Effects of pre‐emulsifying fat/oil on meat batter stability,texture and microstructure

The effects of pre‐emulsified beef fat and canola oil (CO) (25%) with Tween 80 (T‐80) or sodium caseinate (SC) were studied in beef meat batters prepared at three protein levels (9%, 12% and 15%). Raising meat protein level to 15% resulted in low emulsion stability of products prepared with CO. Using pre‐emulsified beef fat with Tween 80 (BF‐T80) showed significantly higher fat and water losses at all protein levels. There were no differences in fat and water losses between pre‐emulsified beef fat and CO when SC was used at the 9% and 12% protein levels compared to the controls (non pre‐emulsification). Light microscopy revealed fat globule coalescence in the CO meat batters prepared with 15% protein and BF‐T8 treatments, as well as formation of fat channels and more protein aggregation; both resulted in lower emulsion stability. Using SC to emulsify fat/oil produced a finer dispersion of fat globules compared to all the other treatments.     

Lipid oxidation in n-3 fatty acid enriched Dutch style fermented sausages

Dutch style fermented sausages were manufactured with a substitution of 10%, 15% and 20% of pork backfat by flaxseed oil and canola oil, pre-emulsified with soy protein isolate. The 15% and 20% substitution were also reached by adding encapsulated flaxseed oil and encapsulated fish oil and by adding flaxseed oil, pre-emulsified with sodium caseinate, respectively. The products were sliced, packaged in an oxygen-enriched atmosphere and stored in the dark for 12 weeks at 7°C. No differences were detected in moisture, protein and fat content between control and modified sausages, with the exception of the formulation with sodium caseinate. The PUFA/SFA ratio increased from 0.30 in the control to 0.42-0.48 in the sausages with canola oil and to 0.49-0.71 in the sausages with flaxseed oil. The n-6/n-3 ratio decreased from 11.20 in the control to 6.94-5.12 in the sausages with canola oil and to 1.93-1.05 in the sausages with flaxseed oil. The addition of canola oil and encapsulated flaxseed oil resulted in a comparable shelf life as the control in terms of lipid oxidation. In the samples with addition of pre-emulsified flaxseed oil, especially with sodium caseinate, lipid oxidation clearly increased during storage. Physical and sensory analysis showed that the sausages with encapsulated fish oil and flaxseed oil resembled the control most.     

Physicochemical Effects of the Lipid Phase and Protein Level on Meat Emulsion Stability,Texture, and Microstructure

ABSTRACT: The effects of beef fat (25%) substitution with rendered beef fat, canola oil, palm oil, or hydrogenated palm oil at varying meat protein levels (8%, 11%, and 14%) were studied in emulsified beef meat batters. There was no significant difference in fat loss among meat batters made with beef fat, rendered beef fat, or palm oil. Hydrogenated palm oil provided the most stable batters at all protein levels. Increasing meat protein to 14% resulted in high fat loss in batters prepared with canola oil, which did not occur in the other formulations. This indicates that the physicochemical characteristics of fat/oil affect emulsion stability. Cooked batter hardness was higher (P < 0.05) when protein level was raised; highest in hydrogenated palm oil batters when compared at similar protein levels. As protein level was raised springiness values were increased in all the meat treatments. Springiness was higher in the canola oil treatments. Light microscopy revealed fat globule coalescence in canola oil meat batters prepared with 14% protein, as well as the development of fat channels and more protein aggregation; both seem to result in lower emulsion stability. Hydrogenated palm oil batters showed fat particles with sharp edges as opposed to the round ones seen in all other treatments.     

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.     

