CTAB electrophoresis and immunoblotting: a new method for the determination of soy protein in meat products

A CTAB electrophoresis method that is able to separate soy protein on the basis of molecular mass is introduced. The cationic detergent CTAB (N-cetyl-N,N,N-trimethylammoniumbromide) is not as denaturing as sodium dodecyl sulphate (SDS), and thereby allows separation of proteins that are virtually unchanged from their naturally occurring state. After blotting on a nitrocellulose (NC) membrane, the protein can be detected by a soy-specific antibody. Soy protein isolates, concentrates and hydrolysates as well as meat products containing these soy protein products were separated by CTAB electrophoresis and blotted on NC membranes. As little as 0.5% soy protein in meat products could be detected, even if the meat product had been heated to 120°C for 30 min during the manufacturing process.     

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.     

Quantitation of Soy Protein in Frankfurters by Gel Electrophoresis

A modified Laemmli procedure was utilized to obtain gel electrophoretie resolution of protein components in soy and beef isolates and in processed meat products containing soy protein isolate (SPI). Height and area ratios of selected soy and beef components (α', α-subunits of β-conglycinin and actin) were calculated from densitometric scans and compared with similar ratios calculated for soy and beef mixtures of known composition. This method permitted the quantitation of soy protein (±0.14%) in raw and pasteurized frankfurters and should be applicable to other selected soy-containing meat products.     

Aqueous Extraction and Membrane Techniques Improve Coconut Protein Concentrate Functionality

Functional properties of coconut protein concentrates (CPC) from fresh coconut meat and commercial desiccated coconut meat were assessed and compared with other protein sources. Coconut proteins were extracted from undefatted meats at pH 7 in 0.5M NaCl solution. Protein recovery in the ultrafiltration retentates was about 40% (as % nitrogen) in the starting meats. Water absorption capacities of CPC products were lower than those of soy protein concentrates (SPC) and Na-caseinate, but there was no difference in oil absorption values among CPC, SPC and Na-caseinate. CPC products were more soluble than SPC, but less soluble than Na-caseinate at pH 8 and 10. Emulsifying properties of CPC were superior to those of caseinate and SPC. Total essential amino acids contents of CPC products were lower than caseinate, but similar to SPC.     

Soybean Products as a Phosphorus Source in Meat Products

Phosphorous levels were measured in 10 soybean products intended for application in the meat industry. The results showed that theoretical meat products containing 12% of protein from meat contain 2.915 g/kg of phosphorus, while products containing 10% of protein from meat and 2% of protein from soybean products (except lecithinated flour) contain 3.004 g/kg of phosphorus. For lecithinated soy flour, the difference was slightly larger. If soybean products are added into meat products at the recommended level of 2-4%, they would not significantly increase the final phosphorus levels, in comparison to meat products which do not contain added soybean products.     

Use of poultry protein isolate as a food ingredient: sensory and color characteristics of low-fat Turkey bologna

The potential of using poultry protein isolate (PPI) as a food ingredient to substitute either soy protein isolate (SPI) or meat protein in turkey bologna was investigated. PPI was prepared from mechanically separated turkey meat using pH-shift technology and the prepared PPI was added to turkey bologna at 2 different concentrations (1.5% and 2% dry weight basis). Product characteristics were compared with those prepared with the addition of 2% SPI, 11% meat protein (control-1), or 13% meat protein (control-2). All the 5 treatments were subjected to sensory analysis to evaluate aroma, appearance, color, flavor, saltiness, juiciness, firmness, and overall acceptability of the turkey bologna samples using 9-point hedonic scales. A turkey bologna control sample with 11% meat protein appeared to be softer compared to other treatments as revealed by texture profile analysis while purge loss during storage in a retail display case was significantly (P < 0.05) higher compared to other treatments. Lightness (L*) value of the products decreased during 4 wk of retail storage. A turkey bologna control sample with 13% meat protein appeared to be darker and more reddish compared to other treatments. Replacing meat protein with protein isolates caused increase in yellowish color of turkey bologna. Sensory analysis concluded that 1.5% PPI and 2% PPI could be used as substitute of SPI or lean meat and the treatments could be improved by increasing saltiness and decreasing firmness. PRACTICAL APPLICATION: The study revealed that with slight modifications in saltiness, turkey bologna can be prepared with the addition of poultry protein isolates as an acceptable substitute for soy protein isolate or meat protein. This will help to avoid usage of nonmeat ingredients (as SPI substitute) and to reduce the cost of production (as meat protein substitute) of low-fat turkey bologna.     

