Sensory Texture Characteristics Research Articles

Effects of gluten and transglutaminase on microstructure, sensory characteristics and instrumental texture of oat bread

Effects of added gluten and transglutaminase on microstructure, instrumental texture and sensory characteristics of bread baked with 51% wholemeal oat flour were compared in order to determine how changes in the state of macromolecules – protein and starch – correlate with changes in sensory and instrumental structure. Light microscopy, instrumental texture profile analysis, and descriptive sensory analysis were used to analyse the test breads. Addition of gluten and transglutaminase affected the structure of the protein network and distribution of water between the protein and starch phases. The differences in microstructure were quantified by determining the areas of starch and protein in the micrographs by image analysis. Breads baked with added gluten and water were softer and less gummy than the oat and wheat reference breads in the texture profile analysis. Addition of transglutaminase made the breads harder and gummier than the breads baked without the added enzyme. In the descriptive sensory analysis breads baked with added gluten or added gluten and water were evaluated as more soft and springy than the reference oat bread. Sensory characteristics of bread texture correlated well with the texture and microstructure measured instrumentally.;

Compensatory growth response as a strategy to enhance tenderness in entire male and female pork M. longissimus thoracis

The effects of restrictive feeding strategies aimed at promoting a compensatory growth response were investigated with respect to tenderness improvement in pork M. longissimus thoracis. Compensatory growth response is defined by increased weight in pigs fed ad libitum after a period with restricted feeding compared to pigs fed ad libitum the entire fattening period. Specifically, the aim was to study the sensory textural characteristics after female and entire male pigs have been exposed to restrictions in either energy, protein or both in specific growth periods. It was found that textural differences were caused by feeding strategies and not related to variation in intramuscular fat, which did not vary significantly between genders. The female pigs demonstrated compensatory growth response and the texture was significantly ( P < 0.001) improved by low dietary level of energy from day 50 to 90 and normal dietary level of protein during the entire feeding period. For the entire male pigs, low level of protein in the late feeding period significantly ( P < 0.05) improved the texture. Also, low level of protein and normal level of energy in the early feeding period resulted in improved tenderness. However, these texture improvements were deemed not to be an effect of compensatory growth since the entire male pigs did not compensate for the feeding restriction in the early feeding period. The tenderness enhancement for the entire male pigs compromised the production results in terms of 7–15% lower carcass weight.

GELÉIA DE GABIROBA: AVALIAÇÃO DA ACEITABILIDADE E CARACTERÍSTICAS FÍSICAS E QUÍMICAS

Gabiroba is a native fruit from the Brazilian Cerrado, characterized by a high productivity rate and good acceptance by the local population. The objective of this experiment was to evaluate the physical and chemical characteristics of the gabiroba jelly, with positive results in sensory data, during 180 days of storage. The jellies were formulated with the following ratios of gabiroba pulp: sugar 50 : 50, minimum 65% of soluble solids, 0.5% of pectin and increasing proportions of citric acid (0 to 1.5%). The jellies with acceptable sensory attributes and higher purchase intention level were stored at room temperature and monthly evaluated, until 180 days of storage, for physical and chemical characteristics (moisture, pH, titrable acidity and soluble solids). The jellies containing 1.0 and 1.5% of citric acid were considered acceptable (scores higher or equal to 6.0), concerning the sensory characteristics of flavor, aroma, texture (global acceptance), and appearance. The proportions of soluble solids and titrable acidity increased and the pH decreased, according to the storage time. Gabiroba jellies with adequate chemical characteristics and acceptable sensory attributes may be prepared with 0.5% of pectin and addition of 1.0% and 1.5% of citric acid. KEY-WORDS: Gabiroba; jelly; sensory analysis; hysicochemical analysis.