Effects of protein level and fat/oil on emulsion stability,texture, microstructure and color of meat batters

Beef meat batters formulated with increasing protein level (10–15%) and containing 25% beef fat were compared to batters prepared with 25% canola oil. Emulsion stability of the canola oil treatments was higher (less separation during cooking) at the 10–13% protein level compared to the beef fat treatments. However, above 13% protein this was reversed and the canola oil treatments showed high fat and liquid separation, which did not occur at all in the beef fat treatments. This indicates differences in stabilization of fat versus oil in such meat emulsions. Hardness of the cooked meat batters showed significantly (P < 0.05) higher values when the protein level was raised, and was higher in canola oil than in beef fat meat emulsions at similar protein levels. Products’ chewiness were higher in the canola oil treatments compared to the beef fat emulsions. Lightness decreased and redness increased in canola oil batters as the protein level was raised. The micrographs revealed the formation of larger fat globules in the beef fat emulsions compared to the canola oil meat emulsions. The canola oil treatment with 14% protein started to show fat globule coalescence, which could be related to the reduced emulsion stability.     

Effect of Gradual Heating and Fat/Oil Type on Fat Stability,Texture, Color,and Microstructure of Meat Batters

The effects of endpoint cooking temperature (40, 50, 60, 70, 80, and 90 °C) on emulsion stability, texture, color, and microstructure of meat batters prepared with different fats/oils were studied. Canola oil treatments showed the highest cooking loss whereas hydrogenated palm oil provided the most stable meat batters. Rendered beef fat was less stable than regular beef fat. Increasing endpoint cooking temperatures resulted in a progressive reduction of water holding capacity in all treatments. As temperature was raised, meat batters showed higher hardness and cohesiveness values, but no appreciable changes in cohesiveness above 60 °C. Canola and hydrogenated palm oil treatments showed the highest hardness and chewiness values. Lightness (L^*) values of all meat batters increased significantly with increasing temperature from 40 to 60 or 70 °C; no major changes observed above 70 °C. Light microscopy revealed no substantial changes in the microstructure of all the stable meat batters cooked to between 50 and 70 °C. Heating to 90 °C changed the microstructure in all meat batters except the hydrogenated palm oil treatments, which still showed nonround fat particles and a less aggregated protein matrix.     

Structural and Water Binding Properties of Meat Emulsions Prepared with Emulsified and Unemulsified Fat

The structural and water binding properties of sausage emulsions containing the fat component as a pre-emulsified fat or as water and fat separately are presented. Optimal parameters of sonic emulsification were established: frequency of ultrasound, time of emulsification, and concentration of stabilizers, sodium orthophosphate, gelatin, sodium caseinate, nonfat dry milk. Comminuted meat products with pre-emulsified fat rather than unemulsified fat had higher water-binding capacity, and viscosity, which increased with time of holding. Utilization of a pre-emulsified fat in comminuted meat products resulted in an increase in the amount of emulsified fat in the finished product, a more uniform distribution of the fat component in the structure of products and a 6 - 7% increase in the yield of finished product.     

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.     

绿茶提取物添加及脂肪替代对低脂猪肉香肠品质及脂质氧化稳定性的影响

采用柯罗纳油或预乳化后的柯罗纳油取代50%的猪后背脂肪,并添加不同含量的绿茶提取物（100 mg/kg或1 000 mg/kg）制作低动物脂肪猪肉香肠。对蒸煮后不同处理香肠的感官特性及脂肪氧化稳定性进行分析。结果表明直接采用植物油部分替代动物脂肪并不影响产品颜色（亮度和红度）、硬度和变形性,显著改善了产品的脂肪氧化稳定性（P＜0.05）,但增加了蒸煮损失并显著降低了产品破断强度。对植物油预乳化处理在一定程度上降低了脂肪替代引起的产品质构恶化。添加绿茶提取物（100 mg/kg或1 000 mg/kg）几乎完全抑制了香肠在贮藏过程中的脂质氧化。但值得注意的是,尽管没有观察到统计学上的显著差异（P＞0.05）,添加高含量绿茶提取物（1 000 mg/kg）倾向于破坏产品质构。     

