Journal of Muscle Foods最新文献

ABSTRACT

Injection enhancement with lactate darkens beef; however, the mechanism is unclear. Our objective was to assess the effects of lactate on beef myoglobin oxygenation. Nine strip loins were divided in half and one of three injection treatments (negative control − not injected, positive control − injected with water, and 3% lactate − injected with a water solution of lactate) was assigned to each half using an incomplete block design. Positive control and 3% lactate loins were pumped to 110% of green weight, cut into 2.54-cm thick steaks, overwrapped in polyvinyl chloride and stored at 4C. Steak surface darkening (L*), color stability (a* and metmyoglobin-reducing activity), depth of oxygen penetration and myoglobin oxygenation (1 h at 4C) were evaluated on days 0, 7 and 12 of storage. Lactate darkened color, decreased surface myoglobin oxygenation and limited oxygen penetration compared with controls (P < 0.05). Color stability was improved (P < 0.05) by lactate injection. The darkening effect of lactate may be associated with decreased myoglobin oxygenation.

PRACTICAL APPLICATIONS

Case-ready packaging has allowed beef purveyors to enhance meat with various ingredients, resulting in increased color and shelf life. Lactate is added as an antimicrobial agent; however, this beneficial effect can be somewhat diminished by lactate-induced darkening. Research assessing the mechanism(s) of lactate-induced beef color darkening is limited with previous research focused on determining the mechanism of lactate-induced color stability. The current research will give a better understanding of the role of lactate as an ingredient in beef steak darkening and, thus, provide a foundation that can be used to develop strategies to improve meat color.

ABSTRACT

Sixteen beef carcasses were harvested to determine the effect of pre-rigor foreshank positioning on the ultimate sarcomere length and objective tenderness values of seven chuck muscles. After final inspection, the left side foreshank was positioned caudal to the point of the shoulder and secured until the completion of rigor. The right side foreshank served as the control and was allowed to hang in the normal position, cranial to the point of the shoulder. Biceps brachii, infraspinatus, pectoralis profundus, serratus ventralis, supraspinatus, teres major and triceps brachii muscles were excised from each carcass half for sarcomere length and Warner–Bratzler shear force determinations.

Results indicate that sarcomere length was altered (P < 0.05) for all muscles. When the foreshank was placed in the caudal position pre-rigor, both the serratus ventralis and triceps brachii muscles had higher (P < 0.05) shear values than when the foreshank was allowed to remain in its natural position.

PRACTICAL APPLICATIONS

As the beef industry continues to search for methods to add value to the chuck, these data may offer insight into a practical method to increase sarcomere length and enhance palatability and marketability of underutilized muscles.

ABSTRACT

The effects of apple polyphenol (AP) on color, lipid and protein oxidation in sliced cooked cured hams (SCCHs) made of pork and beef during chilled storage were investigated. SCCH samples with no antioxidant added and those treated with vitamin C were used as controls. The results indicated that addition of 500 ppm AP to the samples significantly inhibited discoloration in pork SCCH, but not in beef; all the AP treatments (with 300, 500 and 1,000 ppm AP) successfully inhibited lipid oxidation of both pork and beef SCCHs with the lipid of pork SCCH more effectively protected than that of beef SCCH. However, no effect on protein oxidation as measured carbonyl group accumulation was observed in both pork and beef SCCH treated with AP at the dose used in this study. AP was generally an effective antioxidant.

PRACTICAL APPLICATIONS

The results of the present study indicate that apple polyphenol (AP) may be used to retain the quality of hams in chilled storage and of other meat products in quality storage. However, different concentrations of AP have different effects on stored meat products, and the same concentration of AP may produce different effects on different meat products. Therefore, a test should be performed before application of AP to a specific meat product in meat industry.

ABSTRACT

Midwestern meat processors were surveyed to determine whether consensus existed among industry processing practices for jerky production. Seventy-eight plants were contacted, 37 responded and 33 plants sent 61 samples consisting of whole muscle (56%) or chopped and formed (44%) jerky. Samples had mean water activity, salt (NaCl) and pH of 0.74, 6.85% and 5.85, respectively. Plants used either smokehouses (34) or commercial ovens (3). Nine plants measured wet bulb temperature, and one used a relative humidity instrument. However, 35 plants claimed that they were able to control humidity. Controls included closing dampers, steam injection, direct addition of water, placing a pan of water in the house, or a combination of methods. Plants used sodium nitrite (32), sodium erythorbate (15) and potassium sorbate (5), and vacuum (78%), no vacuum (32%) and gas flush (14%) packaging. Most products were stored at room temperature (38%) or refrigerated (32%); or a combination of methods was used.

