Bread crumb quality assessment: a plural physical approach

The aim of this study was the assessment of pan bread crumb quality attributes of commercial samples using a plural physical approach to better match consumer awareness. Static (texture profile analysis, firmness AACC and relaxation test) and dynamic (innovative oscillatory test) deformation techniques, image analysis, sensory analysis and colour measurements (colorimeter and Photoshop system) were used for white/whole commercial pan bread quality evaluation over 10 days of storage. Static (k ₁, k ₂, cohesiveness, springiness, hardness, chewiness and resilience) and dynamic (stress) bread crumb rheological properties were correlated illustrating that both techniques can be useful in evaluating crumb physical characteristics. In addition, sensory perceiveness with regard to softness and overall acceptability exhibited dependence with either dynamic stress or static firmness. Despite the fact that empirical measurements are closely linked to macroscopic features whilst dynamic tests are strongly linked to molecular characteristics, the obtained results support that both techniques are complementary since derived instrumental parameters are related to some sensory attributes. As data achieved using the proposed novel approaches might be better linked to the consumer awareness than those obtained from classical analyses, the obtained results are promising for a proper bread crumb quality assessment.     

Correlation between instrumental and sensory ratings by evaluation of some texture reference scales

The objective of this study was to investigate instrumental–sensory relationships of some texture scales using argentine foods as references. Textural characteristics of these foods were instrumentally investigated by the texture profile analysis technique. Principal component analysis (PCA) was used to describe the main attributes of the food samples. High Pearson’s correlation coefficients were found between hardness and fracturability (r = 0.94; P < 0.0001), hardness and gumminess (r = 0.71; P < 0.0001) and springiness and cohesiveness (r = 0.85; P < 0.0001). PCA identified two significant principal components, which accounted for 81.2% of the variance in the instrumental data. Additionally, a trained panel described the texture characteristics of the food samples according to the standard reference scales. The correlation curves showed nonlinear relationships (R² between 85.6% and 99.9%) which were used to predict sensory attributes of other food samples. Some texture attributes like hardness and fracturability were accurately predicted by mechanical properties, while others like cohesiveness and adhesiveness were less representative.     

Technological and functional properties of reduced-salt pork batter incorporated with soy protein isolate after pressure treatment

To investigate the effects of different pressures (0.1–400 MPa), the techno-functional properties, water distribution and mobility of reduced-salt pork batters (1% NaCl) supplemented with soy protein isolate (SPI, 2%) were examined. Compared with the batters treated at 0.1 MPa, those treated at 100–300 MPa showed significantly increased the cooking yield, hardness, springiness, cohesiveness, chewiness, and G′ values of gel and reduced the initial relaxation times of T_2b, T₂₁ and T₂₂, as observed from the results of low-field NMR. Among all samples, those treated at 200 and 300 MPa had the highest L^* value, cooking yield, hardness, springiness, cohesiveness, chewiness and G′ value of gel, with the largest peak ratio of P₂₁ and the smallest peak ratio of P₂₂. Overall, treatments at 200 and 300 MPa improved the gel properties and lowered the water mobility of reduced-salt pork batters supplemented with SPI.     

TEXTURAL CHARACTERISTICS OF FROZEN BLUE SQUAT LOBSTER (CERVIMUNIDA JOHNI) TAILS AS MEASURED BY INSTRUMENTAL AND SENSORY METHODS

Instrumental and sensory textural characteristics of frozen blue squat lobster (Cervimunida johni) tails stored at ?22C for 0, 15 and 60 days were evaluated. The influence of fishing area (north or south) was also studied. Instrumental texture was evaluated by shear and compression testing using a Warner–Bratzler blade for firmness and a flat plunger with two‐cycle compression for texture profile analysis (TPA) testing. A trained panel was utilized to evaluate textural attributes using the score method. Results showed that fishing area and frozen storage did not affect the textural quality of blue squat lobster tails. However, a strong correlation (r > 0.9) between sensory and instrumental texture parameters was observed. Instrumental chewiness (r = 0.91), cohesiveness (r = 0.96) and sensory hardness (r > 0.84) obtained the strongest correlations. In this way, the use of instrumental analysis may be useful as an alternative to sensory analyses to evaluate the textural characteristics of blue squat lobster tails.     

