Study on biphasic pasting characteristics for amylose and lipid complexation

• Main Authors: Hsin-Tien Hsieh, 謝欣湉
• Other Authors: Lin-Huei Ferng
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/02560530807514323613

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 96 === Maize and rice are the most important crops in the world. When aqueous dispersions of maize and rice starch are cooked, they will form amylose-lipid complexes (AML) in the final products. It will affect the gelatinization and rheological properties of final products. In general, the pasting behavior of starch formed a single peak curve on RVA graph, but some studies have found a biphasic phenomenon on pasting curve. The second pasting peak is attributed to the formation of complexes between amylose and lipid present in the starches. The objectives of this research were to investigate the effects of cooling rate, heating rate, heating temperature, holding time, starch concentration and stirring rate on amylose and lipid complexation of rice and maize starch by biphasic pasting curves, and to study the changes of starch properties by light microscopy, SEM, amylose and resistant starch content. Light microscopy revealed that some particles were observed in maize and rice starch dispersions at the second peak of the biphasic pasting curve. The results were consistent with the theory that there were crystallization of helical inclusion complexes formed from amylose and the native lipid material present in cereal starch granules. The amylose content of the paste did not change significantly, but the resistant starch content either increased or kept constant with the formation of second peak on the biphasic pasting curve. These results revealed that the formations of the second peak in the biphasic pasting curve were related to AML. The cooling rate of the processing did not affect the formation of second peak significantly. However, by using slower cooling rate the second peak would be enlarged to estimate the pasting properties easier. Stirring rate and starch concentration was the most significant factors of formation of AML in the cooking process. By comparing the results of rice starch with maize starch, rice starch was easier to form AML than maize starch during cooking procedure.