Fiorella Sinesio

Attitudes, habit, sensory and liking expectation as determinants of the consumption of milk

A total of 111 subjects took part in a survey in which attitudes, habits, surveyed ratings of liking and of sensory attributes, and consumption frequency of the three types of milk, skimmed, semi-skimmed and whole fat, were studied. The frame of reference for design and analysis was based in part on the Fishbein and Ajzen model of reasoned action. Habit was found to be more important than attitude in the prediction of the behavioural intention. Liking was more important than intention for predicting behaviour with the exception of semi-skimmed milk for which the intention was equally important, whereas the inclusion of surveyed ratings of sensory/hedonic components for milk into the model failed to improve the prediction of attitude. The relationships between beliefs, evaluations and attitudes were examined.

Use of electronic nose and trained sensory panel in the evaluation of tomato quality

In this paper the performances of an electronic nose based on metalloporphyrin-coated quartz microbalance sensors and of an experienced panel of seven human assessors in the evaluation of gases derived from degradation reactions in tomatoes are presented and discussed. The performances are measured in terms of the capability of both systems to distinguish between samples of different quality coming from conventional and organic production systems. The study deals with the application of pattern recognition techniques based on either multivariate statistical methods (PCA, GPA) or artificial neural networks using a self-organising map (SOM). The response pattern of the sensor array and the sensory data are analysed and compared using these methods. Similarities in the classification of the data by electronic nose and human sensory profiling are found.

Electronic nose and sensorial analysis: comparison of performances in selected cases

Abstract Sensorial analysis based on the utilisation of human senses, is one of the most important and straightforward investigation methods in food analysis. It provides a unique information about the ‘food–man interaction’. Nevertheless, human senses, when considered as instruments, show several problems of reproducibility, stability and difficulties of expression, making it very hard to compare results between different panels. The electronic nose has been proven to be sufficiently accurate as an artificial approximation of the human olfaction apparatus when applied to well defined problems in food analysis. In this paper results obtained for tomato pastes and milk analysis, comparing a panel of tasters and an electronic nose will be presented and discussed.

Sensory evaluation of walnut fruit

Abstract The paper provides an in-depth examination of the sensory differences between cultivars of walnut fruit (Juglans regia L.) from different countries. Eighteen samples, belonging to three clonal cultivars, plus some other genetic selections, collected from five European countries (France, Greece, Italy, Portugal and Spain) were analyzed for their sensory characteristics by a panel trained in Descriptive Analysis (DA). Fifteen descriptors were selected to describe the fruits, covering the following attributes: external appearance of the shell and kernel, colour, visual, manual and oral texture, taste and flavour. Principal Component Analysis (PCA) adequately reduced the multidimensional structure of the data and distinguished the regions of origin of the walnut samples more effectively than the cultivars. Generalized Procrustes Analysis (GPA) was also included to describe relationships between samples and to evaluate assessor performance.

Qualitative data analysis for an exploratory sensory study of grechetto wine

Grechetto is a traditional white-grape vine, widespread in Umbria and Lazio regions in central Italy. Despite the wine commercial diffusion, little literature on its sensory characteristics is available. The present study is an exploratory research conducted with the aim of identifying the sensory markers of Grechetto wine and of evaluating the effect of clone, geographical area, vintage and producer on sensory attributes. A qualitative sensory study was conducted on 16 wines, differing for vintage, Typical Geographic Indication, and clone, collected from 7 wineries, using a trained panel in isolation who referred to a glossary of 133 white wine descriptors. Sixty-five attributes identified by a minimum of 50% of the respondents were submitted to a correspondence analysis to link wine samples to the sensory attributes. Seventeen terms identified as common to all samples are considered as characteristics of Grechetto wine, 10 of which olfactory: fruity, apple, acacia flower, pineapple, banana, floral, herbaceous, honey, apricot and peach. In order to interpret the relationship between design variables and sensory attributes data on 2005 and 2006 wines, the 28 most discriminating descriptors were projected in a principal component analysis. The first principal component was best described by olfactory terms and the second by gustative attributes. Good reproducibility of results was obtained for the two vintages. For one winery, vintage effect (2002-2006) was described in a new principal component analysis model applied on 39 most discriminating descriptors, which globally explained about 84% of the variance. In the young wines the notes of sulphur, yeast, dried fruit, butter, combined with herbaceous fresh and tropical fruity notes (melon, grapefruit) were dominant. During wine aging, sweeter notes, like honey, caramel, jam, become more dominant as well as some mineral notes, such as tuff and flint.

