% LSEP had the lower melanosis score throughout the storage of 12 days and showed a higher score for colour and odour, as well as overall likeness, compared with the control (without treatment) and 1.25% sodium metabisulphite treated samples at day 12 (P < 0.05). Meat of shrimps treated with LSEP at both levels had the increase in mimosine content up to 8 days, suggesting the migration of mimosine into shrimp muscle during extended storage. Therefore, 0.5% LSEP can be used as a novel melanosis inhibitor for Pacific white shrimp.     

Occurrence of heterocyclic amines in cooked meat products

Heterocyclic amines (HCAs), potent mutagens and a risk factor for human cancers, are produced in meats cooked at high temperature. The aim of this study was to determine the HCA content in cooked meat products (beef, chicken, pork, fish) prepared by various cooking methods (pan frying, oven broiling, and oven baking at 170 to 230 °C) that are preferred by U.S. meat consumers. The primary HCAs in these samples were PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine) (1.49-10.89 ng/g), MeIQx (2-amino-3,8-dimethylimidazo [4,5-f]quinoxaline) (not detected-4.0 ng/g), and DiMeIQx (2-amino-3,4,8-trimethyl-imidazo [4,5-f]quinoxaline) (not detected-3.57 ng/g). Type and content of HCAs in cooked meat samples were highly dependent on cooking conditions. The total HCA content in well-done meat was 3.5 times higher than that of medium-rare meat. Fried pork (13.91 ng/g) had higher levels of total HCAs than fried beef (8.92 ng/g) and fried chicken (7.00 ng/g). Among the samples, fried bacon contained the highest total HCA content (17.59 ng/g).     

Oxidation in HiOx-packaged pork Longissimus muscle predisposes myofibrillar and sarcoplasmic proteins to N-nitrosamine formation in nitrite-curing solution

The effect of meat protein in situ oxidation on the formation of N-nitrosodiethylamine (NDEA) was investigated. Fresh minced pork was untreated (Con) or treated with 700 mg/kg α-tocopherol (Toc) or 300 mg/kg tea polyphenols (PPE), packaged in a HiOx atmosphere (78.8% O₂, 18.8% CO₂, 2.4% N₂), then stored at 2 ± 1 °C for up to 10 days. Crude myofibrillar (MP) or sarcoplasmic (SP) protein (20 mg/mL) extracted from stored meat was reacted with 43 μM sodium nitrite at 80 °C for 1 h. Lipid oxidation was totally inhibited in PPE pork but increased in Con and Toc samples after 10 days. There was significant protein oxidation (losses of sulfhydryls, formation of protein carbonyls) in both MP and SP in all samples during storage. However, the Con group suffered more extensive protein oxidation than Toc and PPE and produced more NDEA (P < 0.05), indicating that protein oxidation promoted nitrosation.     

Evaluation of the effects of selected phytochemicals on quality indices and sensorial properties of raw and cooked pork stored in different packaging systems

The effects of lutein (100, 200 μg/g muscle), sesamol (250, 500 μg/g muscle), ellagic acid (300, 600 μg/g muscle) and olive leaf extract (100, 200 μg/g muscle) on lipid oxidation (thiobarbituric acid-reactive substances TBARs), colour (CIE L∗, a∗, b∗), pH, texture profile analysis (TPA), water holding capacity (WHC), cooking losses and sensorial properties of fresh and cooked pork patties were investigated. Raw and cooked minced pork (M. longissimus thoracis et lumborum) containing added lutein, sesamol, ellagic acid or olive leaf extract were stored aerobically or in modified atmosphere packs (MAP) for up to 8 and 12 days, respectively. Lutein, sesamol, ellagic acid and olive leaf extract had no significant effect on microbial status, cook loss, pH or WHC. Lipid oxidation was reduced (P < 0.001) in raw and cooked pork patties stored in aerobic packs and in MAP following addition of sesamol, ellagic acid and olive leaf extract. Antioxidant effectiveness in raw and cooked patties was in the order: sesamol = ellagic acid > olive leaf extract > lutein. Lutein increased (P < 0.001) b∗ yellowness values in raw pork patties. Addition of lutein, sesamol, ellagic acid and olive leaf extract to pork had no detrimental effects on the organoleptic properties of cooked patties but altered (P < 0.05) instrumental textural attributes. Results highlight the potential of using natural functional ingredients in the development of functional pork products with enhanced quality and shelf-life.     

