GEL-FORMING ABILITY OF COMMON CARP FISH (CYPRINUS CARPIO) MEAT: EFFECT OF FREEZING AND FROZEN STORAGE

Effect of freezing and frozen storage on gel‐forming ability of muscle from fresh water fish, common carp (Cyprinus carpio), was investigated. Fresh carp meat had good gel‐forming ability as revealed by large strain test (gel strength of 1027 g·cm) and dynamic viscoelastic behavior. Freezing and frozen storage at ?18C for 180 days significantly (P < 0.01) reduced the gel‐forming ability of common carp meat. Reduction in protein solubility and calcium‐activated adenosinetriphosphatase enzyme activity of common carp meat during frozen storage was also significant (P < 0.05). Structural change of proteins during frozen storage was evident from reduced viscosity and gel filtration profile. Higher drip loss and reduction in gel‐forming ability of carp meat is attributed to denaturation of proteins during frozen storage.     

Dynamic Rheological and Thermal Properties of Soft Wheat Flour Dough Containing Structured Lipid

ABSTRACT: The effect of substituting canola oil/caprylic acid structured lipid for shortening (at 0%, 25%, 50%, 75%, and 100% levels) on the viscoelastic and thermal properties of soft wheat flour dough (28.4% total lipid, 43% moisture) was determined using dynamic rheological and differential scanning calorimetry tests. Ambient frequency scans produced higher G" (loss modulus) and G' (storage modulus) values at increasing frequencies. Temperature scans revealed rapid G" and G' increases for dough heated to above 56 °C, apparently because of starch gelatinization. Three differential scanning calorimetry endothermic peaks were observed at 54 °C, 69 °C, and 93 °C, which were attributed to shortening transition and gelatinization of starch granules.     

Comparison of various types of starch when used in meat sausages

Technological and sensory properties of meat sausages formulated with 4·0% of either potato flour, modified (acetylated distarch phosphate) potato starch, wheat, corn or tapioca starch were compared. Sausages were analyzed after cooking at temperatures between 65 and 85°C followed by storage at 5°C and -25°C. Characteristics evaluated were weight loss during cooking and storage, instrumentally and sensory assessed firmness, taste and smell of sausages. The results revealed differences in the suitability of starches for use in meat sausages. Part of the differences could be ascribed to differences in gelatination properties of the starches. With the criteria used for evaluating quality, potato flour was rated as the best suited starch followed by wheat starch while tapioca was rated as the least suited. Corn starch required cooking temperatures above 75°C and showed relatively low freeze/thaw stability. The modified potato starch stored well both above and below the freezing point.     

Physico‐chemical and functional properties of proteins from green mussel (Perna viridis) during ice storage

The effect of ice storage on the properties of proteins from green mussel (Perna viridis) has been investigated. Ice storage of green mussel for a period of 19 days revealed a marginal increase in moisture and decrease in total nitrogen content. There was significant reduction (P < 0.05) in non‐protein nitrogen content and calcium activated adenosine triphosphatase enzyme activity. The solubility of the total proteins in high ionic strength buffer decreased marginally. The ice storage of green mussel had a significant effect on association‐dissociation/denaturation phenomenon of proteins as revealed by gel filtration profile, reduced viscosity values and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) pattern. The dynamic viscoelastic behaviour of green mussel meat in the temperature range of 30–90 °C revealed higher storage modulus (G′) values at a later part of ice storage. The emulsion capacity of green mussel did not show significant variation (P < 0.05) during ice storage. Copyright © 2006 Society of Chemical Industry     