PRACTICAL APPLICATIONS

Because of the high variability of processing times and temperatures, processing environment relative humidity, and methods to control humidity used by small and very small plants, there is a need to educate these processors about jerky processing parameters and the need for routine product analysis. Lack of processing knowledge and equipment capabilities also highlights the need for lethality studies in this area in addition to education on jerky process control and food safety for processors. On the basis of the averages from this study, lethality studies should target A_w 0.74 (Food Safety Inspection Service requires an A_w of ≤0.85), NaCl 6.85% and pH 5.85. Lethality studies should be conducted with cure for most studies. Marinade pH and length of time held in marinade prior to thermal processing as well as packaging effect and subsequent shelf life on pathogen lethality during storage should be considered. This research information could potentially decrease plants' operating costs while helping ensure food safety and public health protection.

ABSTRACT

The effects of meat protein substitution (2%) with sodium caseinate, milk protein isolates or whey protein isolates (WPI) at varying levels of meat protein (13–15%) were studied in emulsified beef meat batters prepared with canola oil (25%). Increasing meat protein to 14 and 15% resulted in less stable emulsions (higher cook loss) compared with the 13% protein. At an equal protein level, all dairy proteins reduced cook loss (P < 0.05) compared with the all meat protein treatments. Overall, WPI provided the best emulsifying and moisture retention. Increasing the protein content also resulted in higher hardness and springiness values in all treatments. The addition of dairy protein resulted in softer, lighter and less red products compared with the all meat controls; colors being affected by the dairy protein source and protein content. Light microscopy revealed that increasing protein content caused some fat globule coalescence and more protein aggregation. WPI formed distinct dairy protein gel regions within the meat batter matrix, which appeared to interact with meat protein matrix.

PRACTICAL APPLICATIONS

The main goal of this study was to understand the effects of partially substituting meat proteins with dairy proteins on the performance (cook loss and textural properties) of comminuted meat batters prepared with canola oil. The incorporation of canola oil, instead of animal fat, offers a new healthy alternative to the consumer but has its challenges in terms of keeping this liquid oil (high unsaturation level) within the meat product).

ABSTRACT

Changes in salt extractable protein (SEP) and Ca^{2 +} -ATPase activity of actomyosin from washed and unwashed silver carp stored at −10 and −20C were investigated. The resultant decrease of SEP and Ca^{2 +} -ATPase activity mainly occurred in the first 5 and 7 weeks, and the changes obeyed first-order model. The kinetic models of SEP and Ca^{2 +} -ATPase changes were established during frozen storage. The rate constant k of decline in SEP and Ca²⁺-ATPase activity of samples stored at −10C were higher than that of samples stored at −20C; the D value of samples stored at −10C were lower than that of samples stored at −20C. Compared with washed samples, unwashed samples had a higher rate constant k and activation energies E, and a lower D value. Activation energies E of SEP were higher than E of Ca²⁺-ATPase activity in all samples.

PRACTICAL APPLICATIONS

Silver carp is one of the main freshwater fish species in China. Washing is an important step for fish processing and temperature is an important factor on fish protein storage. The changes of the kinetic models of SEP and Ca²⁺-ATPase during frozen storage can explain the effect of temperature and time on silver carp mince quality. These kinetic models can be used to predict the silver carp protein functional changes during frozen storage, and help to provide better methods to effectively utilize silver carp protein resource.

ABSTRACT

This study was carried out to evaluate the antioxidant potential of pomegranate juice (PJ) and vitamin C (VC) in cooked chicken patties during storage at 4C. Freshly minced chicken meat were assigned to one of the following six treatments: control (meat without any antioxidant); PJ 5 (5 mg eq PJ phenolics per 100 g meat); PJ 10 (10 mg eq PJ phenolics per 100 g meat); PJ 15 (15 mg eq PJ phenolics per 100 g meat); PJ 20 (20 mg eq PJ phenolics per 100 g meat); VC 50 (50 mg VC per 100 g meat). The PJ exhibited significantly (P < 0.05) higher reducing power compared with VC. Total phenolic content (as tannic acid equivalent) significantly (P < 0.05) increased from 226 in control to 432 ug/g in PJ 20 patties. Incorporation of 15 mg eq PJ phenolics per 100 g patties was sensorily acceptable. The thiobarbituric acid values were significantly (P < 0.05) reduced from 1.358 in control patties to 0.341 mg malonaldehyde per gram samples in PJ 15 and PJ 20 patties. PJ treatment (PJ 10, PJ 15 and PJ 20) inhibited (P < 0.05) lipid oxidation in cooked chicken patties to a greater extent than VC treatment. Hence, naturally available PJ can be utilized as an alternative to synthetic antioxidants in chicken meat patties with added health benefits.

