Physicochemical and functional characteristics of cocosin and its unique emulsifying behavior
2008
Angelia, M. R. N., Philippines Univ. Los Banos, College, Laguna (Philippines). Inst. of Chemistry | Garcia, R. N., Philippines Univ. Los Banos, College, Laguna (Philippines). Inst. of Plant Breeding | Prak, K. | Utsumi, S., Kyoto Univ. Uji, Kyoto (Japan). Lab. of Food Quality Design and Development | Tecson-Mendoza, E. M., Philippines Univ. Los Banos, College, Laguna (Philippines). Inst. of Plant Breeding
Coconut is mainly cultivated as an oil seed. It is widely distributed and abundant all year round in the Philippines. Aside from supplying oil, the endosperm is also rich in proteins. However, coconut proteins are not utilized extensively as a source of proteins for animal and human consumption. The major protein in the endosperm is cocosin. The authors determined the physicochemical and functional properties of cocosin toward its commercial applications in food systems. Cocosin was purified by a combination of salt extraction, selective precipitation and gel filtration chromatography. The total globulins were composed of 73% 11S and 27% 7S. Cocosin was more soluble at different pH at high ionic strength than at low ionic strength. The 24 and 21 kD basic polypeptides of cocosin were more resistant to digestion with chymotrypsin than the 35 and 32 kD acidic polypeptide. Cocosin emulsions were most stable at 0 M NaCl, followed by emulsions in 0.1 and 0.4 M NaCl. The available SH groups of cocosin were found to be 21.6 mole SH/mole cocosin. The thermal denaturation midpoint temperature, Tm, of the trimeric cocosin was 77.6 deg C while that of the hexameric form was 100.5 deg C. The percentage secondary structures of cocosin are 15.0% regular helix, 12.9 distorted helix, 10.3% regular []-strand, 11.0% distorted []-strand, 23% turns, and 29% unordered structures. The physicochemical properties of cocosin were found to be comparable with the other 11S globulins like the soybean and pea globulins. Hence, cocosin may be used as a potential ingredient for processed foods. Moreover, the ability of cocosin to produce stable emulsions in the absence of salt is unique and could be the basis for developing new processed foods.
显示更多 [+] 显示较少 [-]