Properties of starches separated from potatoes stored under different conditions

Starches from 11 potato cultivars stored at five temperatures (4, 8, 12, 16 and 20 °C) for 120 days were evaluated for physicochemical, thermal and pasting properties. Amylose content and swelling power increased with increase in storage temperatures. The proportion of small size granules was higher in starches from potatoes stored at 4 °C. The starch granules of stored potatoes were slightly rough-surfaced and pitted; the effect was pronounced in those stored at 4 °C. Starches from potatoes stored at 4 °C showed lower onset gelatinization temperature and conclusion temperature than did starches from potatoes stored between 8 and 20 °C. Starches from potatoes stored at higher temperature (20 °C) showed higher peak viscosity, set back, as well as gel hardness, chewiness and gumminess than did starches from those stored between 4 and 16 °C. Amylose content showed significant positive correlation with gumminess and setback while swelling power showed significant positive correlation with peak viscosity and hot-paste viscosity.     

抗氧化处理对风干肉贮藏期间质构特性的影响

以风干肉为研究对象,2.0 g/L壳聚糖＋1.0 g/L乙酸＋ 0.5 g/L茶多酚混合涂膜处理作为抗氧化处理组,未处理的风干肉作为对照组,所有样品真空包装后,分别贮藏于4 ℃和－20 ℃,测定其在0～120 d贮藏期内的pH值、水分含量及质构特性等指标。结果表明：在120 d的贮藏期内,抗氧化处理能够将风干肉的水分含量保持在22%左右,对防止其硬度及咀嚼性的增加有显著效果（P＜0.05）,并保持风干肉的内聚力处于合适水平,对风干肉的弹性和黏性影响不显著,且能够显著降低风干肉的过氧化值（P＜0.05）;在4 ℃条件下贮藏时,抗氧化处理对降低风干肉的硫代巴比妥酸值有显著效果（P＜0.05）。因此,抗氧化涂膜处理可以有效保持风干肉贮藏期间的水分含量和质构特性,并明显抑制风干肉的脂肪氧化。     

Textural and physicochemical changes in salmon (Salmo salar) treated with commercial liquid smoke flavourings

The textural and physicochemical properties of fillets of farmed Atlantic salmon (Salmo salar) treated with two commercial liquid smoke flavourings (LS1 and LS2) were examined after 15, 30 and 45 days of storage at 2 °C in oxygen impermeable bags. Salmon flesh treated with LS1 was characterized by high water-soluble protein, fat and moisture contents, plus low hardness, fracturability, gumminess and chewiness, and a low alkali-insoluble protein content. These characteristics were similar to those of control salmon (not treated with liquid smoke flavouring). Storage time changed these properties similarly in both. Salmon flesh treated with LS2 was characterized by high hardness, fracturability, gumminess, chewiness and alkali-insoluble protein levels, plus low water-soluble protein, fat and moisture contents. Storage time appeared to have a far less important effect on salmon flesh treated with LS2.     

不同冻结条件下罗非鱼片的质构分析

对不同条件(-7,-21,-31℃)下冻结的罗非鱼片进行质地剖面分析(TPA)。研究罗非鱼片的硬度、内聚性、弹性、胶着性、咀嚼性的参数变化;分析罗非鱼片的干耗、汁液流失率的品质变化特征。结果表明,随着冻结温度的降低,弹性呈下降趋势;硬度、内聚性、胶着性、咀嚼性呈上升趋势;干耗、汁液流失率也呈现明显下降趋势,说明低温快速冻结条件比缓冻条件抑制罗非鱼体内酶活性更有效,减少蛋白质分解变性,从而保持鱼片的风味和品质。     

pH值、NaCl浓度和加热温度对猪肉匀浆物凝胶质构特性的影响

采用二次通用旋转试验设计,研究了pH值、NaCl浓度和加热温度对猪后腿肉匀浆物热诱导凝胶质构特性的影响。结果表明:不同处理条件对凝胶质构特性的影响存在差异。不同加热温度下,pH值和NaCl浓度对凝胶硬度、弹性、内聚性、胶粘性和咀嚼性影响的总体趋势一致且两者存在明显的交互作用。pH值较低时,随着NaCl浓度的增加,凝胶的硬度、弹性、内聚性、胶粘性和咀嚼性均增大;pH值较高时,NaCl浓度对凝胶硬度、弹性和胶粘性影响较小,内聚性随着NaCl浓度增加而降低。同时,随着加热温度的升高,凝胶的硬度和胶粘性增大,内聚性和咀嚼性减小,而凝胶弹性变化较小。     

