László Sipos

Discrimination of mineral waters by electronic tongue, sensory evaluation and chemical analysis.

Mineral, spring and tap water samples of different geographical origins (7 classes) were distinguished by various methods, such as sensory evaluation, electronic tongue measurement, inductively coupled plasma atomic emission spectroscopy and ion chromatography. Samples from the same geographical origin were correctly classified by chemical analysis and electronic tongue (100%), but it was found that only 80% classification rate can be achieved by sensory evaluation. Different water brands (different brand names) from the same geographical origin did not show definite differences, as expected. Forward stepwise algorithm selected three chemical parameters namely, chloride (Cl(-)), sulphate (SO(4)(2-)) and magnesium (Mg) content and two electronic tongue sensor signals (ZZ and HA) to discriminate according to the geographical origins.

Sweetener Recognition and Taste Prediction of Coke Drinks by Electronic Tongue

Natural and artificial sweetener monitoring methods are getting more important, since soft drinks with low energy play a considerable role in the market. Our objective is to describe the relevant sensory attributes and to determine the applicability of the electronic tongue to discriminate the coke drink samples with different sweeteners. Furthermore, the aim is to find a relationship between the taste attributes and measurement results received by the electronic tongue. An Alpha astree electronic tongue and a trained sensory panel are used to evaluate coke samples. Panelists found significant differences between the samples in 13 cases from the 18 sensory attributes defined previously by the consensus group. The samples are definitely distinguished by the electronic tongue. The main difference is found according to the sweetener content of the samples. The electronic tongue is able to distinguish samples containing different kinds of artificial and natural sweeteners, as well. The electronic tongue is able to predict, by the partial least squares regression method, the taste attributes of the coke drinks determined by the sensory panel with close correlation and low prediction error.

Make a choice! Visual attention and choice behaviour in multialternative food choice situations

This study investigates the relationship between gazing behaviour and choice decision in multialternative forced choice tasks, focusing on the consistency across different food product groups including apple, beer, bread, chocolate, instant soup, salad, sausage, and soft drink. Each choice task consisted of pictures of four alternatives, similar in familiarity and liking ratings, of the corresponding product group. A Tobii T60 eye-tracker was used to present the stimuli and to analyse the gazing behaviour of 59 participants during decision-making. The results showed strong correlations between choice and gazing behaviour, in forms of more fixation counts, longer total dwell duration, and more dwell counts on the chosen alternative. No correlations for first fixation, time to first fixation, and first fixation duration were observed. These results were consistent across the eight tested product groups.

Coherences of Instrumental and Sensory Characteristics: Case Study on Cherry Tomatoes

The aim of this study was to investigate 6 cherry tomato varieties in terms of morphological, instrumental, and sensory attributes. Hungarian cherry tomato landraces have not been investigated in comparison with new commercial varieties for these traits. Parameters investigated were water-soluble antioxidant capacity (FRAP, DPPH, and TEAC), and total polyphenol, vitamin C, β-carotene, lycopene, total soluble solids, and acid contents. Colorimetric measurements as well as sensory analyses were conducted. It was concluded that varied antioxidant assays should be used in parallel to overcome the selectivity of any 1 method. Total phenolic content significantly contributed to results of antioxidant assays for the investigated varieties. The sensory profiles of the 6 cherry tomato varieties have been created. The differences between the products based on the 18 attributes were analyzed by Tukey post hoc test. The biplot of the principal component analysis showed that the sensory panel could discriminate the samples along the principal components. No correlation was found between colorimetric data a* and b* measured from pulp and lycopene, but a negative connection of β-carotene and hue was noted. Total polyphenol content showed correlations with colorimetric results, except for b*. The influence of tomato skin color on color perception is significant as in the present study instrumental data measured from pulp did not match that of the panelists evaluating intact fruit. Instrumental results of sugar content were supported by the ratings of the sensory panel.

Mineral Water Taste Attributes Evaluated By Sensory Panel And Electronic Tongue

The objective of the current research was to determine relationships between sensory evaluation and measurement results obtained by electronic tongue for mineral waters. Furthermore, the purpose was to predict the sensory characteristics of the mineral waters measured by the electronic tongue and to determine taste differences that cannot be detected by the sensory evaluation. Two mineral waters were definitely different from the others according to the sensory attributes based on profile analysis. With the electronic tongue measurements the PCA and CDA analysis were found to be able to discriminate mineral waters having chemical composition similar to each other. Very good correlation was found between the sensory attributes and the electronic tongue measurements. However, the results of the measurements performed with the electronic tongue showed a more accurate discrimination of the different mineral waters than the sensory evaluation.

