Instrumental and Sensory Texture Attributes of High‐Protein Nutrition Bars Formulated with Extruded Milk Protein Concentrate

Previous instrumental study of high‐protein nutrition (HPN) bars formulated with extruded milk protein concentrate (MPC) indicated slower hardening compared to bars formulated with unmodified MPC. However, hardness, and its change during storage, insufficiently characterizes HPN bar texture. In this study, MPC80 was extruded at 2 different conditions and model HPN bars were prepared. A trained sensory panel and instrumental techniques were used to measure HPN bar firmness, crumbliness, fracturability, hardness, cohesiveness, and other attributes to characterize texture change during storage. Extrusion modification, storage temperature, and storage time significantly affected the instrumental and sensory panel measured texture attributes. The HPN bars became firmer and less cohesive during storage. When evaluated at the same storage conditions, the texture attributes of the HPN bars formulated with the different extrudates did not differ significantly from each other. However, textural differences were noted most of the time between the control and the HPN bars formulated with extruded MPC80. An adapted HPN bar crumbliness measurement technique produced results that were correlated with sensory panel measured crumbliness (r = 0.85) and cohesiveness (r = –0.84). Overall, the HPN bars formulated with extruded MPC80 were significantly softer, less crumbly, and more cohesive than the control during storage.     

TRAINING A TEXTURE PROFILE PANEL AND CONSTRUCTING STANDARD RATING SCALES IN ARGENTINA

A method is described for constructing reference scales for the sensory texture profile method in countries outside the U. S., such as Argentina. A complete set of 13 reference scales were constructed for Argentine foods: hardness, adhesiveness to palate, fracturability, cohesiveness, denseness, wetness, adhesiveness to lips, roughness, selfadhesiveness, springiness, cohesiveness of mass, moisture absorption and adhesiveness to teeth. Scores given by the panel trained using these scales were compared to those given by a panel trained using the US scales and found to be similar, in direction and magnitude, among the tested food samples.     

PREDICTING SENSORY COHESIVENESS, HARDNESS AND SPRINGINESS OF SOLID FOODS FROM INSTRUMENTAL MEASUREMENTS

ABSTRACT

The sensory evaluation of cohesiveness, hardness and springiness of 15 solid food samples was performed by eight trained assessors. The rheologic response of the 15 samples was estimated by performing cyclic compression tests and stress–relaxation tests. From the force–deformation curves of the first two cycles of the compression test, texture profile analysis parameters related to cohesiveness, hardness and springiness were calculated. Young's modulus (E), strain (d_i) and stress (s_i) at peak as well as irrecoverable strain (r_i) and irrecoverable work (L_i) were monitored during the first five cycles. From the stress–relaxation response, Peleg's linearization model parameters, K₁ and K₂, were estimated by best‐fit regression. These parameters were used for predicting sensory attributes. Hardness and springiness were both accurately predicted by rheologic properties, while cohesiveness prediction was less representative.

PRACTICAL APPLICATIONS

This study contributes to enhance the knowledge in the research area of sensory instrumental correlation. Also, the research allows to better understanding that no single instrument is able to measure all texture attributes adequately. In fact, the results demonstrate that both stress–relaxation and cyclic compression tests need to be performed for the correct prediction of sensory responses.     

Effect of Thermal Treatment on Selected Cereals and Millets Flour Doughs and Their Baking Quality

Selected cereals (rice and sorghum) and millets (finger millet and pearl millet) were steamed for 20 min at ambient pressure. The rheological properties of doughs, made from these steamed as well raw grain flours, were characterized in addition to examining their baking quality. The two-cycle compression test was employed and instrumental values were correlated with sensory attributes (color, aroma, taste, stickiness, chewiness, tearing strength, cohesiveness, and rollability) using principal component analysis (PCA). Rice doughs made from both raw as well as thermally treated flour imparted maximum hardness (96.6–99.3 N) and least cohesiveness (0.05–0.09) with highest stickiness values (105–110°) among all the dough samples at the same moisture content. Pearl millet and raw sorghum flour doughs possessed the least instrumental hardness, adhesiveness, and stickiness and were the easiest to flatten. The PCA biplot showed that sensory and instrumental cohesiveness formed a cluster on the left side on the x axis while shear force, and sensory attributes like tearing strength, chewiness, stickiness, and rollability formed another cluster on the other side of the axis. Raw rice and finger millet doughs were associated with the high extent of instrumental and sensory stickiness. Thermally treated pearl millet and sorghum doughs were the best followed by treated rice and finger millet samples to give the desirable dough characteristics, and were quite close to wheat chapathi in texture.     

