Publications in year 2014

Vol. 21, Issue 4



Optical properties of whey protein isolate films with the addition of selected plant oils

International Agrophysics
Year : 2014
Volumen : 21
Issue : 2
Pages : 131 - 141
  PDF 234.77 KB
Authors: Sabina Galus1, Justyna Kadzińska1

1Department of Food Engineering and Process Management, Faculty of Food Science, SGGW – Warsaw University of Life Sciences ul. Nowoursynowska 159C, 02-776 Warszawa
Abstract :

The aim of this study was to investigate the effect of the addition and the content of rapeseed oil, pumpkin seed oil, and hazelnut oil on the optical properties of whey protein films. The films were prepared from 10% aqueous film-forming solutions of whey protein isolate and 50% (w/w of protein) addition of glycerol as the plasticiser. Plant oils at 0, 1, 2, and 3% were added to the mixture and homogenised until homogenous emulsion was obtained. Film-forming solutions at constant amount of volume were poured out on Petri dishes and dried at 25ºC and 50% relative humidity during 24h. Colour was analysed in the CIE L*a*b* system with parameter of total colour difference. Opacity was analysed at a wavelength of 600 nm. The addition of plant oils to film forming solutions caused that all films obtained were matt and opaque. There was observed a decrease in lightness of films with an addition of pumpkin seed oil and an increase of this parameter for films with an addition of hazelnut oil. There were obtained lower values of parameter a* and higher of parameter b* with increase in the concentration of pumpkin seed oil and hazelnut oil. The increasing concentration of plant oils caused an increase of the values of total colour difference and opacity at wavelength of 600 nm for all investigated whey films.

Keywords : edible films, whey protein, plant oils, colour, opacity
Language : Polish