Authors:Tímea Kaszab, Ferenc Firtha, and András Fekete
The objective of the work reported here was to determine changes in the moisture content, firmness characteristics, color attributes and NIR absorbance of two carrot cultivars during storage. There was a definite loss in the moisture content that caused changes in the firmness. This result shows that carrot firmness is very sensitive to the moisture content. The firmness — especially the cutting force — is a good characteristic for predicting changes in carrot moisture content during storage. The color characteristics — a* and b* — showed a slight change in the function of the moisture content. However, these color characteristics are suitable for distinguishing the phloem and xylem parts of carrot cultivars. There were not found definite changes in the NIR absorbance as the function of the moisture content. Consequently, the specific cutting force and the impact stiffness coefficient are good characteristics of the carrot moisture content and the mass reduction during storage under non-ideal conditions.
Authors:Zoltán Kovács, Dániel Szöllősi, and András Fekete
The objective of the research was to compare the taste attributes of different commercial soya drinks. Furthermore, the task was to determine the effect of different ingredients and processing technologies on the taste attributes of the product. Based on the results of electronic tongue measurements the instrument is able to determine the effect of the applied technology and to distinguish soya juice samples according to sensory preferences. Canonical discriminant analysis showed that the groups of two measurements of the same products were overlapping. Therefore, the electronic tongue measurements are supposed to be of acceptable repeatability. The canonical discriminant analysis showed that the taste attributes of soya juice made of hulled soybeans was beneficial for the taste attributes relative to that of the juice made of not-hulled soybeans. Three main groups could be observed from the analyzed six commercial soya drink samples based on canonical discriminant analysis. There is a group of top market brands having definite taste improver additives and another one containing three products having low amount of additives. However, the group of samples made of soybean and rice is located between the above-mentioned two groups in the discriminant score plot.
Authors:István Dalmadi, Dávid Kántor, Kai Wolz, Katalin Polyák-Fehér, Klára Pásztor-Huszár, József Farkas, and András Fekete
High hydrostatic pressure (HHP) processing technology offers the possibility to preserve quality attributes. Objective test methods describing quality in a complex form have an important role in the development of new products and in the quality assurance of different technologies. Therefore, research was performed to compare the effects of HHP treatment and heat pasteurization on visual appearance, volatile composition, taste and texture properties of strawberry purees measured by sensorial and objective methods. Sensory evaluation did not show significant differences between samples. Similar result was obtained from the color measurements. Viscosity of purees changed only slightly as a result of the treatments. Electronic nose and electronic tongue were found to be promising tools for discrimination of strawberry purees treated by different levels of high hydrostatic pressure or thermal treatment. Canonical discriminant analysis showed that control and “600 MPa for 5 minutes” samples were quite similar. Samples treated by 600 MPa for 15 minutes were distinguished from the above mentioned ones. The heat treated samples (80°C for 5 and 15 minutes) were definitely separated from the control samples. Fusion of the data from the electronic nose and tongue showed the same trend and improved the classification of the treated puree samples.