RELATIONSHIP BETWEEN SENSORY AND INSTRUMENTAL MEASUREMENTS OF TEXTURE FOR ARTISANAL AND INDUSTRIAL MANCHEGO CHEESES

ABSTRACT Rheological characteristics of eight Manchego cheeses (four artisanal produced from raw ewe milk and four industrial cheeses from pasteurized ewe milk) with different ripening time (2, 4, 6 and 12 months) were evaluated by uniaxial compression and descriptive sensory analysis. Both the instrumental texture measurements and the intensity of the sensory texture attributes evaluated were found to vary during ripening time because of the manufacturing procedure (artisanal and industrial). Partial least square regression was used to predict the sensory texture characteristics of these cheeses, as expressed by different parameters of texture; hardness, Young's modulus or elastic modulus, stiffness, breaking force and strain at breaking point. The models obtained yielded good results for the prediction of sensory texture characteristics of Manchego cheeses: the root mean square error of calibration and the root mean square error of prediction by cross‐validation were both below 1.1 on the unstructured 10‐point scale used in descriptive sensory texture analysis. PRACTICAL APPLICATIONSWhile fundamental rheological tests reveal important information in relation to network structure and molecular arrangement, the results obtained in this study indicate that empirical texture evaluations work equally as well or even better at predicting sensory texture properties. The eating and cutting properties of Manchego cheese depend not only on conditions of curd formation and handling, but also on storage conditions. Not only functional properties like eating and cutting, but also flavor properties change during storage. Understanding how these changes occur can reduce the variability of the properties of current commercial cheese and can assist in new product development.

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

ABSTRACT 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 &gt; 0.9) between sensory and instrumental texture parameters was observed. Instrumental chewiness (r = 0.91), cohesiveness (r = 0.96) and sensory hardness (r &gt; 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.

RELATIONSHIPS BETWEEN SENSORY AND RHEOLOGICAL MEASUREMENTS OF TEXTURE IN MATURING COMMERCIAL CHEDDAR CHEESE OVER A RANGE OF MOISTURE AND pH AT THE POINT OF MANUFACTURE

ABSTRACTS Textural characteristics of 10 Cheddar cheeses with a range of moisture contents and pH values were investigated by sensory and instrumental methods, over a 9‐month maturing period. A trained panel of nine assessors described the sensory texture characteristics of the cheeses using 11 texture parameters. Instrumental parameters were derived using texture profile analysis. Relationships between sensory, instrumental, compositional and maturation properties of the cheeses were determined with the aid of principal component analysis and multiple linear regression. Nine sensory parameters significantly correlated with instrumental parameters, e.g., sensory rubbery correlated with instrumental firmness (R = 0.696, P &lt; 0.001), chewiness (R = 0.679, P &lt; 0.001), fracture stress (R = 0.669, P &lt; 0.001) and springiness (R = 0.643, P &lt; 0.001). Sensory firmness corresponded closely with instrumental firmness (R = 0.539, P &lt; 0.001) and fracture stress (R = 0.518, P &lt; 0.001). Sensory and instrumental texture parameters were significantly affected by changes in moisture content, pH and maturation.

Effect of Vital Gluten and Gum Arabic on the Textural Properties of Pasta Made from Pre-gelatinised Broken Rice Flour

Broken rice flours of three indigenous rice cultivars were utilised for the formulation of tube type pasta (Ziti-cut) using four levels of vital gluten (14-20%, flour weight basis) and gum Arabic (0.5-2.0%, flour weight basis). The textural qualities of pasta were analysed using a texture analyser (TAXT-2i) and by descriptive sensory analysis. The pasta made from native broken rice flour and pre-gelatinised broken rice flour supplementing with vital gluten to obtain 14% protein content were compared for their instrumental texture qualities (hardness and shear strength of raw pasta as well as stickiness and adhesiveness of cooked pasta) and sensory texture analysis (colour, hardness, chewiness, smoothness and grittiness). The pre-gelatinised broken rice flour was found suitable for pasta preparation based on its firmer, larger shear strength and less stickiness and adhesiveness than its native broken rice flour. Among the three varieties, the pre-gelatinised broken rice flour of variety PR-114 with 14% protein content (supplemented by vital gluten) and 1.5% gum Arabic has been found most suitable for the pasta preparation with desirable quality attributes on the basis of instrumental and sensory textural characteristics.

