Effect of sodium starch octenyl succinate-based Pickering emulsion on the physicochemical properties of hairtail myofibrillar protein gel subjected to multiple freeze-thaw cycles

A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were investigated.The whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(P<0.05).Meanwhile,Raman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and t-g-t.At an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the control.After F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering emulsion.These findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.

Oxidative mechanism of chicken wooden breast myofibrillar protein

To explore the oxidation mechanism of wooden breast myofibrillar protein(WBMP),oxidative breast MP(OBMP)was obtained from different doses(3,10,and 20 mmol/L)of H2O2 oxidized normal breast MP(NBMP).The results showed that the Zeta-potential,particle size,solubility,sulfhydryl,and carbonyl contents of OBMP-3(3 mmol/L,low-dose free radicals)and WBMP were similar.Fluorescence spectrum analysis showed that the oxidation of low-dose free radicals led to a significant increase in the surface hydrophobicity(from 214.03±10.03 to 393.50±10.33)and tryptophan fluorescence intensity(from 185.71 to 568.32).In addition,theα-helix content of WBMP decreased significantly from(37.46±1.15)%(NBMP)to(34.70±2.04)%,whileβ-sheet and random coil contents increased significantly(P<0.05)from(14.37±0.69)%and(22.24±0.78)%(NBMP)to(17.70±0.87)%and(25.20±1.47)%(WBMP).In summary,low-dose free radical oxidation attacks protein groups,inducing secondary and tertiary structural changes,leading to the formation of WBMP.This work will provide a theoretical basis at the molecular level for exploring the mechanism of functional degradation of WBMP.

The effect of protein oxidation on the formation of advanced glycation end products after chicken myofibrillar protein glycation

Investigation that protein oxidation to the formation of advanced glycation end products(AGEs)after chicken myofibrillar protein glycation is limited.Models of protein oxidation induced by different concentrations of hydroxyl radicals(·OH)were developed after the chicken myofibrillar protein mild glycation(MPG).Results exhibited that levels of AGEs and surface hydrophobicity(H_(0))steadily increased with the a ddition of h ydrogen peroxide(H_(2)O_(2))concentration.However,levels of s ulfhydryl group,free amino group,and particle size gradually decreased with the H_(2)O_(2)concentration.The protein carbonyl value increased in H_(2)O_(2)concentration until 10 mmol/L.Pearson's correlation indicated that MPG structure modification(unfolding and degradation)induced by protein oxidation were significantly positively correlated with AGEs concentration(P<0.05).Finally,a mechanism was proposed to hypothesize t he effect of protein oxidation on the formation of AGEs under MPG conditions.

Changes in Myofibrillar and Mitochondrial Compartments during Increased Activity: Dependance from Oxidative Capacity of Muscle

Striated muscle tissue contains fibers with high oxidative capacity (heart muscle), higher oxidative capacity (type I and IIA fibers of skeletal muscle) and low oxidative capacity (type IIB/X fibers of skeletal muscle). Muscle fibers with higher oxidative capacity contain large mitochondria tightly packed with cristae as well as small forms of mitochondria containing relatively few cristae. The intensive development of the mitochondrial apparatus in the post-activity period reflects the adaptive processes, which is intended to supply the increased energy requirements of muscle fibers with higher oxidative capacity. Muscle fibers with low oxidative capacity contain significantly less mitochondria than fibers with higher capacity. It is typical to type IIB fibers that after intensive muscle activity there are damaged myofibrils in a relatively small area, some myofibrils are twisted and lose the connection with the neighboring structures. It is still not fully known how skeletal muscles with different oxidative capacity respond to an increased functional activity and what differences exist in these fibers between oxidative capacity and function of myofibrils. The aim of the present short review was to compare structural-functional changes in mitochondrial and myofibrillar compartments of heart and skeletal muscle fibers with different oxidative capacity and the effect of increased functional activity on the interaction of these compartments.