油脂预乳化液替代脂肪对乳化肠品质的影响

制备鱼油和玉米油预乳化液,研究油脂预乳化液替代猪背膘（质量替代比例分别为25%、50%、75%、100%）对乳化肠主要组分、蒸煮损失、色泽、质构特性、流变特性和感官特性的影响。结果表明：随着预乳化液替代比例的增加,脂肪含量显著降低（P＜0.05）;蒸煮损失也逐渐降低。油脂预乳化液处理组间硬度差异显著并明显高于对照组（P＜0.05）,随预乳化液替代比例增加,乳化肠硬度先增加后降低,当替代比例为50%时,硬度最大;弹性差异不显著（P＞0.05）,咀嚼性差异显著（P＜0.05）且变化趋势和硬度一致。温度扫描动态储能模量G’显示：与对照组相比,添加鱼油与玉米油预乳化液处理组的动态储能模量更高,且添加50%替代比例的预乳化液时,G’值最高。感官评价显示：预乳化液替代比例为50%时,乳化肠在外观、风味和总体接受度得分最高。因此,油脂预乳化液替代乳化肠质量50%的猪背膘可以有效降低乳化肠中脂肪含量,提高质构特性,改善产品的顾客接受程度。     

Pre-Emulsified Corn Oil, Pork Fat, or Added Moisture Affect Quality of Reduced Fat Bologna Quality

Replacing fat with additional water prevented the increase in firmness normally associated with low-fat meat products. Pre-emulsifying the fat or oil also decreased the firmness of reduced-fat bologna. The color of reduced fat bologna was darker for all except the pre-emul-sified corn oil treatments. Redness values for the intact (reduced) fat were the highest of all treatments. Pre-emulsifying fats caused a reduction in redness values for bologna. Flavor and overall acceptability scores from a consumer sensory panel did not differ among bologna samples, but juiciness scores were higher in bologna containing additional water. Accumulated purge in vacuum packages increased with water content in the products and with addition of pre-emulsified oil.     

Influence of the addition of mechanically recovered meat on the physico-chemical properties of meat model blends

The physico-chemical properties of meat model blends (basic composition: fresh lean pork, pork back fat, 2% NaCl, water with ice), with added mechanically recovered pork (MRM), were studied. Fresh MRM was added at levels of 10% and 20% substitution of meat protein with or without further substitution by 10% sodium caseinate or soya isolate. The addition of MRM to meat blends caused an increase in the pH, the water-holding capacity, the viscosity, the dominant wavelength and colour purity. No effects on emulsifying capacity were observed but thermal cooking losses and lightness of colour were reduced. The addition of blends of MRM and soya isolate or sodium caseinate caused lower values of the investigated features than those observed when only MRM was used.     

酪蛋白酸钠-葵花籽油协同对乳化肠品质特性的影响

以猪后腿肉为原料肉,酪蛋白酸钠、葵花籽油预乳化液替代猪背膘制备乳化肠,研究不同比例（0、25%、50%、75%、100%）预乳化液替代对乳化肠蒸煮损失率、物理化学组成、色泽、质构、脂肪酸组成及硫代巴比妥酸值的影响。结果显示：随着预乳化液替代比例增加,乳化肠中蛋白质、水分的含量显著增加（P＜0.05）,灰分含量变化差异不显著,脂肪含量显著下降（P＜0.05）,从18.58%降低到10.17%;蒸煮损失率降低;乳化肠的亮度值随预乳化液代替猪背膘比例的增加呈上升趋势,红度值和黄度值呈下降趋势;预乳化液替代组乳化肠的质构特性优于对照组;预乳化液替代猪背膘制备乳化肠还可以改变乳化肠的脂肪酸组成,随替代比例的增大,乳化肠中必需脂肪酸亚油酸在总脂肪酸中所占的比例显著增加（P＜0.05）,多不饱和脂肪酸所占的比例增加,高达55.92%,饱和脂肪酸从39.72%降低到13.52%,满足消费者对低脂多不饱和脂肪酸肉制品的需求;随替代比例的增大,乳化肠的TBARS值逐渐减小,用预乳化液替代猪背膘可增强乳化肠的氧化稳定性。因此,酪蛋白酸钠、葵花籽油预乳化液替代猪背膘可显著改善乳化肠的品质及营养特性。     