TEXTURAL CHARACTERISTICS OF PASTA MADE FROM RICE FLOUR SUPPLEMENTED WITH PROTEINS AND HYDROCOLLOIDS

ABSTRACT Broken pieces of three indigenous rice cultivars were utilized for the formulation of tube type pasta (Ziti‐cut) using four levels each of vital gluten and guar gum. The rice flours were modified by pregelatinization and the pregelatinized flour was found suitable for pasta preparation based on instrumental and sensory texture analysis. The cooking time for pasta was reduced from 10 to 6 min by using pregelatinized rice flour. The textural quality of pasta was analyzed using texture analyzer (TAXT‐2i) and descriptive sensory analysis techniques. A protein level of 16% was found suitable for production of rice pasta, which was comparable to commercial semolina sample whereas a gum level of 1.5% supplemented to pregelatinized rice flour containing 14% protein was judged the best on the basis of instrumental as well as sensory textural characteristics.

SENSORY AND INSTRUMENTAL EVALUATIONS OF TEXTURE IN CHEESES MADE FROM OVINE MILKS WITH DIFFERING FAT CONTENTS

ABSTRACTThe present study considers the influence of reducing the fat content of ovine milk on the sensory and instrumental texture characteristics of the resulting cheeses. Three manufacturing runs were performed. In each run three cheese batches were manufactured using milks with differing percentage fat contents (8%, 4%, and 2% fat). Analysis of cheese samples was performed at 60, 90, and 120 days of ripening.The instrumental method used to evaluate cheese texture was uniaxial compression at constant speed, taking readings of stress, strain, and modulus of elasticity (E). Statisticalanalysis revealed differences forboth the differentfat contents and the ripening times considered. Instrumental parameter values increased with lower cheese fat contents; with a 20% reduction in the fat to dry matter content from full‐fat to reduced‐fat cheeses, resulting in a 35% increase in maximum stress and in the slope of the stress‐strain curve at the end of ripening. The greatest sensory differences between samples were recorded for firmness.

SENSORY CHARACTERISTICS AND NEAR‐INFRARED SPECTROSCOPY OF BROILER BREAST MEAT FROM VARIOUS CHILL‐STORAGE REGIMES

ABSTRACTThe terms “fresh” and “frozen” often refer to the physical state of the product (i.e., soft, hard) as well as quality state (i.e., good, inferior). This study addressed quality issues of breast meat subjected to chill‐store regimes that simulate possible scenarios at points between processing, distribution by retailers, and final preparation by consumers. Five temperatures (+4,0, −3, −12, and −18C) at storage regimes (2 days, 7 days, and 7 days at the five temperatures followed by an additional 7 days at −18C) were evaluated. The statistical differences in descriptive sensory texture and moisture characteristics among cooked samples could not be predominantly attributed to temperature, storage, or temperature‐storage treatments. Visible and near‐infrared reflectance spectra of stored raw skinless breasts did not discriminate between individual temperature groups. However, a two‐class model (98.5% correct classification) discriminated between unfrozen (+4, 0, and −3C) and frozen (−12 and −18C) samples, partially due to spectra of myoglobin and oxidative states.

Prediction of Cooked Rice Texture Using an Extrusion Test in Combination with Partial Least Squares Regression and Artificial Neural Networks

ABSTRACTSpectral stress strain analysis was used in combination with partial least squares (PLS) regression and artificial neural networks (ANN) to predict nine sensory texture attributes of cooked rice. The models calculated with ANN were significantly more accurate in predicting most of the sensory texture characteristics evaluated than the PLS models. Furthermore, ANN models were more robust and discriminative than PLS models.

