Browsing by Subject "camelinaöljy"

Lipid oxidation presents one of the most important challenges for the processing and storage of edible oils by lowering the shelf life, nutritional value, and organoleptic properties of oils. Microencapsulation is a process where oil droplets are coated within a wall material matrix, and it offers a suitable solution to protect edible oils against oxidative deterioration. This study aimed at exploring the effects of wall material composition and relative humidity (RH) on the potential of microencapsulation to protect camelina and blackcurrant seed oils against lipid oxidation. Camelina and blackcurrant seed oils were emulsified using whey protein isolate (WPI) and maltodextrin (MD) as wall materials in 1:1, 1:3, and 1:9 ratio, and the total solids content and wall-to-oil ratio were kept constant. Microencapsulation was conducted by spray drying, and various parameters were analyzed, including emulsion viscosity, water sorption properties, and the surface oil content of microencapsulated powders. The powders were conditioned at 11% and 44% RHs at 21 °C, after which the sample vials were closed to maintain constant water content. The oxidative stability of the conditioned microencapsulated powders was analyzed over 10 weeks of accelerated storage conditions at 40 °C by measuring the volatile secondary lipid oxidation products every two weeks by headspace-solid phase-microextraction-gas chromatography-mass spectrometry method. The results showed that the best oxidative stability during the storage period was obtained by WPI-MD 1:1 ratio in both of the microencapsulated oils, even though this wall material composition resulted in the highest surface oil content and the lowest encapsulation efficiency. In blackcurrant seed oil powders, the water content obtained at 44% RH seemed to provide better protection against lipid oxidation than that of 11% RH. Regarding camelina oil powders, water content obtained in different RHs did not seem to affect the oxidative stability of the powders. However, based on the peak areas of volatile compounds detected at week 10, the water content obtained at 44% RH might provide better storage stability for camelina oil containing powders in long-term storage than that of 11% RH.