非肉蛋白对肌原纤维蛋白及肉品品质影响的研究进展

肌原纤维蛋白的乳化特性和凝胶特性对食品的质地、风味及感官特性都极为重要。非肉蛋白由于具有较高营养价值及价格低廉的优势,逐渐成为肉制品中外源添加物的更好选择。本文主要综述非肉蛋白的添加对肌原纤维蛋白乳化和凝胶体系稳定性的影响,进一步分析非肉蛋白对肉制品品质的影响,旨在为非肉蛋白改善肉制品品质提供理论指导,进而为非肉蛋白在食品中的应用提供理论参考。     

Effect of lactic or acetic acid on degradation of myofibrillar proteins in post‐mortem goose (Anser anser) breast muscle

The effects of lactic acid (LA) and acetic acid (AA) on changes in myofibrillar proteins of post‐mortem goose breast muscle marinated for 24 h at 5 °C were studied. Purified myofibrils were prepared from 0.1 M LA or AA samples and controls (non‐marinated samples) after 0, 1, 3, 7 or 14 days of storage at 5 °C. The changes in myofibrillar proteins of goose muscle were examined by SDS‐PAGE. Goose breast muscle marinated in LA and AA exhibited degradation of myosin heavy chains. The appearance of ∼95 and ∼27 kDa components and the disappearance of titin and nebulin were also more rapid than for control muscle. These results suggest that acid marination enhanced the post‐mortem proteolysis of goose breast muscle. © 2000 Society of Chemical Industry     

Texture, Color and Sensory Characteristics of Ground Beef Patties Containing Bovine Blood Proteins

Three levels of bovine plasma (BP; 1.5, 2.5, 3.5%), red cell (RC; 0.5, 0.75, 1.0%) and decolorized red cell (DC; 0.75, 1.5, 2.25%) proteins were substituted for lean in ground beef patties. Increased RC decreased HunterLab L* and b* values and DC increased L* values, b* values, nonheme iron, and heme iron in uncooked and cooked patties. Soy-type flavors with BP, bloody and metallic flavors with RC and sour flavors with DC increased compared with control patties. Color, iron, cooking loss, and oxidative stability were minimally changed in ground beef with 0.5% RC, 0.75% DC, or 3.5% BP.     

高压均质处理次数对肌原纤维蛋白水溶液结构及理化特性的影响

以鸡肉中的肌原纤维蛋白（myofibrillar proteins,MP）为对象,研究在103 MPa压力条件下不同高压均质（high pressure homogenization,HPH）处理次数（1～6 次）对MP水溶液结构以及理化特性的影响。结果表明：HPH可以显著提高MP在水中的溶解性（P＜0.05）。随着HPH处理次数的增加,MP在水溶液中的粒径先减小后变大;表观黏度减小,流动能力增强;表面疏水性和活性巯基含量先增加后减少;圆二色光谱结果显示不同HPH处理次数对MP水溶液的二级结构构象的影响不同;过多的HPH处理次数会导致MP水溶液中蛋白质聚集,从而影响其溶解性和稳定性;经过4 次HPH处理的MP水溶液具有较好的溶解性和稳定性。说明通过选择适当次数的HPH处理可以实现对MP在水中溶解性的调控,为其在食品加工中的应用提供新思路。     

Impact of pulsed electric fields and post‐mortem vacuum ageing on beef longissimus thoracis muscles

The impact of pulsed electric field (PEF) processing (0.2–0.6 kV cm^?1, 1–50 Hz, 20 μs) followed by vacuum ageing (1 and 3 days) on the quality traits of beef longissimus thoracis (LT) was assessed. The results show that pH, colour stability (L*, a* and R630/580 values) and cooking loss were unaffected by PEF treatments, whilst moisture content significantly (P < 0.05) decreased by 0.7–3.6%. No significant (P > 0.05) difference was found in shear force between PEF treated and untreated samples. However, the shear force values significantly reduced in response to ageing times regardless of the PEF treatments. After 3 days post‐treatment ageing, the shear force decreased by 20–22% compared to 1 day ageing for all samples. Furthermore, Cryo‐SEM results suggest that PEF treatments have led to more porous tissue structure leading to more water loss. Protein profile was unchanged by PEF treatments applied.     

