Effects of Collagen and Alkaline Phosphate on Time of Chopping, Emulsion Stability and Protein Solubility of Fine-Cut Meat Systems

Four meat emulsions were prepared with two levels of collagen and alkaline phosphate. Samples were taken at five different chopping temperatures and evaluated for total chopping time, emulsion stability and protein solubility. Adding additional collagen to meat emulsions shortened total chopping time, and decreased emulsion stability but had no effect on protein solubility. The addition of 0.25% sodium tripolyphosphate (STPP) improved emulsion stability but resulted in no significant (p>0.05) change in chopping time or protein solubility. The high-collagen-phosphate (HCP) treatment resulted in less fat, gelliquid, solid and total cookout when compared with high-collagen no-phosphate (HC) and low-collagen no- phosphate (LC) treatments. Maximum emulsion stability was obtained at 13°C.     

Textural attributes and oxidative stability of pork longissimus muscle injected with marbling-like emulsified lipids

The objective of the study was to create marbling-like fat in lean pork with acceptable oxidative stability through the injection of canola/olive oil-substituted emulsions. Pork loins were injected with 5% water as control (CW) or 5% emulsion containing no tocopherols (E) or 0.07% tocopherols (ET) and stored at 2 °C in an oxygen-enriched package for up to 3 weeks. Lipid oxidation was totally inhibited in ET pork but increased 3-fold to 0.20mg malonaldehyde/kg in CW and E pork after 3 weeks. ET treatment also had a positive effect on meat red color. Emulsion-containing pork, showing less protein oxidation (carbonyl and disulfide formation), had reduced drip loss and shear force than CW samples (P<0.05). The results indicated that incorporation of antioxidant-containing emulsions could create marbling-like texture in lean pork without compromising oxidative stability.     

Cook Yield, Texture and Gel Ultrastructure of Model Beef Batters as Affected by Low Levels of Calcium, Magnesium and Zinc Chloride

Effects of 0.05% CaCl₂, MgCl₂, or ZnCl₂, with or without 0.4% sodium tripolyphosphate (STPP), were investigated in high fat (HF; 30% fat) or low fat (LF; 10% fat) model beef batters. Cook yield (CY), texture, and gel ultrastructure were evaluated. With STPP, CaCl₂ increased CY, and in the absence of STPP, ZnCl₂ decreased CY and cohesiveness (p<0.05). Low-fat, ZnCl₂-treated batters without STPP had the lowest (p<0.05) hardness. Addition of STPP resulted in a homogeneous matrix in HF batters. In MgCl₂-treated HF batters, protein film surrounding fat globules had greater integrity than control, CaCl₂ or ZnCl₂ treatments. In ZnCl₂-treated HF batters (without STPP) a protein sheet was present without evidence of film encased droplets. Low-fat batters with STPP had finer, more porous networks than those without STPP.     

Effect of sodium phytate, sodium pyrophosphate and sodium tripolyphosphate on physico-chemical characteristics of restructured beef

The effects of 0.5% sodium phytate (SPT), sodium pyrophosphate (SPP), and sodium tripolyphosphate (STPP), along with 1% NaCl, on physico-chemical properties of restructured raw and cooked beef were evaluated. In raw beef stored for 1 day at 4 ° C, the SPT, SPP, and STPP increased pH and salt-soluble protein level and decreased %MetMb and thiobarbituric acid reactive substances (TBARS), compared to the control with salt alone (p < 0.05). In cooked beef, SPT, SPP, and STPP increased bind strength, cook yield, moisture level, and pH, and decreased TBARS (p < 0.05). SPP and STPP increased orthophosphate in both raw and cooked beef (p < 0.05), compared to the SPT and control. SPT, SPP, and STPP decreased the Hunter color L and b values and increased a value in raw beef (p < 0.05) but had no effect on the Hunter color values in cooked beef. The binding value of SPP and STPP were similar over time, and the time to reach maximum binding strength was 10s longer than SPT and 25s longer than the control. These results indicate that SPT compares favorably with traditional phosphates for bind strength and cooked yield, but SPT was slightly more effective than other phosphates for reduction of TBARS 1 day after cooking.     