Texture and color characteristics of swell-dried ready-to-eat Zaghloul date snacks: Effect of operative parameters of instant controlled pressure drop process

In this work, development of ready-to-eat snacks from Zaghloul date using swell-drying process was studied. Pre-dried Zaghloul date samples having 12% water content on dry basis were textured by instant controlled pressure drop technique (DIC) at different operative parameters, saturated steam pressure (p) and processing time (t), ranged from 0.2 to 0.6 MPa and from 9 to 35 s, respectively. The effect of these operative parameters on texture, color, and sensory characteristics of swell-dried (SD) Zaghloul date snacks were determined and optimized through the response surface methodology. Textural (expansion ratio, hardness, springiness, cohesiveness, and chewiness) and color (L*, a*, b*, C*, and ΔE*) characteristics were significantly affected by the operative parameters of DIC. The optimized textural characteristics was identified for SD Zaghloul date at p = 0.6 MPa and t = 22 s with slight yellowness, while the best color properties were observed for texturing conditions of p = 0.2 MPa and t = 22 s. The expansion ratio ε_r was then 46% higher and the hardness was 262% lower for SD than airflow-dried date. Instrumental analysis such as texture profile analysis and Hunter's Lab color analyzer could be used to describe the texture and color changes occurred during food drying. Beside these analyses, the expansion ratio could be used to describe the texture as well. Swell-drying process, an alternative drying process, is defined as DIC-assisted hot air drying. The thermo-mechanical effects of DIC are mainly induced by the abrupt pressure drop toward a vacuum after short-time treatment (9–35 s) by saturated steam pressure (0.2 up to 0.6 MPa). The abrupt pressure drop rate induces an autovaporization of product's water immediately decreasing the product's temperature allowing it to cross the glass transition Tg border. The impact of DIC operative parameters on Zaghloul date could be observed through the expansion ratio, and the textural characteristics (hardness HA, springiness SP, cohesiveness CO, and chewiness CH).     

Effects of high O2 levels on post-harvest quality and shelf life of table grapes during long-term storage

Freshly harvested Kyoho table grapes (Vitis vinifera × V. labrusca) were stored in controlled atmospheric chambers, either in air, 80% O₂, or 40% O₂ + 30% CO_2, for up to 60 days at 0 °C in 95% relative humidity followed by 5 days in air at 20 °C. Physical and chemical properties were recorded initially and at 15-day intervals during storage. Storage in 80% O₂ or 40% O₂ + 30% CO₂ improved berry hardness, springiness, chewiness, flavors and membrane integrity over control stored in air. In addition, these high O₂ storage conditions significantly reduced fruit decay, berry drop, rachis browning and weight loss, delayed the decrease of soluble solids, titratable acidity and ascorbic acid of table grapes, compared with storage in air. Treatment in 80% O₂ resulted in a significantly firmer berry, better texture, berry adherence strength, and sensory scores than those treated with 40% O₂ + 30% CO₂, but did not significantly affect cohesiveness, springiness, aroma and membrane integrity. Data obtained in this study suggest that high oxygen treatment improve the quality of table grapes and extend its shelf life.     

INSTRUMENTAL TEXTURE OF A TYPICAL SPANISH CONFECTIONERY PRODUCT XIXONA TURRON AS AFFECTED BY COMMERCIAL CATEGORY AND MANUFACTURING COMPANY

Three different instrumental tests, Magness–Taylor, compression and texture profile analysis (TPA), were used to study the hardness, adhesiveness, cohesiveness, springiness and chewiness of Xixona turron products from three commercial categories: (1) extra; (2) supreme; and (3) improved supreme (IS), and four manufacturing companies. All three tests succeed in finding softer products of one of the companies because of the presence of a fraction of the noninverted product trapped in the final product because of homogenization difficulties with the highly viscous mass during the inversion process step. The TPA provided more information than the other two tests. Manufacturers are aware of consumers' demands for softer and nonoily Xixona turron, and these characteristics are sought in their star products, IS, through optimization of the time and temperature values in the boixet process and the use of longer standing periods to eliminate residual amounts of oil.     

Vane Rheometry for Textural Characterization of Cheddar Cheeses: Correlation with Other Instrumental and Sensory Measurements

The relationship between instrumental (vane method, texture profile analysis (TPA), uniaxial compression) and sensory texture measurements of Cheddar cheeses was investigated. A Haake VT 550 viscotester equipped with a four-bladed vane rotor was used for the vane test. Instrumental TPA was performed with a TA.XT2 Texture Analyser, and compression variables were calculated from TPA data. Vane parameters were significantly correlated with respective variables of compression and TPA (r=0.56-0.91), and sensory tests (r=0.54-0.88). Multivariate analysis indicated that seven sensory attributes of ten commercial Cheddar cheeses were satisfactorily predicted (calibration regression coefficient,R_cal >0.62) by variables of the vane, uniaxial compression and TPA tests. In particular, cheese firmness and cohesiveness evaluated by sensory panel were well described by vane stress and apparent strain. The results validate the vane method as an alternative to the existing cheese testing methods for rapid evaluation of cheese texture.     