Proteins Associated with Thermally Induced Gelation of Turkey Breast Meat

ABSTRACT:  Principal component analysis was performed on turkey breast muscle that originated from a pool of genetically distinct turkeys by separating the salt-soluble from the salt-insoluble proteins. The salt-soluble proteins (SSP) formed thermally induced meat gels and the viscoelastic properties of the gels were analyzed. The storage modulus (G') at 80 °C of thermally induced gels derived from the SSPs ranged from 3 to 400 Pa. Each protein fraction was analyzed using 5% to 20% sodium dodecyl sulfate polyacrylamide gel electrophoresis. Reverse stepwise regression analysis of the electrophoretic fingerprints of the protein fractions showed that G' at 80 °C was associated with the 2 protein bands from the salt-soluble fraction ( R ²= 0.87, P < 0.01) and 1 protein from the salt-insoluble fraction ( R ²= 0.27, P < 0.05). Primary sequence analysis identified one of the SSPs positively associated with G' at 80 °C as α-tropomyosin and the other SSP negatively associated with G' at 80 °C as pyruvate kinase. The salt-insoluble protein identified as triose phosphate isomerase was negatively associated with G' at 80 °C. These findings are unique in that they show that proteins other than myosin and actin participate in the mechanisms of forming thermally induced meat gels.     

Biochemical Properties of Natural Actomyosin Extracted from Normal and Pale, Soft, and Exudative Pork Loin After Frozen Storage

ABSTRACT: The studies of natural actomyosin (NAM) extracted from normal and pale, soft, and exudative (PSE) pork longissimus muscle stored at -20°C for up to 6 mo, revealed that the surface hydrophobicity (S₀-ANS) of NAM from PSE pork was significantly ( P < 0.05) higher than that from normal pork indicating greater conformational changes in proteins from PSE meat that resulted in the exposure of hydrophobic aromatic amino acid residues on the surface. Also, the S₀-ANS of NAM was a function of storage time. The equations were as follows: S₀-ANS = 16.9 × storage mo + 123 for normal and S₀-ANS = 17.5 × storage mo + 164 for PSE. NAM from frozen normal pork had lower α-helical content than comparable fresh pork. With extended frozen storage, viscosity of NAM from PSE meat was lower than that from normal pork. The sulfhydryl and disulfide contents were unchanged. Electrophoresis revealed an extra 95 to 100 kDa band from PSE meat NAM, possibly from α-actinin or myosin degradation. Water-binding capacity (WBC) of normal and PSE meat decreased with increasing storage time; however, there were only minor changes in thaw loss. The decrease of WBC of pork meat partially can be explained by the increase of S₀-ANS observed for the NAM. These results suggest that proteins from PSE pork are more susceptible to denaturation and degradation in fresh meat and following frozen storage.     

Improvement of Gelling Properties of Lizardfish Mince as Influenced by Microbial Transglutaminase and Fish Freshness

ABSTRACT:  The effects of microbial transglutaminase (MTGase) at different levels (0 to 0.8 units/g sample) on the properties of gels from lizardfish ( Saurida undosquamis ) mince set at 25 °C for 2 h or 40 °C for 30 min prior to heating at 90 °C for 20 min were studied. Breaking force and deformation of gels increased with increasing MTGase amount added ( P < 0.05). At the same MTGase level used, gels with the prior setting at 40 °C for 30 min showed a higher breaking force compared with those subjected to prior setting at 25 °C for 2 h ( P < 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoretic study revealed that myosin heavy chain (MHC) underwent polymerization to a higher extent in the presence of MTGase. Regardless of setting condition, microstructure of gel added with MTGase was finer with a smaller void compared with that of gel without MTGase. Therefore, setting temperature affected the property of gels added with MTGase. Gel properties of mince obtained from lizardfish stored in ice for different times (0 to 10 d) with and without MTGase at a level 0.6 units/g were determined. Irrespective of MTGase addition, breaking force and deformation of all gels decreased as the storage time of lizardfish increased ( P < 0.05). The addition of MTGase was able to increase both breaking force and deformation of the resulting gel produced from lizardfish kept in ice for all storage times used. Therefore, both freshness and MTGase addition had the direct impact on gel properties of lizardfish mince.     