BAG3-Related Myofibrillar Myopathy Presenting as Hypercapnia:A Case Report and Literature Review

Objective BAG3-related myopathy is a rare condition so far reported in twenty patients worldwide.The purpose of this study was to draw attention to this rare disease and to the fact that BAG3-related myopathy should be considered as a rare differential diagnosis of hypercapnia.Methods We report a sporadic case of a 14-year-old Chinese girl with a de novo p.Pro209 Leu mutation in BAG3 and reviewed the literatures for reported cases related to this mutation.Results We described a 14-year-old Chinese girl who presented with gradually appearing symptoms of hypercapnia that required assisted ventilation.The muscle biopsy and the blood whole-exome sequencing results confirmed the diagnosis of myofibrillar myopathy with a de novo p.Pro209 Leu mutation in BAG3.Totally twentyone patients from twenty families with a confirmed diagnosis of BAG3-related myopathy were reported to date,including this patient and literature review.The male to female ratio was 11:10 and most showed initial symptoms in the first decade of life.Most patients presented toe/clumsy walking or running as the onset symptom,followed by muscle weakness or atrophy.Creatine kinase levels were elevated in fourteen patients and were normal in three.Eighteen patients developed respiratory insufficiency during the disease course and thirteen(one could not tolerate non-invasive assisted ventilation)required non-invasive assisted ventilation for treatment.Except for one not reported,heart involvement was found in seventeen patients during the disease course and seven underwent heart transplantation.Z-disk streaming and aggregation could be observed in most of the patients’muscle histology.In the long-term follow-up,five patients died of cardiac or respiratory failure.Conclusion BAG3-associated myopathy is a rare type of myofibrillar myopathy.It should be considered as a rare differential diagnosis of hypercapnia.

Effects of phosphorylated ovalbumin on the quality of pork myofibrillar protein gel:an insight into gelling and physicochemical properties

This study aimed to investigate the effects of phosphorylated-ovalbumin(P-OVA)at different concentrations(0.5%and 1.0%)on the gel properties of pork myofibrillar protein(MP).The results showed that the textural properties such as gel hardness,cohesiveness,springiness and chewiness were improved with P-OVA addition at 0.5%.The water holding capacity(up to 75.89%)and gel strength(up to 168.56 g·mm)of MP gel were markedly increased after P-OVA addition.The absolute value of zeta potential reached 13.85 mV and maximum hydrophobicity(15.2μg)resulted from the addition of 0.5%P-OVA.The storage modulus(G’)and loss modulus(G’’)of MP gel were significantly increased from 50°C,and the G’and G’’significantly increased after 1.0%P-OVA addition,evidencing that the cross-linking effect of MP protein gel was enhanced.In addition,the P-OVA addition improved the structure of MP gel protein by reducing theα-helix,while increasing theβ-sheet and the r-value(the ratio between two ultraviolet second-derivative peak-to-trough distances),which further promoted the uniform and compact gel network structure.This work demonstrated that P-OVA is a highly effective modifier that significantly improves the quality of MP gel.From a view of practice,0.5%P-OVA is the optimal addition amount.

抗冻蛋白对冷冻猪肉品质的影响

研究抗冻蛋白(antifreeze proteins,AFP)对猪肉冷冻过程中品质变化的影响。以商业抗冻剂海藻糖(4 mg/m L)的抗冻效果为参考,以未添加AFP组为对照组,研究不同添加量(0.05、0.1、0.2、0.3 mg/mL)AFP对冷冻猪肉品质、肌原纤维蛋白理化性质、微观结构和水分分布的影响。结果表明:AFP可以减少冷冻猪肉的水分损失,有利于维持猪肉色泽和微观结构;在冷冻贮藏过程中,0.3 mg/mL AFP组猪肉的蒸煮损失、解冻损失及色泽的保护效果最好,其次是0.2 mg/mL AFP组和4 mg/mL海藻糖组;0.2、0.3 mg/mL AFP组剪切力和肌原纤维蛋白总巯基含量显著高于未添加AFP组(P<0.05);核磁共振成像验证了AFP的渗入降低了猪肉中结合水和不易流动水损失;扫描电子显微镜结果显示,0.2 mg/mL AFP使猪肉肌纤维排列整齐,更加紧凑和致密。总体而言,添加AFP对改善冷冻猪肉品质有积极作用,是一种潜在的安全、高效冷冻保护方法。

