The Effect Of High-voltage Pulsed Electric Field On The Properties Of Black Bean Lipoxygenase And Black Bean Protein

Black beans are rich in protein and amino acids, is a nutritious food, and black beans also has good medicinal value. However, black beans contain a variety of enzymes and some anti-nutritional factors, will make the beans and their products have certain side effects and produce unpleasant beany flavor. Traditional pasteurization, easy to make black bean protein denaturation, affect the quality and nutritional value of its products. Pulsed electric field treatment is a new non-heat sterilization techniques. The purpose of this study is the use of pulsed electric field processing beans, initially explore the impact of pulsed electric field on the black beans and black beans lipoxygenase protein isolate functional properties.Study on the enzyme showed that soybean lipoxygenase, poor stability, the optimal reaction temperature is 30, the optimum pH was 9. Citric acid, cysteine and tea polyphenols on soybean lipoxygenase inhibition. In inorganic salt on soybean lipoxygenase-1 synthase activity stability test, sodium salt is better than a potassium salt, black soybean lipoxygenase-1 synthetic role in the stability of enzyme activity weakened gradually with the strengthening of the alkaline.HPEF voltage, pulse width, frequency, processing time, and have a certain influence on the material thickness black bean lipoxygenase activity. Which pulsed electric field voltage, frequency, pulse width and processing time on large black bean lipoxygenase activity, can clearly be seen that with the increase of pulse electric voltage, frequency, pulse width, and processing time, black beans lipoxygenase activity in the fall; The influence of black material thickness lipoxygenase activity is relatively small, but the trend, the treated sample was dispersed in an electric field, and can not accumulate together. Data analysis on the basis of single-factor test response surface analysis to determine the optimum conditions for pulsed electric field to suppress black bean lipoxygenase activity are:voltage 23 kV, the frequency of 800 Hz, pulse width of 8 us, the processing time of 6 s.Pulsed electric field processing, the functional properties of the black bean protein isolate such as solubility, foaming and foam stability, emulsifying capacity and emulsion stability, water retention rate are influential. With increasing voltage and high-voltage pulsed electric field processing time, black beans isolated protein solubility, foaming, emulsifying and water holding capacity rate has increased, but there is a maximum, while continuing to enhance and extend the voltage pulse processing time solubility black bean protein isolate, foaming, emulsifying and water holding capacity rate will decline.Electron microscopy showed that black beans after pulsed electric field treatment, the cell surface is damaged, becomes rough, there are cracks and small holes; black bean protein isolate electric field after treatment, the sulfhydryl content and surface hydrophobicity have changed, are the first improve after a downward trend.