Waxy corn starch affecting texture and ultrastructure of sardine surimi gels

 The effect of waxy corn starch (WCS) on the texture, water-holding capacity and microstructure of sardine (Sardina pilchardus) surimi gels in two different systems was studied. In the type A system, increasing amounts of WCS (2, 4, 6 or 8 g/100 g surimi) were added to surimi while maintaining the gel moisture constant at 78%; in the type B system, WCS was added without correcting the gel moisture. Gels were made using two different heat treatments [heat-induced setting (HS) and direct cooking (DC)]. When starch was replaced by surimi (type A) and a heat treatment was applied that favoured formation of a preliminary actomyosin (AM) network (i.e. HS), gel strength (GS) was lower than in the control and decreased as more starch was added, despite an increase in the amount of water held by the gel. Scanning electron microscopy (SEM) showed that the matrix network was fibrillar with a globular surface. Starch appeared to be totally gelatinized and surrounded by a continuous matrix. When the amount of dry matter in gels was increased (type B), in no case did starch have a reinforcing effect, despite an increasing water-holding capacity; SEM showed a denser continuous matrix surrounding the gelatinized starch. Both types of gel made using the heat treatment that allows simultaneous gelling of surimi and gelatinization of starch (i.e. DC) exhibited much poorer GS than did HS gels, while addition of starch made practically no difference to gel texture. The findings suggest that the effect of starch is related to the type of gel matrix that forms upon addition of ingredients. Although such gels contained more water or dry matter, their texture parameters were lower, possibly because of the type of network formed by sardine surimi. Nonetheless, gels of acceptable quality were successfully made with added starch by incorporating less surimi. Received: 18 March 1996     

不同种类淀粉对罗非鱼鱼糜凝胶品质的影响

为了改善淡水鱼鱼糜制品的品质,以冷冻罗非鱼鱼糜为原料,分别添加4%木薯原淀粉、3种木薯变性淀粉（磷酸酯淀粉、羟丙基淀粉和乙酰化二淀粉磷酸酯）及复配木薯变性淀粉（乙酰化二淀粉磷酸酯与羟丙基淀粉质量比为3∶2）,考察淀粉添加对鱼糜凝胶质构、流变学特性、持水性及水分分布和微观结构等的影响,探讨不同种类淀粉对鱼糜凝胶品质的改善。结果表明,与对照组相比,添加5种淀粉均会显著降低罗非鱼鱼糜凝胶的白度（P<0.05）,但其凝胶强度、硬度和咀嚼性显著增大,凝胶持水性显著提高（P<0.05）,蒸煮损失率显著下降（P<0.05）,结合水含量显著增加（P<0.05）,凝胶微观结构更加均匀致密,且添加了复配木薯变性淀粉的凝胶质构特性最好,持水性最高。低场核磁共振成像和光学显微镜观察结果显示,不同种类的淀粉均能有效锁住鱼糜凝胶基质中的水分;升温过程中淀粉吸水膨胀,在鱼糜凝胶网络结构中起浓缩和填充作用;添加了复配木薯变性淀粉的鱼糜凝胶结构最致密均匀。因此,添加复配木薯变性淀粉可以有效改善罗非鱼鱼糜制品的品质,为淡水鱼鱼糜制品的开发提供了理论支撑。     

The effect of modified starches on the gel properties and protein conformation of Nemipterus virgatus surimi

The study investigated the effect of native cassava starch (NCS), hydroxypropylated starch, acetic acid esterification starch (AAES), acetylated distarch phosphate on gel properties and protein conformation of Nemipterus virgatus surimi. Addition of 10 g kg^?1 NCS or 20 g kg^?1 AAES could significantly promote the gel strength and textural profiles of the surimi gels (p < .05). The water holding ability and whiteness of surimi were remarkably increased when the four types of starch were added at all concentrations (p < .05). In rheological test, the lower G′ was observed in surimi samples added with starch at low temperature, suggesting starch played an inactive filler role in surimi. Along with the increase of starch additive amount, ionic bond and hydrophobic interaction first increased and then decreased, while hydrogen bond first decrease and then increased. According to Raman spectroscopy data, small content of starch promoted the heat‐induced conformational transition of surimi protein from α‐helix to β‐sheet, leading to the change in gel properties of surimi gels. Scanning electron microscopy photographs showed surimi gels added with 20 g kg^?1 starch had the finer and denser network structure. Therefore, 20 g kg^?1 AAES or 10 g kg^?1 NCS or 10 g kg^?1 HS could be proposed to a potential modifier to effectively improve the quality of surimi products.     