带鱼香肠加工工艺初探

本试验以冷冻带鱼为原料,研究了漂洗工序和擂溃时间及食盐和淀粉的添加量对带鱼香肠质量的影响,结果表明:漂洗工序影响带鱼香肠的颜色和弹性;确定擂溃时间以25min为宜,食盐的添加量为肉重(鱼肉+猪肉)的2.5%,淀粉的添加量为肉重的10%。     

Effect of Freezing Rate and Starch Granular Morphology on Ice Formation and Non-Freezable Water Content of Flour and Starch Gels

Ice formation and non-freezable water (W_NFW) of rice flour and tapioca starch gels were studied at two different freezing rates (–10 and –100°C/min) using differential scanning calorimetry. Ice crystal growth was observed in the slow freezing but not in the fast one. Ice melting enthalpies, however, were similar since more ice formed in holding and reheating steps. Melting enthalpy of fully gelatinized systems with water contents ~ 0.50–0.66 was associated to starch composition and granule morphology. Highly swollen tapioca starch gave the lowest enthalpy and the highest W_NFW (0.40 g/g dry starch versus 0.32 and 0.38 g/g dry starch of normal and waxy rice flours, respectively). The further studies revealed that the W_NFW values were associated to swelling power, solubility, and granule morphology.     

淀粉对磷酸化的虾蛄肌原纤维蛋白凝胶特性的影响

将马铃薯、木薯和玉米淀粉分别添加到磷酸化的虾蛄肌原纤维蛋白中,探讨在不同淀粉添加量、不同三聚磷酸钠添加量及不同温度下对磷酸化蛋白所形成凝胶特性的影响。结果表明：随着三聚磷酸钠添加量的增加,3 种淀粉形成的复合蛋白凝胶强度和保水性均提高;随着淀粉添加量的增加,马铃薯、木薯淀粉对复合蛋白的凝胶特性有显著影响（P＜0.05）,玉米淀粉对蛋白凝胶特性没有显著影响（P＞0.05）;随着温度的升高,3 种淀粉均能使蛋白的凝胶强度升高,但保水性下降。本研究结果为进一步研究虾蛄中肌原纤维蛋白凝胶特性以及淀粉的利用提供了一定的基础。     

变性淀粉在午餐肉中的应用效果研究

将木薯变性淀粉与玉米原淀粉在午餐肉中的应用效果进行了对比,结果表明,添加了变性淀粉的产品在弹性、组织状态、口感及贮存稳定性方面明显优于玉米原淀粉。     

Physicochemical Nature of Banana Pseudostem Starch

SUMMARY: Starch was isolated from banana pseudostem and its properties were compared with those of potato, corn and tapioca. The starch granules are irregular in shape and are bigger in size than those of the fruit starch. At 60°C, the granules start to swell, gradually increase in size, attain their maximum size at 75°C and do not rupture even after heating to 100°C. The intrinsic viscosity of the starch (2.05) is similar to that of potato starch (2.00). The amylose content of the starch compares well with that of banana fruit and potato (tuber) starch (21%). In general, banana pseudostem starch resembles potato starch.     

Characteristics of pressurised pork meat batters as affected by addition of plasma proteins,apple fibre and potato starch

Pork meat (low‐fat) batters were prepared without and with the addition of three non‐meat ingredients: (blood) plasma proteins, (dietary) apple fibre and potato starch. The batters were processed by cooking‐alone (70 °C) and by high‐pressure/temperature combination (400 MPa/70 °C). Protein denaturation and starch gelatinisation through the different processings were followed by differential scanning calorimetry. Batter characteristics such as water holding (weight loss) and different texture parameters (texture profile analysis) were used as quality criteria for comparisons among different formulations and processes. Plasma proteins and apple fibre behaved as inert fillers in both kinds of processed batters. Potato starch effects depended on processing conditions to the extent that these influenced the degree of gelatinisation. In pressurised batters (pressure and heating in sequence), regular preservation effects against subsequent thermal denaturation of proteins were observed. Differential scanning calorimetry revealed that starch was also pressure‐preserved from subsequent thermal gelatinisation, which was confirmed by scanning electron microscopy. The presence of native‐like proteins and ungelatinised starch produced cumulative softening effects in pressurised batters. © 2000 Society of Chemical Industry     

