Because collagen is inherently piezoelectric, research is being actively conducted to utilize it to harvest energy. In this study, a collagen solution was prepared using edible low-molecular-weight peptide collagen powder, and collagen films were fabricated using a dip coating method. The collagen films prepared by dip coating showed a smooth surface without defects such as pinholes or cracks. Dehydrothermal treatment of the collagen films was performed to induce a stable molecular structure through cross-linking. The collagen film subjected to dehydrothermal treatment at 110 °C for 24 h showed a thickness reduction rate of 19 %. Analysis of the collagen films showed that the crystallinity of the collagen film improved by about 7.9 % after dehydrothermal treatment. A collagen film-based piezoelectric nanogenerator showed output characteristics of approximately 13.7 V and 1.4 μA in a pressure test of 120 N. The generator showed a maximum power density of about 2.91 mW/m2 and an output voltage of about 8~19 V during various human body movements such as finger tapping. The collagen film-based piezoelectric generator showed improved output performance with improved crystallinity and piezoelectricity after dehydrothermal treatment.

This experiment was carried out to find the quality characteristics of yanggaeng added antioxidant rich collagen powder in the color, sugar contents, texture, radical scavenging activity and electronic nose detected flavor. L value and a value kept decreased as the more collagen powder was added in the yanggaeng while b value was increased significantly at the same time. Sugar contents was increased significantly from 43 °Brix in the control to 48% in the 10% treatment (p<0.05). Hardness in the 10% treatment of collagen powder increased biggest among the treatments but springiness decreased when hardness increased. And adhesiveness, cohesiveness, gumminess and chewiness were also increased with more the collagen powder in the treatments, therefore 10% treatment showed biggest result significantly. Radical scavenging activity kept increased with higher addition of collagen powder and it resulted 60% of radical scavenging activity in the 10% treatment. In the flavor test under electronic nose experiment, 10% of collagen powder treatment was believed it flavored most for it was found in the furthest from the AIR location. Control was found also in the nearest from the AIR, which meant it has least flavor than any other treatment. Also 2.5% and 5% of collagen powder added treatments showed little differences of flavor from control, which meant 5% of treatment was believed idea condition in the treatments. With the above experimental results, 5% of collagen powder treatment in the yanggaeng manufacturing was chosed as the best mixture ratio in the test.

Physicochemical and functional properties of collage from skate skin (Raja Kenojei) are examined depending on pH and NaCl concentration in the medium. The solubility decreased as NaCl concentration increased but, turbidity increased as concentration of collagen increased. Oil-holding capacity and water-holding capacity were similar to other fish skin collagens. Emulsion activity, creaming stability, and viscosity were lowest at where pH levels were isoelectric point regions of collagens. However, the higher pH values at 7.0-9.0 caused increasing foam expansion, foam viscosity, and gel strength. These results indicated that collagen from skate skin could be used as a functional ingredient for food and industrial applications.