海藻膳食纤维对低脂低盐鸡肉法兰克福香肠品质的影响

以低脂低盐鸡肉法兰克福香肠为研究对象,探讨不同添加量（0.5%、0.75%、1%、1.25%、1.5%、1.75%）的海藻膳食纤维对其食用品质的改善效果。结果表明,随着海藻膳食纤维添加量的增加,低脂低盐鸡肉法兰克福香肠的蒸煮损失、L*值和b*值显著降低（P<0.05）,而乳化稳定性、弹性、回复性、脆性和感官评价（致密性、多汁性、风味和总体可接受性）显著增大（P<0.05）,且1.5%为最佳添加量（P<0.05）。扫描电镜结果表明海藻膳食纤维能够促进鸡肉蛋白凝胶形成致密的三维网状结构。因此,海藻膳食纤维能够提高低脂低盐肉糜体系的持水性和凝胶特性,进而改善产品的食用品质,为低脂低盐肉制品的开发提供技术指导。     

TG酶协同超高压处理对鸡肉糜制品品质的影响

为了提高鸡肉糜制品的品质,优化加工工艺,把TG酶添加到肉糜制品中,然后经超高压处理,经过二段加热形成凝胶,测定其质构特性和保水率。结果表明,酶活度、压强和保压时间对鸡肉糜凝胶的质构特性（硬度、咀嚼性）和保水率影响显著（P＜0.05）。通过Box-Behnken试验设计所得结果和二次多项回归方程确
立了最优的工艺条件,即：酶活度1.95 U/g、压强450 MPa、保压时间22 min。此条件下验证实验得到凝胶保水率可达到（90.1±0.5）%。酶活度与压强和保压时间交互作用显著（P＜0.05）,而压强与保压时间交互作用不显著（P＞0.05）。研究表明,TG酶和超高压结合能够促进鸡肉糜形成良好的凝胶,在鸡肉糜加工中具有广泛的应用前景。     

脂肪含量对低盐猪肉凝胶品质的影响

以未添加磷酸盐的低盐猪肉凝胶作为研究对象,考察脂肪添加量(0～20%)对猪肉凝胶保水、质构和色泽的影响。结果显示,脂肪添加量在15%～20%范围内,凝胶保水性显著增加(P<0.05);添加5%以上的脂肪,可显著提高猪肉凝胶的L*值(P<0.05);在脂肪添加量不高于5%条件下,猪肉凝胶可形成良好的硬度、弹性、凝聚性和咀嚼性,并能保持较好的红度值(a*值),利于开发低脂猪肉制品。     

大豆分离蛋白添加量对低盐木质化鸡肉糜凝胶特性的影响

探究大豆分离蛋白(soy protein isolates,SPI)添加量对低盐和正常盐木质化鸡胸肉糜凝胶特性的影响.实验设置正常鸡胸肉为对照组.将不同量(0％、1％、2％)SPI分别添加到含1％和2％食盐的木质化和正常鸡胸肉糜中,测定热诱导凝胶的质构特性、颜色、蒸煮损失、水分分布以及蛋白质二级结构等指标.结果表明:相...     

山梨醇对预调理猪肉糜制品品质的影响

研究无磷持水剂山梨醇对预调理肉糜制品(猪肉丸)品质的影响.将0%、1%、5%、8%、10%的山梨醇分别加入猪肉丸中,研究其对猪肉丸的持水、质构、感官指标的影响.结果表明:山梨醇的添加能够显著减少猪肉丸滴液损失、解冻损失、蒸煮损失,提高猪肉丸得率(P<0.05);对猪肉丸的硬度有明显的改善作用(P<0.05),但对质构的其他指标影响不显著;感官各项指标加权综合评分,添加量为5%时,评分最高.     