Thermal stability of fish myofibrils: a differential scanning calorimetric study

The variation in myofibrillar protein thermostability was compared for various fish species, using differential scanning calorimetry. The tropical fish, catfish ( Clarius gariepinus ), carp ( Cyprinus carpio ), Nile perch ( Lates niloticus ), red snapper ( Lutianus sebae ), red mullet ( Parpeneus barberinus ), sea bream ( Gymnocranius rivalatus ), and cold-water reared trout ( Salmo gairdneri ) and cod ( Gadus morhua ) were analysed. Onset temperature of myofibrillar protein denaturation occurred at up to 11°C higher for tropical species (43.5°C, catfish), than cod (32.6°C) at pH 7 and low ionic strength (I). As pH (6.0-8.0) and I (0.05-1.00) were increased, thermal denaturation temperatures of myosins from tropical, but not cold-water, species decreased. Enthalpies of myofibrillar denaturation decreased for all species with increasing pH and I. Only one thermal transition was detected for myosin at pH 6 and low I, increasing to three as pH and I were increased. Changes in thermal characteristics of myosin subunits over iced and frozen storage suggest more rapid deterioration in cold-water than in tropical fish. The differences in myofibrillar stability of fish from different habitat temperatures have implications for the processing and storage of tropical fish.     

Effect of frozen storage on protein denaturation in bovine muscle 1. Myofibrillar ATPase activity and differential scanning calorimetric studies

The effect of frozen storage on myofibrillar ATPase activity and thermal transitions in bovine muscle was investigated. Myofibrillar ATPase activity and total enthalpy of denaturation (ΔH) decreased with time of storage. The rate of decrease was lower at −20°C than at −5°C or −10°C. Differences in behaviour during storage of muscle after fast or slow freezing could be attributed to differences in ice recrystallization. The observed decreases in area of the first peak seen in the thermograms and Ca²⁺-myo-fibrillar ATPase activity show that the myosin head denaturated progressively during storage. The myosin tail also denaturated during storage but the thin filament remained unaltered. Kinetic analysis suggested that the denaturation of the myofibrillar proteins took place through two consecutive first order reactions; an initial rapid reaction followed by a slower one.     

Physicochemical and morphological characterisation of açai (Euterpe oleraceae Mart.) powder produced with different carrier agents

Physicochemical and morphological properties of açai powder produced with different carrier agents were evaluated in this work. Powders were produced by spray drying, using maltodextrin 10DE, maltodextrin 20DE, gum arabic and tapioca starch as carrier agents. Powder characterisation included analysis of moisture content, water activity, solubility, hygroscopicity, particle size distribution, morphology, total polyphenolics and antioxidant activity. Results showed that the samples produced with maltodextrin 20DE and gum arabic presented the smallest size and highest hygroscopicity. The powder produced with tapioca starch exhibited the lowest hygroscopity and solubility, and the highest mean diameter. With regard to morphology, all particles exhibited spherical and shrivelled surfaces, except those produced with tapioca starch, which exhibited rounded and smooth surfaces. Powders produced with maltodextrins and gum arabic showed high polyphenolic retention and antioxidant activity preservation after storage at 40 °C for 15 days, while for the particles produced with tapioca starch, this protective effect was less pronounced.     

Influence of sodium chloride and sodium tripolyphosphate on the quality of UK-style grillsteaks: relationship to freezing point depression

Grillsteaks were prepared from lean beef flaked at –4°C and subsequently mixed at nominal temperatures of either –3°C or +1°C with each combination of five sodium chloride levels (0, 0.5, 1.0, 2.0 and 4.0%) and three levels of sodium tripolyphosphate (Na5P3O10) (0, 0.25 and 0.50%).
Sodium chloride was more effective than sodium tripolyphosphate in lowering the initial freezing point (ifp) of meat, as measured by differential scanning calorimetry which also showed that the freezing point depression was proportional to the solute concentration.
Cooking losses generally were lower with higher levels of sodium chloride and sodium tripolyphosphate, and when the meat was mixed at +1°C. It is argued that localized salt concentrations can influence product quality, as can the relative proportions of ice and water when meat is processed below the ifp.     