芬顿氧化体系处理对白斑狗鱼肌原纤维蛋白结构和功能特性的影响

研究芬顿氧化体系诱导的不同氧化水平(0、1、5、10、20?mmol/L?H2O2)对白斑狗鱼肌原纤维蛋白结构和功能特性的影响.随着氧化水平的升高,肌原纤维蛋白的羰基和浊度增加、溶解度显著降低(P<0.05).十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析结果显示氧化后的肌原纤维蛋白中产生更多交联和蛋白质聚合.傅里叶变换红外光...     

Myofibrillar protein degradation of carp (Labeo rohita (Hamilton)) muscle after post‐mortem unfrozen and frozen storage

The degradation of myofibrillar proteins of rohu carp (Labeo rohita (Hamilton)) muscle was analysed after post‐mortem storage. Muscle fillets were kept either unfrozen at 2 °C for up to 15 days or frozen at ?8 °C or ?20 °C for up to 6 months. A co‐ordinated histochemical, biochemical and electrophoretic study showed a differential response of the carp muscle, revealing clear degenerative/degradative changes specific to the post‐mortem storage temperatures. The myofibrillar protein fractions, namely myosin light chains and α‐actinin, showed degradative changes during the above storage conditions, whereas other protein fractions in the high‐molecular‐weight range fragmented to give lower‐molecular‐weight proteins. The importance of the post‐mortem storage temperature for controlling the degradation of the myofibrillar proteins was emphasised. This is the first report on this popular fish species, known for its culinary importance, showing that specific protein fractions of the myofibrils degrade during post‐mortem storage. © 2001 Society of Chemical Industry     

Efficacies of Garlic and L. sakei in Wine‐Based Marinades for Controlling Listeria monocytogenes and Salmonella spp. in Chouriço de Vinho,a Dry Sausage Made from Wine‐Marinated Pork

Chouriço de vinho is made from roughly minced (10 to 30 mm) pork and fat, seasoned with a marinade made from wine, salt, garlic, and other facultative seasonings used according to the recipe of each producer. The batter is maintained at 4 to 7 ºC for 24 to 48 h. It is then stuffed into natural thin pork gut, cold smoked and matured at a low temperature for 1 to 4 wk. The effect of garlic used in wine‐based marinade and a starter culture of indigenous Lactobacillus sakei on the behavior of Listeria monocytogenes and Salmonella spp. in the processing of chouriço was investigated. The garlic (as powder and fresh juice) was found to contribute (P < 0.05) to the control of both pathogens in broth. Garlic dose, as tested within the usual limits used for seasoning, did not impact the reduction of pathogens. Garlic‐wine‐based marinade and a starter culture of indigenous L. sakei contribute to controlling L. monocytogenes and Salmonella spp. in the processing of chouriço. Their presence was responsible for the loss of viability of L. monocytogenes and Salmonella spp. following 5 d of drying, even sooner than situations where no garlic was used. The results of the present work show that the use of a wine‐based marinade with garlic has an important role in ensuring the safety of the product.     

褐藻寡糖对鲢鱼鱼糜稳定性、分子间作用力及肌原纤维蛋白结构的影响

为区别不同质量浓度（0.5、1.0 g/100 mL）褐藻寡糖,包括酸解甘露糖醛酸寡糖（acidolyzed mannose oligosaccharide,AMO）、酸解古罗糖醛酸寡糖（acidolyzed guluronic oligosaccharide,AGO）和酶解褐藻酸钠寡糖（enzymolysis alginate oligosaccharide,EAO）对鲢鱼鱼糜及肌原纤维蛋白结构的影响,对鲢鱼鱼糜热稳定性、分子间作用力以及肌原纤维蛋白傅里叶变换红外光谱、内源荧光光谱及紫外吸收光谱进行分析。结果表明：AMO质量浓度对鲢鱼鱼糜热稳定性作用无规律,但在总体上,EAO提高了鱼糜的热稳定性,且与EAO质量浓度呈正相关,低质量浓度AMO与AGO更容易降低鱼糜的冰点和可冻结水含量,在提高鱼糜的抗冻性方面性能更优越;1.0 g/100 mL AGO保护离子键效果最好,EAO保护了肌原纤维蛋白的离子键、降低了氢键含量;褐藻寡糖修饰后,所有鱼糜-褐藻寡糖复合物的β-转角、α-螺旋含量减少,β-折叠、无规则卷曲含量上升;3 种褐藻寡糖对肌原纤维蛋白三级结构的展开有不同影响。     