Evaluation of various salt contents on quality characteristics with or without curdlan of pork myofibrillar protein gels and the development of low-salt pork sausages

The objective of this study was to evaluate the gelling properties of pork myofibrillar protein (MP) gels at various salt concentrations with or without curdlan, and its application to model sausages with reduced salt levels. When curdlan was incorporated into MP mixtures, cooking yield (CY) at 0.15 m salt was similar to that of 0.45 m salt (P > 0.05). Gel strength of MPs at 0.45 m salt was highest among other salt concentrations. Increased salt concentration tended to be high shear stress values, regardless of the presence of curdlan (P < 0.05). MP gels with increasing salt concentration showed fewer pores and swollen structures. Addition of curdlan improved CY and expressible moisture of low-fat model sausage with increased salt levels. The addition of curdlan at 1.0% salt reduced the hardness and gumminess, and similar to those at 1.5% without curdlan. These results indicated that curdlan improved the water-holding capacity and textural properties of low-fat and low-salt sausage.     

多糖协同超声波处理对低盐鸡肉糜凝胶特性的影响

本实验分别采用添加壳聚糖（chitosan,CH）和瓜尔豆胶（guar gum,GG）协同超声波处理（ultrasonic treatment,UT）提升低盐鸡胸肉糜凝胶品质,并通过测定蒸煮损失率、硬度、色泽、流变特性、水分分布和观察微观结构以评估其效果。结果表明：与对照组相比,添加GG会显著提高凝胶白度（P＜0.05）,增加体系表观黏度,使更多自由水转化为不易流动水,减少微观结构中的孔隙,且在加热过程中GG填充至肉糜凝胶网络可改善其凝胶品质;添加CH会显著降低凝胶白度（P＜0.05）,降低体系表观黏度,使水分流动性减弱,CH通过与蛋白质发生交联改善凝胶品质。而在添加多糖的基础上协同超声处理可进一步降低凝胶蒸煮损失率,显著提高硬度（P＜0.05）。结论：多糖协同超声波处理是一种有效提升低盐鸡胸肉糜凝胶品质的方法,能够为低盐健康的肉糜制品开发提供理论支持。     

Impact of Added Encapsulated Phosphate Level on Lipid Oxidation Inhibition during the Storage of Cooked Ground Meat

The effect of levels (0.1%, 0.2%, 0.3%, 0.4%, 0.5%) of added encapsulated (e) phosphate (sodium tripolyphosphate, STP; sodium hexametaphosphate, HMP; sodium pyrophosphate, SPP) on lipid oxidation inhibition during storage (0, 1, and 7 d) of ground meat (chicken, beef) was evaluated. The use of eSTP and eSPP resulted in lower and higher cooking loss (CL) compared to eHMP, respectively (P < 0.05). Increasing encapsulated phosphate level (PL) enhanced the impact of phosphates on CL in both chicken and beef samples (P < 0.05). Encapsulated STP increased pH, whereas eSPP decreased pH (P < 0.05). pH was not affected by PL. The highest orthophosphate (OP) was obtained with eSTP, followed by eSPP and eHMP (P < 0.05). The level of OP determined in both chicken and beef samples increased (P < 0.05) during storage. Increasing PL caused an increase in OP (P < 0.05). The highest reduction rate in the formation of thiobarbituric acid reactive substances (TBARS) and LPO for both meat species were obtained with eSPP, followed by eSTP and eHMP (P < 0.05). Increasing PL resulted in lower TBARS and LPO (P < 0.05). Findings suggest that encapsulated phosphates can be a strategy to inhibit lipid oxidation for the meat industry and the efficiency of encapsulated phosphates on lipid oxidation inhibition can be enhanced by increasing PL.     

Xanthan Enhances Water Binding and Gel Formation of Transglutaminase-Treated Porcine Myofibrillar Proteins

