Abstract
Whey protein hydrolysate (WPH) has functional food potential. However, the bitter taste
and high hygroscopicity of WPH may limit its application to use as food ingredients.
To reduce the shortcomings of WPH, it was encapsulated by γ-cyclodextrin (γ-CD)
as inclusion complexes. The aim of this work was to study the effect of inclusion
conditions on the various properties of spray dried inclusion complex of WPH/γ-
cyclodextrin. Effects of incubation temperature (20-50 °C), incubation time (3-9 hr)
and mixing ratio between γ-CD and WPH (20:80, 40:60 and 60:40) were studied.
Spray drying of WPH/γ-CD inclusion complexes were operated at an inlet temperature
of 180°C to produce the encapsulated WPH powder. The properties of encapsulated
WPH powder including moisture content, bulk density, particle size distribution,
solubility, morphology, color values, surface hydrophobicity, bitterness and
hygroscopicity were investigated. It was found that all of encapsulated WPH showed
the better properties than non-encapsulated WPH, especially hygroscopicity and
bitterness. The hygroscopicity of encapsulated WPH reduced in the range of 27.42%
to 57.67%, bitterness reduced in the range of 51.61% to 89.78% compared to that
of non-encapsulated WPH. For the incubation time effect, moisture content and
bitterness score of encapsulated WPH decreased with decreasing of incubation time.
The incubation temperature did not significantly affect on various properties of
encapsulated WPH. For the effect of ratio between WPH and γ-CD, higher content of γ-CD
led to lower values of hygroscopicity and bitterness score. From the results in this study,
encapsulation of WPH by inclusion method and spray drying improve the characteristics
of whey protein hydrolysate used as food ingredients in a variety of food products.
