食盐用量对四川腊肉加工及贮藏过程中肌肉蛋白质降解的影响

以不同食盐用量（食盐用量分别为原料肉质量的3%、4%、5%、6%、7%,用A、B、C、D、E来表示）腌制的四川腊肉为研究对象,分析了肌肉中非蛋白氮（non-protein nitrogen,NPN）、游离氨基酸（free amino acids,FAA）含量以及肌浆蛋白和肌原纤维蛋白在加工贮藏过程中随时间变化的规律。结果显示：A、B、C组NPN含量较高;C组FAA含量最高,含量最高时达到11.75 mg/g;肌浆蛋白、肌原纤维蛋白在腊肉的腌制期和烟熏期大量降解,而肌原纤维蛋白的降解主要集中在分子质量大于99 kD的区域,A、B、C组的两种蛋白变化趋势一致,D、E组一致。结果表明：食盐用量会抑制蛋白质的降解,当食盐用量为肉质量的5%时,最有利于游离氨基酸的生成,并且腊肉中较低的食盐用量会缩短贮藏阶段肌浆蛋白含量达到最大值的时间,却延缓了肌原纤维蛋白含量达到最大值的时间。     

食盐对普通玉米杂交种淀粉糊化性质的影响

采用快速粘度分析仪（RVA）研究了食盐对18种普通玉米杂交种淀粉糊化性质的影响。结果表明：食盐显著降低了所有普通玉米杂交种淀粉的峰值、破损值和回生值;提高了谷值、终粘度、出峰时间和成糊温度。但对不同的普通玉米杂交种淀粉的糊化性质的影响程度有显著差别。随着食盐溶液质量分数的增加,普通玉米杂交种淀粉的谷值、终粘度、出峰时间和成糊温度也逐渐增加,破损值和回生值则显著降低,峰值受食盐溶液质量分数的影响很小。     

芒果皮粉对淀粉糊化与老化特性的影响

采用布拉班德黏度仪、差示扫描量热仪等测定芒果皮粉的添加对玉米淀粉和大米淀粉黏度、热特性、透光率、沉降率、凝胶硬度与色泽的影响。结果表明,随芒果皮粉添加量(0%~15%)的增加,2种淀粉的起糊温度逐渐降低,玉米淀粉糊峰值黏度在添加15%芒果皮粉时显著升高,崩解值增大;大米淀粉糊峰值黏度呈降低趋势,崩解值先降低后升高,2种淀粉回生值都显著降低。芒果皮粉的添加显著降低了2种淀粉的糊化和老化焓值及贮藏中透光率与沉降率的下降程度,减小玉米淀粉凝胶的硬度,降低了2种淀粉凝胶色泽的变化程度。说明芒果皮粉的添加影响淀粉的糊化特性,且影响趋势随淀粉品种不同而异,但能有效抑制2种淀粉的老化。     

氯化钠对鸡肉冷藏过程中肌原纤维蛋白氧化的影响

为探究氯化钠对鸡肉腌制冷藏过程中肌原纤维蛋白氧化的影响,采用不同添加量（0.0%、1.5%、3.0%、4.5%、6.0%、7.5%）的氯化钠处理鸡胸肉,冷藏不同时间（0、2、4 d）后提取肌原纤维蛋白,通过测定其表面疏水性、粒径、羰基、巯基含量等判断肌原纤维蛋白氧化程度。结果表明：随着氯化钠添加量的增加及贮藏时间的延长,鸡肉肌原纤维蛋白羰基含量逐渐增加,巯基含量则显著减少（P＜0.05）;肌原纤维蛋白产生一定的聚集交联现象,平均粒径呈增大趋势;肌原纤维蛋白中α-螺旋相对含量随着氯化钠添加量的增加而降低,而色氨酸荧光强度随氯化钠添加量的增加先升高后降低。综上所述,氯化钠对鸡肉腌制冷藏过程中的肌原纤维蛋白氧化有一定促进作用,其中氯化钠添加量4.5%时对鸡肉肌原纤维蛋白的氧化效果最为明显。     

葡萄糖酸内酯对猪肉肌原纤维蛋白功能性的影响

在猪肉肌原纤维蛋白中添加不同质量分数(0.5%、1.0%、1.5%、2.0%)的葡萄糖酸内酯(GDL),研究其对肌原纤维蛋白乳化能力和凝胶性的影响。结果显示,添加GDL 能显著提高肌原纤维蛋白的乳化性和乳化稳定性(P ＜ 0.05),但是不同添加量之间差异不显著;凝胶白度随GDL 添加量的增加呈下降趋势;0.5% 以下添加量对凝胶保水性没有显著影响,0.5% 以上的添加量会大幅提高保水性;除凝胶黏附性随GDL 质量分数增加而下降外,凝胶硬度、胶黏性和回弹性都在GDL 添加量0～1.0% 之间有不同程度的下降,然后随着GDL 质量分数增大而升高。综合来看,1.5% 的GDL 添加量对猪肉肌原纤维蛋白的功能性有较好的改善作用。     