ABSTRACT: In this study, the effect of xanthan on dynamic rheological properties, textural profile, and water binding of transglutaminase (TG)-treated myofibrillar protein (MP) gels was investigated. In experiment 1, MP suspensions (40 mg/mL protein, 0.6 M NaCl) at pH 6.45 with or without 0.05% xanthan were treated with 0%, 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% TG; in experiment 2, MP suspensions (40 mg/mL protein, 0.6 M NaCl) at pHs 6.13, 6.30, 6.45, 6.69 with or without 0.05% xanthan were treated with 0.3% TG. Treated samples were analyzed with differential scanning calorimetry for thermal stability and oscillatory rheometry and Instron penetration tests for gelation properties. The TG treatments lowered the transition temperature (T_m) of MP by as much as 6 °C (P < 0.05) but increased apparent enthalpy of denaturation. However, there was no detectable thermal stability difference between MP samples with or without xanthan. The shear storage modulus (G′) of MP gels increased markedly upon treatments with ≥0.3% TG, and the presence of xanthan further enhanced the gel strength (P < 0.05). The addition of 0.05% xanthan decreased cooking loss of TG-treated MP gels by 17% to 23% when compared with gels without xanthan at all pH levels evaluated (6.13 to 6.67). Thus, the combination of TG and xanthan offered a feasible means to promote cross-linking and gelation of MP while reducing cooking losses.     

Relationship between the solubility,dosage and antioxidant capacity of carnosic acid in raw and cooked ground buffalo meat patties and chicken patties

Antioxidant capacity of oil soluble and water dispersible carnosic acid (CA) extracted from dried rosemary leaves using HPLC was evaluated at two different dosages (22.5 ppm vs 130 ppm) in raw and cooked ground buffalo meat patties and chicken patties. Irrespective of total phenolic content, CA extracts reduced (p < 0.05) the thiobarbituric acid reactive substances (TBARS) by 39%–47% and 37%–40% in cooked buffalo meat and chicken patties at lower dosage (22.5 ppm) relative to control samples. However, at higher dosage (130 ppm) the TBARS values were reduced (p < 0.05) by 86%–96% and 78%–87% in cooked buffalo meat and chicken patties compared to controls. The CA extracts were also effective in inhibiting (p < 0.05) peroxide value and free fatty acids in cooked buffalo meat and chicken patties. The CA extracts when used at higher dosage, were also effective in stabilizing raw buffalo meat color.     

甲基纤维素添加量对低盐肉糜凝胶特性的影响

将甲基纤维素(methyl cellulose,MC)作为替代物加入肉糜中等量替代食盐,采用5个不同MC添加量(0％、0.4％、0.8％、1.2％、1.6％)即肉糜中的食盐质量分数分别为2％、1.6％、1.2％、0.8％、0.4％.通过测定肉糜凝胶的蒸煮损失率、色泽、质构、低场核磁共振横向弛豫时间(T2)以及流变特性,...     

Effects of high pressure level and holding time on properties of duck muscle gels containing 1% curdlan

The effect of high pressure processing (HPP) on properties of duck muscle gels (DMG) containing 1% curdlan was investigated. The application of > 300 MPa could result in the decrease of cooking loss of DMG in water binding capacity, the increase of L value and the decrease of a value and b value in color, the increase of hardness, springiness, cohesiveness and chewiness in textural parameters (P < 0.05), while the pressure-holding time had no obvious influence. Those experimental results could be attributed to the interactions among protein molecules and the interactions between protein molecules and curdlan molecules created or enhanced by HPP. Overall, the use of curdlan instead of fat and the application of HPP may provide a novel approach to achieve low-fat (< 6% fat) and low-salt (1% salt) DMG products with good properties and high yields.

Industrial relevance

To provide healthier meat foods like low-fat (< 6% fat) and low-salt (about 1% salt) duck meat products, the application of HPP might be of great interest for industrial manufacture and can yield the products bearing high water binding capacity and good textural properties.     

