Search results for "Colour difference"
showing 3 items of 3 documents
Tomato peel drying and carotenoids stability of the extracts
2014
Summary Tomato peels were firstly dried by different methods (hot air, freeze-drying, and fluidized bed drying) to evaluate the recovery of lycopene, β-carotene and DPPH radical scavenging activity. Comparison of the results showed that hot air drying at 50 °C was a suitable method and alternative to freeze-drying to preserve carotenoids compounds and antioxidant activity in tomato peels. Then, ethanol/ethyl acetate (1:1) extracts from tomato peel, previously dried at 50 °C by hot air, were submitted to heat (100 °C) and light treatment (1000 lumen) to evaluate their stability as natural food dyes. Heating of the extracts caused a progressive reduction of total carotenoids, up to about 30% …
STUDY OF RASPBERRY EXTRACT APPLICATIONS AS TEXTILE COLORANT ON NATURAL FIBERS
2014
The present study deals with the biomordant assisted application of natural extracts obtained from red raspberry (Rubus idaeus L.) fruits onto two different cellulosic supports – flax and bamboo. The study relies on the improvement of multifunctionalities such as colour fastness, washing and rubbing fastness, due to the synergism provided by the co-assistance of both a biomordant, and the complex resulted by inclusion of the pigment molecule, in the cavity of MCT-β-CD; it is well known that natural dye molecule have a good selectivity binding to the hydrophobic monochloro-triazynil-cyclodextrin’s (MCT-β-CD) cavity to form inclusion complexes. An investigation system provided the characteriz…
Multispectral analysis and cone signal modelling of pseudoisochromatic test plates
2013
The aim of the study is to determine the consistency of the desired colour reproduction of the stimuli using calibrated printing technology available to anyone (EpsonStylus Pro 7800 printer was). 24 colour vision assessment plates created in the University of Latvia were analysed right after their fabrication on august 2012 and after intense use for 7 months (colour vision screening on 700 people). Multispectral imagery results indicate that the alignment of the samples after seven months of use has maintained on the CIExy confusion lines of deutan deficiency type, but the shift towards achromatic area in the diagram indicate decrease in the total colour difference (ΔE*ab) of test backgroun…