Method for determination of texture of rice

November 18, 2020

Palatability of rice is an important evaluation index of rice taste quality [1-2].
With the development of society and the improvement of people's living standard, the palatability of rice is attracting more and more attention [3-4].
At present, the evaluation of rice palatability is mainly sensory evaluation, which has some shortcomings such as complicated operation procedure and strong subjectivity.
Therefore, in recent years, people have been trying to measure the palatability of rice by means of instruments, in order to replace the sensory evaluation and provide a more objective, accurate and rapid evaluation method for the palatability of rice.
Texture Profile Analysis (TPA) can simulate the chewing process of oral teeth through the mechanical process of continuous compression twice on the sample, so as to digitize and objective the palatability index.
At present, the methods to determine the rice quality and structure of two kinds: one is the grain method, namely, randomly selected from the rice grain number of grain, appropriate in different ways (radial, star, parallel, circular) is put in the determination of structure instrument platform [6], but as a result of the test selected MiFanLi less (usually 3 pills), which resulted in increased error;
The other is the rice cake method, that is, the rice is cooked in a selected container, and the rice is directly measured after it is sorted after cooling. This method reflects the overall texture characteristics of the rice, but does not reflect the texture characteristics of a single rice grain.
This paper by the methods of grain and rice cakes were determined rice quality and structure, through the analysis of variance and coefficient of variation analysis and comparison of the differences between the test data and stability, to find the method for determination of rice quality and structure, at the same time, the main method to determine parameters (compression ratio and compression rate) optimization, suitable for rice quality and structure of the testing parameters, for the quality and structure instrument quickly and accurately determine the quality and structure of rice quality.
The above is excerpted from grain, oil and Food Science and Technology, Vol. 21, No. 6, 2013

Texture analyzer, as a kind of food sensory analysis instrument, has been widely used in the field of leisure food, with the advantages of simple operation, objective data and the ability to observe the stress curve of the sample.
The texture of jelly can be measured by texture analyzer in order to study and discuss the processing technology or technology.
St-z16 texture analyzer (physical property analyzer) can be used to test the physical properties of samples in the fields of food, biology, pharmacy and chemical industry, including hardness, elasticity, crispness, mastication, firmness, toughness, ductility, resilience, gel strength and other texture analyzer (physical property analyzer).
St-z16 structure instrument is a electromechanical integration product, adopting modern mechanical design concept and ergonomic design criteria, using advanced dual CPU microcomputer processing technology for careful and reasonable design.
Apparatus needed for experiment
1. Instrument: ST-Z16 automatic texture tester, automatic detection throughout the test process;
Fully computer controlled, the test results can be stored;
You can view the historical data;
Automatic printing.
Test mode: TPA mode
Test probe: P/35 cylindrical probe.
Test index: it can measure the hardness, elasticity, cohesiveness, viscosity, stickiness, resilience, and mastication of steamed rice and rice grains.

3. Test conditions:
Test mode: TPA mode
Trigger force: 10g
Speed before test: 1m/min
Test speed: 1mm/min
Speed after test: 2mm/min
Target mode: 70% deformation
Interval between two presses: 5S
Experimental steps:
The braised rice was cooled to room temperature (about 20 min), and 3 grains of rice were randomly selected and placed on the texture tester test platform for determination in a radial manner.
Compression probe: P /35 cylindrical compression probe;
Induction force: 5 g;
Pre-test speed: 0.
50mm /s;
Test speed: 1.
00 mm /s;
Post-test velocity: 2.
00mm /s;
Compression ratio: 70%.
After each measurement, wipe the probe gently with a clean wet gauze and repeat the test operation.
10 parallel tests were carried out respectively. The maximum and minimum values were removed and the average values were taken.