Addition of peppermint oil slightly increased oxidative stability with noneffect on protein network. Microstructure of low‐fat set yogurts containing microemulsions showed a more compact and dense structure compared to control. Yogurt enriched with blended oil microemulsions was lower in viscosity than other samples with decreasing in firmness along storage time. The viscosity was increased with all yogurts enriched with carboxymethyl cellulose (CMC) and pullulan microemulsions. Fortification of low‐fat set yogurt samples with microemulsions of tuna oil and peppermint oil blend had a significant effect on the retention of docosahexaenoic acid and eicosapentaenoic acid. The microencapsulation process was an important factor to maintain somewhat on the stability of the color for yogurt, in addition to increase water holding capacity and to decrease syneresis during cold storage as well. Moreover, the microencapsulation process in collaboration with peppermint oil increased of sensory characteristics of yogurt, continued presence of mint flavor, and mask fishy flavor until the end of cold storage.
Practical applications
Dairy products are an excellent delivery vehicle for omega‐3 oils. Despite this, omeg‐3 oils are susceptible to oxidative deterioration, which causes not only “fishy” off‐flavors but also might lead to many health problems. The aim of this study was to develop a low‐fat set yogurt enriched with microemulsions of tuna oil only or with tuna oil–peppermint oil blend formed using whey protein isolate as emulsifier and CMC or pullulan as stabilizers. Also, to evaluate the potential impact of microencapsulation process and addition of peppermint oil on the physiochemical, microbiological, rheological, and sensorial characteristics of low‐fat set yogurt enriched with omega‐3 oil.