Acidic and steaming treatments of tteokbokki rice cake to improve its microbial and textural properties

To improve the storage and firmness of Tteokbokki tteok Korean-style rice cakes with spicy sauce, steaming of the rice dough, soaking of the rice cake in acidic solution, and heat sterilization were conducted sequentially. The untreated control could be stored for 1 month under cold conditions, but this was extended to 10 months at room temperature (15-30^oC) after immersion in lactic acid solution (pH 4.0) for 20 min and heating to 100^oC for 30 min. The mechanical strength, which was related to firmness, was significantly increased to 11.4 kgm/s² compared with the untreated rice cakes (8.8 kgm/s², p<0.05) and the overall descriptions of the sensory evaluation, including texture, was significantly higher than the control (p<0.05). The average size of the pores in the treated rice cakes was smaller than that of the conventional sample and the texture was improved as a result of decreased starch elution from smaller pores.