Sensory acceptability of raw and extruded bovine rumen protein in processed meat products

The use of bovine rumen protein (raw and extruded) as a replacement for extruded soy protein concentrate in three meat products (pork sausage, chicken hamburger, and kibbe) was investigated. Similarity between rumen and soy protein meat products was assessed using triangle tests and sensory acceptability evaluated by consumer panelists using a nine-point hedonic scale. The addition of raw rumen protein was detected in all meat product types tested, while extruded rumen protein was only detected in kibbe. The addition of raw rumen protein decreased the acceptability of pork sausage aroma and flavor, but improved kibbe appearance, texture and overall acceptability. The addition of extruded rumen protein reduced the acceptability of chicken hamburger texture, but improved pork sausage flavor. Replacement of soy protein by bovine rumen protein is feasible based upon sensory results, but depended upon its form and the type of meat product to which it was added.     

Effect of Chemically Modified Soy Proteins and Ficin-tenderized Meat on the Quality Attributes of Sausage

ABSTRACT: The purpose of this investigation was to use ficin‐tenderized meat and cysteine‐modified soy proteins in the production of bologna and to evaluate the effect of these modifications on water‐holding capacity (WHC), emulsion stability (ES), texture, and protein solubility. The effect of ficin on meat protein was also evaluated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Results indicated that both ficin‐tenderized meat and modified soy proteins substantially improved WHC, ES, and other quality factors. SDS‐PAGE results showed the disappearance of several protein bands in ficin‐treated meat. Solubility of meat proteins increased when ficin was used for meat tenderization. The results of this study indicated that some quality attributes of meat products can be improved by enzymatic and chemical modification of protein sources in the manufacture of meat products.     

蛋白质和淀粉对肉制品品质影响的研究

选取了三种蛋白(谷朊粉、花生分离蛋白和大豆分离蛋白)和三种淀粉(玉米淀粉、红薯淀粉和绿豆淀粉)作为肉制品的脂肪模拟品,经比较分析可知,大豆分离蛋白和绿豆淀粉均为肉制品的最佳脂肪模拟品.通过单因素试验和正交试验,结果表明,当大豆分离蛋白和绿豆淀粉的比例为1:4,添加量为15%(占鲜肉质量分数),水分添加量为20%时,肉制...     

Use of Soy Protein and Microbial Transglutaminase as a Binder in Low-sodium Restructured Meats

ABSTRACT: Pork sticks were prepared by mixing pork chucks with various amounts of bisulfite-treated soy protein and microbial transglutaminase (MTGase) to evaluate the potential of using soy protein as meat binders. According to tensile strength, the favorable conditions for binding the restructured pork chunks were 5% soy protein containing 0.2% NaHSO₃ and 20 unit MTGase/g, and the setting condition was 60 min at 40°C. The tensile strength and cooking yield of restructured pork sticks made with bisulfite-treated soy protein and MTGase were much higher than those of using salt, suggesting the high potential of using soy protein and MTGase as binders in products where NaCl reduction is desired.     