Finishing steers with diets based on corn, high-tannin sorghum or a mix of both: Color and lipid oxidation in beef

We tested the hypothesis that feeding high-tannin sorghum (HTS) to steers would produce beef more resistant to oxidative deterioration. We observed lower thiobarbituric acid-reactive substances (TBARS) in Gluteus medius of steers fed HTS before it was displayed (P=0.028), which could be explained by a reduced response to stress in these animals. While steers finished with corn and corn+HTS had elevated plasma cortisol at the end of the feeding period (P=0.047 and 0.093, respectively), animals fed HTS and corn+vitamin E did not. However, feeding HTS increased the rate of discoloration and TBARS accumulation after aerobic display of Longissimus lumborum and Gluteus medius. Diet did not affect the activity of oxidation-related enzymes and fatty acid composition of muscle. The accelerated rate of lipid oxidation during display of beef could be partially explained by a numerically lower concentration of tocopherols in the tissue.     

Stability of protein‐stabilised β‐carotene nanodispersions against heating,salts and pH

BACKGROUND: Milk proteins are used in a wide range of formulated food emulsions. The stability of food emulsions depends on their ingredients and processing conditions. In this work, β‐carotene nanodispersions were prepared with selected milk‐protein products using solvent‐displacement method. The objective of this work was to evaluate the stability of these nanodispersions against heating, salts and pH. RESULTS: Sodium caseinate (SC)‐stabilised nanodispersions possessed the smallest mean particle size of 17 nm, while those prepared with whey‐protein products resulted in larger mean particle sizes (45–127 nm). Formation of large particles (mean particle size of 300 nm) started after 1 h of heating at 60 °C in nanodispersions prepared with SC. More drastic particle size changes were observed in nanodispersions prepared with whey protein concentrate and whey protein isolate. The SC‐stabilised nanodispersions were fairly stable against Na⁺ ions at concentrations below 100 mmol L^?1, but drastic aggregation occurred in ≥ 50 mmol L^?1 CaCl₂ solutions. Aggregation was also observed in whey protein‐stabilised nanodispersions after the addition of NaCl and CaCl₂ solutions. All sample exhibited the smallest mean particle size at neutral pH, but large aggregates were formed at both ends of extreme pH and at pH around the isoelectric point of the proteins. CONCLUSION: The nanodispersions prepared with SC were generally more stable against thermal processing, ionic strength and pH, compared to those prepared with whey proteins. The stable β‐carotene nanodispersions showed a good potential for industrial applications. Copyright © 2008 Society of Chemical Industry     

The Effect of pH and Chloride Concentration on the Stability and Antimicrobial Activity of Chlorine‐Based Sanitizers

Chlorinated water and electrolyzed oxidizing (EO) water solutions were made to compare the free chlorine stability and microbicidal efficacy of chlorine‐containing solutions with different properties. Reduction of Escherichia coli O157:H7 was greatest in fresh samples (approximately 9.0 log CFU/mL reduction). Chlorine loss in “aged” samples (samples left in open bottles) was greatest (approximately 40 mg/L free chlorine loss in 24 h) in low pH (approximately 2.5) and high chloride (Cl^?) concentrations (greater than 150 mg/L). Reduction of E. coli O157:H7 was also negatively impacted (<1.0 log CFU/mL reduction) in aged samples with a low pH and high Cl^?. Higher pH values (approximately 6.0) did not appear to have a significant effect on free chlorine loss or numbers of surviving microbial cells when fresh and aged samples were compared. This study found chloride levels in the chlorinated and EO water solutions had a reduced effect on both free chlorine stability and its microbicidal efficacy in the low pH solutions. Greater concentrations of chloride in pH 2.5 samples resulted in decreased free chlorine stability and lower microbicidal efficacy.     