Some Physical Parameters Involved in the Addition of Inorganic Phosphates to Reduced-Sodium Meat Emulsions

The effects of preblending, order of addition and the physical state of alkaline phosphates on the stability of reduced sodium chloride (0.75%) meat emulsions were determined. Preblending meat batches with reduced sodium chloride for 16 hr resulted in no significant effect upon the stability of meat emulsions, with or without the presence of alkaline phosphates. However, the addition of sodium tripolyphosphate (STPP) and tetrasodium pyrophosphate (TSPP) significantly improved emulsion stability. Neither the order of TSPP addition in relation to that of sodium chloride nor the physical state of its addition (dry or in solution) affected emulsion stability or the soluble protein level.     

Emulsifying properties of β-lactoglobulin and Quillaja bark saponin mixtures: Effects of number of homogenization passes,pH, and NaCl concentration

The effects of number of homogenization passes, pH, and NaCl concentration on the formation and stability of oil-in-water emulsions comprising a mixture of a biosurfactant (Quillaja bark saponin) and a globular protein (β-lactoglobulin) were investigated. The emulsions were characterized as to visual appearance, droplet size, droplet surface charge, and rheology. The emulsions obtained by different conditions (4, 6, or 8 passes; pH 7, 8, or 9; and 0, 100, or 200 mmol L^?1 of NaCl) were polydisperse, presented relatively small average droplet sizes (z-average < 323 nm) as well as negative droplet charge (between –20 and –79.6 mV) in all evaluated conditions. Regardless of the number of homogenization passes, the emulsions exhibited low apparent viscosity and pseudoplastic behavior with small yield stress. Viscoelastic behavior was also observed, thus the emulsions were characterized as weak gels. Four homogenization passes were enough to obtain small droplets in the evaluated conditions. Droplet size was not significantly affected by NaCl concentration and pH (p > 0.05). On the other hand, the absolute ζ-potential values significantly decreased and increased upon increased NaCl content and pH, respectively. Regardless of the tested conditions, all emulsions had good stability against phase separation and droplet aggregation, since no significant changes in average droplet size were observed throughout storage (p > 0.05). In the presence of NaCl, in which droplet charge significantly decreased, emulsion was also stable. Thus, we can conclude that electrostatic repulsion as well as steric repulsion was responsible for stabilization.     

Evaluation of salt, polyphosphates and their blends at different levels on physicochemical properties of buffalo meat and patties

The effects of sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP), sodium hexametaphosphate (SHMP), sodium acid pyrophosphate (SAPP) and their blends at different levels (0·3, 0·5 and 0·7%), along with 2% sodium chloride on certain quality parameters of buffalo meat and patties were evaluated. The SPP, STPP and phosphate blends significantly increased pH, water-holding capacity (WHC), emulsifying capacity (EC), extractability of salt soluble proteins (SSP), colour of ground meat, decreased cooking loss (CL), improved emulsion stability (ES) and enhanced yield, texture and moisture retention of cooked patties. Compared to these phosphates, SAPP and SHMP had significantly poorer effects on improving the quality of meat and patties. The order of effectiveness of phosphates was SPP > STPP > SHMP. In general, pH, WHC, SSP, ES, yield and moisture content of patties increased progressively with increasing level of phosphate while CL decreased. Among blends containing two polyphosphates, those of 90% SPP + 10% SHMP and 75% SPP + 25% STPP were relatively more effective. A phosphate blend consisting of 65% SPP, 17·5% STPP and 17·5% SAPP was equally effective as that of SPP in improving the functionality of hot and chilled meat and had the advantage of reducing the amount of sodium by 3%.     

Effect of glycerol and vegetable oil on physicochemical properties of Arabic gum-based beverage emulsion

The effect of two emulsion components namely glycerol (0.5, 1 and 1.5% w/w) and vegetable oil (2, 3 and 4% w/w) on ζ-potential, conductivity, pH, apparent viscosity, fluid behavior, turbidity and cloud stability of orange beverage emulsion was investigated. The negatively charged ζ-potential significantly (p < 0.05) increased with increasing glycerol content. A slight increase in ζ-potential was observed by adding 2% (w/w) vegetable oil to the emulsion formulation, while it was slightly decreased when vegetable oil content was increased up to 4% (w/w). Apparent viscosity, pH and turbidity of orange beverage emulsions significantly (p < 0.05) increased when the concentration of glycerol or vegetable oil was increased. All prepared beverage emulsions behaved as non-Newtonian (i.e., pseudoplastic or shear thinning) fluids. The addition of different concentration levels of both supplementary emulsion components except for 0.5% (w/w) glycerol significantly (p < 0.05) improved the cloud stability of orange beverage emulsions.     

