Visualization of sensory profiling data for performance monitoring

Simple graphical techniques can be utilized to investigate the performance of individual assessors and to detect individual differences among assessors in a sensory panel. By visualizing different type of information in a set of various plots the panel leader can extract relevant information without the need of extensive knowledge in statistics. The joint information content gained from the plots can then be used as a basis for selective training in order to improve performance of single assessors and the panel as a whole.     

Differentiation of port wines by appearance using a sensory panel: comparing free choice and conventional profiling

Received: 2 July 1999     

Consumer perceptions of novel fruit and familiar fruit: a repertory grid application

To explore how consumers perceive novel and familiar fruit, repertory grid interviews were carried out with 60 New Zealand women. Participants described their perceptions of nine fruit varying in familiarity. The data analysis established a two‐dimensional stimuli space that separated samples with respect to familiarity and the amount of preparation required. Fruit that was familiar was characterised as being well liked, easily available in shops and by a number of different use situations. The primary association with novel fruit was that it was expensive. The participants could not readily think of use situations for fruit they were unfamiliar with. Consumers were separated into groups according to the trait of food neophobia, which pertains to an individual's stable propensity to approach or avoid novel foods. When comparing the most neophobic (n = 14; avoids novel foods) and most neophilic (n = 14; approaches novel foods), individuals perceptual differences were uncovered pertaining to which of the fruit were considered novel and to the suitability of some usage situations (cooking and for children). This finding contributed to the growing evidence of the relationship between food neophobia and consumers' everyday food‐related behaviour. Copyright © 2004 Society of Chemical Industry     

Taking individual scaling differences into account by analyzing profile data with the Mixed Assessor Model

Scale range differences between individual assessors will often constitute a non-trivial part of the assessor-by-product interaction in sensory profile data (Brockhoff, 2003, 1998; Brockhoff and Skovgaard, 1994). We suggest a new mixed model ANOVA analysis approach, the Mixed Assessor Model (MAM) that properly takes this into account by a simple inclusion of the product averages as a covariate in the modeling and allowing the covariate regression coefficients to depend on the assessor. This gives a more powerful analysis by removing the scaling difference from the error term and proper confidence limits are deduced that include scaling difference in the error term to the proper extent. A meta study of 8619 sensory attributes from 369 sensory profile data sets from SensoBase (www.sensobase.fr) is conducted. In 45.3% of all attributes scaling heterogeneity is present (P-value <0.05). For the 33.9% of the attributes having a product difference P-value in an intermediate range by the traditional approach, the new approach resulted in a clearly more significant result for 42.3% of these cases. Overall, the new approach claimed significant product difference (P-value <0.05) for 66.1% of the attributes compared to the 60.3% of traditional approach. Still, the new, and non-symmetrical, confidence limits are more often wider than narrower compared to the classical ones: in 72.6% of all cases.     

Use of sense masking to study sensory modalities singly: Interest for the understanding of apple in-mouth perception

The relative contribution of aroma, taste and texture modalities to overall perception, as well as the interactions which can occur between them, were studied during the consumption of natural foods, i.e. apples. Aroma, taste and texture perceptions were masked in that order by employing different masking agents, separately or combined, allowing one or several of these senses to be omitted during various matching tasks. By means of Common Components and Specific Weight Analysis (CCSWA), matching results were compared to those of rating tests performed by a trained panel, without masking agents. Taste was the modality which contributed most to apple discrimination, followed by texture and aroma. While taste did not seem to interact with texture, its perception may have been amplified by odorant information. A perceptual taste-taste interaction may also occur during apple consumption. The use of masking agents could thus become a useful tool to better understand the perception of several sensations of real natural foods whose formulation cannot be modulated.     

白酒产品关键感官特征与质量性价比研究

目的研究某品牌不同价位白酒产品感官特征质量及其与定价的相互关系。方法采用感官剖面和多重比较分析不同产品感官特征差异,通过相关性分析与回归分析影响质量的关键感官特征,通过拟合回归分析评价产品的性价比。结果 6款白酒的窖香、粮香、柔和度、丰满度、谐调度和纯净度特征差异显著,陈香、持久度的差异较小。产品酒体香味设计均衡合理,感官特征符合其产品的质量档次。其中窖香与甜度是影响品酒师的风格质量评价的关键特征。根据性价比指数,大部分产品的价位设置合理。结论感官定量描述分析方法可为白酒感官质量与价位评价提供技术依据。     

Multiplicative mixed models for the analysis of sensory evaluation data

Multiplicative mixed models have recently been proposed for the analysis of data from series of plant variety trials. Such approaches may be useful for other applications, including the analysis of data from sensory evaluation experiments. Implicit in these data are two-way tables of product by assessor effects. Several authors have suggested the need to accommodate heterogeneity of product and error variance between assessors. This provides information on the discriminating ability and reliability of individual assessors. Additionally it is of interest to examine the level of agreement between assessors. These issues can be explored with the use of a mixed model that includes a multiplicative model for product by assessor effects. This allows examination of product by assessor effects whilst accommodating important covariate information, for example, associated with the experimental design. In this paper we use the approach to analyse data from two sensory evaluation experiments.     