A DSC study on the effects of various maltodextrins and sucrose on protein changes in frozen‐stored minced blue whiting muscle

A DSC heat denaturation study on the effects of various maltodextrins and sucrose on protein changes in minced blue whiting muscle during frozen storage at −10 and −20 °C was carried out. All maltodextrins slowed down the decreases in the denaturation enthalpies (ΔH_d) ascribed to myosin and actin, making evident a noticeable effectiveness against protein denaturation, especially at −20 °C. Sucrose was as effective as maltodextrins at −20 °C, but was the least effective treatment at −10 °C. Significant correlations between both ΔH_ds and either protein solubility or formaldehyde production were found at each storage temperature. A low protein sensitivity to the small amounts of formaldehyde produced during the first weeks of storage and errors associated with the determination of enthalpies led to poorer correlations at −20 °C. Maximum denaturation temperatures (T_max) correlated with protein solubility only at −20 °C. No clear relationship between either T_max and the effectiveness of cryostabilisation was found, as T_max also depends on the effectiveness of the treatments against the thermal denaturation of proteins. © 2001 Society of Chemical Industry     

Effects of Carbonation on Probiotic Survivability,Physicochemical, and Sensory Properties of Milk‐Based Symbiotic Beverages

Drinkable yogurt is a popular beverage in the United States and there may be a niche for carbonated drinkable yogurt in the functional foods market. Pomegranate (P) and vanilla (V) yogurt beverages were formulated, containing inulin as a prebiotic, along with probiotic bacteria Lactobacillus acidophilus and Bifidobacterium, to produce symbiotic products. These beverages were stabilized with high‐methoxyl pectin and whey protein concentrate and compared to samples with approximately 2 volumes of added carbon dioxide (CO₂). Samples were stored in sealed glass bottles at 4 °C for 9 wk for evaluation of physicochemical and functional properties. Trials were carried out in triplicate and 3 replicates from each trial were analyzed. Physicochemical attributes were analyzed using standard AOAC methods. Survivability of the probiotics and changes in pH and viscosity were measured weekly. Chemical composition of the carbonated beverages was: protein: 1.58 ± 0.05%, 1.59 ± 0.06%, fat: 1.24 ± 0.2%, 1.18 ± 0.11%, total solids: 14.78 ± 0.11%, 14.93 ± 0.05%, ash: 0.49 ± 0.02%, 0.46 ± 0.03%, and carbohydrate (by difference): 11.47 ± 0.12%, 11.69 ± 0.14% for P and V, respectively. Both L. acidophilus and Bifidobacterium were stable and remained above 10⁶ CFU/g for both flavors of beverage both with and without carbonation. The new manufacturing technology for these prototypes may have potential for commercialization of carbonated symbiotic milk‐based beverages.     

Effects of Metmyoglobin Reducing Activity and Thermal Stability of NADH‐Dependent Reductase and Lactate Dehydrogenase on Premature Browning in Ground Beef

Premature browning is a condition wherein ground beef exhibits a well‐done appearance before reaching the USDA recommended internal cooked meat temperature of 71.1 °C; however, the mechanism is unclear. The objectives of this study were: (1) to determine the effects of packaging and temperature on metmyoglobin reducing activity (MRA) of cooked ground beef patties and (2) to assess the effects of temperature and pH on thermal stability of NADH‐dependent reductase, lactate dehydrogenase (LDH), and oxymyoglobin (OxyMb) in‐vitro. Beef patties (lean: fat = 85:15) were packaged in high‐oxygen modified atmosphere (HiOX‐MAP) or vacuum (VP) and cooked to either 65 or 71 °C. Internal meat color and MRA of both raw and cooked patties were determined. Purified NADH‐dependent reductase and LDH were used to determine the effects of pH and temperature on enzyme activity. MRA of cooked patties was temperature and packaging dependent (P < 0.05). Vacuum packaged patties cooked to 71 °C had greater (P < 0.05) MRA than HiOX‐MAP counterparts. Thermal stability of OxyMb, NADH‐dependent reductase, and LDH were different and pH‐dependent. LDH was able to generate NADH at 84 °C; whereas NADH‐dependent reductase was least stable to heat. The results suggest that patties have MRA at cooking temperatures, which can influence cooked meat color.