PRACTICAL APPLICATIONS

Since many of the synthetic antioxidants are associated with potential health risks, the meat industry is looking for natural ingredients to prevent lipid oxidation. Pomegranate juice (PJ) has been demonstrated to be high in antioxidant activity and could be used as a natural source of polyphenols in poultry meat products. The PJ was also reported to be effective in the prevention of atherosclerosis, low-density lipoprotein oxidation, prostate cancer, platelet aggregation and various cardiovascular diseases. Hence, the meat industry should take notice of the use of these fruits as a potential source of phenolics which have immense nutraceutical value or can be utilized to produce functional meat products of great commercial interest.

ABSTRACT

Effects of modified tapioca starch (hydroxypropylated distarch phosphate) at various levels (0, 1, 2 and 3% w/w) on the chemical, physical, textural and sensory properties of bigeye snapper (Priacanthus tayenus) mince gels subjected to different freeze-thaw cycles (zero, one, three and five) were investigated. Breaking force, deformation and expressible moisture content of the control mince gels (without modified starch) increased with increasing freeze-thaw cycles (P < 0.05). The protein solubility study revealed that disulfide bond was formed in the gel as the freeze-thaw cycles increased (P < 0.05). However, the addition of 1% modified starch could reduce those changes and rendered the gel subjected to five freeze-thaw cycles with the highest score for texture, appearance and overall liking. Scanning electron microscopic study indicated that mince gel added with 1% modified starch had the finer matrix with smaller strands compared with the control mince gel at all freeze-thaw cycles used.

PRACTICAL APPLICATIONS

During frozen storage, surimi or mince gels are susceptible to the textural changes associated with losses in water-holding capacity. As a consequence, the rubbery texture is generally formed, leading to lower acceptability. The addition of modified starch, particularly hydroxypropylated distarch phosphate, at the appropriate level could minimize such an alteration and could maintain the quality of gel products during the extended frozen storage.

ABSTRACT

In this research were investigated protein, lipid and fatty acids contents of commercially important anchovy (Engraulis encrasicolus) during the catching season. The protein content of anchovy ranged from 17.24 to 16.94%. The lipid content of anchovy was maximum (18.57%) in November and minimum (15.57%) in January The total saturated fatty acids content were determined as 38.62, 35.20 and 33.57% in November, December and January, respectively. Palmitic acid (C_16:0) was found at the highest levels among the saturated fatty acids through all commercial catch season. The monounsaturated fatty acids content ranged from 25.45 to 29.50%. Concerning the monounsaturated fatty acids, oleic acid (C_18:1n-9) constituted the larger percentage than others. Docosahexaenoic acid (DHA; C_22:6n-3) and eicosapentaenoic acid (EPA; C_20:5n-3) contents were determined as average 9.37% and 7.92%, respectively. n-3 Polyunsaturated fatty acids (n-3 PUFAs) of anchovy were higher than n-6 PUFAs. Thrombogenicity and atherogenicity index values were 0.43, 0.40, 0.36 and 1.94, 1.69, 1.52 in November, December and January, respectively. The n-6/n-3 ratio of anchovy was 0.23, 0.20 and 0.17 in November, December and January, respectively.

PRACTICAL APPLICATIONS

The anchovy is very important a fish for Turkey. Annual per capita fish consumption is around 8 kg in Turkey, which 40% is anchovy. This research provides useful information on the proximate composition of anchovy during the catching season. Results of this research will be reference for the fish processing technology, dieticians and similar academic studies.

ABSTRACT

Composition and amount of intramuscular connective tissue vary among muscles, age and breed. The purpose of this study was to determine in vivo the proportion of collagen I and III fibers in the Longissimus thoracis (LT) and Gluteus medius (GM) muscles at different ages (6, 12 and 24 months) in the Criolla and Aberdeen Angus bovine breed (24 months) Muscular samples were taken and histological cuts were treated with the picrosirius-red polarization method. The study was performed by light microscope with Polaroid filters and ocular reticulum. Type I fibers between GM and LT muscles, has shown differences only at 12 months old. Regarding Type III fibers, no differences were found between the both muscles at the three ages. When GM muscle was studied, differences were observed in the Type I fibers among the three ages, the major percentage was observed at 24 months. Significant differences were found in Type I as well as Type III fibers in LT at 24 months between Aberdeen Angus and Criolla breeds.

PRACTICAL APPLICATIONS

The variation in proportion of Types I and III collagen in muscles and its relationship to meat texture has been investigated, although results are not conclusive and they are often contradictory. The present inability to elucidate the relationship between phenotypic variations in the intramuscular connective tissue (IMCT) and meat texture is due to our rudimentary understanding of fibril composition.

Investigation of post-mortem treatment of meat to reduce the IMCT contribution to meat toughness has not been completely successful. The knowledge and manipulation in vivo of the proportion and maturity of IMCT may be a possible means of reducing unwanted variability in meat tenderness.

Evaluation of collagen fibers Type I and III by the present histological technique could be used as a potential indicator of meat tenderness.