Plant polyphenols, also known as plant tannins, have outstanding effects in many aspects such as anti-oxidation, anti-mutation, anti-tumor and a wide range of health care functions. The most important of these is its anti-oxidation function.
The existing extraction methods of plant polyphenols mainly include ultrasonic-assisted extraction, solvent extraction, ion precipitation, microwave-assisted extraction, biological enzyme extraction, and supercritical CO2 extraction.
Taking jackfruit seeds as the research object, supercritical CO2 extraction technology was used to extract the polyphenols, and the extraction process was optimized through single factor and orthogonal experiments.
The dried jackfruit seeds are crushed and passed through a 30-mesh sieve.
Weigh 5.0g of jackfruit seed powder, wrap it with qualitative filter paper and gauze, and place it in the extraction kettle. Set the extraction pressure, ethanol concentration, ethanol consumption, CO2 flow, and extraction time. When the temperature and pressure of the extraction kettle reach the set value, the cycle extraction is constant. Discharge after time. The fixed separation pressure is 10bar and the temperature is 30°C.
Influence of extraction pressure
The ethanol concentration was fixed at 80%, the ethanol consumption was 6mL/g, the extraction temperature was 50°C, the CO2 flow rate was 30g/min, the extraction time was 1h, and the extraction pressure was controlled at 100, 150, 200, and 250 bar for extraction.
As the extraction pressure increases, the extraction effect shows an upward trend. After 150 bar, the extraction effect is basically stable. The extraction effect is best at 200 bar, and the polyphenol yield is 0.1602mg/g.
The influence of cosolvent ethanol concentration
Fixed extraction pressure 200bar, ethanol consumption 6mL/g, extraction temperature 50°C, CO2 flow rate 30g/min, extraction time 1h, change the ethanol concentration (volume fraction) with 60%, 65%, 70%, 75%, 80%, respectively , 90% storage and extraction.
With the increase of ethanol concentration, the extraction effect rises rapidly. When it reaches 70%, the extraction effect is the best. The yield of polyphenol is 0.2894mg/g. Over 70%, the effect drops significantly.
Influence of the amount of cosolvent ethanol
The fixed extraction pressure was 200bar, the ethanol concentration was 70%, the extraction temperature was 50°C, the CO2 flow rate was 30g/min, the extraction time was 1h, and the ethanol consumption was controlled at 4, 5, 6, 7, and 8 mL/g.
With the increase of the amount of ethanol, the yield of polyphenols increased first, and the extraction effect was the best at 5mg. The yield of polyphenols was 0.5062mg/g, and then the overall trend of decline.
Effect of extraction temperature
The fixed extraction pressure is 200bar, the ethanol concentration is 70%, the ethanol consumption is 5mL/g, the CO2 flow rate is 30g/min, the extraction time is 1h, and the extraction temperature is controlled at 45, 50, 55, and 60 °C.
It is found that temperature has a great influence on the extraction effect of jackfruit seed polyphenols, and the best effect is reached at 50°C. The yield of jackfruit seed polyphenols is 0.5062mg/g.
The impact of CO2 flow
The fixed extraction pressure was 200bar, the ethanol concentration was 70%, the ethanol consumption was 5mL/g, the extraction temperature was 50°C, the extraction time was 1h, and the CO 2 flow was controlled at 25, 30, 35, and 40g/min for extraction.
With the increase of CO2 flow rate, the extraction effect showed an upward trend. The best effect was reached at 30g/min, and the yield of polyphenol was 0.5062mg/g, after which the effect decreased.
The effects of extraction pressure, CO2 flow rate, extraction temperature, ethanol concentration, ethanol consumption and other factors on the yield of jackfruit seed polyphenols extracted by supercritical CO2 were investigated through single factor and orthogonal experiments.
The experimental results show that the order of the influence of each factor on the yield is CO2 flow rate>extraction temperature>ethanol concentration>ethanol consumption>extraction pressure;
The optimal extraction process conditions are: extraction pressure 175bar, ethanol concentration 70%, ethanol consumption 5mL/g, extraction temperature 50°C, C()2 flow rate 30g/min, extraction time 1.5h, under these conditions jackfruit seed polyphenols The yield is 0.6254mg/g.