野生与池养刀鲚肌肉品质特性及抗氧化性的比较分析

比较研究了野生和池养刀鲚（Coilia nasus）肌肉营养成分组成、质构特性和抗氧化特性。结果显示,野生刀鲚肌肉中水分、羟脯氨酸、胶原蛋白含量以及胶原蛋白/总蛋白比值均显著低于池养型,而脂肪含量则显著提高;两者的蛋白质含量、pH均无显著性差异;池养刀鲚肌肉弹性、硬度、咀嚼度、胶着性相较于野生型呈上升趋势,但无统计学差异。野生刀鲚肌肉中SOD、CAT、T-AOC、MDA、GSH-PX、iNOS、GSH/GSSG均显著高于池养型。表明野生和池养刀鲚营养品质存在差异,建议在人工养殖刀鲚中应该注意饵料的种类和丰度,其养殖模式有待进一步改善。     

Lipid and colour stability of M. longissimus muscle from lambs fed camelina or linseed as oil or seeds

Reduced-fat pork patties produced with the addition of Laminaria japonica powder were evaluated for the chemical composition, cooking characteristics and sensory properties. Reduced-fat pork patties containing L. japonica powder had significantly higher moisture, ash, carbohydrate content, yellowness, and springiness than the control sample (P<0.05). Protein and fat contents, energy value, lightness, redness, cooking loss, reduction in diameter, reduction in thickness, hardness, gumminess, and chewiness of the regular-fat (20%) control samples were significantly higher than reduced-fat pork patties containing L. japonica (P<0.05). The sensory evaluations indicated that the greatest overall acceptability in reduced-fat pork patties was attained at a L. japonica concentration of 1 or 3%. Pork patties with fat contents reduced from 20% to 10% and supplemented with 1 or 3% L. japonica had improved quality characteristics that were similar to the control patties containing a fat content of 20%.     

不同熟度牛肉与高水分组织蛋白品质特性的比较研究

使用低场核磁共振、TPA(Texture Profile Analysis)等分析方法对不同熟度牛肉与高水分组织蛋白(High Moisture Texturized Vegetable Protein,HMTVP)的弛豫时间、质构特性进行比较,并结合感官评价实验,寻找HMTVP的目标参照指标,选择最佳HMTVP配方,为仿牛肉的高水分组织蛋白制备提供适宜的参考范围。研究结果表明:横向弛豫时间T21结果显示,与牛肉相比HMTVP口感较紧致;5种HMTVP水分分布与五级熟度牛肉较相似,结合水、不易流动水含量分别为12.58%、85.11%。随着中心温度的升高,牛肉硬度、咀嚼度、胶黏性呈幂函数递增,极大值分别为12.34、8.93、6.97 kg。综合感官评价结果得出,5种HMTVP与牛肉咀嚼口感相似,以牛肉质构特性的极值为参照,高湿4号为最佳配方,参照技术指标为硬度、咀嚼度、胶黏性。     

TEXTURE PROFILE PARAMETERS OF COOKED FRANKFURTER EMULSIONS AS INFLUENCED BY COOKING TREATMENT2

Texture profile parameters of frankfurters were found to be generally related to cooking temperatures, except for degree of elasticity, hysteresis loss, and work ratio. Cohesiveness, elasticity, gumminess, and chewiness all were polynomial functions of cooking temperature and were smallest at 70-75° C where physico-chemical changes in proteins important to texture development appeared to be occurring. Hardness, compression energy of first bite, brittleness, apparent moduli of elasticity, stress at 20% compression and strain energy of compression per unit volume were all linearly related to the cooking temperature. Texture profile parameters were higher for samples with higher protein and lower moisture contents at all cooking temperatures.     