Quality assessment of baby food made of different pre-processed organic raw materials under industrial processing conditions

The market for processed food is rapidly growing. The industry needs methods for “processing with care” leading to high quality products in order to meet consumers’ expectations. Processing influences the quality of the finished product through various factors. In carrot baby food, these are the raw material, the pre-processing and storage treatments as well as the processing conditions. In this study, a quality assessment was performed on baby food made from different pre-processed raw materials. The experiments were carried out under industrial conditions using fresh, frozen and stored organic carrots as raw material. Statistically significant differences were found for sensory attributes among the three autoclaved puree samples (e.g. overall odour F = 90.72, p < 0.001). Samples processed from frozen carrots show increased moisture content and decrease of several chemical constituents. Biocrystallization identified changes between replications of the cooking. Pre-treatment of raw material has a significant influence on the final quality of the baby food.

Comparison of multivariate methods of analysis to evaluate panellists' performance

Abstract To evaluate the effectiveness of training, performance monitoring of assessors is necessary. This study shows how multivariate statistical analysis may be used to explore the effect of training in improving assessors ability. Ten non-experienced assessors were asked to measure descriptive flavour and texture parameters in brands of frozen and canned peas. Sensory evaluations were made before and after training. Principal Component Analysis (PCA) and Cluster Analysis (CA) were carried out to explore the homogeneity of behaviour among panellists.

A comparison between an electronic nose and human olfaction in a selected case study

An electronic nose is now becoming available as a commercial product. Nevertheless its performances are not fully understood and interpreted. Also the differences between electronic noses and the human olfaction have not yet been sufficiently studied. This is an important issue in many industrial sectors, such as food analysis. In this paper a comparison between the performances of an electronic nose and a panel of human tasters is presented in a selected case (tomato paste). An extensive set of tools for data analysis was available. A number of chemometrics based methods (principal component analysis and cluster analysis) and neural networks (feedforward backpropagation trained networks, self organizing maps, adaptive resonance theory based networks) have been utilized to analyze electronic nose data in order to extract the relevant information. The electronic nose and the human panel show strong similarities but the former displays a more concise classification capability for the data.

How to understand the complexity of product quality and the challenges in differentiating between organically and conventionally grown products—exemplified by fresh and heat-processed carrots (Daucus carota L.)

Quality traits are highly focused upon in the marketing of organic food products. There is a need to define and measure quality as consumers seem to have preconceived notions about the superior health value and taste of organic compared to non-organic products. A commonly held opinion among many consumer groups is that organic farming guarantees optimum quality, despite the fact that this remains unproven. The aim of this paper is to contribute to a better understanding of the complexity of quality traits in a plant-based food product, using carrots as an example. Selected designated quality aspects are presented to describe the complexity of quality and discuss the challenges of using these aspects in differentiating between organic and conventional products. The paper concludes we have insufficient tools to be able to adequately authenticate organically produced carrots. The same may be the case for most vegetables and fruit products. Suggestions for further studies include the soil and location aspect (terroir), in order to trace a product back to its origin in an organically or conventionally farmed field by finding a unique fingerprint for chemical constituents of samples.

Capturing consumer perception of vegetable freshness in a simulated real-life taste situation

Consumer testing in re-created purchase or consumption contexts may produce results with a higher external validity than laboratory testing and be a valid alternative to consumer testing in real-life contexts. Hence, the present study evaluates the utility of a novel immersive approach in sensory consumer testing. An immersive multisensory room was designed to reproduce consumption conditions close to real life, with large wall screen projections, audio and olfactory stimuli and furniture consistent with the video scenario. Overall liking and perceived freshness of two vegetable products (salad tomato and wild rocket) at different storage time were evaluated by a group of volunteers, regular consumers of the products. Evaluations were performed both in a immersive environment setting - the scenario was the dining room of a holiday farm overlooking a patio and the countryside - and in a traditional sensory lab setting, as a control. The magnitude of liking was higher when evaluations were performed in the immersive environment setting than in the traditional lab setting. However, the discrimination efficacy for freshness and liking of stored and un-stored vegetables was reduced in the immersive environment with respect to the control lab. Additional research, aimed at exploring other products and other consumption or purchase immersive scenarios, will further clarify whether these findings are product-dependent or determined by the contingent immersive situation.