Determination of the changes in oxidative stability of sunflower oil used in frying the dough containing encapsulated carvacrol

In this study, encapsulated or unencapsulated carvacrol was added to the sunflower oil and the dough and used in repeated deep frying experiments. Carvacrol (5%) was added into the mixture composed of Gum Arabic (GA), maltodextrin (MD) and modified starch and the coarse emulsion was prepared by using a high speed homogenizer. The emulsion was powdered by using spray dryer used in the experiments. The size of the particles was lower than 20 μm. Encapsulated carvacrol, which was encapsulated with 3 selected shell materials with the highest encapsulation activity, was used as antioxidant in frying experiments. Among these, the microcapsules composed of 100% GA has the highest encapsulation efficacy value (66.24%), while those of GA + MD (75:25) and [Starch + (GA + MD, 3: 1), 1: 9] were 60.8% and 62.0%, respectively. The effect of carvacrol fortification into the sunflower oil and dough, in encapsulated or unencapsulated forms, on the oxidative status of sunflower oil samples taken from each of the fifth frying was evaluated during repeated (25 times) frying experiments. Compared to other shell materials, the lowest conjugated diene formation was provided by carvacrol encapsulated with [Starch + (GA + MD, 3: 1), 1: 9]. The same antioxidant structure also lowered the peroxide and secondary oxidation products formation. This finding was also supported by TOTOX value. The addition of carvacrol to the oil in the form of microcapsules prevented the oxidation of linoleic acid significantly. L* value of the sunflower oil was superior with carvacrol encapsulated with [Starch + (GA + MD, 3: 1), 1: 9] during repeated dough frying experiments. The results obtained from frying experiments were analyzed by Principal Component Analysis (PCA) and the PCA graph evidently discriminated the differences between the applications. There was a clear discrimination between frying batches in terms of the effect of encapsulated and unencapsulated carvacrol which was added to sunflower oil or dough. It was found that the addition of carvacrol into the oil in encapsulated forms with selected 3 shell materials, was found to be superior to the others. Therefore, the use of encapsulated carvacrol as an antioxidant may be recommended in deep frying processes.