An investigation about the release of microencapsulated Melissa officinalis oil in the yogurt using DLLME/gas chromatography

Today, Melissa essential oil has been drawn a lot of attention in food researches. This essential oil has good antioxidant and antimicrobial activity, so it is a good candidate to incorporate in the nutritional and biological systems. The aim of this study was to investigate the release of Melissa essential oil (encapsulated via isolated proteins and sodium caseinate) in yoghurt by dispersive liquid-liquid microextraction (DLLME) /gas chromatography technique. In this study, yogurt samples with different percentages of essential oil (0, 0/75, 1/5 g/l) were prepared by sonication method. The effect of two factors, including storage time (1, 11 , 21 days) and the percentage of encapsulated essential oil on the gas chromatography profile were studied based on the central composite design (CCD). 10 grams of yogurt samples containing various percentages of essential oil was centrifuged and the liquid part was passed through a sterilization filter. The released essential in the yogurt was extracted (from the liquid part) by DLLME method and was injected into the gas chromatography and its chromatographic profile (total peak area and total peak height) was investigated. The results show that there is a significant relationship between the total peak area and the amount of essential oil released into the yogurt. By studying total peak area in chromatography, it is possible to estimate the amount of essential oil released into the yogurt sample, and it is possible to study the rate of release.