AN ASSESSMENT OF ANTIOXIDANT AND ANTIMICROBIAL EFFECTS OF LAVENDER (Lavandula angustifolia Mill.) AND CUMIN (Bunium persicum) ESSENTIAL OILS IN PRESERVATION OF BUTTER OF MILK

For the adverse effects that synthetic antioxidants have on human health and also due to the increasing willingness of consumers to use natural products, the efforts to replace synthetic preservatives with natural ones are growing. In the present study antioxidant and antimicrobial properties of bioactive compounds found in the herb lavender (Lavandula angustifolia Mill. essential oil, LAEO) and cumin (Bunium persicum essential oil, BPEO) were tested in butter of milk. LAEO (at levels of 1500, 2000 and 2500 ppm), BPEO (at levels of 5000, 7500 and 10000 ppm) and essential oils were added to butter of milk and then peroxide (PV) and thiobarbituric acid (TBA) values, acidity, microbial factors were evaluated and sensory evaluations were tested. According to Iranian standard (acceptable level of butter PV is 7/1 meq O2 kg-1 oil), these two essential oils showed to have good antioxidant properties until day 27. The results revealed that LAEO had higher antioxidant capacity than BPEO because of very low levels of PV. During 69 days of storage, TBA value in all levels of two essential oils were lower than control sample but the performance of BPEO at all 3 levels was better. Acidity of the samples during 69 days of storage, in samples containing BPEO at higher levels was better than other levels and also better than LAEO at all levels. The results indicated numerical differences in the number of colonies counted in butter containing essential oils revealing its capacity in preventing the growth of mold and yeast. It is also marked that on the 80th day, the number of colonies grown in butters containing BPEO was far less than in other samples. Sensory evaluation results showed that the highest score in color has been allocated to the sample containing LAEO (2500 ppm) and the best score in odor, taste and overall acceptability was in control sample. In all indices, butter containing LAEO had higher score in comparison with BPEO. In all indices (except of the color) LAEO at 1500 ppm had higher score in various levels of the two essential oils.