乳清抗氧化肽对冷藏猪肉糜肌原纤维蛋白功能性及品质的影响

研究乳清抗氧化肽对冷藏猪肉糜肌原纤维蛋白功能性及品质的影响。实验分为6组,第1组为空白对照,第2组加入质量分数20%未水解乳清蛋白,第3~5组中分别加入质量分数10%、15%、20%的乳清抗氧化肽冻干粉,第6组加入质量分数0.02%的丁基羟基茴香醚(butyl hydroxyanisd,BHA)。在肉糜4℃冷藏0、1、3、5、7 d时分别测定浊度、Ca~(2+)-ATPase活力、乳化稳定性、挥发性盐基氮(totalvolatilebasicnitrogen,TVB-N)含量、蒸煮损失率、表面疏水性以及肌原纤维蛋白溶解性的变化。结果表明:添加质量分数15%的乳清抗氧化肽能有效抑制冷藏肉糜肌原纤维浊度的升高,抑制Ca~(2+)-ATPase活力的下降,减少TVB-N的产生,抑制肌原纤维蛋白乳化稳定性和溶解性的降低。添加质量分数20%的乳清抗氧化肽则在抑制生肉糜蒸煮损失和猪肉糜肌原纤维蛋白表面疏水性增加方面效果最佳,其作用与质量分数0.02%BHA相当。上述结果表明,乳清抗氧化肽具有改善冷藏猪肉糜肌原纤维蛋白功能性及品质的作用。     

茶多酚对羊肉肌原纤维蛋白-多糖复合体系乳化及质构特性的影响

分别以卡拉胶、魔芋胶和淀粉为乳化剂,与羊肉肌原纤维蛋白形成3种复合体系,研究不同质量分数的茶多酚对羊肉肌原纤维蛋白-多糖复合凝胶的乳化及质构特性的影响。研究结果显示:0.10%茶多酚的存在使3种混合体系的表面疏水性均达到最小值,其中魔芋胶处理组的值最小(0.39μg),说明凝胶蛋白分子内部疏水基团的暴露数量最少。各凝胶的乳化活性随茶多酚质量分数的增加而增加,在茶多酚质量分数为0.10%时达到最大值,之后又降低(P0.05)。在所有茶多酚水平下(除茶多酚添加量为1.00%),淀粉处理组凝胶的乳化活性最好;卡拉胶处理组凝胶的乳化稳定性效果最好。凝胶质构特性和微观结构分析表明,卡拉胶处理组凝胶结构均匀且致密,对凝胶质构有一定的改善作用。结论:茶多酚质量分数及多糖种类均会对羊肉肌原纤维蛋白的乳化与质构特性产生影响,低质量分数的茶多酚(≤0.10%)与卡拉胶有助于改善复合体系的乳化及质构特性。     

芡实黄酮对鸭肉肌原纤维蛋白变性的抑制作用

文章通过对热处理过程中鸭肉肌原纤维蛋白进行蛋白质交联程度、氨基酸侧链氧化程度、羟基自由基清除率测定及DSC分析,研究了芡实黄酮对加热过程中肌原纤维蛋白变性的抑制作用。通过实验得知:当蛋白-芡实黄酮混合溶液中芡实黄酮质量分数为10%,且混合溶液热处理时间为15 min,芡实黄酮对蛋白质氧化损伤的抑制较显著(P0.01),肌原纤维蛋白羟基自由基清除率由41.00%增至50.10%;同时,芡实黄酮质量分数为40.00%时,蛋白质吸热吸收由1825.00 J/g降至118.42 J/g。高温条件下,芡实黄酮能通过抑制蛋白氧化损伤以及维持蛋白热稳定性进而预防肌原纤维蛋白变性。     