性早熟蟹肉和白鲢鱼糜混合凝胶工艺优化及其凝胶特性

通过向白鲢鱼糜中添加蟹肉和0.3%谷氨酰胺转氨酶（transglutaminase,TG）,以凝胶强度和持水性为指标,研究蟹肉比例、凝胶化时间以及凝胶化温度3 个因素对混合凝胶特性的影响。在单因素试验基础上,采取3因素3水平的Box-Behnken设计进行响应面分析,得到最佳工艺条件为：蟹肉比例10%,凝胶化时间3.0 h,凝胶化温度35 ℃。验证实验结果显示,与传统鱼肠相比,优化后的鱼糜与蟹肉混合肠,其凝胶强度有显著的提升（P＜0.05）,持水性略有降低,但并不显著（P＞0.05）;聚丙烯酰胺凝胶电泳和扫描电镜结果表明,TG的添加可使混合凝胶中肌球蛋白重链明显减少,且凝胶表面更均匀、致密。     

Effect of fasting on energy metabolism and tenderizing enzymes in chicken breast muscle early postmortem

Pre-slaughter fasting is a very important practice in the meat industry. The present study was designed to investigate the effect of fasting on energy metabolism and tenderizing enzymes in chicken muscle early postmortem. A total of 30 Yellow-feathered chickens were deprived of feed for 0 h, 12 h and 24 h before slaughter (n = 10 each group). Breast muscles were removed and cut into 3 parts and stored at 0 °C for 0 h, 3 h and 10 h. Samples were used for analyses of zymography, cathepsins, pH, glycogen/ATP/ADP/AMP, hormones and ultrastructure. Fasting caused the accelerated depletion (p < 0.05) of glycogen, ATP and ADP before or immediately after slaughter, but no difference existed in ATP at 3 and 10 h (p > 0.05). Fasting resulted in greater ultimate pH (p < 0.05). Zymography indicated that fasting delayed the activation of μ/m-calpain (p < 0.05), however, it accelerated the release of lysosomal enzymes (p < 0.05). Fasting for 24 h resulted in greater ultrastructural changes and plasma corticosterone levels than fasting for 12 h and control groups. Therefore, fasting for no more than 12 h is acceptable in practice.     

Optimization of edible Alyssum homalocarpum seed gum-chitosan coating formulation to improve the postharvest storage potential and quality of apricot (Prunus armeniaca L.)

Edible coating based on Alyssum homalocarpum seed gum (AHSG) and chitosan for coating of fresh apricot was optimized using response surface methodology (RSM). The independent variables included concentrations of AHSG and chitosan in coating solution. The response variables studied were total soluble solid, weight loss, titratably acidity, pH, reducing sugar, moisture content, and firmness. Results indicated that RSM models were significantly (p < .05) qualified for all response variables, except for total soluble solid and titratable acidity. The regression models demonstrated R² ranging from .78 to .99. AHSG concentration influenced the weight loss, pH, and firmness, while chitosan concentration had an effect on pH and moisture content. This study showed that the coating can improve apricot firmness and stability in terms of weight loss, pH, and moisture content. The study suggested that a combination of AHSG 1.02% (w/w) and chitosan 0.33% (w/w) is the best one to achieve the desirable responses.     

Role of Reduced Ionic Strength and Low pH in Gelation of Chicken Breast Muscle Protein

ABSTRACT: Elastic gels with a high moisture content of 88% were prepared at an acidic pH and low ionic strength. The relationship among pH, ionic strength, water-holding capacity, and fold score of gels was investigated. A decrease of pH from 4.1 to 3.7 or below increased gel elasticity and significantly decreased water loss under pressure ( P < 0.05). In the presence of sodium chloride, gels made at pH 3.5 to 3.7 had decreased elasticity and increased water loss under pressure. Prior freezing increased the water loss of gels under pressure. Gels made with phosphoric acid and hydrochloric acid lost less water under pressure than those made with citric acid. The percentage loss of water from cylindrical gels was inversely related to the height of the cylinders, suggesting that surface effects were involved. These results suggest that net positive charges on the protein molecules at low pH produced electrostatic repulsion, which was a major driving force for water uptake in the low-salt gels.     