不同浓度丁香酚对肌原纤维蛋白结构和乳液凝胶特性的影响

为了探究丁香酚添加量对肌原纤维蛋白乳液凝胶特性的影响,本文以猪肌原纤维蛋白为研究对象,模拟乳化香肠的加工过程,通过测定不同浓度的丁香酚(0、5、10、20、50、100 mg/g蛋白质)添加对蛋白的二级结构、凝胶强度、保水率、水分分布、流变和微观结构等指标的影响,探讨丁香酚添加量对蛋白凝胶形成的作用规律。结果表明,添加低浓度的丁香酚(20 mg/g)显著提升了蛋白的凝胶强度、保水率(P<0.05),凝胶中不易流动水的含量和储能模量明显增加,蒸煮损失和冻融损失显著降低(P<0.05),凝胶中自由水含量减少。然而,当添加高浓度的丁香酚(100 mg/g)时,凝胶强度和保水率明显降低,蒸煮损失、冻融损失明显升高,且在扫描电镜下可清晰地看到凝胶网络结构粗糙、孔隙明显增大。综上,添加低浓度丁香酚(20 mg/g)可以有效地提高蛋白的凝胶特性,其有潜力成为一种新型的肉制品品质改良剂。

真空热处理与谷蛋白添加对罗非鱼肌原纤维蛋白凝胶性能的影响

为探索真空热处理与谷蛋白对肌原纤维蛋白(Myofibrillar Protein,MP)凝胶性能的影响,实验以罗非鱼MP为原料,以质构、持水、分子间作用力等为指标研究了真空热处理与谷蛋白添加对罗非鱼MP凝胶的影响。结果表明,在水浴条件下,加入0.7%的谷蛋白显著提高了MP的硬度、凝胶强度。微观结构结果表明谷蛋白使MP凝胶网络趋于平整,孔洞减小,有利于凝胶的形成。与水浴加热相比,经过一段式真空热处理1 h后,MP凝胶的内聚性、弹性、凝胶强度显著提高,真空热处理2 h后,MP凝胶的内聚性与凝胶强度进一步提高。另外,真空热处理和谷蛋白添加改善了MP凝胶的水分状态,T22固定水的含量下降,同时T22固定水与T23自由水的迁移受到限制,使凝胶内水分趋于稳定。分子间作用力结果显示,离子键与疏水相互作用增强,促进了MP的凝胶化。综上所述,真空加工和谷蛋白添加促使MP结构伸展,形成更加致密的三维凝胶网络。

Extraction and Characterization of Myofibrillar Proteins from Different Meat Sources:A Comparative Study

In the present study,myofibrillar proteins were extracted from the meat proteins of beef,lamb,chicken,tuna and emperor fish using non-denaturation method,and their physico-chemical and rheological properties were assessed.The myofibrillar proteins of beef,emperor and lamb samples had higher percentage of protein extractability than tuna and chicken samples.The tuna sample showed significantly higher bound bromophenol blue(BPB)value while lamb samples showed lower value(P<0.05).The myofibrillar protein of chicken sample was found to have more ionic and hydrogen bonds than all other myofibrillar samples.The disulphide bonds in tuna and lamb myofibrillar protein samples were significantly higher than other three samples(P<0.05).The myofibrillar protein samples showed major bands myosin heavy chain,α-actinin,desimin,actin,troponin,tropomyosin and myosin light chain with wider molecular weight distribution in the range of 20-200 ku.The myofibrillar proteins exhibited Newtonian and shear thickening nature behaviour at lower protein concentration(1 mg/mL)as revealed by flow profile and visco-elastic analysis using rheometer.

Dynamic viscoelastic behaviour,gelling properties of myofibrillar proteins and histological changes in shrimp(L.vannamei)muscles during ice storage

Changes in protein quality during ice storage affects the muscle structure,the textural quality,functional properties and the eating quality.Dynamic viscoelastic behaviour and gelling properties ofmeat proteinsin relation to histological changes in white leg shrimp muscles were assessed for 14 days in ice storage.Reduction in Ca2+ATPase activity of fresh myofibrillar protein(MFP),fading of myosin banding pattern and increased gapping in myofibrils were clearly observed with progress of storage.The quality indices of the shrimp muscle were well correlated with histological and functional properties as a function of ice storage.Solubility of fresh MFP was 86.76%which decreased to 77.06%on the 14th day of storage period.Emulsion capacity found to increase during storage period.Gel strength of white leg shrimp meat was low(81±14 g cm)and further,reduced nearly 60%compared to fresh sample at the end of storage.The considerable reductions(from 535.77 kPa to 246.56 kPa)in storage modulus values were evident of diminishing elasticity and gelling ability of the meat due to ice storage.Therefore,this study usherd that the histological deterioration in myofibrils may be used as an indication of diminishing biochemical quality and gelling behaviour of the proteins.