Prediction of Rice Sensory Texture Attributes from a Single Compression Test, Multivariate Regression, and a Stepwise Model Optimization Method

ABSTRACT: Sensory texture characteristics of cooked rice (92 samples) were predicted using a compression test and a novel multivariate analysis method (that is, Partial Least Squares Regression optimized by a stepwise method). 11 sensory texture characteristics were evaluated via a trained descriptive panel, and 14 instrumental parameters from a compression test were used in combination with Partial Least Squares Regression to evaluate predictive models for each of the sensory attributes studied.Among the texture attributes evaluated by the panel, 7 (cohesion of bolus, adhesion to lips, hardness, cohesiveness of mass, roughness of mass, toothpull, and toothpack) were satisfactorily predicted after the optimization by the stepwise method (optimized Rcal &gt; 0.6).

Instrumental Assessment of Cooked Rice Texture Characteristics: A Method for Breeders

ABSTRACTSensory textural characteristics of cooked rice (61 samples) were predicted using a miniature extrusion cell and the novel data analysis method Spectral Stress Strain Analysis (SSSA). Thirteen sensory texture characteristics evaluated using a trained descriptive panel and stress values from an extrusion test were used in combination with partial least squares regression to evaluate predictive models for each of the sensory attributes studied. Among the textural attributes evaluated by the panel, four (stickiness, hardness, cohesiveness of mass, and uniformity of bite [relative ability of prediction values (RAP) &gt; 0.6, n = 61]) could be satisfactorily predicted using an instrumental test and subsequent SSSA. The quality of the models determined varied for the two grain types evaluated. This instrumental method provides a valuable screening tool for rice breeders.

Effect of Cooking Method on Sensory and Instrumental Texture Attributes of Low-fat Beefburgers

The effect of cooking method (grilling, frying, griddling, roasting or deep fat frying) to an internal temperature of 72°C on the quality of low-fat (72±12 g fat/kg) beefburgers was assessed. Proximate analysis, sensory analysis, instrumental texture assessment, cook loss, dimensional changes and pH measurements were carried out. Cooking method significantly affected moisture content after cooking with deep fat fried burgers having the lowest values (P<0.05). Deep fat frying and grilling resulted in the highest cooking losses (P<0.001). The sensory characteristics of overall acceptability, tenderness, overall flavour, meaty flavour, overall appearance (P<0.001), overall texture, moistness/juiciness (P<0.01) and fattiness (P<0.05) were significantly affected by the cooking method. Warner Bratzler peak force (P<0.01), Warner Bratzler peak energy (P<0.05) and cohesiveness (P<0.05) (measured by texture profile analysis) were also significantly affected by cooking method. Burgers that were roasted or grilled had the lowest Warner Bratzler peak force (P<0.05) and energy values (P<0.05). Griddling resulted in the most acceptable low-fat beefburgers while deep fat frying produced the least acceptable ones.

PREDICTION OF RICE TEXTURE BY SPECTRAL STRESS STRAIN ANALYSIS: A NOVEL TECHNIQUE FOR TREATING INSTRUMENTAL EXTRUSION DATA USED FOR PREDICTING SENSORY TEXTURE PROFILES

ABSTRACTSensory texture characteristics of cooked rice for three cultivars (74 samples) were predicted using an extrusion cell and a novel data analysis method (i.e. Spectral Stress Strain Analysis). Eight sensory texture characteristics were evaluated and force values from the instrumental tests were used in combination with Partial Least Squares regression to evaluate predictive models for each of the sensory attributes studied. Relative Ability of Prediction (RAP) values were evaluated for each model; they ranged from 0.06 to 0.85. Satisfactory models are proposed for the two major texture characteristics of cooked rice, namely hardness (RAP=0.85) and stickiness as evaluated by adhesion to lips (RAP=0.76). Other sensory attributes such as roughness of mass (RAP=0.73) and toothpack (RAP=0.81) were also satisfactorily predicted. Sensory attributes such as toothpull (RAP=0.12) and loose particles (RAP=0.06) could not be predicted using the Spectral Stress Strain Analysis.

