Near-infrared reflectance spectroscopy for predicting chemical, instrumental and sensory quality of beef

The aim of this study was to assess near-infrared reflectance (NIR) spectroscopy as a tool for determining sensory and texture characteristics of beef. Chemical, instrumental, texture and sensory characteristics were predicted by near-infrared reflectance spectroscopy carried out on longissimus dorsi muscle samples from 190 young bulls. The use of first derivative gave best predictions together with NIR spectra, except for myoglobin and water holding capacity, which had an R(2) of prediction of 0.91 and 0.82, respectively, using visible and NIR spectra. Tenderness was the best-predicted variable (R(2)=0.98) demonstrating the potential of NIR spectroscopy in the prediction of sensory variables. Chemical composition variables and Warner-Bratzler shear force were predicted with an R(2) of prediction of around 0.7, but protein was not predicted with accuracy.     

PREDICTION OF INSTRUMENTAL AND SENSORY TEXTURAL CHARACTERISTICS OF MAHON CHEESE FROM ULTRASONIC MEASUREMENTS

Ultrasonic velocity was related to sensory and instrumental texture measurements. A semi-logarithmic model (Weber-Fechner) was used to relate the sensory and instrumental texture measurements. The ultrasonic velocity ranged from 1650 to 1723 m/s for the softest and hardest cheese, respectively. As expected from theoretical equations, the ultrasonic velocity was related to the square root of the instrumental measurements. The deformability modulus (r²=0.93) and the slope in puncture (r²=0.85) were the most closely related parameters. A model developed from the relationship between sensory and instrumental texture and the relationship between ultrasonic velocity and instrumental texture, was used to relate velocity to sensory measurements. Elasticity (r²= 0.84) and firmness (r²= 0.81) were the sensory attributes which best correlated with ultrasonic velocity. From the obtained results, it was concluded that ultrasonic velocity measurements could be used to assess instrumental and sensory properties of Mahon cheese texture nondestructively, and therefore could be used for grading purposes.     

Rheological and Sensory Properties of Reduced-Fat Processed Cheeses Containing Lecithin

Reduced fat processed cheeses were prepared with granular or hydrogenated soy lecithin. Trained sensory panelists (n = 11) determined that reduced-fat cheeses containing lecithin were more similar in texture attributes to full-fat control cheeses than reduced fat cheeses without lecithin (P<0.05). Consumer flavor and acceptance scores (n =60) for cheeses with lecithin were not different from control cheeses, but texture acceptance scores for cheeses with lecithin were higher than scores for reduced fat control cheeses (P.0.05). Cheeses containing lecithin were less elastic than reduced fat control cheeses as determined by sensory panels and instrumental percent creep recovery. Lecithin improved processed cheese texture without negatively affecting acceptance.     

PREDICTION OF SENSORY TEXTURE OF FETA CHEESE MADE FROM ULTRAFILTERED MILK BY UNIAXIAL COMPRESSION AND SHEAR TESTING

The ability to predict sensory texture properties of Feta cheese made from ultrafiltered milk (UF-Feta) from uniaxial compression, small shear deformation measurements (frequency sweep, strain sweep, relaxation) and indices of proteolysis was studied. In principal component analysis (PCA) some of the instrumental variables were highly correlated, e.g. the moduli from uniaxial compression and shear measurements; and strain at fracture from uniaxial compression and indices of proteolysis. PCA of the six sensory attributes determined by a trained panel showed that mainly one type of information was present in the sensory results. Partial Least Squares regression (PLS) of all results revealed that stress at fracture from uniaxial compression was the individual instrumental parameter having the highest correlation with the sensory texture attributes. Of these, the three firmness attributes were best predicted by the instrumental parameters. As the shear measurements were not very useful for prediction of sensory texture properties by themselves, and as the increase in prediction precision by inclusion of these measurements was marginal, it is suggested that either stress at fracture alone, or together with three other parameters from uniaxial compression should be used to describe texture properties of UF-Feta cheese.     

Non-destructive determination of components in processed cheese slice wrapped with a polyethylene film using near-infrared spectroscopy and chemometrics

This paper explored a novel non-destructive method for the determination of ingredients, fat, protein and sodium chloride (NaCl), in processed cheese slice wrapped with a polyethylene (PE) film by using near-infrared (NIR) diffuse reflectance spectroscopy. A simple mathematical way, partial least squares (PLS) regression combined with second-order derivative, is proposed for removing the contributions of PE film from NIR spectra. During the operating of this method, the peak separation was enhanced and the essential information directly related to the analytes was condensed. The result of second-order derivative pre-treatment indicates that it effectively removes the film's effect from NIR spectra of wrapped processed cheese samples, and the PLS regression for fat, protein and NaCl reveals that it enables the building of satisfactory calibration models for the ingredients in cheese slices even within PE film. The use of such analytical techniques potentially makes it possible to remove an intensity contribution from PE film simply in a mathematical way for easy-to-use high quality analytical methods in dairy industries.     