Effectiveness of L-arginine/L-lysine in retarding deterioration of structural and gelling properties of duck meat myofibrillar protein during freeze-thaw cycles

This study aimed to investigate the protective effects of L-arginine(L-arg)and L-lysine(L-lys)on the structure and gel properties of myofibrillar protein(MP)in duck meat during several freeze-thaw(F-T)cycles.The analysis of the Ca2+-ATPase activity as well as total sulfhydryl and carbonyl contents demonstrated that L-arg and L-lys could slow down the oxidative denaturation of MP during F-T cycles.Circular dichroism,fluorescence spectroscopy,and rheology measurements indicated that L-arg and L-lys improved the stability of the secondary and tertiary structure of MP and preserved its gel properties.In summary,L-arg and L-lys had the potential to preserve the structural stability and gel properties of MP during F-T cycles.

The effect of fat on properties and filling characteristics of myofibrillar protein emulsion microgels

Emulsion microgels are micron-sized particles formed by one or more emulsion droplets surrounded by soft solids.It is inferred that their special structure affords interesting filling properties in protein gels.Different fat types affect the properties of emulsion microgels leading to different filling effects.The influence of fat types(soybean oil,lard,and coconut oil)on the myofibrillar protein emulsion microgels was studied by particle size,microstructure,and rheology.The filling properties were investigated in a protein gel model.The results show that coconut oil emulsion microgels had the smallest particle size,the thickest gel shell and the highest storage modulus.The apparent viscosity of all treatments showed shear thinning behavior and that of coconut oil treatment was significantly higher.With the increase in fat contents,the thixotropic ring area of coconut oil and lard treatment increased,while that of soybean oil treatment decreased.The filling properties in the protein gel model were analyzed by rheology,texture,microstructure and cooking loss measurement.Adding emulsion microgels to pure gels could increase the storage modulus of gels,and the storage modulus of gels filled with coconut oil emulsion microgels was the highest,indicating that emulsion microgels were active fillers.When the amount of addition was more than 10%,the texture properties of the filled gels improved,which was attributed to the enhanced density of the microstructure.In addition,the cooking loss was also reduced,and the gels filled with coconut oil emulsion microgels had the best performance.

Effects of citrus fiber on the emulsifying properties and molecular structure of mutton myofibrillar protein:An underlying mechanisms study

The effects of water-soluble citrus fiber(SCF)and water-insoluble citrus fiber(ICF)on emulsifying properties and molecular structure of the mutton myofibrillar protein(MP)were studied.The emulsifying activity index and emulsifying stability index of MP emulsion,treated with 5%SCF significantly improved to 36.80%and 65.27%,respectively.The droplet size of the emulsion significantly reduced,forming smaller and more uniformly dispersed droplets.SCF promoted the unfolding of MP,and showed a significant increased(p<0.05)in total sulfhydryl content and fluorescence intensity,but a significant decreased(p<0.05)in surface hydrophobicity.Besides,SCF treatment showed a significant reduction(p<0.05)inα-helix content and a significant enhancement(p<0.05)inβ-turn content of the MP secondary structure.The EAI,ESI,and solubility of MP significantly decreased after the addition of ICF,but there was no significant change in the secondary structure.These data demonstrated that,the addition of the appropriate amount of SCF could improve the emulsifying properties and molecular structure of MP.

