Effects of lettuce (sativa Lactuca) and (Foeniculum vulgare) powder as a natural source of nitrate on the physical, chemical and microbiological properties and sensory evaluation of vacuum packed sausage

Due to the risks of using synthetic preservatives such as nitrite and its salts in meat products, there have been some efforts to reduce these synthetic preservatives in food. This study aimed to investigate the replacement of part of nitrite in 55% sausage formulation based on the conventional formula of a manufacturer.

For this purpose, Samples were produced with 120 ppm nitrite and a combination of lettuce and Foeniculum vulgare powder in four formulas including T1 (90 ppm nitrite+ 30 ppm lettuce and fennel powder), T2 (60 ppm nitrite+ 60 ppm lettuce and fennel powder), T3 (30 ppm nitrite+ 90 ppm lettuce and fennel powder) and T4 (120 ppm lettuce and fennel powder) and a control sample with 120 ppm nitrite (without lettuce and fennel powder). Physicochemical sensory, and microbial properties were investigated during 30 days of refrigerated storage.

The lowest pH (2.75%) did observe in T1 treatment on the 30th day of the experiment (p<0.05). The lowest moisture content (56.52%) and ash (2.43%) related to the control treatment on the 30th day of the experiment (p<0.05). Application of 30, 60, 90, and 120 ppm levels of lettuce powder and fennel in the treatments showed a decrease of 17, 18, 16, and 24% in the nitrate content of the samples, respectively (p<0.05). The highest and lowest peroxide value was 1.15 meq O2/Kg for the control sample on the 30th day and 0.3 meq O2/Kg for the T4 sample on the first day of the experiment, respectively. Regarding thiobarbituric acid index, the highest and lowest values were for the control sample with 24 mg Malone Aldehyde / Kg on the twentieth day and 15.76 mg Malone Aldehyde / Kg for the T4 sample on the 30th day of the experiment, respectively (p <0.05). The bacterial growth rate is lower in treatments containing combination lettuce, Foeniculum vulgare powder, and nitrite but in general, an increasing trend in microbial load observed in all treatments during 30 days of storage (p<0.05), While Clostridium perfringens, coliform, mold, and yeast did not grow on the treatments for 30 days (P> 0.05). In the sensory evaluation of treatments, the lowest a * observed in T4 treatment. The highest and lowest b* related to T1 and T4 treatments, respectively, While the combination lettuce and Foeniculum vulgare powder did not show any effect on the L*. The results of the sensory evaluation showed that the addition of lettuce and Foeniculum vulgare powder up to 60 ppm had no effect on the taste and smell of the treatments and showed a decrease in the aroma score in the treatments with increasing combination powder. Finally, the results of this study showed the possibility of successful replacement of some nitrite (at least 60 ppm) with a combination of lettuce and fennel powder.