Evaluation of Texture Differences among Varieties of Cooked Quinoa

Texture differences of cooked quinoa were studied among 13 different varieties. Correlations between the texture parameters and seed composition, seed characteristics, cooking quality, flour pasting properties, and flour thermal properties were determined. The results showed that texture of cooked quinoa was significantly differed among varieties. ‘Black,’ ‘Cahuil,’ and ‘Red Commercial’ yielded harder texture, while ‘49ALC,’ ‘1ESP,’ and ‘Col.#6197’ showed softer texture. ‘49ALC,’ ‘1ESP,’ ‘Col.#6197,’ and ‘QQ63’ were more adhesive, while other varieties were not sticky. The texture profile correlated to physical?‐chemical properties in different ways. Protein content was positively correlated with all the texture profile analysis (TPA) parameters. Seed hardness was positively correlated with TPA hardness, gumminess, and chewiness at P ≤ 0.09. Seed density was negatively correlated with TPA hardness, cohesiveness, gumminess, and chewiness, whereas seed coat proportion was positively correlated with these TPA parameters. Increased cooking time of quinoa was correlated with increased hardness, cohesiveness, gumminess, and chewiness. The water uptake ratio was inversely related to TPA hardness, gumminess, and chewiness. Rapid Visco Analyzer peak viscosity was negatively correlated with the hardness, gumminess, and chewiness (P < 0.07); breakdown was also negatively correlated with those TPA parameters (P < 0.09); final viscosity and setback were negatively correlated with the hardness, cohesiveness, gumminess, and chewiness (P < 0.05); setback was correlated with the adhesiveness as well (r = ?0.63, P = 0.02). Onset gelatinization temperature (T_o) was significantly positively correlated with all the texture profile parameters, and peak temperature (T_p) was moderately correlated with cohesiveness, whereas neither conclusion temperature (T_c) nor enthalpy correlated with the texture of cooked quinoa.     

TEXTURAL PROPERTIES OF RESTRUCTURED BEEF PRODUCTS WITH FIVE BINDERS AT FOUR ISOTHERMAL TEMPERATURES1

Texture profile analysis (TPA) and shear force of restructured beef products with one of five binders (isolated soy protein, sodium caseinate, waxy modified corn starch, carrageenan, and oat flour) were analyzed at 35, 45, 55 and 65 C. Hardness, cohesiveness, springiness, gumminess, and chewiness were significantly affected (p<0.05) by binders, temperatures and their interactions. Hardness and gumminess showed no significant (p<0.05) differences among binders and temperatures below 45C, but each increased between 45 – 65C. Isolated soy protein gave the highest hardness and gumminess values; oat flour, the lowest at 55 and 65C. Except for oat flour, cohesiveness, springiness and chewiness decreased from the raw state until 45C, and then increased. Oat flour gave the highest values for cohesiveness, springiness and chewiness < 45C; the lowest at 55 and 65C. Oat flour gave the lowest shear force (N) values at 55 and 65C. Conclusions were reached that the influence of these binders on the textural parameters of restructured beef products was temperature-dependent.     

Changes in quality characteristics of tofu with freezing treatment of soybeans

The aim of this study was to investigate the influence of length of freezing time (?18°C for 5 or 24 h) on the quality characteristics of tofu. The yield and moisture content of tofu obtained from frozen soybean were lower than control tofu. Tofu made from frozen soybeans showed higher hardness, gumminess and chewiness than the control. Freezing treatment also made the microstructure of the tofu more uniform than the control. However, after 24-h freezing, hardness decreased and the microstructure of tofu appeared to form pores. Sensory evaluation showed that mouth-feel decreased with an increase of freezing time. Among all of tofu frozen at ?18°C, 5-h freezing treatment showed the highest overall acceptability. These results indicate that the length of time that soybeans are frozen before making tofu affects the quality of tofu.     