Improvement of gelation properties of myofibrillar proteins from porcine longissimus dorsi muscle through microwave combined with air convection thawing treatment

The effects of the microwave combined with air convection thawing(MAT)on the gelling properties of pork myofibrillar proteins(MPs)were further studied and compared with those of fresh meat(FM),and single thawing methods(microwave thawing(MT)and air convection thawing(AT)).Results revealed that the thawing methods,excluding MAT,induced deterioration in the gelling properties of MPs.There was no significant difference(p>0.05)in the water holding capacity(WHC),cooking loss,whiteness,and strength of gel samples subjected to MAT and those of FM samples,demonstrating that the gelling properties were retained after MAT.As well,protein aggregation was limited,since MAT reduced the change in zeta potential and turbidity compared to that observed with MT or AT.The dynamic rheology and scanning electron microscopic results were relatively consistent,revealing that among the different thawing techniques,MAT had the least negative impact on the microstructure of MPs gel,leading to the generation of a more elastic and uniform gel structure than that of the MT or AT gels.Moreover,MAT resulted in higher water retention in the gels than that achieved with MT or AT.These findings indicated that MAT improved the gelling properties of MPs,thereby confirming the suitability of this treatment for use in the meat processing industry.

Identification of a novel nonsense mutation in kyphoscoliosis peptidase gene in an Iranian patient with myofibrillar myopathy

Myofibrillar myopathies(MFMs)are rare genetic and slowly progressive neuromuscular disorders.Several pathogenic mutations have been reported in MFM-related genes including DES,CRYAB,MYOT,LDB3 or ZASP,FLNC,BAG3,FHL1 and DNAJB6.Although MFMs is commonly inherited in an autosomal dominant manner,the inheritance pattern and novel mutated genes are not thoroughly elucidated in some cases.Here,we report discovery of a novel nonsense mutation in a 29-year-old Iranian male patient with motor disorders and deformity in his lower limbs.His parents are second cousins.Hereditary Motor Sensory Neuropathy as initial genetic diagnosis was ruled out.Whole exome sequencing using NGS on Illumina Hi-Seq4000 platform was performed to identify the disease and possible mutated gene(s).Our data analysis identified a homozygous nonsense unreported c.C415T(p.R139X)variant on kyphoscoliosis peptidase(KY)gene(NM_178554:exon4).Sanger sequencing of this mutation has been performed for his other related family members.Sequencing and segregation analysis was confirmed the NGS results and autosomal recessive inheritance pattern of the disease.

冻融与冻藏对乌鳢肌原纤维蛋白与酸菜鱼汤中特征风味物质结合特性的影响

为探究冷冻处理对于鱼片与酸菜鱼汤中风味物质的结合特性影响,以乌鳢的肌原纤维蛋白为对象,研究冻融及冻藏处理对其理化特性及与己醛、辛醛、芳樟醇、月桂烯结合能力的变化。结果表明经过7 d贮藏后,冻融组肌原纤维蛋白溶解度降低了约26%,相较于冻藏组,蛋白质氧化和三级结构变化程度更高,产生了更多可溶性聚集体;冻藏组溶解度降低了约33%,相较于冻融组,溶解度降低更加显著(P<0.05),产生了更多不溶性聚集体。影响肌原纤维蛋白冷冻聚集的主要作用力是非共价键。分子对接结果表明,芳樟醇、己醛和辛醛通过疏水作用和氢键与蛋白质结合,月桂烯与蛋白结合的主要驱动力为疏水相互作用。冷冻处理通过减少蛋白质与醛类化合物结合的巯基基团和氢键,降低了对己醛和辛醛的结合能力,蛋白质表面疏水性的提高,增加了对月桂烯和芳樟醇的结合能力,冻融处理后蛋白质对于月桂烯的结合能力强于冻藏处理组。研究结果可以为冷冻酸菜鱼预制品的风味控制提供理论依据和参考。