Sardine Surimi Gels as Affected by Salt Concentration, Blending, Heat Treatment and Moisture

The effects of simultaneous modification of salt concentration, blending time, moisture content and heat treatment at different setting and cooking temperatures and time on characteristics of sardine (Surdina pilchardus) surimi gels was examined using a randomized incomplete block design. Maximum gel strength (GS) was obtained at highest salt concentrations and 78% moisture. Pre-setting was required to achieve acceptable gel quality. Highest GS values were found in gels set for 30–60 min at 35°C prior to heating at 90°C for 40 min. However, GS decreased after prolonged heating at 90°C. Gels set at 25, 35 and 40°C for 90 min had lower GS values when heated at 90°C for 40 min but were stable during further heating.     

没食子酸对金线鱼鱼糜凝胶特性及其体外消化产物活性的影响

以金线鱼鱼糜为原料,添加没食子酸（gallic acid,GA）,通过二段加热法制备金线鱼鱼糜凝胶,考察GA添加量（0%～0.25%）对鱼糜凝胶特性、微观结构和分子间化学作用力的影响,进行体外模拟消化,研究体外消化产物的抗氧化活性和降胆固醇活性,探讨GA的添加对鱼糜凝胶功能活性的改善。结果表明,添加GA能改善鱼糜凝胶强度和质构特性,而对凝胶的白度不利。当GA添加量为0.15%时,鱼糜凝胶的质构特性最好,白度和持水性最高,凝胶的微观结构致密,维持凝胶的主要化学作用力是二硫键。体外消化结果显示,添加GA后,鱼糜凝胶的蛋白质体外消化率增加（P＜0.05）,消化产物的活性增强（P＜0.05）。当GA的添加量为0.15%时,鱼糜凝胶体外消化产物的1,1-二苯基-2-三硝基苯肼自由基清除率、2,2′-联氮-双-(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率、羟自由基清除率均增加到80%（P＜0.05）,胆固醇酯酶抑制率增加到50.82%（P＜0.05）,胆固醇胶束化抑制率增加到41.88%（P＜0.05）,表明GA添加到鱼糜中经热处理和体外消化后仍保留了自身的生物活性。因此,适量没食子酸的添加能有效改善金线鱼鱼糜的热凝胶性能且能保留其功能活性,为新型功能性鱼糜制品的开发提供一定参考。     

不同淀粉种类对未漂洗革胡子鲶鱼鱼糜凝胶特性的影响

为研究淀粉种类对未经漂洗处理革胡子鲶鱼（Clarias gariepinus,CG）鱼糜凝胶特性的影响,在未经漂洗的CG鱼糜（含2.2%食盐、0.4%转谷氨酰胺酶、20 mmol/kg CaCl2、0.2%浓缩乳清蛋白）中分别添加占鱼糜湿质量6%的木薯变性淀粉（modified cassava starch, MCS）、玉米淀粉（corn starch,CS）、绿豆淀粉（mung bean starch,MBS）及红薯淀粉（sweet potato starch,SPS）,以不添加淀粉的样品为对照组（CK）,5 组样品均通过两段式加热方式制备鱼糜凝胶,分别测定各组CG鱼糜凝胶的凝胶特性、白度、持水性、动态流变学性质和水分迁移变化规律。结果表明：与对照组相比,4 种淀粉的添加均会使CG鱼糜凝胶的持水性增强,但对CG鱼糜凝胶中水分变化的影响不同,其中添加MCS的CG鱼糜凝胶持水性最好,结合水相对含量最高（P21为3.67%）（P＜0.05）;4 种淀粉的添加均显著降低了CG鱼糜凝胶的白度（P＜0.05）,均能提高CG鱼糜的凝胶破断力（P＜0.05）,其中MBS组CG鱼糜凝胶破断力（567.55 g）和凝胶强度（4 739.81 g·mm）最大（P＜0.05）;动态流变特性测定结果表明,4 种淀粉的添加均会增加CG鱼糜的储能模量（G’）和损耗模量（G’’）（P＜0.05）,对G’和G’’的影响从大到小顺序依次均为MCS＞CS＞MBS＞SPS。综合各项指标得出,添加6% MCS最有利于提高未经漂洗处理CG鱼糜的凝胶特性和持水性。     

