Evaluation of physicochemical properties, cooking quality, and heavy metals (lead and cadmium) of Champa rice

Rice is one of the most important agricultural products and main food for more than %25 people in the world. Due to increasing consumption of this product, evaluation of quality and characteristics of cultivated rice in different regions of country is of great importance. Additionally, over the past decades, heavy metals contamination in rice cause to be public concern, thus assessment of heavy metal pollution of rice is necessary. Evaluation the characteristics of rice varieties will allow consumers and producers to prepare rice according to their taste and need. Therefore, this study was conducted to evaluate the amount of lead and cadmium, physicochemical properties and cooking quality of champa rice in different regions of Baghmalek, Khuzestan.

In this study, rice cultivated in different regions of Baghmalek was sampled in three replications and transferred to the laboratory for testing. Physicochemical tests including protein, moisture content, ash, total solid, amylose content and thousand grain weight were evaluated based on national standard of Iran. Cadmium and lead content of rice cultivated in different region of Baghmalek were evaluated. Cooking properties of studied rice including cooking time, water absorption, leakage, gelatinization grade and Elongation of rice were evaluated. The tests were performed in a completely randomized design with SAS software and analyzed by Duncan test at a probability level of 5%.

The results of proximate test including (carbohydrate, protein, total solid, ash and moisture) showed that significant difference was between samples cultivated in different region of Baghmalek. In all samples, except for one samples, amylose content were 20-21%. The results of heavy metal evaluation indicated Cd in all samples were in permissible limit but lead content in imported rice and cultivated rice in Sidon and Meydavoud was more than permissible limit. Studied samples with regard to lenght were in medium category and Elongation of rice was in the range of 1.39-1.74. The gelatinization grade of studied samples was in the range of 3.25-4.17. Evaluation of cooking properties including cooking time, water absorption and leakage indicated it was significant difference between studied samples. Thousand grain weight of studied samples had been significant difference and was in the range of 13.07-18.86.

In general, selected rice samples from different regions of Baghmalek exhibited a significant difference in physicochemical properties. With regard to cooking properties and quality, rice samples had desirable status and were comparable to imported rice. Evaluation of the safety status of studied rice samples suggests that control of cultivated regions is necessary.