谷氨酸螯合钙替代部分食盐对兔肉肌原纤维蛋白热凝胶和乳化特性的影响

为降低凝胶类低温肉制品中的钠离子含量,研究谷氨酸螯合钙替代部分食盐对兔肉肌原纤维蛋白加工特性的影响。从兔腰大肌中提取肌原纤维蛋白,添加质量分数为1.25%的谷氨酸螯合钙,再分别添加0.4%、0.8%、1.2%、1.6%、2.0%的食盐（食盐组成为70%NaCl和30%KCl）,研究肌原纤维蛋白流变特性、保水性、乳化活性和乳化稳定性以及乳化体系复合热凝胶的保油保水性变化,并以3%食盐组作为对照。结果表明：食盐添加量增多,肌原纤维蛋白热凝胶储能模量（G’）增大,1.2%食盐组G’值高于对照组（P＜0.05）;但是凝胶保水性先增强后减弱,1.2%食盐组保水效果最好。食盐添加量增多,乳化活性增大;而乳化稳定性以0.8%和1.2%食盐组最高,与对照组差异不显著（P＞0.05）。1.2%和1.6%食盐组的保油保水性显著高于对照组（P＜0.05）。结论：添加谷氨酸螯合钙可以使兔肉肌原纤维蛋白形成具有良好黏弹性和保油保水性的低钠热凝胶,凝胶类低温肉制品的NaCl添加量可以减至0.84%。     

蕨根淀粉糊的老化特性及影响因素

实验研究了蕨根淀粉糊的老化特性及影响因素。结果表明:蕨根淀粉糊静置贮藏过程中会发生老化现象,在4℃下老化比常温下快;常温下贮藏蕨根淀粉比马铃薯淀粉和玉米淀粉粘度变化稍大,4℃下贮藏24h内蕨根淀粉糊比马铃薯淀粉和玉米淀粉糊的粘度变化小,但24h后稀化比马铃薯快;不同浓度蕨根淀粉糊的老化现象有一些差别;加入蔗糖和葡萄糖能减弱粘度变化趋势,葡萄糖和蔗糖对透光率的减小有一定的阻止能力,浓度达20%时效果明显;pH和盐类也对老化有影响。     

Effect of protein–starch interactions on starch retrogradation and implications for food product quality

Starch retrogradation is a consequential part of food processing that greatly impacts the texture and acceptability of products containing both starch and proteins, but the effect of proteins on starch retrogradation has only recently been explored. With the increased popularity of plant-based proteins in recent years, incorporation of proteins into starch-based products is more commonplace. These formulation changes may have unforeseen effects on ingredient functionality and sensory outcomes of starch-containing products during storage, which makes the investigation of protein–starch interactions and subsequent impact on starch retrogradation and product quality essential. Protein can inhibit or promote starch retrogradation based on its exposed residues. Charged residues promote charge–dipole interactions between starch-bound phosphate and protein, hydrophobic groups restrict amylose release and reassociation, while hydrophilic groups impact water/molecular mobility. Covalent bonds (disulfide linkages) formed between proteins may enhance starch retrogradation, while glycosidic bonds formed between starch and protein during high-temperature processing may limit starch retrogradation. With these protein–starch interactions in mind, products can be formulated with proteins that enhance or delay textural changes in starch-containing products. Future work to understand the impact of starch–protein interactions on retrogradation should focus on integrating the fields of proteomics and carbohydrate chemistry. This interdisciplinary approach should result in better methods to characterize mechanisms of interaction between starch and proteins to optimize their food applications. This review provides useful interpretations of current literature characterizing the mechanistic effect of protein on starch retrogradation.     

绿豆淀粉抗老化技术及在冰淇淋中的应用

为抑制绿豆淀粉在冰淇淋贮藏期间老化而产生的淀粉味感,以绿豆淀粉为原料,经过α-淀粉酶酶解处理,通过正交试验研究不同酶解条件对绿豆淀粉抗老化性质的影响。结果表明：用α-淀粉酶处理绿豆淀粉,使其适度的水解,保持了绿豆特有的口感风味,且保水力较大,糊化性好,老化度明显低于未经过α-淀粉酶处理的绿豆淀粉。酶解最佳工艺为pH6.5、酶解温度70℃、添加0.0008%的α-淀粉酶、酶解8min。在绿豆冰淇淋制作中添加不同量的酶解绿豆浆、CMC-Na、明胶、单甘酯对绿豆冰淇淋膨化率及融化率和口感有不同的影响,酶解豆浆、CMC-Na、明胶、单甘酯的添加量分别为60%、0.1%、0.1%、0.15%时,绿豆冰淇淋的风味口感明显改善。     

Concentration of soy protein isolate affects starch-based confections' texture, sensory, and storage properties