Effects of Bambara Groundnut Protein Isolates and Microbial Transglutaminase on Textural and Sensorial Properties of Surmi Gel from Sardine (Sardinella albella)

Effects of different bambara groundnut protein isolates (BGPIs) at a level of 6 % (w/w) in combination with microbial transglutaminase (MTGase) at a concentration of 0.6 U g^?1 surimi on gel properties of sardine (Sardinella albella) surimi were investigated. In the absence of MTGase, all BGPIs showed the adverse effect on gel-forming properties of surimi, as evidenced by the decreases in breaking force and deformation (P?<?0.05). When MTGase was incorporated, the increases in breaking force and deformation were found for all BGPIs used. Water-holding capacity of all gels was improved when BGPIs were added in combination with MTGase (P?<?0.05). Whiteness of gels slightly decreased with the addition of BGPIs; however, MTGase had no impact on whiteness (P?>?0.05). Surimi gel added with BGPI prepared from defatted flour with heat treatment in the presence of ethylenediaminetetraacetic acid (DF-BGPI-HE) and MTGase showed well-ordered network and exhibited the lowest peroxide value and thiobarbituric acid-reactive substances than those containing other BGPIs. Gel containing DF-BGPI-HE had negligible beany flavour. Additionally, DF-BGPI-HE had the lower amount of volatile compounds after storage of 30 days at room temperature than other BGPIs. Thus, the addition of DF-BGPI-HE and MTGase was an effective means to render sardine surimi gel with improved gel property and caused no beany flavour in resulting gel.     

油茶籽油对鱼糜凝胶特性及凝胶结构的影响

为探讨脂质对鱼糜蛋白凝胶功能特性的影响及其机理,研究不同油茶籽油添加量对鱼糜凝胶特性、水分分布、脂质及蛋白质结构等的影响。结果表明:随着油茶籽油添加量的增加,鱼糜凝胶强度、乳化稳定性和持水性显著增加(P0.05),当油茶籽油添加量增加到8%时各指标基本稳定,此时鱼糜凝胶强度为225.1 g·cm,游离出来的液体质量分数为2.60%。拉曼光谱分析发现,油茶籽油的添加改变了鱼糜凝胶体系中脂质和蛋白质的化学结构,主要表现为C—H谱带峰宽的增加、O—H谱带相对强度的下降,以及鱼糜蛋白中β-折叠、β-转角和无规卷曲结构相对含量的增加和α-螺旋结构相对含量的降低。同时,随着油脂质量分数的增加,水分以更加细小的状态分布在鱼糜凝胶体系之中。以上结果进一步揭示了油茶籽油的添加可增加鱼糜凝胶强度、乳化稳定性和持水性的内在原因。     

Impact of salted duck egg albumen powder on proteolysis and gelling properties of sardine surimi

