Effect of Heat Treatment and Different Concentration Salt Addition on the Quality and Shelf-life of Fresh Noodles

In this paper,the compound water activity regulator was used as the basic formula to explore the effect of heat treatment and different concentration of salt on the moisture content,water activity,water distribution,color,cooking,texture profile analysis and gelatinization characteristics of fresh noodles. The results showed that the heat treatment and different concentration salt addition could reduce the water activity,when the addition amount of salt was 3%,the water activity of the fresh noodles after heat treatment at 98 ℃ reached a minimum of 0.884. After heat treatment,the transverse relaxation peak was left shifted,while the degree of moisture reduced and the content of bound water increased in the fresh noodles. Under the condition that without salt addition,the heat treatment at 98 ℃ increased the brightness of the fresh surface from 91.07 to 92.93,and the total color difference ΔE decreased from 10.04 to 3.06,compared with the sample without heat treatment. Under the 88 ℃ heat treatment,the hardness,breaking force and stretching distance of the fresh noodles increased first and then decreased with the increase of salt content. When the addition amount of salt was 3%,there was no significant difference in the hardness between the fresh noodles with and without heat treatment. Heat treatment decreased the peak viscosity and increased the gelatinization temperature. In addition,heat treatment and salt addition could significantly extend the shelf life of the fresh noodles. The shelf-life of fresh noodles prepared with the salt content of 2% and heat-treated at 98 ℃ for 4 min could reach 96 h when stored at 25 ℃.