Study On Preservation And Quality Improvement Of Fresh Rice Noodle

Qualities varieties of fresh rice noodle during the storage , effects of preservations of preservatives on fresh rice noodle ,and effects of preservation and quality variation of fresh rice noodle by sodium diacetate were studied as the first part of the paper,using fresh rice noodle as raw material.Quality improvement of fresh rice noodle by different amylose content ,rapid determination of rice amylose content,changes of physiochemical indexes of rice during soaking were investigated as the second part of this paper,using rice as raw material.After fresh rice noodle stored under 28℃,RH 24% for 16h,the total fungal reached 4000cfu/g,in excess of the standard requirements(total fungal≤150cfu / g) and the ratio of cooked broken noodle reached to 15.4%,in excess of the physical&chemical index requirements(the ratio of cooked broken noodle≤15%).After stored for 24h,the moisture content decreased to a certain extent and the acidity increased slightly,thus the sensory indexes worsened significantly. After fresh rice noodle stored at 28℃, RH 24% for 24h,effects of preservation of fresh rice noodle with four preservatives(potassium sorbate, sodium dehydroacetate,sodium diacetate and calcium propionate) were studied.The results indicated that sodium diacetate was better than others, adding 0.2g/kg,without remainings.After adding sodium diacetate,the sensory indexes improved obviously, the moisture content decreased to a certain extent and the acidity increased slightly,the total fungal declined significantly.Quality effects (water content,cooked broken noodle,sensory indexes)of fresh rice noodle by different amylose content(18.8%-28.9%) was studied by mixing rice with waxy rice and wheat starch. The results showed that,taken into consideration of cooked broken noodle ratio,and sensory indexes,amylose content between 23.2%-24.6% is sutiable for making fresh rice noodle. Rapid determination of rice amylose content by the color difference of the reaction of NaOH and iodine preparations.Effects of heating time, heating temperature, concentration of NaOH, consumption of NaOH and iodine were studied , the suitable amylose content of rice is 15% -30%,the results indicated that the best process parameters were as follows: temperature = 70℃, heating time = 3min,concentration of NaOH = 1mol / L,consumption of NaOH = 50uL, iodine dosage of 250uL; standard color card was produced according to the results,and several starch samples verified the accuracy is high.Changes of physiochemical indexes of rice during soaking were studied. Results showed that the water content and whiteness index were increased obviously after washing the rice, while the indexes of starch, amylose, protein, fat, ash, pH value were decreased in a small margin in the processing. It is also indicated that during the immersion of rice, the water content and whiteness index increased slightly, the indexes of starch, amylose as well as pH value decreased to a certain extent, however, the content of protein, fat and ash were significantly declined.