The influences of salted duck egg albumen powder (SDEAP) as salt replacer at various levels (0.5–2.5%) on autolysis and gelling properties of sardine surimi were investigated. SDEAP had high salt (33.67%) and protein contents (64.52%) with trypsin inhibitory activity of 5,975 kunits/g solid. SDEAP was white in color with L*‐value of 96.72. It had low moisture content (3.98%) and water activity (0.38). Autolysis of sardine surimi was drastically inhibited when SDEAP was incorporated with increasing levels as indicated by the more retained myosin heavy chain and the reduced trichloroacetic acid‐soluble peptide content. Breaking force and deformation of surimi gel increased, while expressible moisture content decreased as the levels of SDEAP added were increased (p < .05). Gumminess, hardness, chewiness, springiness, and cohesiveness of surimi gels also increased as SDEAP levels increased (p < .05). Lightness and whiteness were higher in all surimi gels incorporated with SDEAP than the control (p < .05). For microstructure, surimi gels incorporated with SDEAP at all levels used had finer gel network with smaller voids and more connectivity than the control gel. Thus, SDEAP could be used as a salt replacer for sardine surimi gel preparation and it could improve the properties of resulting gel.     

KCl复配5’-肌苷酸二钠替代钠盐对鱼糜凝胶特性的影响

为研制低盐鱼糜,探究食盐替代物KCl和5’-肌苷酸二钠（inosine 5’-monophosphate disodium salt,IMP）对鱼糜凝胶品质的影响,以鲢鱼鱼糜为研究对象,设计3 组实验,A组添加2.0% NaCl,B组添加0.8% KCl和1.2% NaCl,C组添加0.7% KCl、0.1% IMP和1.2% NaCl,通过测定鱼糜凝胶的白度、持水性、强度、质构、水分分布与组成以及微观结构变化,探究NaCl的最佳替代方案。结果表明：相比于A组,B组鱼糜凝胶白度、持水性、强度变低,硬度、胶着性、咀嚼性、内聚性显著降低,弹性无显著变化,不易流动水含量减小、自由水含量升高,凝胶网络空间结构形成不完全;C组鱼糜凝胶除咀嚼性显著下降外,其余指标未发生显著劣变,说明KCl和IMP复配是一种理想的NaCl替代方案。     

负载白藜芦醇的红花籽油乳液对金线鱼鱼糜凝胶品质的影响

研究负载白藜芦醇的红花籽油乳液（10 mL/100 g）对金线鱼鱼糜凝胶性能、微观结构和氧化稳定性的影响,比较不同添加量（0.1%～0.3%）的白藜芦醇对鱼糜凝胶品质的影响。结果表明,红花籽油乳液的添加使金线鱼鱼糜凝胶的白度、持水性和结合水含量增加,凝胶质构特性较好,蒸煮损失率较低（P＜0.05）,且凝胶三维网络结构孔径较小,但凝胶基质中油滴分布不均匀,其油滴的平均直径大于2.0 μm,油脂的氧化性随贮藏时间的延长而增加（P＜0.05）;添加负载白藜芦醇的红花籽油乳液后,金线鱼鱼糜凝胶的白度和持水性增加,蒸煮损失率下降（P＜0.05）,且凝胶的质构和油脂氧化性稳定性明显增强（P＜0.05）,白藜芦醇在鱼糜凝胶基质中仍具有强抗氧化性。白藜芦醇能进一步乳化红花籽油,使细小油滴在凝胶基质中均匀分布,且与鱼糜中蛋白质相互作用促进了凝胶网络结构的形成。当白藜芦醇添加量为0.3%时,油滴的平均直径小于1.5 μm,凝胶三维网络结构的孔径最小,具有均匀致密的空间层次感。因此,负载白藜芦醇的红花籽油乳液能改善金线鱼鱼糜的凝胶特性,增强凝胶的氧化稳定性,为新型鱼糜制品的开发提供参考。     

Morphology of starch in surimi gels

 The purpose of this work was to study the changes undergone by starch during heat-induced surimi gel preparation either with or without added egg white, and their effects on the structure of gels using light and scanning electron microscopy. Gels were made from SA-grade Alaska pollack (Theragra chalcogramma) surimi with: (1) salt (3%, w/w); (2) salt and waxy corn starch (3% and 5%, respectively w/w); or (3) salt, waxy corn starch and egg white (3%, 5% and 5%, respectively, w/w). Final moisture was adjusted to 73% or 83%. The gels were prepared by prior setting (40°C, 30 min, followed by 90°C, 30 min) or cooking (90°C, 30 min). The prepared gel was frozen and stored at –20°C (±1°C) until analysis. Samples were observed by light and scanning electron microscopy. The results show that the starch granules alter according to the processing conditions, with the predominance of crystalline or amorphous morphology depending upon the availability of heat and water. Large cavities formed in the protein gel matrix during setting can trap water; as a result, water availability is limited for starch to swell and gelatinize even in the high-moisture gel. Received: 13 March 1997     