Effects of kojic acid on changes in the microstructure and myofibrillar protein of duck meat during superchilled storage

This study investigated the effect of 0.8% (m/v) kojic acid treatment on changes in the microstructure and myofibrillar protein of duck meat covered with oxygen-permeable polyvinylchloride (PVC) film (9 ± 0.5 µM) during superchilled storage (−1.65 ± 0.5°C). The superchilled samples exhibited wider gaps between muscle fibers at 5 weeks storage compared with kojic acid–treated groups. Based on the variation of water status, the water-holding capacity decreased significantly (p < 0.05), and bound water and immobilized water were gradually converted into free water during superchilled storage. For kojic acid–treated samples, however, no major changes were observed with respect to muscle structure, water status, and protein degradation at 6 weeks. The 0.8% (m/v) kojic acid treatment increased the water-holding capacity, reduced carbonyl content and protein degradation, and decreased the α-helix contents loss of myofibrillar proteins. Kojic acid treatment effectively protected myofibrillar protein structure from being destroyed during superchilled storage, suggesting that this method was a good way to reduce protein oxidation and prolonged its shelf life.     

Physicochemical characteristics,proximate analysis and mineral composition of ostrich meat as influenced by muscle

The influence of muscle on the physicochemical characteristics, proximate analysis, and mineral composition of meat from 10 ostriches (10–12 months old), slaughtered according to commercial abattoir procedures, were evaluated. Muscle had no influence (p > 0.05) on L*-values (32.5), a*-values (11.9), water-holding capacity (11.9%), final pH (pH₂₄) values (6.07), and ash contents (1.12 g/100 g edible meat). However, intramuscular lipid contents varied (p < 0.05) from 0.88 (M. fibularis longus) to 1.44 (M. flexor cruris lateralis) g/100 g edible meat, at a mean value of 1.16 g/100 g edible meat for 10 different muscles. Sodium (34.7 mg/100 g edible meat) and iron (3.14 mg/100 g edible meat) contents, both influenced (p < 0.05) by muscle, possessed substantially lower and higher values, respectively, than values reported for beef and chicken.     

Effect of NaCl on physical characteristics and qualities of chicken breast surimi prepared by acid and alkaline processing

We investigated the effect of NaCl on the physical characteristics and qualities of chicken breast surimi prepared by acid (pH 2.5 and pH 3.0) and alkaline (pH 10.5 and pH 11.0) adjustments. Salt addition resulted in increased (p < 0.05) yellowness, but decreased (p < 0.05) lightness and whiteness of surimi, regardless of pH adjustment. Surimi prepared by alkali had the highest (p < 0.001) values of lightness and whiteness. Textural properties except cohesiveness were higher (p < 0.05) in acid-prepared surimi without salt, however, addition of salt caused higher (p < 0.05) springiness, gumminess or gel strength of chicken surimi. Salt addition also caused an increase in the sensory properties. Furthermore, alkali-treated (pH 10.5 or pH 11.0) surimi had higher (p < 0.001) values of all the sensory properties. Therefore, the alkali treatment diminished gumminess and chewiness of texture property, while better color (high lightness or whiteness), gel characteristics and sensory properties were obtained from salt-added surimi. Especially the surimi at pH 10.5 and with salt was better one which had high values of whiteness, springiness and sensory properties among the surimi.     

Effect of chemical preservatives on shelf life of mushroom (Pleurotus ostreatus) cultivated on cassava peels

Short shelf life is a major impediment to the processing and distribution of mushroom. The effect of chemical preservatives on some quality attributes of mushroom during storage was investigated. Mushroom were soaked in four preservatives at two concentrations for 10 mins, packaged, stored at 4 °C for 30 days and analysed at intervals for their microbial population, colour, firmness and weight loss. Sodium benzoate (0.05%, 0.1%) lost its preservative effect on all the micro‐organisms enumerated after 3 days, and samples treated with 0.1% potassium sorbate had the lowest microbial load at the end of the storage period. Change in colour of the potassium sorbate (0.1%)‐treated sample was lower than and significantly different from the citric acid (2%, 4%)‐treated samples. The values of the firmness of the 4% citric acid preserved mushroom were significantly different (P ≤ 0.05) from other samples throughout the storage period. There was a significant negative correlation (r = ?0.807, P < 0.01) between the firmness and weight loss of the preserved mushroom. Potassium sorbate (0.1%) and citric acid (4%) extended the shelf life of mushroom for 24 days.