| Seeking cheap, sustainable protein sources greatly facilitate in alleviating the dependence on expensive animal-based protein in many developing countries. Caragana Korshinskii Kom. was used to forage, mixed with routine forage, due to its high-content of protein, low fertilizer and pesticide requirements, excellent stress (high salty and less water) tolerance and wide adaptability etc. C. korshinskii Kom. release the crisis of proteins resource deficiency and promote the social sustainable development.Since C. korshinskii Kom. is an effective and feasible source of proteins, its airdried twigs and leaves were used in this study as raw materials for extracting protein by different methods such as acetone and TCA-acetone precipitation methods. Many factors were considered in this study, aimed to find the optimum technique and additions of extracting C. korshinskii Kom. protein isolates. The optimal extracting conditions of TCA-acetone precipitation were Solid/Liquid Ratio 1:22, extraction time 7 h and ratio of precipitation solution to supernatant 1:2.5, whose extraction yield was 58.67 mg/g. The best conditions of acetone precipitation were similar than TCA-acetone precipitation, Solid/Liquid Ratio 1:20, extraction time 7 h and ratio of precipitation solution to supernatant 1:3.5, whose extraction yield was 123.64 mg/g.Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE) analysis of protein isolates from Caragana Korshinskii Kom. extracted by three different methods, including TCA-acetone precipitation (TCA-CPI), acetone precipitation (A-CPI) and alkaline method (Al-CPI). The molecular weight of TCA-CPI, A-CPI and Al-CPI ranges from 14.4 to 45.0 kDa,25.0 to 66.2 kDa and 14.4 to 66.2 kDa, respectively. According to two-dimensional electrophoresis (2-DE) of TCA-CPI, it was indicated that protein points of TCA-CPI distributed at both acid and alkaline pH. Furthermore, the molecular weight of proteins at acid pH is larger than that at alkaline pH.Food processing and storage were affected by the functional properties of proteins.So the functional properties of C. korshinskii Kom. protein isolates by three different extraction methods were investigated. C. korshinskii Kom. protein isolates by traditional alkaline extraction (Al-CPI) exhibited well performance on emulsifying activity index, oil and water absorption capacity and foaming property compared with A-CPI (C. korshinskii Kom. protein isolates by acetone precipitation method) and TCA-CPI (C. korshinskii Kom. protein isolates by trichloroacetic acid-acetone precipitation). The water-and oil-adsorption capacities of Al-CPI were observed at 4.99 and 3.45 g/g, respectively, even much higher than those of SPI (3.94 and 2.95 g/g, respectively). The highest foaming capacity was observed by Al-CPI at 185.0%, followed by A-CPI (177.5%), TCA-CPI (142.5%) and SPI (141.9%), respectively. It has to be noted that A-CPI showed good solubility at acidic pH and excellent in-vitro digestibility. After sequential pepsin-trypsin digestion, the %N release of A-CPI reached up to 83.7%, which was 1.63 times that of Al-CPI (51.2%),1.19 times that of TCA-CPI (70.1%), and slightly higher than that of the commercial SPI (82.5%).In our dalily lives, C. korshinskii Kom. was used as forage, mixed with corn and bran. Legume contains a number of antinutrirional factors (ANFs), which affect absorption of nutrition and limit application on forage. This study was conducted on ANFs such as lectine, trypsin inhibitor, tannin and total phenol of C. korshinskii Kom., aiming to provide basic datas on improvement of its palatability in the future.The contents of lectin, trypsin inhibitor, tannin and total phenols were respectively 8.0 mg/g,1.3 mg/g,10.3 mg/g and 48.2 mg/g, only total phenol was higher than other legumes. These results indicate that C. korshinskii Kom. holds a great potential for the application of in animal feed and food additive industry. |
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