不同冷冻策略下木薯淀粉对龙头鱼鱼糜凝胶品质的影响

目的 探究三种冷冻策略下,即冷冻-预凝胶-熟化(Freezing-Setting-Heating,FSH)、预凝胶-冷冻-熟化(Setting-Freezing-Heating,SFH)、预凝胶-熟化-冷冻(Setting-Heating-Freezing,SHF),木薯淀粉的添加对龙头鱼鱼糜凝胶性能及品质的影响。方法 以龙头鱼为原料,通过冻藏期间的质构特性、水分含量、持水性和微观结构观察,阐明不同冷冻策略及木薯淀粉添加对其凝胶品质的影响。结果 随着冻藏时间的增加,鱼糜质构特性逐渐下降,水分含量减少。在相同冻藏时间下,淀粉的添加有利于提高鱼糜凝胶的品质,其硬度、胶粘性和咀嚼性显著提高(P<0.05),持水性显著增强(P<0.05)。其中,经60天冻藏后,SFHW(含淀粉)及SHFW(含淀粉)组样品剩余水分含量分别为48.60%和47.06%,较同一周期下未添加淀粉组及FSHW(含淀粉)组取得较好的实验效果。经微观结构观察,木薯淀粉在加热糊化过程中吸水膨胀并起到一定填充作用,添加淀粉的鱼糜凝胶解冻及复热后较未添加淀粉的样品,均具有更小的孔隙,且孔隙大小趋势为FSHW> SFHW> SHFW。结论 添加木薯淀粉并经预凝胶或熟化后冷冻对龙头鱼鱼糜凝胶品质起到积极作用,可为冷冻龙头鱼鱼糜制品提供理论支持并为其工业化生产提供可能性。     

芋头添加物对金鲳鱼鱼糜凝胶的影响

研究芋头添加物对金鲳鱼鱼糜凝胶品质的影响,分析添加不同量芋头原浆和芋头淀粉时,金鲳鱼鱼糜凝胶的白度、凝胶强度、持水性、水分含量、横向弛豫时间T2的变化规律。结果表明：添加芋头原浆,金鲳鱼鱼糜凝胶的感官品质较好;添加芋头淀粉,金鲳鱼鱼糜凝胶的凝胶强度和持水力较好;芋头添加物可以降低其白度。低场核磁共振结果显示,随着芋头添加物的加入,金鲳鱼鱼糜凝胶的弛豫时间T22、T23减少,弛豫时间T21增大,峰面积S21、S22增加,峰面积S23减少,凝胶中自由水的流动性减弱。     

响应面试验优化超高压制备马铃薯淀粉草鱼鱼糜制品工艺

以草鱼为原料,研究超高压压力、保压时间和马铃薯淀粉含量3 个因素对草鱼鱼糜制品凝胶特性的影响,并应用响应面法对其进行优化。结果表明：超高压处理可明显提高鱼肉肠的凝胶特性,300 MPa条件下样品的凝胶强度最高;白度和持水性均随压力的升高逐渐变大。保压时间10 min以上时,鱼肉肠的凝胶特性无明显变化。添加马铃薯淀粉可明显提高鱼肉肠样品的凝胶强度,其中含量为8%时凝胶强度最大;鱼肉肠的质构特性在马铃薯淀粉含量为4%以上时可得到显著改善。在单因素试验的基础上,通过响应面法优化得出草鱼鱼糜制品超高压处理的最优工艺为压力340 MPa、保压时间12 min、马铃薯淀粉含量8%,在此条件下,草鱼鱼糜制品的凝胶强度为（421.07±19.13）g?cm。     