The effects of increasing soy protein isolate concentration on the physico-chemical properties of starch-based grape confectionery gels were investigated using thermal, textural, and sensory analyses. Soy protein isolate decreased hardness, cohesiveness, and gumminess, demonstrating potential as a texture modifier. Increasing soy protein concentration progressively decreased the elastic properties of the starch network demonstrated by a lower G'-G" crossover frequency. High levels of soy protein also created a more homogeneous water population, one which was lost at lower temperatures compared to standard confections. An improvement in taste and texture acceptability of the confections upon addition of soy protein isolate was found by sensory analysis. Finally, physico-chemical properties were compared up to 20 d of storage at ambient temperature. Soy-containing confections demonstrated lower gumminess and cohesiveness during the entire storage period but a significant increase in hardness after 20 d of storage. PRACTICAL APPLICATION: Soy protein isolate imparted soft texture to starch-based confections on a concentration-dependent basis. Increasing soy protein isolate concentration decreased elastic properties of the starch network in starch confections and significantly improved flavor and texture. Gumminess and cohesiveness of soy protein isolate confection was lower during 20 d of storage.     

Sensory Characteristics of Frankfurters as Affected by Salt, Fat, Soy Protein, and Carrageenan

Continuous variables, salt, fat, and either soy protein or iota-carrageenan, were evaluated using response surface methods to formulate a lower salt/ lower fat franktirter with acceptable palatability attributes. Soy protein increased hardness and off-flavor, and decreased juiciness, saltiness, and flavor intensity. Soy protein should be added to frankfurters at < 3.0% to minimize this effect. Carrageenan increased hardness at low salt concentrations (below 1.7%) and decreased juiciness at fat concentrations > 15%. Flavor intensity increased as carrageenan and fat level increased at 1.3% salt. At 1.65% salt, off-flavor intensity decreased as fat content increased and carrageenan decreased.     

Influence of enzyme active and inactive soy flours on cassava and corn starch properties

The aim of this work was to study the influence of enzyme active and inactive soy flours on the properties of cassava and corn starches. Four starch/soy flour composites were evaluated: cassava/active soy flour (Cas/AS), cassava/inactive soy flour (Cas/IS), corn/active soy flour (Corn/AS) and corn/inactive soy flour (Corn/IS). Starch gelatinization occurred at 58.67°C for Cas and at 64.19°C for corn; gelatinization occurred at higher temperatures when soy flours were present, while ΔH diminished. The presence of AS reduced 80% the retrogradation enthalpy of Cas and 40% that of corn. Cas presented lower pasting temperature than corn starch (67.8 and 76.8°C, respectively) and higher peak viscosity (427.9 and 232.8 BU, respectively). The pasting properties of both starches were drastically reduced by soy flours, and this effect was more noticeable in Cas; AS had higher effect than IS. X‐ray diffraction pattern of retrograded samples showed that both starches recrystallisation (mainly that of Cas) was reduced when AS was added. Tan δ values decreased with AS addition to corn, but they increased when added to Cas. The images obtained using confocal laser scanning microscopy (CLSM) showed that IS was distributed as large aggregates, whereas AS distribution was more homogeneous, especially when incorporated to Cas. These results show that cassava starch interacts specifically with active soy flour (AS, mainly in native state). The delaying effect of AS on cassava starch retrogradation was clearly shown. This finding could be useful in obtaining gluten‐free breads of high quality and low retrogradation rate.     

大豆分离蛋白对湿米粉储藏品质的影响

以湿米粉储藏过程中硬度、蒸煮损失和断条率的变化为指标,研究大豆分离蛋白对湿米粉品质的影响。结果表明,大豆分离蛋白会导致湿米粉硬度的升高,但在储藏过程中添加大豆分离蛋白的湿米粉硬度低于未添加大豆分离蛋白的湿米粉,这表明大豆分离蛋白可显著改善湿米粉在储藏过程中的硬度升高现象;当大豆分离蛋白添加量低于4%时,湿米粉的蒸煮损失和断条率均随大豆分离蛋白添加量的增加而下降;但大豆分离蛋白添加量达6%时,湿米粉的蒸煮损失和断条率上升。结果表明适量的大豆分离蛋白可改善湿米粉的食用品质,但大豆分离蛋白添加量不是越多越好。差示热量扫描和微观结构分析发现大豆分离蛋白可抑制湿米粉中淀粉的回生,赋予米粉蜂窝状多孔结构,有利于米粉在储藏过程中保持水分不发生迁移从而提高湿米粉品质。     