流化床和薄层热风干燥对稻谷品质的影响

研究流化床和薄层热风干燥在干燥温度50、60、70 ℃条件下对高水分稻谷水分变化的影响,分析稻谷加 工品质（爆腰率）和稻米质构品质（硬度、黏着性、咀嚼性）的变化规律。结果表明：初始含水率相同的稻谷, 在同一干燥温度条件下流化床干燥速率大于薄层热风干燥,但是加工品质略差,对发芽率没有影响。干燥温度为 50 ℃时,流化床和薄层热风干燥稻米的品质较好。稻谷干燥温度和整精米率之间呈显著的负相关。流化床干燥后 稻米的硬度、黏着性、胶性与爆腰率呈显著性相关,薄层热风干燥后稻米黏着性、胶性与爆腰率呈显著性相关,其 他质构指标相关性均不显著。     

Physicochemical,cooking and textural characteristics of some Indian black gram (Phaseolus mungo L) varieties

Physicochemical, cooking and textural properties of black gram varieties were studied and related to each other using Pearson correlation. Different varieties showed significant variation in their physicochemical, cooking and textural properties. Varieties having higher seed weight and seed volume had higher values of cooking time, swelling capacity, hydration capacity and hardness. The relationships between textural parameters of cooked grains from different black gram varieties showed a significant positive correlation of hardness with cohesiveness (r = 0.472), gumminess (r = 0.938) and chewiness (r = 0.859). Swelling index, cohesiveness and gumminess of black gram varieties were observed to be related to their fibre content. Swelling capacity and swelling index correlated well with cooking time, hardness and gumminess. Cooking time had a positive correlation with hardness (p < 0.05) and gumminess (p < 0.05) and a negative correlation with springiness. Copyright © 2004 Society of Chemical Industry     

Extrusion studies of mixtures containing certain meat offals: Part 2-textural properties

Thermoplastically extruded products prepared from soy grits alone, and from those containing 20% or 35% of bovine or porcine offal, at various temperatures of extrusion, were subjected to instrumental texture profile analysis (hardness, elasticity, cohesiveness, gumminess, chewiness) and shear force measurements. The offal sources were untreated, or alkali-extracted, protein from bovine and porcine lung and bovine tripe (rumen and reticulum) and protein in extracted by sodium dodecyl sulphate (SDS) from bovine tripe. For products prepared from soy grits alone, hardness, gumminess, chewiness and shear force showed maxima at 170°C, whereas elasticity and cohesiveness increased progressively in the temperature range studied (140-190°C). Products containing SDS-extracted tripe protein required more force to shear, and were more hard, gummy and chewy, than products containing untreated offal, and values for all parameters were greater in the latter than in products containing alkali-extracted offal protein. The effect of extrusion temperature on the textural parameters of the products was less than that due to the mode of offal preparation used (untreated, alkali- or SDS-extracted) or the level of incorporation. Offal source was relatively unimportant. Products containing alkali-extracted offal protein had poor internal structure and were brittle; those containing SDS-extracted protein were tough. The different textural properties of the extracted products might determine their relative suitability for use either alone, as analogues or as extenders.     

绿茶提取物、亚硝酸钠及其混合物对意式发酵肠质地的影响

研究不同处理条件对意式发酵肠在加工和冷藏期间质地的影响.结果表明:绿茶提取物(GTE)、亚硝酸钠(NT)和混合处理(GTE/NT)3种不同的处理方式对于质构特性中的硬度、胶黏度和咀嚼性有较大影响;而对弹性、凝聚性和回复性影响较小.对于硬度、胶黏度和咀嚼性,绿茶提取物(GTE)在各阶段普遍有降低作用;亚硝酸钠(NT)先降低后升高;混合处理(GTE/NT)则普遍有升高作用.     

5种豆类淀粉凝胶特性的比较研究

选取绿豆、豌豆、白芸豆、白豇豆、鹰嘴豆为原料,提取其淀粉,并制备及测定几种豆类淀粉凝胶的特性(凝胶强度及硬度、弹性、黏性等),比较分析各种豆类淀粉特性的差异。结果表明,不同淀粉浓度下,均以豌豆淀粉的凝胶强度最大,白豇豆淀粉的最小;5种淀粉的TPA质构结果显示,白芸豆淀粉凝胶在高浓度下(8%和10%)具有较大的硬度、弹性、咀嚼性和回复性;豌豆淀粉在中等浓度下具有较高的硬度、弹性、咀嚼性,但其回复性在3个浓度下均是最小的;白豇豆淀粉凝胶的硬度和咀嚼性小于其他4种豆类淀粉,但其弹性和回复性却较大;5种豆类淀粉中,豌豆淀粉的凝胶强度和TPA质构特性受浓度的影响最大,且适合在中等浓度(8%)下制作凝胶制品。相关性分析发现,豆类淀粉的凝胶强度与直链淀粉含量呈极显著正相关,而黏聚性呈极显著负相关,而其他质构参数与直链淀粉含量的关系因浓度不同而呈现差异。     