PECAN TEXTURE AS AFFECTED BY MOISTURE CONTENT BEFORE FREEZING AND THAWING RATE

The texture of pecans was determined as affected by initial moisture content before freezing (3 vs 5%), thawing rate (IX, 1.2X, 2.7X, 5.6X), and multiple freeze‐thaw cycles (0, 1X, 3X, 6X, 9X, 12X). Texture was determined by instrumental Texture Profile Analysis (TPA) and sensory evaluation. Initial moisture content before freezing had a significant effect on all of the sensory evaluation parameters (hardness, fracturability, cohesiveness, and denseness) and most of the instrumental TPA texture parameters (hardness, fracturability, springiness, resilience, and chewiness). Thawing rate only affected TPA hardness and resilience. TPA fracturability correlated best with sensory fracturability. The sensory panel could not detect any differences between the different thawing rates. The slowest thawing rate affected more parameters than the medium and faster rates. More freeze/thaw cycles significantly decreased most TPA texture values, especially for pecans at higher moisture content.     

A Novel Tensile Test Method to Assess Texture and Gaping in Salmon Fillets

ABSTRACT: A new tensile strength method was developed to quantify the force required to tear a standardized block of Atlantic salmon muscle with the aim of identifying those samples more prone to factory downgrading as a result of softness and fillet gaping. The new method effectively overcomes problems of sample attachment encountered with previous tensile strength tests. The repeatability and sensitivity and predictability of the new technique were evaluated against other common instrumental texture measurement methods. The relationship between sensory assessments of firmness and parameters from the instrumental texture methods was also determined. Data from the new method were shown to have the strongest correlations with gaping severity (r =−0.514, P < 0.001) and the highest level of repeatability of data when analyzing cold-smoked samples. The Warner Bratzler shear method gave the most repeatable data from fresh samples and had the highest correlations between fresh and smoked product from the same fish (r = 0.811, P < 0.001). A hierarchical cluster analysis placed the tensile test in the top cluster, alongside the Warner Bratzler method, demonstrating that it also yields adequate data with respect to these tests. None of the tested sensory analysis attributes showed significant relationships to mechanical tests except fillet firmness, with correlations (r) of 0.42 for cylinder probe maximum force (P = 0.005) and 0.31 for tensile work (P = 0.04). It was concluded that the tensile test method developed provides an important addition to the available tools for mechanical analysis of salmon quality, particularly with respect to the prediction of gaping during factory processing, which is a serious commercial problem. Practical Application: A novel, reliable method of measuring flesh tensile strength in salmon, provides data of relevance to gaping.     

Instrumental Assessments of Japanese White Salted Noodle Quality

Strong correlations were found between some sensory evaluation results and instrumentally (Instron, Model 4301) assessed quality parameters for Japanese white salted noodles made from 32 Australian wheats. The sensory texture parameter, softness, had a strong negative correlation (r=-0·74, P<0·001) with the instrumental texture parameter, cutting force peak area divided by time. Other sensory texture parameters, smoothness and elasticity, showed significant correlations with another instrumental parameter, compression force peak area divided by time (r=-0·58, P<0·001 and r=0·52, P<0·01 respectively). Brightness, yellowness and discolouration of both raw and cooked noodles were measured using a colorimeter (Minolta, Model CR310). Strong correlations were observed between yellowness and discolouration of raw noodles and CIELAB b* (r=-0·79, P<0·001) and L*a* (r=-0·63, P<0·001) values, respectively. Similar relationships were found for cooked noodles (r=-0·74, P<0·001 for yellowness and r=-0·53, P<0·01 for discolouration). Both flour pasting properties including the flour swelling test and mixograph dough properties showed strong correlations with instrumental measures of noodle texture. Protein and ash content significantly affected noodle colour. In an attempt to simplify objective noodle quality measurements instrumental texture tests were carried out on flour gels. Textural measurements of flour gels showed that sensory softness of cooked noodles was correlated with an instrumental parameter, cutting peak force divided by time (r=-0·46, P<0·01). However, in this study no strong correlations were found between the smoothness and elasticity of noodles and any parameters of compression force-time profiles derived from gels. Yellowness of flour gels measured by a colorimeter showed a significant correlation with that of cooked noodles (r=-0·68, P<0·001). © 1997 SCI.     