A COMPARISON OF THREE INSTRUMENTAL TESTS FOR PREDICTING SENSORY TEXTURE PROFILES OF CHEESE

Multivariate analysis techniques were used to seek correlations between texture sensory attributes assessed by a trained professional panel and instrumental measurements (compression, puncture and penetration) carried out on various types of cheeses. Twenty-nine cheeses were assessed by the panel and instruments. Correlation was sought using Partial Least Squares regression. Hardness (R=0.87), springiness (R=0.98) and cohesiveness of mass (R=0.89) were best predicted by instrumental data from a cone penetration test. The prediction of cohesiveness was acceptable using any of the three instrumental tests performed (0.76相似文献   

Texture of Pecans Measured by Sensory and Instrumental Means

The texture of pecans (Carya illinoensis) from four cuhivars (Barton, Mahan, Western and Wichita) was analyzed using sensory and instrumental methods. Sensory hardness, flexibility and crispness were rated by trained panelists. Ranking of hardness and crispness was also carried out. A Texture Analyser TAXT2 was used for 50% compression, texture profile analysis (TPA), puncture and bending. Puncture and 50% compression gave best reproducibility, least variability and agreement with sensory data. The most relevant TPA parameters were cohesiveness, elasticity and fracturabihty. Parameters from the bending test did not indicate texture of the pecans suitably.     

Descriptors for Texture Profile Analysis of Frankfurter-Type Products from Minced Fish

The texture profile of frankfurter-type products prepared from minced Spanish mackerel (Scomberomorus maculatus) was evaluated. Twelve character notes were identified: springiness, hardness, cohesiveness, moisture release, crumbliness, coarseness, graininess, juiciness, adhesiveness, lumpiness, chewiness, and mouthfeel-oiliness. Overall texture acceptability was also evaluated. Differences in juiciness and mouthfeel-oiliness were not detected. Springiness, hardness, cohesiveness, and lumpiness had the highest correlation with the overall texture acceptability. Products with 10% soy protein fiber (SPF) were better accepted than those having 20% or no SPF. Egg white (to 20%) improved the texture; however, its flavor was detectable when 10% or more was added. The most acceptable texture was exhibited by products containing 5–10% ground drumdried fish.     

熏煮香肠中脂肪、食盐、淀粉和水分含量对其质构的影响

质构是熏煮香肠的重要品质特征之一,脂肪、食盐、淀粉和水分含量是影响其质构的主要原辅料组成。文中应用质构剖面分析方法(textureprofileanalysis,TPA)对脂肪、食盐、淀粉和水分含量四因素的交互效应对熏煮香肠质构的影响进行了研究。结果显示,脂肪含量对熏煮香肠的硬度、粘聚性和咀嚼影响最大(调整R分别为129·34、0·051和33·14),而水分添加量对熏煮香肠的弹性影响最大(调整R为0·20)。通过感官评定与机械测定之间的相关分析,发现感官评定指标与机械测定的相应指标硬度、弹性、粘聚性和咀嚼性相关性较好(特别是硬度r=0·94和弹性r=0·89)。     

豆沙质地特性的感官评定与仪器分析

用质构仪对豆沙进行穿孔、剪切、全质构分析(TPA)以研究其质地特性。分析各质构参数之间的相关性,探索豆沙感官评价和仪器测定参数之间的关系,得出了感官评定指标以仪器测定参数为变量的多元线性回归模型。结果表明：除TPA测试的弹性、凝聚性外,质构仪测试的其他指标如硬度、黏着性、剪切力等均与感官指标有很好的相关性。除感官凝聚性外,穿孔、剪切、全质构分析3种质地测试方法结合使用可以对其余各感官指标进行预测,且各预测模型都有很高的显著性。     

Relationships between rheological properties, texture and structure of apple (Granny Smith var.) affected by blanching and/or osmotic dehydration

