β-carotene is a fat-soluble carotenoid with a molecular formula of C40H54 and a relative molecular mass of 536.88. It is easily soluble in methylene chloride, chloroform, and carbon disulfide. β-carotene is an important source of vitamin A in the human body. It has physiological functions such as protecting eyesight, preventing cancer, anti-cancer, anti-aging, preventing and treating cataracts, anti-radiation and improving immunity. Due to the many functions of β-carotene, its application field has gradually shifted from the original food coloring agent to the four major fields of feed, nutritional food, health products and medicine, and has been widely recognized by consumers.
At present, β-carotene is mainly extracted from sweet potatoes and carrots. However, even in varieties with high β-carotene content, the content of β-carotene is 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.
New process of extraction and purification of β-carotene Specific 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 0.25wt% protease 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: the product of step (3) is separated in a fully automatic filter washing and drying three-in-one, the upper layer is orange supernatant, and the lower layer is filter residue;
(5) Saponification reaction: adding excessive mass concentration to the solution is 0.5% lye to carry out sufficient saponification reaction to remove grease; the saponification reaction solution is washed 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 product of β-carotene obtained in step (5), stir, and then put it into an evaporator to evaporate to obtain the refined product of β-carotene. After testing, the finished β-carotene crystal has a purity of 96.6% and does not contain any organic solvent.