Takeshi Nagai1,2,3, Masataka Saito4, Yasuhiro Tanoue5, Norihisa Kai6, Nobutaka Suzuki7. 1. Graduate School of Agricultural Sciences, Yamagata University, Tsuruoka, 9978555 Yamagata, Japan. 2. The United Graduate School of Agricultural Sciences, Iwate University, Morioka, 0208550 Iwate, Japan. 3. Graduate School, Prince of Songkla University, 90112 Songkhla, Thailand. 4. Kagawa Nutrition University, Sakado, 3500288 Saitama, Japan. 5. Department of Food Science and Technology, National Fisheries University. 6. Department of Integrated Science and Technology, Oita University, Oita, 8701192 Oita. 7. Nagoya Research Institute, Toyoake, 4701131 Aichi, Japan.
Abstract
RESEARCH BACKGROUND: Animal collagen has been widely utilized in foods, cosmetics and biomedical fields. The non-edible portion, such as fish skin and bones, are obtained during cooking. Most of them are currently discarded as wastes, although the nutritional value of the skin and bones is high. The non-edible portion needs to be reused in order to reduce environmental impact, as it is one of the sources of environmental pollution. EXPERIMENTAL APPROACH: Collagen was prepared by cold acetone treatment from Sakhalin taimen skin as a waste produced during cooking. Next, the colour, SDS-polyacrylamide gel electrophoresis, ultraviolet absorption, subunit composition, amino acid composition, denaturation temperature and attenuated total reflectance-Fourier transform infrared spectroscopy analyses were conducted to explore the properties of the collagen. Lastly, we attempted to improve the functional properties of the collagen for future applications using chemical modification technique (succinylation). RESULTS AND CONCLUSIONS: Cold acetone treatment easily removed the fats and pigments from the skin. The odourless and pure white collagen was obtained with high yield. The α3 chain did not exist in the collagen. Sakhalin taimen skin collagen had rich α-helix and low β-sheet structures. Succinylation caused the secondary structural changes of the collagen molecule. Moreover, it made it possible not only to increase the viscosity of the collagen solution but also to improve the solubility of the collagen under the physiological conditions around pH=6. NOVELTY AND SCIENTIFIC CONTRIBUTION: This finding is the first report on the absence of the α3 chain from salmonid fish skin collagens. The succinylated collagen from Sakhalin taimen skins as useful biomass has potential to utilize in foods, cosmetics and related industries.
RESEARCH BACKGROUND: Animal collagen has been widely utilized in foods, cosmetics and biomedical fields. The non-edible portion, such as fish skin and bones, are obtained during cooking. Most of them are currently discarded as wastes, although the nutritional value of the skin and bones is high. The non-edible portion needs to be reused in order to reduce environmental impact, as it is one of the sources of environmental pollution. EXPERIMENTAL APPROACH: Collagen was prepared by cold acetone treatment from Sakhalin taimen skin as a waste produced during cooking. Next, the colour, SDS-polyacrylamide gel electrophoresis, ultraviolet absorption, subunit composition, amino acid composition, denaturation temperature and attenuated total reflectance-Fourier transform infrared spectroscopy analyses were conducted to explore the properties of the collagen. Lastly, we attempted to improve the functional properties of the collagen for future applications using chemical modification technique (succinylation). RESULTS AND CONCLUSIONS: Cold acetone treatment easily removed the fats and pigments from the skin. The odourless and pure white collagen was obtained with high yield. The α3 chain did not exist in the collagen. Sakhalin taimen skin collagen had rich α-helix and low β-sheet structures. Succinylation caused the secondary structural changes of the collagen molecule. Moreover, it made it possible not only to increase the viscosity of the collagen solution but also to improve the solubility of the collagen under the physiological conditions around pH=6. NOVELTY AND SCIENTIFIC CONTRIBUTION: This finding is the first report on the absence of the α3 chain from salmonid fish skin collagens. The succinylated collagen from Sakhalin taimen skins as useful biomass has potential to utilize in foods, cosmetics and related industries.
Authors: Nicholas M H Khong; Fatimah Md Yusoff; B Jamilah; Mahiran Basri; I Maznah; Kim Wei Chan; Nurdin Armania; Jun Nishikawa Journal: Food Chem Date: 2017-12-28 Impact factor: 7.514