Discrimination of mushroom disease‐related mould species based solely on unprocessed chromatograms

Agaricus bisporus A15 species (bisporic button mushroom) and its two main mould diseases (Mycogone perniciosa and Trichoderma aggressivum) were analysed using headspace solid‐phase microextraction sampling coupled with gas chromatograpy–mass spectrometry analysis. The presence or absence of mushroom disease‐related moulds can easily be detected and monitored in the air by headspace solid‐phase microextraction gas chromatograpy–mass spectrometry via their emitted microbial volatile organic compounds. Detrended fluctuation analysis (DFA) was first applied to distinguish different mould samples based on their unprocessed total ion chromatograms, which describe the air polluted by microbial volatile organic compounds. A two‐dimensional plot, generated from the results of DFA, visualizes the relationship of the analysed samples. The pattern found by DFA was compared with the pattern found by the traditionally applied principal component analysis. Cluster analysis (using Euclidean distance and Wards method) of the principal component analysis scores and DFA coefficients showed characteristic groupings. A methodology is introduced, which uses the unprocessed chromatogram, without any time‐consuming feature extraction and can indicate the presence of infected samples. The proposed methodology is able to give a support to the mushroom growers to indicate different mushroom disease‐related infection via air monitoring. Additionally, DFA is a sample‐independent and universal method. Hence, it can be also applied to distinguish unprocessed chromatograms produced by any other analytical equipment. Copyright

Sensory evaluation and electronic tongue for sensing flavored mineral water taste attributes.

In this article a trained sensory panel evaluated 6 flavored mineral water samples. The samples consisted of 3 different brands, each with 2 flavors (pear-lemon grass and josta berry). The applied sensory method was profile analysis. Our aim was to analyze the sensory profiles and to investigate the similarities between the sensitivity of the trained human panel and an electronic tongue device. Another objective was to demonstrate the possibilities for the prediction of sensory attributes from electronic tongue measurements using a multivariate statistical method (Partial Least Squares regression [PLS]). The results showed that the products manufactured under different brand name but with the same aromas had very similar sensory profiles. The panel performance evaluation showed that it is appropriate (discrimination ability, repeatability, and panel consensus) to compare the panels results with the results of the electronic tongue. The samples can be discriminated by the electronic tongue and an accurate classification model can be built. Principal Component Analysis BiPlot diagrams showed that Brand A and B were similar because the manufacturers use the same aroma brands for their products. It can be concluded that Brand C was quite different compared to the other samples independently of the aroma content. Based on the electronic tongue results good prediction models can be obtained with high correlation coefficient (r(2) > 0.81) and low prediction error (RMSEP < 13.71 on the scale of the sensory evaluation from 0 to 100).

Sensory evaluation and electronic tongue analysis for sweetener recognition in coke drinks

Consumption of beverages with low energy has an increasing role. Furthermore hydrolyzed starch products such as inverted syrup show a wide application in the beverage industry. Therefore the importance of methods which can monitor the usage of natural and artificial sweeteners is increasing. The task was to describe the relevant sensory attributes and to determine the applicability of the electronic tongue to discriminate the coke drink samples with different sweeteners. Furthermore the aim was to find relationship between the taste attributes and measurement results provided by electronic tongue. An Alpha Astree Electronic Tongue and a trained sensory panel were used to evaluate the coke samples. Panelists found significant differences between the samples in 15 cases from the 18 sensory attributes defined previously by the consensus group. Coke drinks containing different kind of sweeteners can be characterized according to these sensory attributes. The samples were definitely distinguished by the electr...

Longitudinal Study of Fruit and Vegetable Consumption in Hungary

We studied fresh and processed fruit and vegetable consumption of the last decade in Hungary on Hungarian Bureau of Statistics and GFK Hungaria household study data and on macro-economical data. Methodology difficulties have been explained in categorization of products during data collection. Long term data show increase despite ups and downs, but recent consumption level do not meet the expectations based on recent FAO/WHO suggestion, despite positive moral background and sporadic promotion campaigns in Hungary. Huge differences can be seen in consumption of different products between 1994 and 2004 in the fruit and vegetable category. As a whole, the consumption structure of vegetables is more stabile, but than of fruits. Consumption of processed products increased in case of fruits and vegetables, but the ratio of these products is still low and has minor effect on the total. Ratio of in-home processed products within the total category parallel decreased. It is advised that subcategory, or product level approach is necessary instead of repeated general fruit and vegetable promotion campaigns. Processing industry deserves more involvement from supply level here.