Prediction of color, texture, and sensory characteristics of beef steaks by visible and near infrared reflectance spectroscopy. A feasibility study

Color, instrumental texture, and sensory attributes of steaks from 24 beef carcasses at 2, 4, 8, 14, and 21 days post mortem were predicted by visible/near infrared (visible/NIR) reflectance spectroscopy in 400-1080 nm region. Predicting the Hunter a, b, and E* yielded the coefficient of determination (R(2)) in calibration to be 0.78-0.90, and R(2) was between 0.49 and 0.55 for tenderness, Hunter L, sensory chewiness and juiciness. The prediction R(2) for tenderness was in the range of 0.22-0.72 when the samples were segregated according to the aging days. Based on partial least square (PLS) model predicted tenderness, beef samples were classified into tender and tough classes with a correct classification of 83%. Soft independent modeling of class analogy of principal component analysis (SIMCA/PCA) model of measured tenderness showed great promise in the classification of tender and tough meats with over 96% success.     

Instrumental and Expert Assessment of Mahon Cheese Texture

ABSTRACT: To improve Mahon cheese texture assessment, the relationship between instrumental and sensory measurements was sought. For that purpose 30 pieces of Mahon cheese from different batches and 2 different manufacturers were examined. Textural characteristics at different curing times were evaluated by uniaxial compression, puncture, and sensory analysis. Significant linear correlations were found between instrumental and sensory measurements. A logarithmic model (Weber-Fechner) fitted data better than a linear one. Only 1 factor was extracted when considering all the instrumental and sensory variables, thus indicating that both sets of measurements are related to the same phenomenon. The best predictors for Mahon cheese sensory attributes were found to be cheese moisture, deformability modulus, and slope in puncture.     

Rheology, microstructure, and functionality of low-fat Iranian white cheese made with different concentrations of rennet

A batch of full-fat (23% target fat) and 3 batches of low-fat (6% target fat) Iranian white cheese with different rennet concentrations (1-, 2-, and 3-fold the normal usage) were produced to study the effect of fat content reduction and promoted proteolysis on the textural and functional properties of the product. Cheese samples were analyzed with respect to their rheological parameters (uniaxial compression and small amplitude oscillatory shear), meltability, microstructure, and sensory characteristics. Reduction of fat content from 23 to 6% had adverse effects on the texture, functionality, cheese-making yield, and sensory characteristics of Iranian white cheese. Fat reduction increased the instrumental hardness parameters (storage modulus, stress at fracture, and Young's modulus of elasticity), decreased the cheese meltability and yield, and made the microstructure more compact. Doubling the rennet concentration reduced values of instrumental hardness parameters, increased the meltability, and improved the sensory impression of texture. Although increasing the rennet concentration to 2-fold the normal usage resembled somewhat the low-fat cheese to its full-fat counterpart, it appeared to cause more reduction in yield. Increasing the rennet concentration 3-fold the normal usage produced a product slightly more elastic than the low-fat cheese with normal concentration of rennet. Increasing the rennet concentration to 2-fold the normal usage was useful for improving the textural, functional, and sensory properties of low-fat Iranian white cheese.     

Texture of low-fat Iranian White cheese as influenced by gum tragacanth as a fat replacer

The effect of different concentrations of gum tragacanth on the textural characteristics of low-fat Iranian White cheese was studied during ripening. A batch of full-fat and 5 batches of low-fat Iranian White cheeses with different gum tragacanth concentrations (without gum or with 0.25, 0.5, 0.75, or 1 g of gum/kg of milk) were produced to study the effects of fat content reduction and gum concentration on the textural and functional properties of the product during ripening. Cheese samples were analyzed with respect to chemical, color, and sensory characteristics, rheological parameters (uniaxial compression and small-amplitude oscillatory shear), and microstructure. Reducing the fat content had an adverse effect on cheese yield, sensory characteristics, and the texture of Iranian White cheese, and it increased the instrumental hardness parameters (i.e., fracture stress, elastic modulus, storage modulus, and complex modulus). However, increasing the gum tragacanth concentration reduced the values of instrumental hardness parameters and increased the whiteness of cheese. Although when the gum concentration was increased, the low-fat cheese somewhat resembled its full-fat counterpart, the interaction of the gum concentration with ripening time caused visible undesirable effects on cheese characteristics by the sixth week of ripening. Cheeses with a high gum tragacanth concentration became very soft and their solid texture declined somewhat.     

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.     