Composition and consumer acceptability of a novel extrusion-cooked salmon snack

ABSTRACT:  The objectives of this study were to develop a value-added jerky-style snack from salmon flesh and to minimize loss of healthful lipids during processing. Three formulations were extruded in a laboratory-scale twin-screw extruder. The base formulation included Atlantic salmon (82%, w/w), sucrose (4%), pregelatinized starch (3%), modified tapioca starch (3%), salt (2%), and teriyaki flavoring (2%). Three oil binding agents (tapioca starch, high-amylose cornstarch, oat fiber) were each studied at the 4% level. Barrel temperature, from feed to die, was 65, 155, 155, and 80 °C. Screw speed was 250 rpm. Feed rate was 220 g/min. Extrudates were convection-dried at 93 °C for 40 min. A texture analyzer was used to evaluate textural properties. Sixty-three consumers evaluated the hedonic attributes of the snacks. Extrusion cooking did not adversely affect content of omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in Atlantic salmon. The oat fiber formulation had the highest lipid (17.49%) content. The other formulations had higher moisture content. A serving (28 g) of the oat formulation provides 0.6 g EPA + DHA. Snacks containing oat fiber had the highest CIE L * and b * values. Snacks containing oat fiber required greater force to bend, cut, and puncture. The oat fiber formulation had the lowest overall acceptability. This portable snack could appeal to consumers who are interested in the health benefits of fish and omega-3 fatty acids and provide salmon processors with a value-added solution for processing by-products.     

疏水改性木薯淀粉的制备及其对肌原纤维蛋白乳化特性的影响

为了提高木薯淀粉的疏水性,使其作为颗粒乳化剂改善肌原纤维蛋白(myofibrillar protein,MP)的乳化特性,实验利用辛烯基琥珀酸酐(octenyl succinate anhydride,OSA)对原料木薯淀粉(native tapioca starch,NTS)进行疏水改性处理,得到不同改性水平和取代度(DS值)的疏水改性木薯淀粉(octenyl succinate tapioca starch,OSTS),并利用OSTS与MP制备复合乳化液。通过XRD、FT-IR、SEM和PLM分析了OSTS的结构变化,并测定了乳化液的乳液指数(EI值)、乳化活性(emulsifying activity index,EAI)、乳化稳定性(emulsion stability index,ESI)、Zeta-电位、粒径分布、巯基含量和界面蛋白含量。结果显示,在木薯淀粉分子中成功引入了疏水基团,疏水改性处理对木薯淀粉颗粒的晶体结构基本无影响;随淀粉改性水平和DS值的增加OSTS-MP复合乳化液的EAI和ESI呈显著增加趋势(P<0.05),3.0%OSTS-MP复合乳化液稳定性最...     

Effect of storage of adzuki bean (Vigna angularis) on starch and protein properties

Differential scanning calorimetry was used to evaluate the effect of storage at 10°C, 20°C and 30°C, and 40% and 65% relative humidity (RH) on adzuki bean starch gelatinisation and protein denaturation temperatures. Storage for 6 months at an elevated storage temperature (30°C) caused increases in the starch gelatinisation onset temperature (T_o) and gelatinisation peak temperature (T_p) for both Bloodwood and Erimo varieties. Storage at 40% RH resulted in higher T_o and T_p values than storage at 65% RH. The T_o of starch from Bloodwood and Erimo beans stored for up to 1.5 months at 10°C and 65% were similar to those of fresh beans.The changes in the salt-soluble protein component were less clear cut than those of the starch. Nonetheless, protein extracted from beans stored at 40% RH exhibited significantly lower T_o and T_p values compared with those stored at 65% RH. This indicates some destabilisation of the protein at the higher RH.These results suggest that detrimental changes occur in starch and, to a lesser extent protein, of adzuki beans stored under unfavourable conditions. On the basis of these results, the best storage conditions to maintain the characteristics of fresh beans are low temperatures (e.g. 10°C) and high RH (e.g. 65%).