Study On Anti-retrogradation And Quality Control Of Instant Rice Noodles

Instant rice noodles is an important rice product in China, but now it is lack of effective anti-retrogradation method and scientific quality safety controlling system. Based on the research of produce technics of instant rice noodles, the paper studied the retrogradation properties of instant rice noodles and the effect of modified starches on storage stabilization of instant rice noodles. Protocol of using modified starches to improve instant rice noodles quality and delay retrogradation was also established. Through hazard analysis of biology, chemistry and physics factors on process of instant rice noodles, the safe production measures based on storage stabilization of instant rice noodles were confirmed. This paper is theoretically and practically important on improving the quality of instant rice noodles, exploiting a new method of anti-retrogradation, revealing retrogradation mechanism and producing safely. Main results were summarized as follows:1. Suitable technologies of instant rice noodles were determined by single factor experiment and orthogonal experiment, respectively. Rice was soaked at 40 ℃ for 16 hs after washed cleanly, then steamed for 8 mins at 1 atmospheric pressure, retrograded for 2 hs at room tempereture, second steamed time for 8 mins at 1 atmospheric pressure, immersed with the lactic acid density was 1.50% for 5 mins. After packing, it was sterilized for 5 mins at 100 ℃.2. Retrogradation characteristic of instant rice noodles during storage was studied. Instant rice noodles produced under above conditions was stored at 4℃. Microcrystalline structures of instant rice noodles were formed after storing thirty days. Physichemical characteristic, sensory quality and texture were checked at certain time. Results showed that rehydration ratio decreased, hardness increased, flexibility and edibility got worse with storage time increase.3. Effect of modified starches on storage stabilization of instant rice noodles was studied. Physical properties of modified starches and retrogradation kinetics properties of instant rice noodles which added modified starches were studied. Sources and modifying methods of starches influenced the quality of instant rice noodles significantly. Modifiedtomato starches could improve rehydration stabilization, modified waxy maize starches could improve flexibility of instant rice noodles, modified tapioca starches could improve ratio of rehydration, flexibility and stabilization of instant rice noodles. Acetate esterification starches could improve flexibility and reduce ratio of transference of instant rice noodles, cross linked etherifying starches could improve ratio of rehydration of rice noodles, cross linked esterification starches could improve the flexibility of rice noodles, and oxidation starches would reduce ratio of transference of instant rice noodles.4. Protocol of resisting retrogradation by modified starches was determinated. Using cross linked etherifying tapioca starches HP-CFT0130 and cross linked esterification waxy maize starches COLFLO67 with the ration of 3% of the total of instant rice noodles with the mass ratio of 1:2 could improve storage stabilization of rice noodles. The trends of the hardness and stickiness of instant rice noodles added compound modified starches were slower during storage than that of instant rice noodles without added the modified starches, and its quality was better than that of added a certain kind of modified starches.5. Safe producing measures of instant rice noodles were established. Purchasing rice materials, immersing with the lactic acid, sterilization were critical control points, HACCP quality controlling system of instant rice noodles was established primarily by checking total number of bacterial and the number of E.coli in the samples of instant rice noodles during process. Products safety would guaranteed by purchasing rice materials, controlling" immersing with the lactic acid density, the temperature and time of sterilization, packing environment and materials.