Synergistic effects of polyglycerol ester of polyricinoleic acid and sodium caseinate on the stabilisation of water–oil–water emulsions

The inherent thermodynamic instability of water–oil–water (W/O/W) emulsions has restrictions for their application in food systems. The objective of this study was to develop a food grade W/O/W emulsions with high yield and stability using minimal concentrations of surfactants. Emulsions were prepared using soybean oil, polyglycerol ester of polyricinoleic acid (PGPR) alone or in combination with sodium caseinate (NaCN) as emulsifier(s) for primary water-in-oil (W/O) emulsions and NaCN as the sole emulsifier for secondary W/O/W emulsions. Increasing the concentration of PGPR (0.5–8%w/v) had no effect on the droplet sizes of the resulting W/O/W emulsions. However, significant increases in droplet sizes of W/O/W emulsions were observed when the concentration of NaCN in external phase was reduced from 0.5 to 0.03% (w/v) (p<0.05). Percentage yields of emulsions (using a water-soluble dye) improved when PGPR concentration in the inner phase was increased from 0.5 to 8% (w/v). A stable W/O/W emulsion with a yield >90% could be prepared with 4% (w/v) PGPR alone as primary hydrophobic emulsifier and 0.5% (w/v) NaCN as external hydrophilic emulsifier. The concentration of PGPR in the inner phase could be reduced to 2% (w/v) without affecting the yield and stability of the W/O/W emulsion by partially replacing PGPR with 0.5% (w/v) NaCN, which was added to the aqueous phase of the primary W/O emulsion. The results indicate that a possible synergistic effect may exist between PGPR and NaCN, thus allowing formulation of double emulsions with reduced surfactant concentration.     

Emulsions stabilization by lactoferrin nano-particles under in vitro digestion conditions

In recent years there has been a spur of interest in the utilization of nano and micro-particles to fabricate novel food-grade Pickering emulsions. Aligned with increased interest and efforts to promote health through food, this study aimed to extend the understanding of Pickering emulsions stabilized by lactoferrin (LF) nano-particles in respect to their stability and responsiveness to physiological conditions of the human mouth and stomach. Analytical centrifugation revealed that LF nano-particles did not alter mean droplet size of coarse emulsions but significantly (p < 0.05) reduced creaming rates by an order of magnitude. In fine emulsions produced through high pressure homogenization, the use of nano-particles increased mean droplet sizes. This resulted in noted (p < 0.05) differences in stability with emulsions stabilized by LF nano-particles and alginate showing poorest stability. Concomitantly, the use of i-carrageenan and LF nano-particles yielded emulsions with the most reduced creaming (<1 μm/s), even compared to emulsions stabilized by native LF. Interestingly, the use of alginate and i-carrageenan with LF nano-particles also altered emulsion stability to artificial saliva and modulated emulsion behavior under gastric conditions, which was linked to reduced rate of LF gastric proteolysis. Overall, this work establishes a new possibility to incorporate LF in emulsions and demonstrates how LF nano-particles could be harnessed to modulate emulsion destabilization and breakdown in the mouth and stomach.     

滚揉和腌制液成分对肉块类西式火腿质构的影响

研究了滚揉时间、腌制液中食盐浓度和三聚磷酸钠(STPP)浓度3因素对肉块类西式火腿的质构影响。采用冷鲜的猪里脊肉为原料,每个因素3个水平,按照L27(313)考虑交互作用的正交实验设计,进行滚揉和腌制液的配制,并制作肉块类西式火腿。利用质构仪测定火腿的硬度和弹性。滚揉时间、腌制液中食盐浓度、三聚磷酸钠浓度以及他们的交互作用对火腿的硬度影响显著(p<0.05),增加滚揉时间不能显著提高火腿的弹性,反而增加电能的消耗,食盐浓度和滚揉时间的交互作用对产品弹性的影响显著(p<0.05),并且其交互效益大于食盐浓度和三聚磷酸钠的单独效益。当滚揉时间8h,腌制液中食盐浓度10%,STPP浓度2.0%时硬度品质最优。当滚揉时间4h,腌制液中食盐浓度8%,STPP2.0%时弹性品质最优。     

