Examination of phisical parameters of pectin gels extracted from fruit presscakes

In our study we aimed to investigate the rheologieal and colour characteristics of the pectin gels extracted from presscakes of berries. The pectins extracted from the presscakes of five different fruits such as black-currant, red-currant, raspberry, blackberry and elderberry, were used for the examinations. Tw o commercial materials were applied as controls: apple and citrus pectins. The rheologieal examinations showed that the pectins obtained from the red-currant presscake have the best gelificator properties. The analysis of the colour coordinates revealed that the gel of the citrus pectin used as control is very clear and translucent such as the pectin gel of the red-currant. The pectin gels of black-currant, blackberry, elderberry and raspberry contain a significant amount of colourants, in this way they are very dark

Method and problem of optical investigation of food colors

The Lambert-Beer law relating to the absorption of optical emission allows the quantitative and qualitative examination of food products, semi-finished products and raw materials whose production can be followed optically. This paper examines the possibilities of food engineering quality analyses with this physical method, the results of the locally developed computerized spectrum analysis, and the restrictions of the applicability of this method, with special emphasis on confectionery colouring substances

The effect of grain size on the colour characteristics of durum semolinas

Pastas made of durum flour are becoming more prevalent also in our country , no eggs are needed for their preparation. The colour of the pasta produced this way is determined essentially by the colour of the durum semolina. Also in industrial practices instrumental colour analysis is applied for the colour qualification of durum semolina. In our work we examined how the grain size influences the colour characteristics and ash content of durum wheat grindings. The correspondence between the ash content and the colour characteristics was also analysed. Durum semolina from 12 different production units were used for our measurements. The semolina were produced from the yields of 2007 and 2008. The grindings were separated into different grainsize fractions by screening. The L*. a* . b* colour coordinates defined in the CIELab colour space were applied for the colour characterization. The measurements were carried out using a Hunter Miniscan colour analyser. The data was analysed applying variance analysis and regression analysis. On the basis of the obtained results we can establish that the grain size significantly influences (p<0.05) the L* lightness the a* redness and the b* yellowness coordinate as well as the variation of the YI yellowness index. When the grain size increases, the L* lightness coordinate decreases. The difference is the biggest between the means of the 0-160 nm and the 160 (im -250 nm fractions though even in the other cases the difference is at least 1 unit. Hence the bigger grains are darker. The a* redness coordinate, the b* yellowness coordinate and the YI yellowness index increases when the grain size increases. On the average the a* coordinate increases by 0.4 unit the b'coordinate by 3-4 units while the YI yellowness index by 5 units. Thus the colour of bigger grains is slightly redder and significantly yellower. The ash content decreases with the increase of the grain size. The mean ash content varied between 0.7-1.1%. The ash content of the whole grinding is equal to that of the 315 nm -500 nm fraction. The difference between the ash content of the subsequent grain size fractions is 0.1% on the average. Also the results have shown that there's a significant linear correlation between the ash content and each colour characteristic. (p<0.01)

Mai és régi idők tenisze A nem teljesen kitöltött páros összehasonlítás mátrixok egy alkalmazása

A többtényezős döntési módszertan egyik fontos eszköze a páros összehasonlítás. Preferenciasorrendek meghatározására, adott tényező szerinti értékelések számszerűsítésére egyaránt felhasználják a páros összehasonlításokból kapott mátrixokat. Tanulmányunk egy viszonylag új kutatási területtel, a nem teljesen kitöltött páros összehasonlítás mátrixok alkalmazásával foglalkozik. Az elmúlt 40 év egymás elleni eredményei alapján profi teniszjátékosok rangsorait adjuk meg. Mivel a játékosok közül nem mindenki játszott mindenkivel, ezért – különböző feltételek mellett – az eredmények nem teljesen kitöltött páros összehasonlítás mátrixokhoz vezetnek. Számításaink nem csak jól értelmezhető rangsorok létrehozására vonatkoznak, hanem a mátrixok bizonyos tulajdonságainak a rangsorokra gyakorolt hatását is megvizsgáljuk

On the coincidence of optimal completions for small pairwise comparison matrices with missing entries

Incomplete pairwise comparison matrices contain some missing judgements. A natural approach to estimate these values is provided by minimising a reasonable measure of inconsistency after unknown entries are replaced by variables. Two widely used inconsistency indices for this purpose are Saaty's inconsistency index and the geometric inconsistency index, which are closely related to the eigenvector and the logarithmic least squares priority deriving methods, respectively. The two measures are proven to imply the same optimal filling for incomplete pairwise comparison matrices up to order four but not necessarily for order at least five.Comment: 10 pages, 1 figur

On the coincidence of optimal completions for small pairwise comparison matrices with missing entries

Incomplete pairwise comparison matrices contain some missing judgements. A natural approach to estimate these values is provided by minimising a reasonable measure of inconsistency after unknown entries are replaced by variables. Two widely used inconsistency indices for this purpose are Saaty’s inconsistency index and the geometric inconsistency index, which are closely related to the eigenvector and the logarithmic least squares priority deriving methods, respectively. The two measures are proven to imply the same optimal filling for incomplete pairwise comparison matrices up to order four but not necessarily for order at least five

An application of incomplete pairwise comparison matrices for ranking top tennis players

Pairwise comparison is an important tool in multi-attribute decision making. Pairwise comparison matrices (PCM) have been applied for ranking criteria and for scoring alternatives according to a given criterion. Our paper presents a special application of incomplete PCMs: ranking of professional tennis players based on their results against each other. The selected 25 players have been on the top of the ATP rankings for a shorter or longer period in the last 40 years. Some of them have never met on the court. One of the aims of the paper is to provide ranking of the selected players, however, the analysis of incomplete pairwise comparison matrices is also in the focus. The eigenvector method and the logarithmic least squares method were used to calculate weights from incomplete PCMs. In our results the top three players of four decades were Nadal, Federer and Sampras. Some questions have been raised on the properties of incomplete PCMs and remains open for further investigation.Comment: 14 pages, 2 figure