EFFECT OF PRESSURE AND STORAGE TIME ON TEXTURE PROFILE PARAMETERS OF SOYBEAN CURD (TOFU)

The pressure applied to soybean curd during processing into tofu has a profound effect on the moisture content, yield and some textural parameters of tofu. As the pressure increased from 0.186P to 0.744 P the moisture content decreased from 82% to 60% and yield decreased from 2.0 kg to 1.2 kg per kg whole dry soybeans. Hardness-1, hardness-2, chewiness andgumminess increased linearly with increasing pressure. Springiness, cohesiveness, adhesiveness and stringiness were hardly affected by increasing pressure. During storage in water at 2–3°C for 3 weeks, hardness, gumminess, and adhesiveness increased moderately; springiness decreased moderately and the other texture parameters were almost unchanged.     

Chemical, physical, and sensorial characteristics of "Terrincho" ewe cheese: changes during ripening and intravarietal comparison

The objectives of this study were to monitor the changes in chemical [moisture, acidity, pH, and water activity (a(w))] and physical (color and texture) parameters of "Terrincho" ewe cheese during 60 d of ripening, and to determine the correlations between the changes in instrumental texture and color parameters and the ripening time of the product. Intravarietal comparison of Terrincho ewe cheese from 5 different dairy plants was performed by evaluation of mechanical parameters from texture profile analysis (TPA) and color parameters in terms of CIELAB color space (L*, a*, and b*). In addition to mechanical and color tests, composition analyses and sensory tests were performed. The results were evaluated with statistical methods (single valued and multivariate analysis). During the first 20 d of ripening, an increase in hardness, fracturability, gumminess, chewiness, and yellowness occurred. Simultaneously, adhesiveness, resilience, L* (inside cheese, "i" and external "e"), and cohesiveness decreased. After 20 d of ripening hardness, fracturability, gumminess, and chewiness decreased and cohesiveness increased. The ripening time of Terrincho cheeses can be estimated with 6 variables: L* (external, e), L* (i), b* (inside cheese, i), hardness, a* (i), chewiness, and a constant. The estimation error was 4.2 d. Evaluation of composition, pH, texture profile analyses, color, and related sensory characteristics of Terrincho cheeses from 5 different dairy plants (with 30 d of ripening) revealed correlations between these parameters.     

Gelling properties of duck albumen powder as affected by desugarization and drying conditions

The effects of desugarization using glucose oxidase/catalase and spray‐drying conditions on gelling properties of duck albumen powder were studied. Gelling temperatures increased as spray‐drying inlet temperatures (140–180C) were increased (p < .05). ΔE*, a*‐, and b*‐ values of gel increased but L* and whiteness decreased when higher spray‐drying temperatures were used (p < .05). However, whiteness and lightness of albumen gel were drastically increased after desugarization (p < .05). Texture profile analysis showed that hardness, springiness, gumminess, and chewiness of gel decreased with increasing spray‐drying temperatures. Moreover, gel of freeze‐dried desugarized albumen powder had higher hardness, springiness, gumminess, and chewiness than that of spray‐dried nondesugarized counterpart (p < .05). Albumen gel prepared from desugarized albumen powder showed the compact network with more connectivity and smaller voids than that from nondesugarized one as visualized by scanning electron microscopy, regardless of drying conditions. Prior desugarization could lower browning and increased gelling properties of duck albumen powder. Higher spray drying inlet temperature generally exhibited the adverse effect on properties of resulting albumen powder. Both desugarization and drying conditions had the profound influence on characteristics and textural property of duck egg albumen.