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     

Novel cheese with vegetal rennet and microbial transglutaminase: Effect of storage on consumer acceptability,sensory and instrumental properties

The aim of this study was to evaluate the consumer acceptance and preference of a novel cheese coagulated with vegetal rennet and microbial transglutaminase (V + TG) as an alternative for lacto‐vegetarian consumers. The evolution of the sensory and instrumental parameters throughout the storage time was studied. Cheese with animal rennnet and microbial transglutaminase (A + TG), vegetal rennet alone (V) and animal rennet alone (A) were also studied as controls. The consumer test showed that the V + TG cheese was preferred and showed high texture and taste acceptance scores. This cheese could be successful for its sensory acceptance and as an alternative for the lacto‐vegetarian market.     

Comparison of full-fat and low-fat cheese analogues with or without pectin gel through microstructure, texture, rheology, thermal and sensory analysis

The effects of pectin gel and protein base on processed semi-solid cheese analogues were studied through microstructure, texture, rheology, thermal analysis and sensory evaluation. Scanning electron microscopy revealed differences in the microstructure of processed cheese analogues. Samples made with full-fat contained higher concentrations of fat globules and were denser compared with low-fat cheese analogues with or without pectin gel. The pectin gel in the products acted as a linkage with other ingredients and made the products more compact and had less cavity compared with the products without pectin gel added. On rheological analysis, the full-fat products manifested a more solid-like form. The storage modulus of pectin gel sample was higher than that without pectin gel. All the samples' rheological parameters were depending on the oscillatory frequency and temperature. In low-fat samples, pectin gel added or not affected the hardness, gumminess, chewiness and adhesiveness significantly. The pectin gel addition show positive effect to the texture profile of the low-fat cheese analogues. Through thermal analysis, the meltability and glass transition temperature of the processed cheese analogues were measured. The low-fat cheese analogue with pectin gel addition got the higher texture and mouthfeel scores through sensory evaluation.     

TEXTURE ANALYSIS OF CHEDDAR CHEESE MADE FROM ULTRAFILTERED MILK

The textural properties of Cheddar cheese made from ultrafiltered milk were assessed. Cheddar cheeses were prepared from 1.5- and 2.0-fold concentrated milk and ripened for three months. Textural characteristics of the UF cheeses were compared to control and commercial Cheddar cheeses by sensory and instrumental measures. The texture of cheese made from UF milk differed from the control commercial Cheddar cheeses. According to the trained sensory panel, the UF cheeses were harder and more rubbery, crumbly, chewy and grainy than the control and commercial Cheddar cheeses (P <0.01). The texture profile analysis (TPA), conducted using the Instron, did not correspond to the sensory measurements nor was it successful in discriminating among the cheese samples. Lack of agreement between the sensory and instrumental tests was attributed to differences in the testing conditions and procedures of the two methods. Instrumental tests should be validated against sensory measures in order to be useful as measures of palatability. Consumer preferences for the commercial, control and UF Cheddar cheeses were significantly different (P < 0.01), the UF cheeses being less preferred in terms of flavor, texture and overall acceptability.     

Application of Near and Mid-Infrared Spectroscopy to Determine Cheese Quality and Authenticity

This paper reviews the current state of development of both near-infrared (NIR) and mid-infrared (MIR) spectroscopic techniques for process monitoring, quality control, and authenticity determination in cheese processing. Infrared spectroscopy has been identified as an ideal process analytical technology tool, and recent publications have demonstrated the potential of both NIR and MIR spectroscopy, coupled with chemometric techniques, for monitoring coagulation, syneresis, and ripening as well as determination of authenticity, composition, sensory, and rheological parameters. Recent research is reviewed and compared on the basis of experimental design, spectroscopic and chemometric methods employed to assess the potential of infrared spectroscopy as a technology for improving process control and quality in cheese manufacture. Emerging research areas for these technologies, such as cheese authenticity and food chain traceability, are also discussed.     

发酵剂、氯化钙及凝乳酶添加量对白牦牛乳Mozzarella干酪质构的影响

以白牦牛乳为原料制作Mozzarella干酪,在单因素试验基础上采用Box-Behnken响应面法对发酵剂、CaCl_2、凝乳酶添加量进行优化,利用质构综合评分筛选最佳的工艺参数。结果表明,白牦牛乳Mozzarella干酪的最佳工艺参数为:发酵剂添加量0.24 g/L、CaCl_2添加量0.23 g/L、凝乳酶添加量0.04 g/L,此时白牦牛乳Mozzarella干酪质构综合评分为11.095,出品率为20.53%,感官评分为93.67。此工艺条件下制作的白牦牛乳Mozzarella干酪香味浓郁,质地均匀,软硬适度。