大豆油和预乳化大豆油对金线鱼鱼糜凝胶品质的影响

为了改善鱼糜制品的品质,研究2?mL/100?g大豆油和10?mL/100?g预乳化大豆油（即经乳清分离蛋白或酪蛋白酸钠预乳化的大豆油乳液,其中含2?mL/100?g大豆油）对金线鱼鱼糜凝胶性能、微观结构和感官特性的影响,比较大豆油和大豆油乳液的添加对鱼糜凝胶品质的影响。结果表明,直接添加2?mL/100?g大豆油后金线鱼鱼糜凝胶的白度增加,但凝胶质构特性较差,持水性下降,蒸煮损失率增加（P＜0.05）,凝胶基质中油滴分布不均匀,有明显的油滴聚集,其油滴直径主要分布在0.10～0.175?μm,凝胶三维网络结构孔径大,油脂的氧化性显著增加（P＜0.05）;添加10?mL/100?g大豆油乳液后,鱼糜凝胶的白度、持水性和结合水含量增加,蒸煮损失率下降（P＜0.05）,且对凝胶质构和油脂氧化性的影响不显著（P＞0.05）,凝胶制品的感官品质明显改善,预乳化的细小油滴在凝胶基质中均匀分布,油滴直径小于0.10?μm,凝胶三维网络结构的孔径小,表面比较光滑。因此,经乳蛋白预乳化大豆油可以有效改善金线鱼鱼糜的凝胶性能和风味,为新型鱼糜制品的开发提供了参考。     

Characteristics of low-fat meat emulsion systems with pork fat replaced by vegetable oils and rice bran fiber

The effects of vegetable oils prepared from olive, corn, soybean, canola, or grape seed, and rice bran fiber on the composition and rheological properties of meat batters were studied. Pork fat at 30% in the control was partially replaced by one of the vegetable oils at 10% in addition to reducing the pork fat to 10%. The chemical composition, cooking characteristics, texture properties, and viscosity of low-fat meat batters were analyzed. The moisture, protein, ash content, uncooked and cooked pH values, b^∗-value, hardness, cohesiveness, gumminess, chewiness, and viscosity of meat batters with vegetable oil and rice bran fiber were all higher than the control. In addition, batters supplemented with vegetable oil and rice bran fiber had lower cooking loss and better emulsion stability. Low-fat meat batters with reduced pork fat content (10%) and 10% vegetable oil plus rice bran fiber had improved characteristics relative to the regular fat control.     

Development of a Hamburger Patty with Healthier Lipid Formulation and Study of its Nutritional, Sensory, and Stability Properties

A modified beef hamburger patty enriched in polyunsaturated n−3 fatty acids and α-tocopherol was developed using technological procedures. Raw meat was obtained from low-cost parts of beef carcasses (brisket and flank) to which visible fat and connective tissue was manually eliminated and substituted by a mixture of pre-emulsified olive, corn, and deodorized fish oil. The developed product was analyzed and compared to conventional beef hamburger patties for their proximate composition, fatty acid profile, and consumer acceptability. The effects of cooking on the fat content and fatty acid profile of the developed product were investigated. Additionally, the lipid oxidation and surface color stability of modified and conventional hamburgers were investigated during 8 days of refrigerated storage while packaged in a modified atmosphere (20%/80% CO₂/O₂) and subsequently cooking. The developed product showed significantly lower total fat, cholesterol, sodium, and calorie content than beef hamburger patties manufactured using conventional procedures. In addition, the polyunsaturated fatty acids/saturated fatty acids and n−6/n−3 ratios matched nutritional recommendations more closely. No evidence of lipid oxidation was found for the modified hamburger patties during 8-day storage period, and surface color, especially redness, was more stable than in conventional ones. Additionally, consumer acceptability of the developed patty after it was cooked was acceptable and similar to that of conventional products. The modified hamburger patty developed by technological methods is viable and can be considered a useful food to preclude nutritional disorders or to assist in nutritional regimens.     