Sensory Descriptive Texture Analyses of Cooked Rice and Its Correlation to Instrumental Parameters Using an Extrusion Cell

ABSTRACTSensory characteristics of cooked rice texture for three cultivars were evaluated using both descriptive sensory methods and an instrumental extrusion cell. Nine sensory textural characteristics were evaluated and five instrumental parameters were used to establish predictive models for the sensory characteristics evaluated. Multiple regression models with R2 ranging from 0.22 to 0.70 were obtained for seven of nine sensory attributes studied. Sensory characteristics most effectively predicted were hardness (R2 =0.62) and toothpack (R2 =0.70). Predictive models of textural sensory characteristics of cooked rice were also evaluated using partial least square regression techniques. Best results were obtained for hardness (relative ability of prediction [RAP] = 0.52), cohesiveness of mass (RAP = 0.60), toothpull (RAP = 0.73), and toothpack (RAP = 0.54).

RESPONSE SURFACES OF SENSORY CHARACTERISTICS FOR REDUCED SODIUM CHLORIDE AND PHOSPHATE SALTS IN EMULSIFIED TURKEY SAUSAGES

ABSTRACTEmulsified turkey sausages (ETS) were prepared using varying concentrations of sodium chloride (NaCl; 1.5 to 2.0%), sodium tripolyphosphate (STPP, 0 to 0.5%), and sodium acid pyrophosphate (SAPP, 0 to 0.25%). The sensory characteristics (response variables) of saltiness, soapiness, and texture were evaluated using a trained taste panel. Response surface methodology was used to design and analyze this study. Over the levels of STPP and SAPP, saltiness increased as levels of NaCl were increased. When STPP and SAPP were evaluated in combination with NaCl, saltiness increased slightly as levels of STPP were increased; and saltiness decreased as levels of SAPP were decreased. Soapiness increased at low levels of NaCl (1.5%) as STPP increased. Texture firmness decreased as SAPP increased and STPP decreased at low levels of NaCl (1.5%). Results suggest that sensory perceptions in ETS products are a combination of NaCl, SAPP, and STPP mixtures.

Utilization of surimi-like products from pork with sex-odor in restructured, precooked pork roasts (1990)

Surimi-like materials from boar and sow muscle and Alaska pollack surimi were evaluated at a 5% inclusion level in a restructured, precooked (158°F) pork roast. Meat batches were formulated to contain 95% chunked ham muscles and either 5 or 0% surimi-like or surimi binder, either 0.2 or 1.0% NaCl, and 0.5% phosphate. The surimi washing process did not remove or decrease boar taint intensity of the binder or enhance instrumental and sensory textural characteristics of the finished product. Products without binder were comparable or superior in textural and microbial characteristics to those with binders. Increasing salt content had detrimental effects on TBA (rancidity) and color but enhanced product textural attributes. Fish surimi did not have greater structural integrity than washed boar counterparts.; Swine Day, Manhattan, KS, November 15, 1990

Effect of Some Insoluble Milk Proteins on Sensory Characteristics of Appearance and Texture in Cookies

ABSTRACTLactalbumin, lactic casein, rennet casein, low‐calcium and high‐calcium co‐precipitates were processed from skim milk and dried using both spray and pneumatic‐conveying ring driers. Ring dried material was further divided into 30, 60 and 100 mesh sizes. All 20 protein products were tested in‘high’and‘low’protein cookies and evaluated by a trained sensory panel, using magnitude estimation scaling, for characteristics of appearance and texture. Processing effects, such as drying method and mesh size, had more effect on the cookies than protein type. These effects were greater in‘high’protein cookies than in‘low’protein cookies and were used to advantage in formulating‘high’protein cookies with a crisp and open texture.