Modelling and analysis of dynamic sensory data

Time intensity (TI) data from earlier reported studies on cream cheese and salad dressing were used to develop models based on both polynomials and ordinary differential equations (ODE) that can be used to describe and interpret TI-data. Polynomials were thus fitted to experimental data. By taking the first and second derivatives of the polynomials one gets new polynomials that express how the perceived intensity changes with time. By integrating the original polynomial one gets a new polynomial that expresses how the classical TI-parameter “Area Under the Curve” is accumulated with time. Graphical display of all these types of polynomials gives an immediate and easily interpretable impression of the influence of different experimental factors on the time dependent perception. In the ODE models experimental factors, both formula and process conditions, were taken into account. Thus it was possible to develop equations that can be used for prediction of TI-curves for intermediate experimental settings.     

Investigation of various extractants for the analysis of aflatoxin B1 in different food and feed matrices

Various extractants were investigated concerning their suitability for aflatoxin B₁ determinations in different matrices including spices, infant formula and animal feed employing an immunoaffinity clean-up procedure. It was shown that the use of aqueous acetonitrile extractants was limited due to the fact that dry sample material can absorb significant amounts of water from theextractant. This canresultin recoveries thataretoo high and therefore in incorrect values for the aflatoxin concentration if aliquots are taken for further analysis. Acorrection of theresultsby recovery calculationusing spiked blank materialis unsuitable, since material from the same group of food (e.g. paprika powder) or feed can vary significantly in the recovery values. Therefore it is recommended that aqueous methanol extractants are used, since no significant interaction with matrix constituents was observed. In addition,aqueous acetone extractants are a useful alternative with some limitations.     

Identification of the character impact flavour compounds of Swiss cheese by sensory studies of models

Flavour models were developed for two samples (A and B) of Swiss cheese which differed in their ripening stage and flavour profile. The models were based on an unripened, freeze-dried cheese of the Mozzarella type. Compounds which, in previous studies had been screened as contributors to the odour and taste of Swiss cheese, were added to the base in various combinations and at concentrations equal to those found in Swiss cheeses A and B. Models composed of methional, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone, acetic acid, propionic acid, lactic acid, succinic acid, glutamic acid, sodium, potassium, calcium, magnesium, ammonium, phosphate and chloride were judged to meet the flavour of Swiss cheese very well.     

Risks and pitfalls of sensory data analysis for shelf life prediction: Data simulation applied to the case of coffee

Shelf life determination by means of sensory analysis is thought to be of paramount importance even in case of a microbiologically stable food. Several approaches are found in literature, both in terms of data collection and data processing. Whatever method is used, the subjectivity in the choice of some parameters for data collection and analysis can deeply influence the final result. We put in evidence some typical pitfalls that the researcher should avoid when planning the test and analysing data. A comparison between the most utilized techniques in sensory data processing for shelf life prediction is reported, taking as a fil rouge the case of coffee. In particular, a non-linear regression, a logistic regression and a survival models were applied to simulated data frames of coffee. We evaluated the influence of the choice of acceptability limits, as well as the effect of data variability and we found out that they strongly influence predictions, as well as the panel and the batch of product do. We suggest that in case of microbiologically stable food, like coffee, shelf life is not univocal and it is a choice of the company or the researcher, rather than the result of the interaction between product and consumer.     

图像分析技术预测吐司面包质构及感官评价模型的建立

对吐司面包切片利用C-Cell仪器分析内部纹理结构,同时利用质构仪测定面包切片的质构数据（硬度、弹性）以及通过感官评价获得相应评价分数。通过对以上数据进行回归分析,我们得到了显著性极高的利用C-Cell数据预测硬度（模型1）及弹性（模型2）数据与感官评价得分（模型3）的预测模型,在模型验证中预测值与实际值数据之间无显著性差异,说明在统计学上该模型能够很好的利用C-Cell数据对硬度、弹性和感官评价结果进行预测,该预测模型方法的建立能够快速、客观、定量及可重复的对吐司面包进行综合的评价。     

A comparison of sensory attribute use by children and experts to evaluate chocolate

Children constitute a complex but interesting market for the food industry. The objective was to compare the sensory attributes generated and rated by a panel of 261 children from 9 to 11 years old with those of a trained panel of 10 adult experts in the food industry, using a range of eight chocolate products belonging to the child segment. In a first phase, a subgroup of 27 children went through attribute generation according to the Kelly-grid method to establish a questionnaire of 13 attributes. The experts used the QDA method to set up a questionnaire of 27 attributes. Data were analysed to find out relationships between attributes, using Partial Least Square regression with experts' attributes as explicative variables and children's attributes as variables to be explained. Surprisingly, some of the attributes most cited by children are not those better explained by experts' attributes.     

The sensory optimum of chicken broths supplemented with calcium di-glutamate: A possibility for reducing sodium while maintaining taste

This study examined the effects of calcium di-glutamate (CDG) supplementation on the sensory and hedonic characteristics of chicken broth. Thirty-four normal weight men and women aged 20-35 years tasted 12 soups containing 4 different concentrations of sodium chloride (.16%, .53%, .85%, and 1.7% w/w) and three concentrations of CDG (0%, .17%, and .33% w/w). Participants tasted all the soups twice over 2 days and used computer-administered visual analog scales to record taste intensity and hedonic ratings. Soups were presented in random order, at least 3 min apart to allow for taste ratings and mouth rinsing. Data were analyzed using repeated measures analysis of variance. Response surface methodology (RSM) was used to determine the hedonic optima for sodium chloride and CDG. Results indicated that CDG could partly replace sodium chloride at constant levels of liking and pleasantness. These data provide evidence that lower sodium broths can be made more palatable with CDG supplementation.