Fat reduction in comminuted meat products-effects of beef fat, regular and pre-emulsified canola oil

The effects of fat reduction (25.0%, 17.5%, and 10.0%) and substituting beef fat with canola oil or pre-emulsified canola oil (using soy protein isolate, sodium caseinate or whey protein isolate) on cooking loss, texture and color of comminuted meat products were investigated. Reducing fat from 25 to 10% increased cooking loss and decreased hardness. Canola oil or pre-emulsified treatments showed a positive effect on improving yield and restoring textural parameters. Using sodium caseinate to pre-emulsify the oil resulted in the highest hardness value. Cohesiveness was affected by fat type and level. The color of reduced fat meat batters was darker for all, except the beef fat treatments. Using canola oil or pre-emulsified oil resulted in a significant reduction in redness. The results show that pre-emulsification can offset some of the changes in reduced fat meat products when more water is used to substitute for the fat and that pre-emulsification can also help to produce a more stable meat matrix.     

THERMO-RHEOLOGY,QUALITY CHARACTERISTICS,AND MICROSTRUCTURE OF FRANKFURTERS PREPARED WITH SELECTED PLANT AND MILK ADDITIVES1

The purpose of this study was to evaluate substitution of nonmeat proteins for meat protein on the thermo-rheology, quality characteristics, and microstructure of frankfurters. Batters were formulated to contain either 2% sodium caseinate or soy protein isolate, or 3.5% whey protein concentrate or wheat germ flour. The storage modulus (G') of all treatments initially decreased during temperature ramping from 20–50C, then increased rapidly from 60–80C, with all-meat batter exhibiting the highest G' at 80C. Substitution with nonmeat proteins decreased G', shear force, compression force, and red color of meat compared with all-meat frankfurters. Increased protein content, cooking yield, and decreased fat content were obtained with nonmeat protein formulations. Electron micrographs showed that nonmeat proteins were able to bind to the meat protein and fat, forming a protein-fat matrix with less coalescence of fat droplets. Sodium caseinate, soy protein isolate, whey protein concentrate, and wheat germ flour can be used as protein additives in comminuted meat products without adversely affecting their physical characteristics.     

Effect of full-fat soy paste and textured soy granules on quality and shelf-life of goat meat nuggets in frozen storage

Goat meat nuggets were prepared using commercially available textured soy granules and reduced beany flavour full-fat soy paste (FFSP) made by simple processing technology to compare the performance of these proteins in a comminuted meat system. Addition of soy proteins (soy paste and soy granules) did not significantly affect the product yield, pH, moisture and fat percentage whereas protein content and water holding capacity (% expressible water) were significantly (p>0.05) lower in nuggets with 15% soy paste. Lower force was required to compress or shear the sample as hardness, springiness, gumminess and chewiness decreased in soy paste incorporated nuggets. Soy proteins either paste or granules, did not affect sensory attributes except flavour and overall acceptability. Nuggets with soy paste and control ones did not differ significantly for flavour and overall acceptability whereas nuggets with soy granules were rated significantly (p>0.05) lower. The nuggets remained stable with minor changes in physico-chemical, microbiological and sensory quality during frozen storage (-18±1°C) for 90days. It is concluded from this study that FFSP could be successfully incorporated in comminuted meat systems for producing quality products similar to commercially available soy granules.     

Frankfurters with Lean Finely Textured Tissue as Affected by Ingredients

Increasing salt concentration from 1.5 to 2.5% increased the emulsion stability of frankfurters made with lean finely textured tissue (LFTT). Sodium tripolyphosphate (STPP) at 0.25% improved stability and texture as well as processing and consumer cooking yields. Kappa (K)-carra-geenan (0.5%) reduced cooking losses and increased firmness. Isolated soy protein (ISP) at 2% also improved product stability and firmness but lowered sensory scores. The effect of ISP on sensory scores was greater for those frankfurters produced from lean finely textured beef than for those with lean finely textured pork. Increasing NaCl concentration or including STPP and K-carrageenan may improve comminuted meat products which contain 50% LFTT substituted for lean meat.     