QUALITY CHARACTERISTICS OF TURKEY BOLOGNA FORMULATED WITH CARRAGEENAN, STARCH, MILK AND SOY PROTEIN

A low-fat (12%) high-added water (27%) bologna was formulated with mechanically deboned turkey meat (MDTM) and either carrageenan (0.5%), milk protein (2%), isolated soy protein (2%), or starch (2%). Cooking loss, purge loss during storage, cooked product bind, sensory characteristics, and batter viscosity were evaluated. Starch added late in the chopping process was the most effective in reducing cooking loss as well as decreasing (P < 0.05) purge loss during storage (both refrigerated and frozen storage). Cooked product hardness was increased (P < 0.05) by all test ingredients, except starch and kappa carrageenan added late in the chopping process. Kappa carrageenan incorporated before chopping significantly (P < 0.05) increased cooked product bind. Overall acceptability (sensory analysis) scores were higher (P < 0.05) when milk protein, isolated soy protein and starch were added during chopping, compared to their addition prior to chopping. However, this order of addition effect was not observed for either of the carrageenan treatments.     

Factors Influencing Gel Formation by Myofibrillar Proteins in Muscle Foods

Abstract: Considerable research has been done to better understand the basis for gel formation by myofibrillar proteins (MPs) in effort to manufacture acceptable processed meats with lower cost and more desirable nutritional characteristics. Results from research available indicate that there is no substitute for the myofibrillar protein myosin in gel formation by proteins from a wide variety of animal and fish species. This report consolidates information on determinants of protein gel formation, examining types of muscles and fibers, the species influence, and interactions of the MPs actin and myosin with each other and with fat, gelatin, starch, hydrocolloids, some protein soy, whey, and nonprotein additives such as phosphates and acidifiers, and the influences of pH, ionic strength, rates of heating, and its absence, protein oxidation, as well as the use of transglutaminase and high hydrostatic pressure. It is of interest that myosin alone will form acceptable gels. Gel formation by MPs is optimized at pH 6, an ionic strength of 0.6 M, and at 60 to 70 °C. The observations that collagen‐derived gelatin can reduce the rubbery texture of low‐fat products and that solubilization of MPs is not always essential for gel formation, and the observation that good gels can be formed in the absence of salt, are exciting developments that should be considered as pressure mounts to continue to reduce fat and salt in the diet.     

Effects of fat level, tapioca starch and whey protein on frankfurters formulated with 5% and 12% fat

The effects of fat level (5% and 12%), tapioca starch and whey protein on the hydration/ binding properties, colour, textural and sensory characteristics of frankfurters were investigated. Decreasing the fat content increased cook loss and decreased emulsion stability and product lightness. Fat reduction increased smoke, spice and salt intensities and increased overall flavour intensity and juiciness. Texture profile analysis (TPA) indicated that fat reduction decreased gumminess and cohesiveness but the other parameters measured were unaffected. Addition of tapioca starch or whey protein reduced cook loss and increased emulsion stability. Whey protein did not effect the sensory characteristics but tapioca starch increased overall flavour intensity. Both ingredients increased hardness, adhesiveness, gumminess and chewiness as measured by TPA. Two-factor interactions between fat level and ingredient were observed for several parameters. The results indicate that both ingredients can partially offset some of the changes which occur in low-fat frankfurters when fat is replaced with added water and protein level is constant.     

薯类淀粉与卡拉胶共混体系特性及其对肌原纤维蛋白凝胶特性的影响

为研究薯类淀粉与亲水性胶体(卡拉胶)之间的相互作用机理及其对肌原纤维蛋白的流变与质构的影响,以马铃薯淀粉、红薯淀粉、木薯淀粉以及混合淀粉(木薯:红薯:马铃薯=1:1:1)为原料与卡拉胶进行不同比例复配,测定卡拉胶对薯类淀粉静态流变、凝胶质构、冻融稳定性以及热力学回生特性的影响。静态流变学实验表明,薯类淀粉与卡拉胶共混体系属非牛顿流体,具假塑性流体特征,卡拉胶的加入增大了体系的表观黏度,在配比为8:2时达到最大。冻融稳定性实验表明,卡拉胶添加量越大,体系析水率越小,冻融稳定性越好;随冻融循环次数的增加,析水率变大。此外,淀粉与卡拉胶配比为9:1时,淀粉的回生率最小。将薯类淀粉/卡拉胶共混体系应用到鸡胸肉肌原纤维蛋白中发现,淀粉、卡拉胶/肌原纤维蛋白共混体系具明显剪切稀化现象,淀粉与卡拉胶的加入增强了肌原纤维蛋白触变性和表观黏度,改善了凝胶质构特性,使得体系的硬度、弹性、粘聚性和咀嚼度都得到了提升。本研究为促进薯类淀粉在肉制品中的应用,及薯类淀粉的开发利用提供一定理论依据。