Journal of Muscle Foods最新文献

ABSTRACT

To determine the effect of antioxidants and irradiation on meat color, myoglobin (Mb) was extracted from beef hearts. Mb was treated with one of four antioxidants (control, citric acid [CA], rosemary extract [RE] or combination of citric acid and rosemary extract [CA/RE]) and irradiated at 0.00 (Control), 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 kGy. Samples were then evaluated for thiobarbituric reactive substances, pH, L*, a*and b*values, hue angles, and Chroma. RE- and CA-containing samples had the highest postirradiation L*, a*and b*values, indicating they were lighter, redder and more yellow than controls. In terms of hue angles, all samples treated with antioxidants were much closer to the true red axis (a* = 0) of the CIE color space, both before and after irradiation, than was the control. The only color attribute affected by irradiation dose was L*value. Samples irradiated at 2.0 kGy were significantly lighter (L* = 5.27) than samples that had not been irradiated (L* = 1.28).

PRACTICAL APPLICATIONS

Irradiation is an effect method for extending the shelf life and improving the safety of fresh meat products; however, it can cause undesirable color changes at the surface of the meat, which appear to be the result of oxidative processes – therefore, reducing oxidation could effectively reduce color change. Studying pigment preservation is difficult in intact muscle tissue, so a myoglobin model system was developed for this purpose. Natural antioxidants were evaluated in this system. Rosemary extract and citric acid maintained color lightness and redness. Surface application of these antioxidants has the potential to preserve red meat color during irradiation.

ABSTRACT

The effects on chemical and physical quality of the addition of beef fat with hazelnut oil were studied in sucuk. Two sucuk formulations were prepared by the addition of 2.5 and 5% hazelnut addition in which 11.11 and 20% of beef fat was substituted with hazelnut oil. The addition of hazelnut oil increased total fat of the product that affected the chemical, physical and sensorial characteristics of products. Added hazelnut oil decreased protein content but increased free fatty acids and thiobarbituric acid reactive substances values. The formulation with 2.5% hazelnut oil, corresponding to 11.11% substitution of beef fat with hazelnut oil, was judged as similar to control.

PRACTICAL APPLICATIONS

The results suggest that the addition of hazelnut oil in the production of sucuk could give a healthier option to consumers. This study showed that substitution of animal fat with hazelnut oil in fermented sausages is a useful application to develop a functional fermented meat product. Additionally, this study indicated that the hazelnut oil was found to be a good oil in fermented sausage and opened the door for new research with a different nut.

ABSTRACT

Seasonal variations in the fatty acid compositions of red mullet (Mullus barbatus) captured from Iskenderun bay, northeastern Mediterranean, were investigated. In all sampling seasons, the major fatty acids of red mullet were palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), palmitoleic acid (16:1), eicosapentaenoic acid (EPA, 20:5ω3) and docosahexaenoic acid (DHA, 22:6ω3). The fatty acid contents of red mullet were influenced by seasonality. The levels of polyunsaturated fatty acid were 17.32% in autumn, 17.69% in winter and 20.13% in spring. The levels of DHA in the total fatty acids in autumn, winter and spring were 4.36, 8.25 and 10.89%, while those of EPA were 7.93, 4.59 and 4.56, respectively. The present study suggest that red mullet is a good source of ω3 series fatty acids, and the weekly consumption of 300 g of red mullet in autumn, winter or summer could meet EPA + DHA requirements of people.

PRACTICAL APPLICATIONS

Red mullet is one of the most commercially important fish species in many Mediterranean countries. Little information is available on the fatty acid composition of red mullet. Therefore, seasonal proximate analysis and the fatty acid composition of red mullet were determined and discussed in this paper. There is much interest in the beneficial effects on human health that is related to consumption of marine lipids. Determination of the effects of different fishing seasons on the fatty acid composition of red mullet will provide valuable information concerning the nutrient value of this seafood for both consumers and the researchers working on nutrient tables. In addition, this basic information will be obtained for the fish processing industry.

ABSTRACT

Beef trimmings, inoculated with Escherichia coli (EC) and Salmonella typhimurium (ST), were treated with 3% potassium lactate (K-L), 4% sodium metasilicate (NMS), 0.1% acidified sodium chlorite (ASC) or 0.02% peroxyacetic acid (PAA) prior to grinding. The ground beef packages were sampled at 0, 1, 2, 3 and 7 days of simulated retail display. All treatments reduced (P < 0.05) EC, coliforms and aerobic plate counts up to and some in excess of 1 log and ST count ≥ 1.5 logs. Sensory panelists found ground beef from all treatments to generally be similar (P > 0.05) to the control in odor and similar (P > 0.05) in color for the K-L and NMS treatments during initial display. Instrumental color results indicated that K-L, NMS and PAA were similar (P > 0.05) in redness (a*) to the control. These findings indicated that use of tested antimicrobial agents can reduce microbial numbers with little impact on sensory odor and color characteristics.