三聚磷酸钠对热诱导全蛋液凝胶性质的影响

本文以新鲜的全蛋液为实验原料,在不同加热温度和不同三聚磷酸钠(Sodium Tripolyphosphate,STPP)添加量下对其进行热处理,通过对全蛋凝胶质构、色泽、蒸煮损失、持水性、低场核磁共振(LF-NMR)的分析测定,探究了STPP对热诱导全蛋液凝胶性质的影响。当加热温度从80 ℃升高到95 ℃时,蛋白凝胶网络结构变得更加稳定,全蛋液凝胶强度增加,当STPP添加比例从0.0%增加到0.6%时,凝胶的硬度和弹性呈现先增大后减小的趋势,在添加量为0.2%时,凝胶硬度、弹性都达到最高。并利用低场核磁共振(LF-NMR)技术检测了凝胶内部不同水分的状态变化,当加热温度从80 ℃升高到90 ℃时,T₂₁(结合水)和T₂₂(中间态水)峰值弛豫时间保持不变,T₂₃(自由水)逐渐增加,当加热温度为95 ℃时,自由水含量增加,中间态水减少;当STPP添加量从0.2%增加到0.6%时,结合水结合更加紧密,中间态水逐渐增多。综合各种指标分析,结果表明STPP的添加改善了全蛋液热诱导凝胶的质构特征和颜色特征,增强了凝胶持水力。实验结果为热凝固蛋制品的开发与改良提供参考。     

Mannans as stabilizers of oil-in-water beverage emulsions

The stabilizing effect of spruce galactoglucomannan (GGM) on a model beverage emulsion system was studied and compared to that of guar gum and locust bean gum galactomannans, konjac glucomannan, and corn arabinoxylan. In addition, guar gum was enzymatically modified in order to examine the effect of the degree of polymerization and the degree of substitution of galactomannans on emulsion stability. Use of GGM increased the turbidity of emulsions both immediately after preparation and after storage of up to 14 days at room temperature. GGM emulsions had higher turbidity than the emulsions containing other mannans. The initial turbidity increased with increasing GGM content, but after 14 days storage at room temperature, the turbidity was the highest for GGM/oil ratio of 0.10:1 when ethanol-precipitated GGM was used. Increasing the storage temperature to +45 °C led to rapid emulsion breakdown, but a decrease in storage temperature increased emulsion stability after 14 days. Confocal microscopy showed that the average particle size in the bottom part of GGM emulsions stored for 14 days was smaller than 1 μm. A low degree of polymerization and a high degree of substitution of the modified galactomannans were associated with a decrease in emulsion turbidity.     

Effects of Inorganic Phosphates and Sodium Hydroxide on the Cooked Cured Color, pH and Emulsion Stability of Reduced-Sodium and Conventional Meat Emulsions

Phosphates that increased meat emulsion stability the most also caused the highest decrease in cured color development. The addition of 0.125% sodium hydroxide also reduced cured color development. Holding uncooked emulsions, containing either sodium tripolyphosphate or tetrasodium pyrophosphate, up to 60 min after emulsion preparation plus adding tetrasodium pyrophosphate later in the emulsification procedure improved cured color development upon cooking. In both cases, cooked pH increased as cured color improved, and emulsion stability declined. This suggested that phosphate effects other than, or in addition to, pH were involved in cured color development and emulsion stability.     

Emulsifying properties of proteins extracted from Australian canola meal

Canola protein albumin fraction, globulin fraction, and canola protein isolate (CPI) were compared to commercial soy protein isolate (SPI) in terms of their emulsifying properties at various pH values. The globulin fraction had higher emulsifying capacity (EC), higher emulsifying activity index (EAI), and the droplet size of emulsions it stabilized was consistently smaller irrespective of pH compared to albumin fraction or CPI. In comparison to SPI, globulin fractions also had higher EC at all pH values tested, higher EAI at acidic pH, and smaller or comparable average emulsion droplet size at both pH 4 and 7. The stability of canola protein based emulsions were comparable to those of SPI based emulsions at most pH values (except the emulsion stabilized by the CPI at pH 4), with no significant (p > 0.05) changes in droplet size during storage for up to 7 days at room temperature. These emulsions, however, experienced separation into the emulsion and serum phases after 24 h storage at room temperature with the exception of CPI- and SPI-stabilized emulsions at pH 9. This study demonstrates the comparable emulsifying properties (forming or stabilizing) of some canola proteins to commercially available SPI, suggesting the potential use of canola proteins in food applications.     

