At present, calcium oleate is mainly produced by chemical synthesis. The molar ratio of calcium ion, citrate and malate, reaction temperature, reaction time, water addition during the reaction and crystallization conditions should be considered in production. Calcium carbonate, calcium oxide and calcium hydroxide are generally used as calcium sources to prevent other ions from being added in the synthesis process. In the synthesis of American patent calcium oleate (no. 15, 186965), it is pointed out that if 300g calcium oleate powder is prepared, 192g citric acid and 20 1g malic acid are dissolved in 1000mL water respectively, and then added quickly at room temperature. Li Weiping of Shijiazhuang Weiping Functional Food Technology Co., Ltd. explored another stable formula for synthesizing calcium oleate in the experiment, namely 0 14mol citric acid, 0 15mol malic acid,115 mol calcium carbonate or calcium oxide, and did some research on its application in beverages. Li Xingyuan, a teacher from huanggang polytechnic college, took solubility as an index, and optimized the best parameters of preparing calcium oleate through orthogonal experiments, that is, calcium oleate was synthesized at 40℃ according to the molar ratio of Ca ∶CA ∶Ma = 12 ∶6 ∶9. When calcium oleate is synthesized, shell materials such as eggshell, oyster shell and clam shell can also be used as calcium sources. For example, Professor Duan Huimin of Hebei University of Science and Technology researched and developed the production process of preparing calcium oleate from eggshells, and determined the technological conditions for preparing high-solubility calcium oleate from eggshells as follows: washing eggshells with tap water, drying them at 65438 080℃ for 65438±0hr, and crushing them. Burning in a high-temperature furnace at 950℃ for 2 hours to obtain eggshell ash (CaO), adding 30mL water into 0 1073mol CaO to make emulsion, adding it into the mixed solution of 0 1022mol citric acid and 0 104mol malic acid, and reacting at 55℃. Teacher Yin Rong used eggshell powder calcined at 950℃ as raw material, and neutralized at 50℃ according to the ratio of n (eggshell ash) ∶n (citric acid) ∶n (malic acid) = 5 ∶2 ∶4. Freeze 1d, filter, wash, dehydrate, freeze 1d again, and take out at 80℃. In addition, Professor Zhang Zhenqian from the Department of Biochemistry of Guangxi Institute of Technology studied the technological conditions of preparing calcium oleate from oyster shells and clam shells. It was found that both oyster shell and clam shell can be used as good calcium sources for preparing calcium oleate. The neutralization reaction conditions were as follows: oyster shell powder: citric acid: malic acid = 01073: 01024: 010334 (molar ratio), reaction at 55℃ 1hr, and the total volume was. Clam shell powder citric acid malic acid = 01073: 010202: 01035 (molar ratio), reaction at 55℃ 1hr, total volume of 50mL, crystallization at-10℃/ In addition, Shandong Food Fermentation Research and Design Institute has successfully developed microbial strains to produce calcium oleate, which is the first in the biological production of calcium oleate and has applied for a national patent.
2 application of calcium oleate
Calcium oleate is a general food raw material with high safety, which belongs to CRAS in the United States and can be used in various foods. Solid calcium oleate can be used as calcium supplement, and liquid dosage form can be used for calcium fortified drinks. In recent years, Europe, America, Japan, China and other countries have conducted extensive and in-depth research on calcium oleate, completed a large number of animal and clinical trials, and vigorously promoted its application in beverages. Beverages with calcium oleate as calcium fortifier are sold in many parts of the world, including the United States (1986), Japan (1990) and Europe (199 1). Japan Baojiu Brewery Co., Ltd. introduced 199 1 orange juice, fruit milk beverage and transparent carbonated beverage containing calcium oleate, which caused a sensation all over the world. Since 1995, it has been approved by the Japanese government as a specific health drink, and CCM has also been approved by the Japanese Ministry of Health and Welfare as a raw material for special health foods. The Canadian government has approved calcium citrate swallowing tablets and chewable tablets as medical calcium supplements. Recently, the mixture of calcium citrate and calcium malate is also commonly used in calcium-fortified drinks and foods in the United States and Japan. At present, calcium oleate has been widely produced and applied in China. For example, China Food Fermentation Industry Research Institute has successively developed a series of calcium-fortified juice drinks on the basis of the successful development of special calcium fruit acid for "Y-97" drinks. These drinks can withstand high temperature treatment, and the acid-base environment is stable. Even if they are stored for a long time, calcium precipitation will not occur, and the pure flavor and taste of the drinks are completely preserved. In addition, Liu Kui, a teacher from Hebei University of Science and Technology, studied the preparation technology of calcium oleate chewable tablets. The calcium content is 90% ~ 1 10% of the labeled amount. This chewable tablet has the characteristics of good taste, convenient carrying and taking, and easy absorption by human body. It is especially suitable for children and people who have difficulty swallowing pills. Teacher Guo studied the production conditions of calcium oleate effervescent tablets. Each effervescent tablet contains 300mg of calcium, which is sweet and sour, refreshing, good in water solubility, high in absorption rate and convenient to eat, and suitable for people of different ages to supplement calcium.