Maize starch granules were used as the sample, and the decomposition reaction mediated by alpha-amylase molecules that did not contain the starch-binding domain (SBD) was elucidated. The starch surface protein (SSP) was found to cover the surface of the maize starch granules. We found that decomposition of maize starch granules by SBD-free alpha-amylase increased in the presence of SSP. When SSP of the maize starch granules was dissolved by treatment with SDS solution, the decomposition rate of starch granules decreased. The decomposition rate recovered when SSP was added to the SDS-treated starch. When SSP was added to the SDS-treated maize starch granules, the rate of alpha-amylase-mediated decomposition recovered. We clearly show that SSP is the maize storage protein zein, which can bind with alpha-amylase and shows film formation capability.

　In the ovaries of mature Japanese sandfish (Arctoscopus japonicas), eggs are enveloped by a jelly-like mucilage to form an egg mass. In a part of Japan, the sandfish egg mass is regarded as a delicacy due to its unique texture. Here, we successfully isolated the mucilage from the egg mass by soaking it in hot water at 70℃. The freeze-dried mucilage was comprised of 72% protein, 1.4% carbohydrate, and 21% crude ash. Because removal of the ash by dialysis did not alter the viscosity of the mucilage, the stickiness was attributed to the protein content of the mucilage. The viscosity of the mucilage was not stable at high temperatures, but the heat stability was improved by the presence of 1～5% NaCl. Interestingly, electrophoretic analysis indicated that the mucilage contains a single predominant protein. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis indicated that the protein had an oligomeric structure, which might result in the viscosity of the mucilage. The N-terminal amino acid sequence of the protein was determined to be NH₂-GRRGDRERNQ, which matched neither to known viscous proteins nor to known proteins in fish species. Consequently, the characteristic viscosity of the sandfish egg mass might be attributed to a novel viscous protein.

　The effect of ovomucin, a glycoprotein, on the viscosity and foaming properties of emu egg white was determined. Compared to Gallus gallusdomesticus (hen) egg white, emu egg white was more viscose and had better foaming properties and stability. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis followed by periodic acid-Schiff staining were performed for emu egg white, and carbohydrate chain bands of size 52, 78, and 207 kDa were observed. The N-terminal amino acid sequence of the 207-kDa protein showed 62.5% homology with the N-terminal region of α2-ovomucin obtained from hen. The ovomucin content in emu egg white was approximately 6.3%, over one from hen egg white. In addition, the ovomucin solution prepared from emu egg white was more viscose than that prepared from hen egg white. The viscosity of ovomucin obtained from each egg white was closely related to the viscosity of the egg white. Therefore, these results suggest that ovomucin affects the viscosity and foaming properties of emu egg white.

　The procedure to make puffed snack food from pigskin of animal by-products was evaluated to make efficient use of the skin. Immersing pigskin after the removal of hair in water at 100℃ for 60 min successfully reduced fat and degraded tissue integrity without altering the shape of the skin. The defatted pigskin was dried at 80℃ for 4 h to reduce the water content to approximately 2% before being deep-fried at 200℃ or baked at 200℃. The resulting puffed pigskin had high-protein content and was rich in collagen. Furthermore, the baked pigskin was low in fat content. Results of sensory evaluation were satisfactory regardless of whether pigskin samples were puffed by deep-frying or baking. These results demonstrate the possibility that pigskin from animal by-products can be used to produce a novel food by a food additives-free method using an ordinary food processing machine.

　We investigated the effect of different temperature and relative humidity conditions on the equilibrium moisture contents (EMCs) and seed quality of stored amaranth seeds. Amaranth seeds were stored for 12 months at temperatures of 5, 15, and 25℃. The seed quality parameters, including germination rate; surface color; populations of total aerobic bacteria, molds, and yeasts; and fat acid contents, were examined. The EMC fitted the Chen-Clayton equation well. No remarkable changes were noted in the amaranth seeds with regard to the germination rate; surface color; and populations of total aerobic bacteria, molds, and yeasts for the tested storage time and temperature conditions. However, fat acidity of the amaranth seeds stored at 25℃ increased significantly with time, whereas that of the seeds stored at low temperatures of 5 and 15℃ showed an insignificant increase. This finding suggests that storage temperatures of 5 and 15℃ are applicable for amaranth seeds.