高内相Pickering乳液替代脂肪对肉糜制品特性的影响

将β-乳球蛋白纳米颗粒（β-lactoglobulin nanoparticles，β-LGNPs）稳定的高内相Pickering乳液（high internal phase Pickering emulsion，HIPEs）应用于肉糜制品中替代动物脂肪，以改善产品品质并减少饱和脂肪酸摄入。结果表明，随着乳液替代比例的增加肉饼品质逐步改善，当替代比例为100%时，肉饼的蒸煮得率从75.53%提升到89.47%，硬度、弹性和咀嚼性等质构特性均有所提升。HIPEs的添加使肉饼加热后脂肪硫代巴比妥酸反应物值下降，说明包埋体系很好地抑制了加热过程中的脂质氧化；此外，肉饼的色泽以及保水保油性也有所改善。微观结构研究显示所有样品因加热导致蛋白质基质聚集并产生具有海绵状（蜂窝状）的结构，所有动物脂肪替代组油滴分布均较均匀，说明加热过程中HIPEs保持很好的稳定性，蛋白质消化率也随着HIPEs替代比例增加而增加。本研究为HIPEs作为脂肪替代物在肉糜制品加工中的应用提供一定理论依据。     

大豆分离蛋白添加方式对猪肉凝胶特性的影响

大豆分离蛋白是肉制品加工中常用的植物蛋白,能够改善肉制品品质,但添加方式影响肉制品质量。本文研究添加大豆分离蛋白和11S球蛋白变性的大豆分离蛋白乳化猪背膘对猪肉肉糜蒸煮得率、乳化稳定性及猪肉凝胶色差和质构的影响,并应用低场核磁共振技术,研究不同处理猪肉凝胶中水分分布状态和水分迁移特性的异同。与添加大豆分离蛋白相比,添加大豆分离蛋白乳化猪背膘显著提高(P0.05)猪肉肉糜的蒸煮得率和乳化稳定性,提高凝胶的L*-值和b*-值,硬度、弹性、内聚性和咀嚼性等。低场核磁共振结果表明:添加大豆分离蛋白乳化猪背膘的凝胶,T_(2b)和T_(22)弛豫时间较短,说明水分可移动性降低;T_(21)的峰比例增加,而T_(22)的峰比例降低,说明不易流动的水分含量增加,凝胶有较好的保水性。     

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.     

Effect of a new emulsifier containing sodium stearoyl-2-lactylate and carrageenan on the functionality of meat emulsion systems

The emulsion capacity and stability of a new emulsifier containing sodium stearoyl lactylate plus iota carrageenan (SSL/iC) in comparison to caseinate and soy isolate was analysed. The emulsion capacity and stability of SSL/iC in oil/water (O/W) model system emulsions was higher than shown by caseinate and soy isolate. However, the O/W emulsion stability was negatively affected by sodium chloride addition, but positively affected by an increase in temperature. Meat batters were made with caseinate, soy isolate, and SSL/iC at the minimum concentration that showed a good performance (>75% stability) in the O/W emulsions. The emulsifier SSL/iC produced high cook yields and good stability when used in meat batters. However, the cooked meat batters containing SSL/iC showed texture characteristics highly detrimental to the sensory analysis. On the other hand, the addition of 2% potato starch reduced the differences in texture parameters among the samples made with the different emulsifiers.     

Study on quality characteristics of camel burger and evaluating its stability during frozen storage

This study investigated the influence of replacing One-humped camel meat instead of cow meat (0, 25, 50, 75 and 100 %) on quality characteristics and frozen storage stability in burgers. For this purpose thiobarbituric acid test (TBA-RS), cooking characteristics, color parameters, texture and sensory properties were studied during 3 months at ?18 °C. Significant differences (p < 0.05) were observed in the moisture retention, diameter reduction, sensory properties, lightness, yellowness and springiness. Cooking yield, TBA-RS, fat retention, cohesiveness, flavor and texture showed significant differences (p < 0.05) through storage. Other evaluated properties of burgers showed no significant differences (p > 0.05) in various levels of camel meat and over storage term. Moisture retention of burgers increased with increasing of camel meat content. The sensory panel scores for flavor, texture, juiciness and overall acceptability increased but color scores decreased with increasing the level of camel meat. Cooking yield, fat retention and cohesiveness decreased by increasing the storage period.