Textural Measurements and Product Quality of Restructured Sweetpotato French Fries

The objectives of this research were to investigate the applicability of using an alginate-calcium gelling system to produce a French fry-type product using high beta-carotene sweetpotato puree as the main ingredient and to compare four instrumental methods of texture measurement for this product type in relation to sensory textural properties. Sweetpotato puree made with Jewel cultivar sweetpotatoes was restructured using optimized alginate-calcium concentrations. A consumer panel scored sweetpotato fries containing 0.35 g alginate/100 g and 0.5 g CaSO₄/100 g highest for appearance, texture, flavor, and overall acceptability. A trained texture profile panel described the product with 15 texture notes. Of these attributes, nine sensory notes describing hardness, mastication shear, cohesiveness, springiness, moistness, and oiliness were highly correlated with some instrumental parameters (r=0.79-0.92) for measuring textural properties. The instrumental methods evaluated were instrumental texture profile analysis, three-point bending force, Kramer shear force, and puncture force. Among these instrumental methods, Kramer shear appeared to be the method of choice because of method's simplicity and high precision (coefficient of variation ≤10%).     

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     

Comparison of Sensory and Instrumental Texture Profile Techniques for the Evaluation of Beef and Beef-Soy Loaves

Relationships among sensory texture profile parameters, among values for textural parameters obtained through different methods of interpreting instrumental texture profile analysis (TPA) curves obtained with an Instron, and between sensory and instrumental TPA values were examined for beef and beef-soy loaves. The only singificant relationship among sensory parameters was between cohesiveness and springiness. Although a number of significant relationships existed between the various methods of interpreting instrumental parameters, a number of these were associated with secondary parameters having common primary parameters. A strong relationship was found between sensory springiness and adjusted downstroke cohesiveness. Sensory cohesiveness was related both to this instrumental parameter and to downstroke cohesiveness. Chewiness values calculated for these two methods for obtaining cohesiveness values showed strong negative associations with sensory fracturability scores.     

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.     

Textural and physicochemical predictors of sensory texture and sweetness of boiled plantain

Boiled pulp is a major form of consumption for plantain. We assessed instrumental (puncture test and texture profile analysis) and sensory texture attributes of 13 plantain cultivars, two cooking hybrids and one dessert banana at different stages of ripeness after cooking in boiling water. Firmness, chewiness, stickiness, mealiness, sweetness and moistness described sensory variability, which was greater between stages of ripeness than between types of cultivars. Firmness and chewiness were well-predicted by instrumental force and hardness (r² > 0.72), and by soluble solid and dry matter content (r² > 0.85). Complementary sensitivity analysis revealed that a pulp puncture force or a hardness of at least 2.1 N or of 0.3 N/mm² was needed before a difference in firmness or chewiness could be perceived; a Brix of 3.7 was required to ensure a detectable difference in sweetness. Rheological and biochemical predictors can be useful for breeders for high-throughput phenotyping.     

建立食品质地参照物体系中量值估计法的改进

当前,在已经建立食品质地参照物体系的国家中,其建立方法的不统一性,以及数据统计分析的模糊性,使将要建立食品参照物体系的国家面临许多困难。在研究现行食品质地参照物体系的基础上,结合中国国情,选用国内具有消费规模的相关知名品牌食品为样品,采用感官排序法和改进的量值估计法对10人评价小组进行培训及评分,建立硬度、黏附性、碎裂性、咀嚼性4个主要参照物体系。研究结果表明:改进的量值估计法用于评价员定量评估参照物体系其量值结果与顺序标度值呈高度相关性(R20.98);通过培训建立起的感官评价小组稳定可靠,可对同类型多种食品进行评价。