Stduy On The Preparation Of Sorbic Acid Nano-dispersion And Its Utilization In Sausage

With the increasing of people's focusing on food safety, the utilization of food preservatives is becoming more and more important in food processing. As a popular food preservative with relatively high security, sorbic acid is tasteless, odorless and stable to heat. It is widely used in foods, feed, Pharmaceuticals, tobaccos and cosmetics industries to extend the shelf life of the products. Because sorbic acid is not water soluble, we change it into potassium sorbate, a kind of sorbate, to increase its solubility and this may be convenient for the consumers. The problem is that, when used in food system, potassium sorbate distributed needs to be transfer to sorbic acid itself to inhibit the growth of microbes and this transformation need the participation of acids. When used in food systems with low acidity or neutral food in which H+ is insufficient, the said transformation won't happen and the growth of microbe could not be suppressed. Therefore, it is of great importance to prepare a kind of "water soluble" sorbic acid nano-dispersion which can be used in all food systems without the dependent upon the pH of the environment.First of all, the experiment parameters were studied.Basing on the single factor experiment, four factors were selected which were rate and content of surfactant and co-surfactant, temperature and rotational speed. The optimal parameters were obtained from the study conducted on the water solubilization and the diameter of the particles. The optimal conditions were:Tween-20 used as surfactant, ethyl as co-surfactant, surfactant and co-surfactant rate 3:1, surfactant and co-surfactant content 86%, rotational speed 120r/min, nano-dispersed at 60℃for lh. The content of sorbic acid in the product reached to 14%.Next, storage stability of the sorbic acid nano-dispersion was studied. The product was stored at 25℃for 30d,60d,90d and 120d, and stored at 4℃,37℃for 28d to study the effect of time and temperature on the stability. The results showed that the product kept high stability, although the diameter of the particles was 25.50nm at 4℃for 2 weeks, which become become larger than others.Under the simulated environment (pH=7.2-7.4), the anti-bacteria of sorbic acid nano-dispersion was tested and OD600 were measured. After Escherichia coli, Bacillus subtitles, salmonella and Staphylococcus aureus were standing-temperature cultured at 25℃for 12h,18h or 24h, the results showed that 56ppm or 84ppm nano-dispersed sorbic acid had the same inhibitory activity on these bacterias as 800ppm potassium sorbate.The anti-bacterial activity of the nano-dispersed sorbic acid was checked in sausage products. The results showed this product could be easily used in neutral food systems and had splendid anti-bacteria activity. The total bacteria of sausage products with no preservatives had reached to 5.6x108cfu/g while the total bacteria of sausage products with 0.8g/kg of nano-dispersed sorbic acid was only 2.0×104cfu/g at 37℃for 21d.