β-carotene can be used as nutritional and coloring additives. β-carotene is a non-toxic, safe and nutritious food additive recognized by the Food and Agriculture Organization of the United Nations and the Joint Committee on Food Additives of the World Health Organization. It has been approved for use by 52 countries and regions in the world.
β-carotene is widely used in food industry, feed industry, medicine and cosmetics industry.
At present, the methods used to obtain β-carotene include natural extraction, chemical synthesis, and microbial fermentation. But at present, β-carotene is mainly extracted from sweet potatoes and carrots. The variety of β-carotene is also very low, only about 40mg/kg, and the purification process is complicated. Using microbial fermentation, β-carotene can accumulate up to 5% to 10% in the dry weight of the bacteria, so it has important research significance.
Whether extracting β-carotene from carrots or microorganisms, the current process mainly uses organic solvent extraction.
Since β-carotene has little solubility in organic solvents commonly used in the food industry, it needs to use a large amount of solvent for extraction. The common extraction method of existing β-carotene is to break the cell wall of the wet mycelium obtained by filtering the fermentation broth, dehydrate it with a dehydrating agent after solid-liquid separation, and then extract β-carotene with a solvent. After drying, β-carotene crystals are obtained. This method uses a large amount of organic solvents in the extraction process, which not only consumes high energy and production costs, but also is difficult to separate the solvents. The residual concentration of solvents in the finished crystals is high, which may cause food safety risks.
Method for preparing three-in-one water-soluble β-carotene powder by filtering, washing and drying Concrete steps
In order to solve the technical problems of β-carotene extraction and purification, the fully automatic three-in-one preparation process of filtration, washing and drying is simple and easy, with large profit margins, easy promotion, and broad market prospects. The specific steps of the new process are as follows:
(1) Cleaning step: clean the collected raw materials and remove impurities;
(2) Solvent extraction step: adding an organic solvent to the raw material for reflux extraction or ultrasonic extraction;
(3) Wall breaking step: add protease with 0.25wt% of the dry weight of the bacteria to the concentrated solution, stir and react at 35°C for 4 hours to break the wall, and the average particle size of the bacteria reaches 575 μm;
(4) Purification step: separate the product of step (3) in the fully automatic filtration, washing and drying three-in-one, the upper layer is the orange supernatant, and the lower layer is the filter residue;
(5) Saponification reaction: add excess mass concentration of 0.5% lye to the solution to carry out sufficient saponification reaction to remove grease; wash the saponification reaction solution with water to remove soap until the soap concentration in the washing liquid is less than 10ppm to obtain β - wet crystals of carotene;
(6) Purification and drying: add water, ethanol, and lye to the crude β-carotene obtained in step (5), stir, and then put it into an evaporator to evaporate to obtain the refined β-carotene. After testing, the finished β-carotene crystal has a purity of 96.6% and does not contain any organic solvent.
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