This is the research project that won the Third Prize of the National Scientific and Technical Research Contest for Secondary and High School Students. The project was conducted by student Trinh Hoang Long - Nguyen Van Troi High School under the guidance of Assoc.Prof. Huynh Nguyen Duy Bao - Faculty of Food Technology, NTU.

Khanh Hoa owns a large amount of tuna, and by-products from tuna processing, especially bones is majority. Tuna bone is also a great source of calcium in the form of hydroxyapatite (which can be absorbed into the human body). Tuna bone wastes have not been used effectively, (mainly used as low-value products such as fertilizer, animal feed) while the need for calcium supplementation of humans is huge.

The research project carried out experiments to investigate the conditions for extracting calcium from tuna bones by hydrolysis with NaOH at appropriate concentrations in order to reduce the time and temperature to obtain calcium preparations in natural form (hydroxyapatite) with high purity, nano size. Therefore, it is easy to apply in small-scale production, minimizing environmental pollution. At the same time, the conductor tested using extracted calcium as an additional ingredients of cookies, creating a calcium supplement food for children to the olders.