Method for extracting blue pigment from purple cabbage

Abstract

The invention discloses a method for extracting a blue pigment from purple cabbage. The method comprises steps as follows: digestion, microwave extraction and purification; purple cabbage pulp is digested through a digestion liquid and then centrifuged, microwave irradiation extraction is performed after a protectant is added to the liquid supernatant, and an ethanol solution of pigment colloid is purified through a silica gel chromatographic column. The method has the benefits as follows: the extraction method is simple and easy to control, consumes short time and is time-saving and labor-saving and suitable for large-scale operation, the process parameters such as temperature, pH values, solid-to-liquid ratio, extraction time, microwave power and the like in an extraction process are effectively controlled, the extraction process is optimized, and the influence of extraction conditions on the blue pigment is reduced to the minimum; a few metal ions in the system can change the color of the pigment and even can change the structure of the pigment, the protectant is added and can form a complex together with the metal ions in the system, and accordingly, the influence of the metal ions on the pigment is avoided. The method for extracting the blue pigment from purple cabbage is safe and efficient.

Description

Technical field [0001] The invention belongs to the field of plant pigment extraction, and particularly relates to a method for extracting blue pigment from purple cabbage. technical background [0002] Purple cabbage is also known as red cabbage, purple cabbage or purple fennel white, commonly known as purple cabbage, a variety of Brassica oleracea and Brassica spp., a type of cabbage. Because the outer leaves and leaf balls are purple-red, they are called purple cabbage, or purple cabbage. The leaves are purple-red, with wax powder on the leaf surface, and the leaf bulbs are nearly round, rich in nutrients, and purple cabbage is rich in nutrients. According to measurements, every 100 grams of fresh vegetables contains 0.11 mg of carotene and vitamin B 1 0.04 mg, vitamin B 2 0.04 mg, vitamin C39 mg, niacin 0.3 mg, carbohydrate 4%, protein 1.3%, fat 0.3%, crude fiber 0.9%, calcium 100 mg, phosphorus 56 mg, iron 1.9 mg. The antioxidant ingredients contained in purple cabbage can ...

AI Technical Summary

Problems solved by technology

[0005] The Chinese invention patent of CN 104017391 B discloses a method for extracting edible blue pigment from onions. The inventive method is to pickle red onions with acetic acid solution until the onions turn blue-green, and then add 95% ethanol solution The filtrate is soaked and extracted, the filtrate is concentrated and separated, and the blue pigment powder is obtained by purification. The method of the invention is simple, and the obtained blue pigment has a bright color and high color value; however, the preparation method is somewhat cumbersome, and the onion needs to be soaked in acetic acid solution for 10 minutes. Days, the purification process needs to use hydroxypropyl dextran gel column and resin column, the extraction process is too time-consuming and labor-intensive, and the content of blue pigment in onion is less, so the yield of the inventive method is low, and it is not popularized limited meaning