PRACTICAL APPLICATIONS

Although antimicrobial interventions have shown promising results in decontaminating meat products, there are only a limited number of antimicrobial products that can be used without causing adverse effects on quality characteristics of the final product. Consumers often discriminate against discolored meat products, and thus any deleterious effects on color and other quality attributes in decontaminated products will lead to a negative economic impact. The outcome of this research will provide information on selection of antimicrobial agents that will maximize ground beef safety without causing deleterious effects on quality attributes. Application of suitable antimicrobial interventions at the end of a production line will be advantageous to supply ground beef with increased shelf-life and decreased or no risk for illnesses caused by pathogens.

ABSTRACT

Effect of different fats such as goat fat, chicken fat, combination of goat and chicken fat and refined mustard oil (RMO) were evaluated in goat meat patties (GMPs). Patties with 10% RMO contributed significantly (P < 0.05) better emulsion stability compared with others. There were no significant effects of different fats on physicochemical and textural attributes of patties. Patties with RMO had significantly (P < 0.05) lower cholesterol content than other groups. GMPs with RMO, chicken fat and chicken and goat fat combination rated higher for all sensory attributes than patties with goat fat, which had significantly (P < 0.05) higher mouth coating and lower overall acceptability. Flavor and overall acceptability were higher in patties with chicken fat. Histological study showed improper dispersion of goat fat in continuous phase of meat protein matrix (emulsion) compared with others.

PRACTICAL APPLICATIONS

Utilization of hard fats from goat, sheep and buffalo in emulsion-based meat products decreases emulsion stability because of its poor dispersibility, and consequently its cooking yield. Goat fat also contributes to a smeary and greasy mouth-coating problem and reduces the palatability of meat products. Alternatively, chicken fat disperses well in meat emulsion because of its high unsaturation and enhances the flavor of the products. However, the efficient utilization of goat fat is essential to support an economical goat meat production system and for developing meat products. The present study showed successful utilization of goat fat when combined with chicken fat, and the products had similar sensory attributes and acceptability as in meat products with chicken fat and refined mustard oil. This study would also help in better use of excess fat from spent hens in other meat products.

ABSTRACT

Thigh muscles from aged (3–4 years) goat were minced, packed in polyethylene bags (250 g each), gamma irradiated with a dosage of 4 kGy and the packets held at 3 ± 1C for 8 days. Nonirradiated muscle mince packed and stored similarly were treated as control. Both irradiated and nonirradiated muscle mince were sampled on 0, 5 and 8 days of storage and analyzed for physicochemical, microbiological and sensory quality attributes. Irradiation resulted in lower (P ≤ 0.05) muscle pH (3.5–5.1%), water holding capacity (4.5–6.7%), thiobarbituric acid values (19.4–34.9%) and higher (P ≤ 0.05) free fatty acid (26.9–61.0%) and Hunter a* (3.3–17.3%) values compared with nonirradiated control muscle samples. A reduction (P ≤ 0.05) of 2 log cfu/g in total aerobic bacteria and psychrotrophs, and 1 log cfu/g in total staphylococci, yeast and molds were also observed in irradiated samples while enterococci, Escherichia coli and Staphylococcus aureus could not be detected in irradiated and stored muscles. Sensory quality scores on a 9-point hedonic scale decreased from 7.5–8.3 to 7.1–7.9 during storage at 3 ± 1C for 8 days and were marginally influenced by irradiation. The results establish that a 4-kGy dosage is appropriate for irradiation to maintain fresh meat quality under chilled condition.

PRACTICAL APPLICATIONS

Muscles are highly perishable primarily because high microbial load and irradiation effectively reduces the microbial counts and helps extension of shelf life of muscle foods. Production and retention of free radicals produced by irradiation cause changes in, apart from bacterial counts, proteins and lipids which in turn may affect functional properties such as water holding capacity and emulsion and sensory characteristics. Many muscle foods, such as sausages, burgers, loaves, kebabs, etc., are emulsion-type products, a quality that is dependent on functional properties of muscles' proteins/lipids. These products are industrially produced and are marketed in India and abroad. The industry is aware of the beneficial effect of irradiation in reducing the microbial load but has an apprehension that irradiation may adversely affect the functional properties and sensory characteristics of muscle foods. The study reported in this paper overcomes that apprehension when meat was irradiated with a permitted dosage of 4 kGy.

ABSTRACT

A great deal of attention has been paid to the most important proteins of the myofibrillar system – myosin, actin, titin and nebulin – because of their potential role in meat processing. Several methods from different sources were reported for their isolation. However, most of them are complex, tedious and focused on the isolation of one protein at a time. In the present research, these four proteins had been co-enriched simultaneously applying a simple methodology.

Myofibrillar proteins extracted from semitendinosus beef muscles were submitted to ammonium sulfate precipitation. Titin and nebulin were precipitated predominantly in the saturation range of 40–60 g/L, and so were myosin heavy chain and actin in the range of 60–100 g/L. Denaturing polyacrylamide electrophoresis and electroelution were employed for the separation and isolation of the proteins of interest from the corresponding salt fractions. Western blot procedure was applied to detect and identify precisely nebulin band.

