Starch quality studies are primarily carried out by texture analysis of starch pastes or starch gels. The characteristics of viscoelasticity and hardness of starch paste and starch gel can objectively reflect its rheological properties and texture properties. The texture properties of starch paste and starch gel are closely related to the quality and stability of starch-based foods. Contact is its special "mechanical taste". When the starch gel was subjected to texture test, the starch was first formulated into a certain concentration of starch milk, heated and gelatinized, and shaken evenly. After cooling to room temperature, it was placed in a refrigerator at 4 ° C for 24 h to determine the texture. The texture of the gel is generally determined by the TPA mode, cylindrical probe or disc probe. At present, more probes for starch gels in the study have P/0.5, P/50, P/6 and so on. It is recommended to use a probe with a larger inner diameter for a thinner sample and a probe with a smaller inner diameter for a thicker sample. (1) The texture properties of different varieties of rice starch, such as hardness, cohesiveness and adhesion, are significantly different. The starch with higher amylose content forms a higher gel hardness, mainly due to the aging of the starch gel due to short-time crystallization of amylose. Studies have shown that rice starch with higher gel hardness usually has higher amylose content and longer amylopectin side chains. (2) The texture characteristics of rice starch paste were analyzed by Universal TA texture analyzer. It was found that the mass fraction of starch and pH had an effect on the gel strength of starch paste. The hardness of starch paste increases with the increase of starch mass fraction; when the pH is between 2 and 10, the hardness of starch paste increases rapidly with the increase of pH. The application of the Universal TA texture analyzer is a good way to link the texture properties of starch with its physical and chemical properties, providing a new way for the study of starch quality. (3) The hardness and adhesion of starch gel are related to the degree of aging. The greater the degree of starch aging, the greater the gel hardness and the lower the adhesion. The addition of dietary fiber (0%, 5%, 10%) of different rice bran also affected the texture characteristics of rice starch. The results showed that under the same storage time, the hardness, adhesiveness and recovery rate of rice starch with 10% dietary fiber added were the slowest, 5%, and the control group was the fastest, which proved that rice bran dietary fiber was added to rice starch. The aging has a certain retardation effect, because it can reduce the mobility of water in the starch gel, thereby slowing the migration of water, and making the starch gel hardness and adhesion change more slowly. (4) In addition to the variety of starch itself, the preparation conditions of starch gel will also affect the quality of starch gel. Changes in texture properties of wheat starch gels prepared at different agitation rates (15, 150, 350 r / min) and different agitation times (95 °C; 10, 30, 45 min). The results show that at the same stirring time, the increasing stirring rate has a significant effect on the texture characteristics of the starch gel. At the same stirring rate, the prolonged stirring time has a relatively small effect on the texture of the gel. Increasing the heating temperature at lower agitation rates has a greater effect on the texture properties of the gel relative to high speed agitation. (5) In addition, the freezing method of the gel also has a great influence on the texture characteristics of the gel. It has been found that compared to conventional box freezing, the cryogenic freezing method representing rapid freezing forms small and evenly distributed ice crystals during the freezing process, which has less damage to the gel network and enables the gel to maintain a better texture. Characteristics, it is also difficult to break when squeezed. (6) In addition, the texture improvement method of the rice flour gel was studied by a Universal TA texture analyzer. The results showed that the addition of tapioca starch can effectively improve the texture characteristics of rice flour gel: The solubility and expansion force of tapioca starch is higher, and the particles can be leached in the gel. These components can be mixed in the gel. Acting as a binder, the rice starch granules are bonded together to improve the elasticity and cohesiveness of the mixed gel, and to prevent it from breaking early when compressed, thereby improving the texture characteristics of the mixed gel. 
Application of texture analyzer in starch quality