The effect of nutmeg (Myristica Fragrans) on the oxidative stability, sensory characteristics and microbiological quality of home-made mayonnaise

Abstract

Strategies to reduce the use of synthetic preservatives and their replacement with natural ones have become very common. Recently, the antimicrobial and antioxidant effect of nutmeg has been widely studied. In this experiment, the effect of different nutmeg powder concentrations ranged between 0% and 1.25% on oxidative stability, sensory characteristics and microbial quality of home-made mayonnaise. The samples were stored at room temperature for 12 weeks and tests were performed every 2 weeks to evaluate their oxidative stability and their microbial safety. Sensory analysis was performed at day 0 on 36 untrained panelists. Results revealed antimicrobial and antioxidative aspects of nutmeg on mayonnaise especially with the samples prepared with 1% and 1.25%. The pH value significantly (P < 0.05) decreased with increasing storage period. Its decreasing rates in mayonnaise samples prepared using 1.0 and 1.25% nutmeg were significantly (p< 0.05) lower than that in the control. Rise in acid values, anisidine and peroxide values was lower as the concentration of the nutmeg increased. After 12 weeks, acid values were 2.7 mg NaOH-1for 1% and 1.25% nutmeg, peroxide values were 7.6 and 6.4 meq kg -1for 1% and 1.25% nutmeg and anisidine values were 20.4 mmol kg-1 for 1% and 17.5 mmol kg-1. These results were significantly (p< 0.05) lower than the control sample that had 3.2 mg NaOH-1 , 17.4 meq kg -1and 24.4 mmol kg-1for the acid value, peroxide and anisidine respectively. At the first month of storage, mayonnaise samples prepared with nutmeg showed a better microbial quality than the control. However, after 6 weeks storage no viable microorganisms were detected mainly due to the decrease in pH. The mayonnaise prepared with 0.5% nutmeg was the most accepted among the panelists but the ones with 1% and 1.25% nutmeg revealed the best results concerning the microbial and the antioxidant activity.