Study On Functional Properties Of Rice Starches And Correlation Analysis

In this study,14rice cultivars with variations in AAC and GT combinations were selected to examine their physicochemical and functional properties, and to determine which were the main factors affecting various functional properties by correlation analysis. Such information can provide a theoretical basis for the improvement of starch quality and starch modification. The main conclusions are as follows:1. The apparent amylose content was analyzed by using the iodine reagent method. The fourteen rice materials represented a wide variation in AAC, ranging from0.1%to28.7%, which can be divided into four kinds, waxy, low-AAC, intermediate-AAC, and high-AAC.2. The granular structure of rice starches from14cultivars showed a significant variation in size and shape as determined by scanning electron microscopy. The granular size ranged from2.3to6.8μm. The starch granules were observed to be polyhedral and irregular in shape.3. Rice starches showed a typical A-type diffraction pattern with the degree of crystallinity ranging from32.3%to45.5%, and AAC was negatively correlated with the degree of crystallinity.4. Swelling power and water solubility index of starches are temperature-dependent, but they showed non-linear increase with temperature. Waxy or low-AAC rice starches exhibited relatively higher swelling power than high-AAC starches, whereas high-AAC starches showed a higher water solubility index.5. Wide differences were observed in the viscosity parameters among the different rice cultivars, and the apparent amylose content is positively related to these parameters.6. Wide differences were observed in the textural parameters among the different rice cultivars. The gel hardness is positively related to apparent amylose content. The starch gel from BP628showed the highest hardness value (45g), whereas the BP601starch gel showed the lowest hardness value (3g). 7. The gellatinization temperature contain three kinds:high, intermediate and low. The thermal parameters are significantly correlated to themselves.8. Correlation analysis showed that apparent amylose content was the major factor affecting the physicochemical properties of rice starch, and the thermal properties of rice starch are mainly determined by the degree of crystallinity.