The effect of technology information on consumer expectations and liking of beef

European consumers increasingly attach value to process characteristics of food. Although beef technologies are hardly communicated to consumers, providing consumer-oriented information about technology application might increase perceived transparency and consumer acceptance. This study investigates how information about beef technologies influences consumer expectations and liking of beef. Beef consumers in Belgium (n = 108) and Norway (n = 110) participated in an information experiment combined with sensory testing in which each consumer tasted three beef muscles treated with different technologies: unprocessed tenderloin M. Psoas major, muscle profiled M. Infraspinatus, and marinated (by injection) M. Semitendinosus. The findings indicate that detailed information about beef technologies can enhance consumers' expectations and liking of beef. However, this effect differs between countries and beef technologies. Information becomes either less relevant when the product is actually tasted, as indicated by the findings in Norway, or more relevant when information is confirmed by own experience during tasting, as indicated by the findings in Belgium.     

Effect of green tea marinades on the formation of heterocyclic aromatic amines and sensory quality of pan-fried beef

The effect of a green tea marinade on the formation of heterocyclic aromatic amines (HAs) was examined in pan-fried beef cooked at 180–200 °C for 4 min each side. Different marinating times were assayed and unmarinated samples cooked in similar conditions provided reference HAs levels. A green tea marinade catechin rich was prepared taking 1 g of green tea and infusing with 125 ml of boiling tap water during 10 min. Four HAs were quantified in unmarinated and marinated meat samples during 1, 2, 4 and 6 h at 5 °C. Compared with the unmarinated samples, marinating in green tea resulted in a significant decrease (p < 0.05) of levels of PhIP and AαC. Person correlation indicated that the reduction of the levels of these HAs in meat marinated with the increase of marinating time was significant (respectively, r = −0.799, p < 0.0001; r = −0.631, p < 0.05). No reduction was observed for 4,8-DiMeIQx and MeIQx.     

Determination of tetracyclines in multi-specie animal tissues by pressurized liquid extraction and liquid chromatography–tandem mass spectrometry

A specific, sensitive and robust pressurized liquid extraction (PLE) and liquid chromatography tandem mass spectrometry (LC–MS/MS) method for determining tetracycline, chlortetracycline, oxytetracycline and doxycycline in bovine, swine, poultry and lamb muscle tissues is presented. PLE was performed using an ASE^® 200 from Dionex and water as extractant, followed by solid-phase extraction (SPE) using an Oasis HLB cartridge. The method was validated for beef, chicken, pork and lamb meat in compliance with the requirements set by Commission Decision, 2002/657/EC [Commission Decision 2002/657/EC (2002). Implementing Council Directive 96/23/EC concerning the performance of analytical methods and interpretation of results. Official Journal of European Communities, L239, 66–98. (Available at: <http://europe.eu.int>)]. The average recoveries of the different meat samples, spiked with the four tetracyclines at three levels (1, 100 and 200 μg kg⁻¹ of each tetracycline), were always higher than 89% with intraday and interday precision lower than 15% and 17%, respectively. A good linearity was established for the four tetracyclines in the range from 5 to 10,000 μg kg⁻¹ with r > 0.995. The limits of quantification (LOQs) were between 0.5 and 1 μg kg⁻¹, which are well below the tolerance levels set by the European Union. The decision limit (CCα) and the decision capability (CCβ) were in the range 101–116 and 112–130 μg kg⁻¹, respectively. Compared with previous methods, sample preparation time required for the analysis and LOQs, are reduced. The method demonstrated its successful application for the analysis of 100 meat samples. Two samples of beef and one sample of chicken out of 25 of each type tested positive while none of 25 samples of either, lamb or pork, tested positive.     

Antioxidant action of ganghwayakssuk (Artemisia princeps Pamp.) in combination with ascorbic acid to increase the shelf life in raw and deep fried chicken nuggets

Raw and deep fried chicken nuggets containing various levels of ganghwayakssuk ethanolic extract (GE) in combination with ascorbic acid (Aa) were evaluated for shelf-life during refrigerated storage (4 °C). The pH and color (lightness, redness, and yellowness) values of raw and deep fried samples were significantly affected by the addition of GE (P < 0.05). All antioxidant combinations except for Aa + GE 0.01 were effective at delaying lipid oxidation (CD, POV, and TBARS) when compared to the control or Aa. Raw samples with GE 0.2 and Aa + GE 0.1 exhibited lower bacterial populations during storage. The sensory characteristics (color, juiciness, flavor, tenderness, and overall acceptability) did not differ significantly in all deep fried chicken nugget samples, except color, whereas storage time had a significant effect (P < 0.05). The results suggest the possibility of utilizing raw and deep fried chicken nuggets with a mixture of ganghwayakssuk and ascorbic acid for the increase of shelf-life and quality.