Physicochemical properties, gel-forming ability and myoglobin content of sardine (Sardinella gibbosa) and mackerel (Rastrelliger kanagurta) surimi produced by conventional method and alkaline solubilisation process

Characteristics and gel properties of sardine and mackerel surimi produced by conventional washing process and alkaline solubilising process were investigated. The decrease in Ca²⁺-ATPase activity with the changes in the surface hydrophobicity was found in surimi produced by alkaline solubilising process (p<0.05), suggesting the denaturation of protein induced by this process. The alkal-ine solubilising process with prewashing could remove myoglobin most effectively from sardine muscle, whereas the process without prewashing resulted in the greatest myoglobin removal in mackerel muscle (p<0.05). Surimi conventionally prepared by water or NaCl washing showed the gel with greater breaking force and deformation than that from alkaline solubilising process (p<0.05). The hig-her expressible moisture was found in the gels of surimi pre-pared by alkaline process, indicating the poor water holding capacity of the gel matrix. The highest whiteness was found in the gel of sardine surimi produced by alkaline process with prewashing but the highest whiteness was obtained in the gel of mackerel surimi washed with distilled water.     

乳化鱼油对冻藏期间狭鳕鱼糜热凝胶持水性和冰结晶形成的影响

评估乳化鱼油对冻藏期间狭鳕鱼糜热凝胶持水性和冰结晶形成的影响。鱼糜经盐擂后,加入5%鱼油经乳化制得乳化鱼糜热凝胶。随后用快速冻结和慢速冻结2 种方式冻结样品并评估其在冻藏期间热凝胶品质的变化。研究结果表明：与对照相比,乳化热凝胶在冻藏期间的解冻损失和压榨损失均有降低。显微观察结果显示经3 个月冻藏后乳化热凝胶内的冰结晶平均粒径与其对照相比均有减小,其中快速冻结乳化样品为7.2 μm,对照样品为13.1 μm,慢速冻结乳化样品为13.7 μm,对照样品为31.2 μm。以上结果表明乳化鱼油可能对冻藏期间的热凝胶的冰结晶形成和其分布的影响而导致其持水性不同。     

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。     

高脱乙酰度魔芋葡甘聚糖对鲢鱼鱼糜凝胶特性的影响

本研究探讨了高脱乙酰度魔芋葡甘聚糖(KGM)对鲢鱼鱼糜凝胶特性的影响。将不同添加量0.5 wt%、1.0 wt%、1.5wt%的高脱乙酰度KGM分别添加到鱼糜中,测定其流变、质构特性、持水性、弛豫时间T2及微观结构的变化。发现复合鱼糜的弹性模量G'和损耗模量G"均比纯鱼糜高,且随添加量的增加呈上升趋势,且与纯鱼糜相比,G'和G"最大分别提高了27.98%和49.24%;复合鱼糜的硬度、粘度和咀嚼性比纯鱼糜显著性提高,最大分别提高了10.70%、10.53%和9.52%,但弹性降低;通过低场核磁共振发现,与纯鱼糜相比,复合鱼糜凝胶中T_(22)峰高下降,T_(23)的峰比例上升;复合鱼糜凝胶的持水性总体呈下降趋势,在添加0.5wt%KGM时最低;扫描电镜结果显示复合鱼糜凝胶的网络结构变得更加完整有序。高脱乙酰度KGM影响了蛋白热聚集行为,促进蛋白分子的相互交联,改善了其凝胶网络结构,从而改变了鱼糜凝胶特性。     

变性淀粉对白鲢鱼鱼糜凝胶特性和蛋白构象的影响

为了研究原木薯淀粉、羟丙基淀粉、乙酰化二淀粉磷酸酯和醋酸酯淀粉对白鲢鱼鱼糜凝胶特性和蛋白构象的影响,分析不同淀粉添加量条件下,白鲢鱼鱼糜白度、凝胶强度、持水性、质构特性、储能模量(G')、化学作用力、蛋白二级结构和微观结构的变化规律.结果表明,添加淀粉可以显著提高鱼糜凝胶的持水性.当其添加量为1％时,可提高鱼糜凝胶的白...