The objective of this work was to evaluate and correlate rheological properties (small-scale dynamic oscillatory and creep/recovery measurements and large-scale compression force-deformation testing), texture (sensory evaluation by trained panel) and structure (optical and transmission electronic microscopy observations) of apples osmotically dehydrated to water activity (a _w) 0.97 with glucose, with or without previous blanching. All apple samples showed a solid behavior (G′?>?G″) dominating the viscoelastic response, but both dynamic moduli were reduced due to processing. The instantaneous elastic compliance (J ₀) and the retarded compliances (J ₁ and J ₂) increased for treated tissues and the steady-state viscosity (η _N) was approximately 15% to 29% of the value of fresh apple. In general, compression parameters decreased for all treated tissues. Changes in structural features were mainly evidenced in heated samples. Partial least squares regression analysis regression models revealed that texture could be well predicted by rheological properties (compression and creep parameters). Juiciness, crispness and sensory hardness were negatively correlated to J ₀, J ₁ and J ₂, and η _N was negatively correlated to sensory fracturability. Some mechanical parameters (fracturability, hardness 2, area 2, modulus of deformability and cohesiveness) were positively related to sensory fracturability, crispness and sensory hardness; and juiciness was negatively correlated to hardness. Compression and creep parameters showed ability to evidence structure differences (rupture of membranes, swelling of cells and degradation of cell walls) and to explain texture of treated apples.     

Prediction of sensory textural properties from rheological analysis for process cheeses varying in emulsifying salt,protein and moisture contents

Textural characteristics of process cheeses varying in emulsifying salt (disodium phosphate), protein and moisture contents were evaluated by rheological compression using texture profile analysis and by sensory evaluation. The primary objective of this study was to predict sensory textural parameters using instrumental rheological parameters. All sensory parameters correlated with one or more instrumental parameters, e.g. rheological firmness versus sensory firmness (R = 0.98, P < 0.001), rheological chewiness versus sensory rubbery (R = 0.92, P < 0.001) and rheological chewiness versus sensory chewy (R = 0.86, P < 0.001). Partial least squares calibration models were developed for each of nine sensory parameters using instrumental parameters. Principal component analysis of instrumental and sensory parameters illustrated relationships among parameters. It was shown that instrumental parameters could be used to supplement sensory evaluation of process cheese texture. Increasing emulsifying salt content increased firmness, springiness and chewiness and decreased adhesiveness, mouthcoating and mass formation. Increasing protein content resulted in increased fracture strain and stress and chewiness and decreased melting. Increasing moisture content increased cohesiveness and decreased firmness and chewiness. Copyright © 2007 Society of Chemical Industry     

Rheological and Textural Characteristics of Date Paste

The rheological properties of two commercial date pastes were investigated in the temperature range of 20–70°C. From typical flow behavior curves, it was observed that date pastes exhibited pseudoplastic behavior. The shear stress-shear rate data were fitted using six common rheological models. The Casson model best described the experimental data at all temperatures. The Arrhenius model described successfully the temperature dependence of apparent viscosity of date pastes (R² > 0.99) with an E_a value in the range of 25,392.6–25,485.7 kJ/kmol. The textural attributes measured were: hardness, springiness, gumminess, cohesiveness, chewiness, and adhesiveness for the texture profile analysis test, and firmness, adhesive force, mean load, and total positive area for the Ottawa test. There was a significant difference in textural attributes between two varieties of date paste studied. Texture profile analysis results showed that all parameters obtained for black date pastes were higher than golden date pastes except for springiness and cohesiveness. However, the Ottawa results showed that golden date pastes were firmer and less adhesive than black date pastes.     

鸡肉火腿肠添加物对质构的影响

采用质构剖面分析法(texture profile analysis,TPA)及感官评定,探讨了脂肪、淀粉、焦磷酸钠和大豆分离蛋白对鸡肉火腿肠质构的影响。结果表明:当鸡肉火腿肠的配方为脂肪10%、淀粉4%、焦磷酸钠0.4%、大豆分离蛋白1.5%时,鸡肉火腿肠的质构特性较好,其硬度为1488.11g、弹性0.9、内聚性0.73、恢复性0.28。其中脂肪含量对火腿肠的硬度、内聚性和恢复性影响最大(R分别为335.49、0.033和0.32),而焦磷酸钠添加量对鸡肉火腿肠的弹性影响最大(R为0.046)。通过感官评定与机械测定之间的相关分析,发现机械硬度-感官硬度、机械恢复性-感官恢复性和机械硬度-感官总体接受性相关性极其显著。