Effect of Thymus haussknechtii and Origanum acutidens essential oils on the stability of cow milk butter

Abstract

The aim of this study was to investigate the effects of different essential oils (from Thymus haussknechtii Velen and Origanum acutidens Hand.-Mazz. Letswaart; endemic species in Turkey) on butter stability. These essential oils were added to butter at two concentrations (0.1 and 0.2 wt-%). The antioxidant activities of the essential oils were compared with control samples (without antioxidant) and containing butylated hydroxytoluene (BHT). All samples were stored at 4 6 1 7C for 90 days and their peroxide values (PV), thiobarbituric acid (TBA) values, % titratable acidity and some microbiological properties were analyzed. As a result, the lowest PV and TBA values were determined in the samples containing BHT and 0.2% essential oils; however, TBA and PV were at the highest levels in the control samples during storage. The amount of 0.2% of essential oils exhibited strong antioxidant activity, which was almost equal to that of BHT. T. haussknechtii essential oil showed a stronger antioxidant effect as compared to O. acutidens. None of the essential oils showed remarkable antifungal activity. However, the antimicrobial activity of O. acutidens on coliform bacteria was found to be higher than that of T. haussknechtii. Sensory analysis of the butter showed that the samples containing 0.2% essential oils had lower flavor scores than those with 0.1% essential oils. The present results indicate that these essential oils can be considered as an alternative source of natural antioxidants in the manufacture of butter.

Tereyağı Stabilitesi Üzerine Çörekotu (Nigella sativa L.) Uçucu Yağı Kullanılabilirliğinin Araştırılması

“…Control sample showed the highest value (Table 1). Our results were in agreement with Dagdemir et al [8] who indicated that there were no significant differences between Thymus haussknechtii, Origanum acutidens 0.2 and 0.1%, BHT and control butter samples on the 60 th day of storage. Antioxidant activity of N. sativa L., using two TLC screening methods showed that thymoquinone, carvacrol, t-anethole and 4-terpineol demonstrated important radical scavenging property [17] .…”

“…The lowest LAB count was found 5.65±0.07 in NS3 sample (0.2% essential oil) at the end of the storage period (Table 2). This result was in agreement with studies by Ozkan et al [38] and Dagdemir et al [8] who indicated, respectively, that the LAB counts of butter samples containing Saturaja cilicica essential oils and T. haussknechtii and O. acuditens were decreased. It can be concluded that the concentration of essential oil was an important factor of the growth of coliform bacteria.…”

“…That is why researchers have been focusing on new natural sources that have high antioxidant activity and harmless for health to prolong shelf-life and to increase food stability [7][8][9] . Nigella sativa L. belongs to Ranunculaceae family, which is commonly known as "black cumin" in English and "çörekotu" in Turkish.…”

“…The TBA value was calculated by using a standard curve [8] . The TBA value was the estimated as mg malonaldehyde/kg butter.…”

“…The peroxide value (PV) was determined according to the method described by Atamer [27] and Dagdemir et al [8] . PV is expressed as milliequivalents (meq) of active oxygen per kg of butter.…”