USE OF ESSENTIAL OIL FOR NIGELLA (Nigella sativa) AND SPEARMINT (Menthaspicata) TO PROLONG SHELF LIFE DURATION OF SOFT WHITE CHEESE

Abstract

The effects of essential oilNigella sativa and Menthawas study on the chemical, microbial and sensory properties for soft white cheese that produced from it during storage at 0, 7 and 14 days .The results show significantly percent decrease in moisture for all samplesand maximum decrease was at the latest storage period for all them .The reduced in moisture was accompanied with increase in percentage of protein and fat during of storage period for all samples.
The control sample showed increased in bacterial logarithmic for total count bacterial, coliform, Staphylococcus aureus, proteolytic bacteria, lipolytic bacteria and mold and yeasts during of storage period , the highest results showed at the latest storage period 14days, it was 8, 4.96, 4.43, 4.43, 4.33 and 4.23 cfu/g respectively, these numbers were significantly decrease when nigella and spearmint was added compared with control sample at zero time for all microorganisms and it reach at the end of storage periodto be 6.29, 2.54, 1.95, 2.2, 1.91 and 1.3 cfu/g and 6.28, 2.76, 2.27, 1.69, 1.94 and 1.47 cfu/g for soft white cheese respectively.
The acidity value was significantly increase during storage periods for all cheese samplescontrol, Nigella and Spearmint to reach after 14days to be 0.67, 0.79 and 0.93% respectively. The pH value was reduced for all samples to reach at the end of duration of storage 5.21, 5.35 and 5.43 respectively,accompanied of change in total acidity and pH increase in the numbers of lactic acid bacteria during of storage periods, to reach at the end of storage to be 4.42, 3.72 and 3.5 cfu/g respectively.
The results indicate the superiority of the cheese sample added spearmint oil in sensory properties which included flavor, color, texture and bitterness during of storage periods compared with cheese added nigella oil and the control sample.