虾肉蛋白在乳酸菌发酵过程中的降解及其体外抗氧化活性的动态变化

本实验探究了在乳酸肠球菌发酵过程中虾肉肌原纤维蛋白和肌浆蛋白的降解及其产物(肽)抗氧化活性变化。结果表明,与未发酵时相比,随发酵时间的延长,两种蛋白的pH值均显著下降(P<0.05),蛋白酶活力均显著升高(P<0.05)。凝胶电泳结果表明,发酵使两种蛋白质均发生了降解,其中肌浆蛋白的降解程度更为明显。发酵后两种蛋白体系的2,2’-联氮双(3-乙基苯并噻唑啉-6-磺酸)(2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid),ABTS)阳离子自由基清除率、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、Fe^(3+)还原力均显著增强(P<0.05),其中肌浆蛋白降解产物(肽)的抗氧化能力显著高于肌原纤维蛋白降解产物(P<0.05)。相关性分析显示,蛋白酶活力与肌浆蛋白的水解度及其产物的ABTS阳离子自由基清除率、DPPH自由基清除率以及Fe^(3+)还原能力呈显著正相关(P<0.05、P<0.01)。综上,通过乳酸肠球菌发酵虾肉蛋白,尤其是肌浆蛋白可得到具有较高抗氧化能力的肽。本研究可为水产加工(如鱼糜)过程中产生肌浆蛋白的充分利用和抗氧化活性肽的开发提供理论依据。

4种提取方法对对虾肌原纤维蛋白提取率、空间结构和热稳定性的影响

【目的】获取提取率高且结构完整的凡纳滨对虾(Litopenaeus vannamei)肌原纤维蛋白。【方法】通过0.5 mol/L KCl、53 kHz超声辅助0.5 mol/L KCl、53 kHz超声辅助质量分数5%十二烷基硫酸钠(SDS)和RIPA裂解液这4种提取方法提取对虾肌原纤维蛋白,以肌原纤维蛋白提取率和结构完整性为评价指标,采用光谱学和凝胶电泳生化,评价四种提取方法对对虾肌原纤维蛋白提取率、空间结构和热稳定性的影响。【结果】53 kHz超声辅助0.5 mol/L KCl、0.5 mol/L KCl、53 kHz超声辅助5%SDS和RIPA裂解液4种方法所得提取率分别为(87.99±3.08)%、(53.76±3.90)%、(75.59±0.95)%和(95.46±4.49)%。53 kHz超声辅助0.5 mol/L KCl提取的蛋白中肌钙蛋白和原肌球蛋白蛋白丰度较高,0.5 mol/L KCl和53 kHz超声辅助质量分数5%SDS提取的肌球蛋白重链和肌动蛋白蛋白丰度较高;相较于0.5 mol/L KCl,超声辅助提取可最大限度保持肌原纤维蛋白天然结构,α-螺旋结构保留完好;0.5 mol/L KCl提取可较好维持肌原纤维蛋白的酰胺Ⅰ带结构。RIPA裂解液提取对肌原纤维蛋白二级结构有明显破坏,热稳定性仅为原蛋白的(60.63±4.46)%。【结论】综合提取率、空间结构和热稳定性结果,采用53 kHz超声辅助5%SDS提取可获得质量最佳的凡纳滨对虾肌原纤维。本研究可为后续深入解析冷藏对虾品质劣变和开发高效控制技术提供高质量的肌原纤维蛋白。

坛紫菜多糖对微冻南美白对虾仁肌原纤维蛋白氧化和结构特性的影响

该研究通过探讨坛紫菜多糖浸泡的南美白对虾仁在微冻过程中肌原纤维蛋白氧化特性和结构特性的变化规律,从蛋白质角度揭示坛紫菜多糖抗冻保鲜的潜在机制。将虾仁分别用5 mg/mL坛紫菜多糖,蒸馏水(空白对照)和5 mg/mL焦磷酸钠(阳性对照)浸泡处理后于-3℃微冻贮藏,每5 d测定指标。结果表明,与对照组相比,坛紫菜多糖浸泡虾仁可显著延缓总巯基含量下降,防止羰基含量和表面疏水性上升,阻碍平均粒径增加和Zeta电位绝对值的下降(P<0.05),抑制肌原纤维蛋白的氧化和聚集。圆二色光谱分析表明,坛紫菜多糖显著抑制肌原纤维蛋白α-螺旋相对含量的降低(P<0.05)。内源荧光光谱分析表明,坛紫菜多糖能缓解肌原纤维蛋白中发色基团暴露,维持蛋白空间结构稳定性。扫描电镜结果显示,坛紫菜多糖能保持虾肌肉组织微观结构的完整性。该研究为坛紫菜多糖作为新型绿色无磷抗冻保鲜剂添加到水产品冷冻过程中保护蛋白质特性提供理论依据。