PRACTICAL APPLICATIONS

The described isolation method will provide enriched myofibrillar proteins, which can be used for more specific analysis or for analysis that requires a further isolated sample. For instance, these proteins could be submitted to microscopy studies, immunological and differential scanning calorimetric analysis.

ABSTRACT

The effect of Urtica dioica L. on the growth of Staphylococcus aureus was investigated in “sucuk,” a Turkish dry fermented sausage. The different levels of dried ground U. dioica L. (0, 1, 3 and 5%) were added to sucuk batters, and these batters were contaminated with S. aureus (10⁴ cfu/g). Numbers of S. aureus, Micrococcus/Staphylococcus and lactic acid bacteria (LAB) were determined during the ripening period. In addition, values of pH and a_w were analyzed.

The different usages of U. dioica L. and the ripening period had very significant effects on pH value and on S. aureus numbers (P < 0.01). Because U. dioica L. increased the value of pH, initial pH value was determined above 6.0 in groups including U. dioica L. During fermentation, the pH did not decrease rapidly in all groups (including the control). Because of this situation, the S. aureus number was increased. The usage of U. dioica L. has a very significant effect (P < 0.01) on the number of Micrococcus/Staphylococcus but does not have any effect on the numbers of LAB (P > 0.05). The a_w value was affected very significantly (P < 0.01) by U. dioica L. addition.

PRACTICAL APPLICATIONS

Staphylococcus aureus is an important foodborne pathogen in fermented dry sausage like “sucuk.” The behavior of this pathogen has not been investigated in fermented meat products with Urtica dioica L. In this research, the effects of different levels of U. dioica L. on the behavior of S. aureus were determined during sucuk production. The use of U. dioica L. increased the pH value in sucuk batter. Because of this, S. aureus growth was better in sucuks containing U. dioica L. than in the control group. In order to control the growth of S. aureus, lactic acid bacteria is required to be used as starter culture in sucuk with U. dioica L. as well.

ABSTRACT

The main objective of this study was to explore an edible coating for improving the quality of frozen pork. The results show that coating pork with sodium alginate can decrease thawing loss of meat, and is very useful to maintain the functional properties of frozen pork and can affect total protein solubility. Both sodium alginate and CaCl₂ concentration had significant influences on reactive sulphydryl; CaCl₂ could reduce shear force and pH significantly. The optimum coating conditions in the experiments were sodium alginate concentration: 3%, concentration of CaCl₂: 7% and the time of sodium alginate solution reacts with CaCl₂ solution on the meat surface: 5–7 min. During frozen storage, the treatment using the optimum coating condition can decrease thawing loss, shear force and thiobarbituric acid reactive substances, and can increase total protein solubility and sarcoplasmic protein solubility of the frozen pork. This indicates that coating pork with sodium alginate can maintain its quality during frozen storage. There were no significant differences of structures between the control and the treatment using the optimum coating condition.

PRACTICAL APPLICATIONS

Frozen storage is an economically favorable method of meat storage. However, the freezing procedure and frozen storage can deteriorate meat quality attributes. In our experiment, we found that coating pork meat with sodium alginate can decrease thawing loss and maintain the functional properties of frozen pork meat. Our research is very useful to develop an economical method to lower the amount of drip loss on thawing, and enhance the eating quality and monetary value. Coating the foods with edible materials can also serve as a means to improve the freezing procedure. The optimal coating conditions found in our experiment could maintain the quality of pork meat during frozen storage. These provide an economically favorable method of meat storage.

ABSTRACT

To determine the effect of antioxidants and irradiation on meat color, myoglobin (Mb) was extracted from beef hearts. Mb was treated with one of three antioxidants (control, grape seed extract, rosemary extract [RE] or oregano extract) and irradiated at 0.00, 1.25 or 2.50 kGy. The samples were then evaluated for pH, Commission Internationale de l'Eclairage L*, a* and b* values, hue angle, chroma and thiobarbituric reactive substances (TBARS). Antioxidants influenced pH. RE-containing beef Mb samples had lower pH values before and after irradiation. Antioxidants also had significant effects on the color of the beef Mb model system. RE-containing samples had the best pre- and postirradiated color in terms of a* value (redness) and chroma (color intensity). TBARS values were very low and did not differ regardless of antioxidant or irradiation dose.

PRACTICAL APPLICATIONS

Irradiation can reduce the microbial load on meat products and improve product safety for consumers. However, irradiation, because of its potential to cause oxidative damage, can compromise the red color of fresh meat. Off-color will result in consumer rejection of products which may be safe. Antioxidants have the potential to preserve meat color by affecting the state of myoglobin and maintaining the iron in the reduced state such that it can oxygenate to the bright cherry red color, which consumers expect. However, studying these effects in vivo is challenging because of the complexity of the system. In this model system, devoid of enzymatic reducing systems and equivalents, natural antioxidants, including grape seed extract, rosemary extract (RE) and oregano extract, were evaluated for their potential to preserve color during irradiation. RE appeared to be the most effective in preserving red color intensity. Extracts of this herb appear to have potential for ameliorating some of the color damage that often accompanies the irradiation of fresh red meat.