Research on the Imitative Natural Air-dried Processing of Shallow Fermented Sausage

In this paper, the effects of air-drying temperature, air velocity, and humidity on the drying time, uniformity, and sensory quality of shallow fermented sausage were studied. On the basis of single factor experiment, response surface methodology employing Box-Behnken design was applied to get the optimal air-drying process conditions. Furthermore, the effects of different temperature gradients on the air-drying characteristics and product quality of sausage were investigated. The results showed that, the optimum conditions of constant temperature air-drying were as follows: Temperature 9.0 ℃, the air velocity 1.0 m/s, and the humidity 64%. A suitable temperature gradient could improve the drying efficiency and product quality. The optimal process conditions of the gradient air-drying method were temperature gradient 7~13 ℃ (alternating every 12 hours), air velocity 1.0 m/s, and humidity 64%. Under these conditions, the time to air-dry the shallow fermented sausage to the ideal moisture content was 66 h. The product quality indexes were as follows: Uniformity 0.987, moisture content 37.693%, a_w 0.875, pH5.54, and TBA 0.735 mg/kg. The ideal product quality could be obtained at the same time of considering air drying efficiency under this gradient air-drying condition.