EFFECT OF COOKING OIL TYPE ON FINAL CHOLESTEROL CONTENT AND FATTY ACID COMPOSITION OF GROUND BEEF

The purpose of this study was to compare three oils for extraction of cholesterol when used to cook ground beef and to determine the effect of oil type on fatty acid composition of the ground beef. Ground beef (30 % fat) was cooked in 1 L of corn, canola or palm oil at 100–110C and then rinsed with 500 ml of boiling water, which significantly decreased ether-extractable fat. Control hamburger was skillet-fried without any added oil. Total lipids were extracted and analyzed for fatty acid composition and cholesterol content. Changes in fatty acid composition of residual fat on the meat after cooking reflected those of the oils used for cooking. Cholesterol was significantly lower in all oil-cooked hamburger than in the control. In conclusion, cooking ground beef in any of the three vegetable oils will extract cholesterol, and the lipid remaining after a boiling water rinse will contain fatty acids characteristic of the cooking oil.     

Physical Characteristics and Microstructure of Reduced-fat Frankfurters as Affected by Salt and Emulsified Fats Stabilized with Nonmeat Proteins

Functional properties and microstructure of frankfurters containing 1.5% or 2.5% salt and 15% pre-emulsified fat (PEF) stabilized with 2% pea protein, soy protein, or sodium caseinate were studied. With the exception of frankfurters with pea protein and 1.5% NaCl, all the others made with PEF" had greater (p < 0.01) thermal stability than all-meat frankfurters. Frankfurters containing soy protein or sodium caseinate had greater (p < 0.01) shear force than those with pea protein. Reducing NaCl in the frankfurters containing PEF did not influence the shear force. Microstructure examination revealed that many fat globules were entrapped physically within soy protein or sodium caseinate, which stabilized the meat emulsions and contributed to a firmer texture. Key Words: emulsified fat, reduced-fat, low-salt, microstructure, frankfurters     

Effect of regular and hydrolysed dairy proteins on texture,microstructure and colour of lean poultry meat batters

The use of 2% milk protein isolate (MPI), and some of its fractions which included caseinate, whey protein isolate (WPI), two whey protein hydrolysates (5.2% and 8.5%; WPH‐I and WPH‐II respectively) and β‐lactoglobulin (β‐lac) was evaluated in lean chicken breast meat batters. Adding caseinate and MPI resulted in the highest fracture force values, and caseinate also provided higher yield compared with the control. Both proteins were observed to form distinct protein islands embedded within the meat protein matrix, which appeared to enhance the gel structure. The two hydrolysates provided the highest yield compared with all other treatments. However, adding WPH‐II also resulted in the lowest fracture force and hardness values, while WPH‐I provided similar values to the control. The low hardness value could be explained by the light micrograph which showed WPH‐II interfering with the binding of the meat proteins. The WPI and β‐lac provided similar yield, fracture and hardness values as the control. The colour of the products was most affected by the WHP‐I and WHP‐II; both resulted in lower lightness, yellowness and overall spectra reflectance curves. A cost analysis revealed that caseinate addition was the most economical in this lean meat system.     

EFFECTS OF BINDING SUBSTRATE, TYPE OF NONMEAT ADDITIVE AND METHOD OF TENDERIZING ON CURED CHICKEN ROLLS

Chicken rolls were manufactured using ground dark fowl meat or mechanically deboned poultry meat as a binding substrate, sodium caseinate or soya isolate and a meat block that was mechanically tenderized or chunked. Effects of these treatments on yield, chemical composition, sensory and texture profile attributes were evaluated in this study. Inclusion of soya isolate increased the cook yield and improved color over sodium caseinate (P < 0.05). Likewise, rolls containing ground-dark fowl meat were lighter in color than those made with mechanically deboned poultry meat. Rolls made with mechanically deboned poultry meat had greater chewiness, while those made with sodium caseinate had greater cohesiveness. Texture profile analysis indicated that mechanical tenderization was the predominant factor in producing a softer and more springy chicken roll. Sensory evaluation revealed that mechanical tenderization decreased chewiness as compared to cubing (P < 0.05).