Spinach chlorophyll extraction method

Ultrasonic Extraction of Chlorophyll in Spinach Leaves

Chlorophyll porphyrins, a natural pigment found widely in green plants. Chlorophyll and its sodium salt are widely used in the food, medicine, sanitation and daily chemical industries due to its bright color and functions such as sterilization, deodorization, antipyretic and hemostasis.

Ultrasonic extraction process

The traditional process was improved, and the process conditions for ultrasonic extraction of chlorophyll using a mixture of ethanol and acetone as solvent were studied.

Extractant selection

Different extractants have different extraction effects, and the extraction effect of mixed liquor is better than that of a single reagent. The efficiency of direct extraction of chlorophyll from the leaves of the mixture was significantly improved, and it can be considered as a synergistic phenomenon.

Extractant dosage

Different extractant dosages have a significant effect on the extraction effect. When the solute concentration of the solution containing the solid is equal to the solute concentration of the leaching solution during extraction, the extraction reaches equilibrium. When the amount of extractant is small, the absorbance of chlorophyll extract is small. When the amount of extract is increased to 9 mL (the ratio of material to solution is 1:9), the absorbance increases significantly. Then when the amount of extract continues to increase, the absorbance continues to increase, but the magnitude is not large. Considering the solvent consumption and the cost of recovering the solvent, the ratio of material to liquid is 1:9 (W/V).

Extraction time

In the initial stage of extraction, the absorbance increases with the extraction time. When the extraction time is 30 min, the absorbance is the largest, but then the absorbance decreases. The reason is that in the process of ultrasonic radiation, the energy is directly transmitted to the inside of the spinach leaf, making it instantly heated and the temperature rises. The longer the irradiation time, the higher the temperature, and the stability of chlorophyll to heat is not good, so the absorbance decreases.

Spinach moisture content

The moisture content of the sample has a certain degree of influence on the absorbance of the extract. When the moisture content of the sample is 20%, the absorbance is the largest, and the extraction amount of chlorophyll is the most.

The principle of ultrasonic extraction is based on the fact that the ultrasound can rapidly heat the sample through the extractive agent and the evaporation of residual water in the vascular system causes the expansion, causing the rupture of these systems and allowing the contents to flow through the extractant. The appropriate moisture content in the medium facilitates ultrasonic extraction of chlorophyll. However, when the moisture content of the sample is higher than 20%, it can be seen from the figure that the absorbance begins to decrease. This is because when the moisture is present in a large amount, the chlorophyll is difficult to be extracted because it is insoluble in water.