Iron Availability from Soy, Meat and Soy/Meat Samples in Anemic Rats With and Without Prevention of Coprophagy

The biological availability of iron from samples of soy proteins (nontextured, extruded and spun), meat (chicken and beef) and spun soy/meat combination products was compared to ferrous sulfate using a hemoglobin regeneration bioassay. Compared to ferrous sulfate (55%) iron availability from the various soy proteins ranged from 29-57%, for the meat samples 32-39% and for soy/meat combination products 61-92%. There was no significant improvement in iron availability by fortification with ferrous sulfate or ascorbic acid. Prevention of coprophagy in the anemic rats during the bioassay using aluminum anal cups produced varying degrees of reduction in iron availability for various samples and this effect clearly needs further investigation.     

The application of wheat fibre and soy isolate impregnated with iodine salts to fortify processed meats

The aim was to use wheat dietary fibre and soy protein isolate as carriers of KI and KIO₃ for fortification of processed meat with iodine. Products from minced pork were prepared with addition of iodised wheat fibre and soy isolate, and iodised table salt for comparison and the effects of thermal processing and storage on changes in iodine content were determined. It was shown that both alternative carriers limited the iodine changes in meat products compared with iodised table salt. However, wheat fibre was more effective in limiting iodine losses during thermal processing and soy protein during storage of the products. The greatest effect of the carriers was found in meat products fortified with the less stable KI.     

高功能性大豆浓缩蛋白的性能及在肉制品中应用的研究

高功能性大豆浓缩蛋白（FSPC）的乳化活性及乳化稳定性与大豆分离蛋白相似，对固体脂肪的乳化能力超过分离蛋白，在乳化型碎肉制品中添加可使产品得率及质构超过添加分离蛋白的肉制品。作者认为FSPC的功能性质可能与蛋白分子形成可溶性聚集体有关。     

The application of wheat fibre and soy isolate impregnated with iodine salts to fortify processed meats

The aim was to use wheat dietary fibre and soy protein isolate as carriers of KI and KIO₃ for fortification of processed meat with iodine. Products from minced pork were prepared with addition of iodised wheat fibre and soy isolate, and iodised table salt for comparison and the effects of thermal processing and storage on changes in iodine content were determined. It was shown that both alternative carriers limited the iodine changes in meat products compared with iodised table salt. However, wheat fibre was more effective in limiting iodine losses during thermal processing and soy protein during storage of the products. The greatest effect of the carriers was found in meat products fortified with the less stable KI.     

大豆蛋白生产与应用现状

该文综述大豆蛋白制品—大豆蛋白粉、大豆分离蛋白、大豆浓缩蛋白、大豆组织蛋白生产现状、存在问题及大豆蛋白在面制品、肉制品、乳制品、饮料制品等中应用现状。     

Effects of two types of soy protein isolates,native and preheated whey protein isolates on emulsified meat batters prepared at different protein levels

The effects of substituting 1.5% of the meat proteins with low gelling soy protein isolate (LGS), high gelling soy protein isolate (HGS), native whey protein isolate (NWP), and preheated whey protein isolate (PWP) were compared at varying levels of proteins (12, 13 and 14%), with all meat control batters prepared with canola oil. Cooking losses were lower for all the non-meat protein treatments compared to the all meat controls. When raising the protein level from 12 to 14%, cooking losses increased in all treatments except for the NWP treatments. Using LGS increased emulsification and resulted in a more stable meat batters at the 13 and 14% protein treatments. Textural profile analysis results showed that elevating protein level increased hardness and cohesiveness. The highest hardness values were obtained for the PWP treatments and the lowest for the HGS, indicating a strong non-meat protein effect on texture modification. Non-meat protein addition resulted in lighter and less red products (i.e., lower red meat content) compared to the all meat controls; color affected by non-meat protein type. Light microscopy revealed that non-meat proteins decreased the frequency of fat globules' agglomeration and protein aggregation. The whey protein preparations and HGS formed distinct “islands” within the meat batters' matrices, which appeared to interact with the meat protein matrix.