Method for extracting ascorbic acid from vegetables and fruits

Abstract

The invention belongs to the technical field of analysis chemistry, specifically to a method for extracting ascorbic acid from vegetables and fruits by using a nitrogen protection micro wave-assisted extracting technology. The method comprises the following steps of: taking fresh vegetables and fruits, adding a weak acid solution with certain concentration in 1:6-1:12 g / ml times of volume as an extracting solvent, discharging the oxygen in the system via a nitrogen protecting device, extracting at a micro wave condition with certain power for a certain time, cooling, compensating weight, uniformly mixing, centrifuging, taking out supernatant fluid, diluting, analyzing and detecting the content of the ascorbic acid in the vegetables and fruits via high performance liquid chromatography. According to the method, nitrogen protection is combined with micro wave-assisted extraction to discharge the oxygen in the system, thus the oxidization of the ascorbic acid is reduced and the extracting rate is greatly improved. The method is combined with the high performance liquid chromatography for exactly detecting the content of the ascorbic acid in the vegetables and fruits, and is applicable to extracting and separating other components which are easy to oxidize by heating.

Description

technical field [0001] The invention belongs to the field of analytical chemistry, and relates to a method for extracting ascorbic acid from fruits and vegetables, in particular to a method for extracting ascorbic acid from fruits and vegetables by utilizing a nitrogen-protected microwave-assisted extraction technology. Background technique [0002] Analytical chemistry pretreatment technology is always an important part of instrumental analysis experiments. Especially for samples with many and complex components such as food and traditional Chinese medicine, how to extract the desired compounds efficiently and quickly is a key issue. [0003] Microwave-assisted extraction (Microwave-assisted Extraction, MAE) is a series of techniques for extracting soluble materials in plants with microwave energy, which is mainly carried out in organic solvents. Research has shown that microwave has a strong penetrating power, can heat uniformly and rapidly inside and outside the material...

AI Technical Summary

Problems solved by technology

[0005] Research also shows that ascorbic acid is unstable, and under the condition of heat, it is easily oxidized by the oxygen in the air, and undergoes a series of complex degradation reactions such as dehydration, decarbonation, ring opening, and ring closing, and loses its nutritional value.

The enediol group in the ascorbic acid molecule has extremely strong reducibility, and is easily oxidized to a diketone group to become dehydroascorbic acid, but it can still be reduced, and ascorbic acid can be further hydrolyzed into diketone ancient in alkaline or strongly acidic solution Lulonic acid, since this step is irreversible, ascorbic acid is easily inactivated

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