Study On The Mechanism Of Cell Broken During Processing Of Potato Granules

Potato granules is an important kind of middle product in potato food processing and cell integration is a key problem for potato granule manufacturing. Studies on this problem, which will promote both theory understanding and technique improving, have been seen abroad but not in China before.Using var. Atlantic, we studied cell structural changes during steaming in the processing of potato granules with add-back processing method (A-B) and the influence of preheating and calcium soaking on them. The best A-B processing condition, the influence of calcium on the potato starch swelling power, gelatinizing temperature, viscosity and solubility, the isolation, inspection and calcium influence on potato cell wall are also studied, as well as the cell broken of potato granules made by freeze thaw processing method (F-T), the optimum F-T processing condition and the influence of many factors.Experiment results show that steaming time has important influence on the changes of cell structure. The gelatinization of potato starch after 2 minutes steaming contributes a lot to cell separation but not to cell broken. With further steaming, the pectin materials in potato cell wall break down and dissolved which cause cell broken. Preheating can make more connection among pectin chains and make the cell wall stronger. Calcium treating can cause more pectin connection and less swelling power of potato starch. Preheating and calcium soaking together make A-B potato granule cells more integrate. 65 ℃ preheating, 100ppm calcium soaking, 10 minutes steaming is the optimum A-B processing condition. We creatively found that when the breaking force of potato pieces is about 1500g after steaming, the A-B final product made by these pieces have the lowest free starch content thus the lowest cell broken rate. In F-T processing method, preheating has the negative way to the integration of potato granules. On the contrary, lower temperature and quick freezing make the potato cell integrity. Of cause, in F-T processing method, steaming time has important influence on cell broken but the influence of calcium soaking is negligible. Contrast with A-B potato granules, F-T granules have more cell integrity, lower free starch and superbproduct quality. Without preheating, -40℃ freezing, 50ppm calcium soaking, 7 minutes steaming is the optimum F-T processing condition.