CN1957756A - Spray drying method for water-soluble iron chelate of glycine - Google Patents

Abstract

The invention discloses a spray-drying method for water-soluble glycine chelated iron, belonging to the technical field of amino acid chelate preparation. In the present invention, an appropriate amount of water is added to the glycine chelated iron that has reached the requirements of good water solubility to dissolve, and then maltodextrin, anti-caking agent and composite antioxidant are added, homogenized under a certain pressure, and finally sprayed in a spray drying tower Dry to obtain a product with excellent oxidation resistance and moisture absorption resistance. After spray drying, the amino acid content of the product reaches 31.30%, the total iron content reaches 7.17%, the ferrous iron content reaches 5.89%, and there is almost no free iron. The product's anti-oxidation, anti-hygroscopicity and water solubility are all better than glycine after vacuum drying Chelated iron products. The method of the invention has the advantages of industrial scale production, simple operation process, low cost, stable product quality, convenient storage and the like.

Description

A kind of spray drying method of water-soluble glycine chelated iron

technical field

The invention relates to a spray drying method of water-soluble glycine chelated iron, belonging to the technical field of amino acid chelate preparation.

Background technique

Glycine chelated iron is an iron nutritional enhancer that is easily absorbed by mammals including humans. It has many advantages such as non-toxic, non-irritating, fast absorption, and significant iron and blood supplementation. It is widely used in feed additives . In recent years, some researchers in the United Kingdom and the United States have gradually increased the research on the application of amino acid chelated iron as an iron nutritional fortifier in food.

In our country, the mid-1980s began to study trace element amino acid chelates, and great progress has been made in amino acid chelated ferrous. Yang Wenbing and Yao Fenying reported in the early 1990s that the complex amino acid solution obtained by acid hydrolyzing soybean cake and ferrous sulfate chelation reaction was used to prepare complex amino acid chelated ferrous. On this basis, Qin Weidong et al. (2003) studied the process of enzymatically hydrolyzing defatted soybean meal into a compound amino acid solution and chelating with ferrous salt to prepare compound amino acid chelated ferrous. Xu Haiqing and Mingxia (2001) introduced the method of using chicken feathers as raw materials, hydrolyzing them with hydrochloric acid, and complexing them with iron salts to prepare complex amino acid iron complexes.

The invention patent CN1280260C "a preparation method of food nutrition enhancer ferrous glycinate chelate" applied by the inventor can prepare ferrous glycinate chelate content of more than 80%, and the rehydration rate of ferrous glycinate chelate is greater than 95% of glycine chelated iron. The product glycine chelated iron is a water-soluble substance, its oxidation stability and aqueous solution stability are much higher than that of ferrous sulfate, but it also has the defects of easy moisture absorption and partial oxidation during long-term storage. Therefore, the glycine chelated iron synthesized by this method needs to be dried to obtain an easy-to-preserve product, while ensuring the water solubility of the dry product, so as to facilitate the nutritional enhancement of liquid foods such as dairy products, soy sauce, and oil, and facilitate processing and application. Adopting vacuum drying method to dry glycine chelated iron can meet the above-mentioned technical requirements, but the process is intermittent operation, the drying cycle is long, the output is low, and the product particles need to be pulverized, which is not convenient for continuous production, and the dried product is still relatively large. Strong hygroscopicity.

Contents of the invention

The purpose of the present invention is to provide a spray drying method of food nutrition enhancer water-soluble glycine chelated iron, which can realize industrial scale production with low cost, and the obtained product has oxidation resistance, moisture absorption resistance and excellent water solubility . It is obviously better than the product obtained by vacuum drying method.

Technical scheme of the present invention: use glycine and ferrous chloride as raw materials to synthesize glycine chelated iron, add maltodextrin, anti-caking agent and composite antioxidant to ferrous chloride aqueous solution, and homogenize under certain pressure , and finally spray-dried in a spray drying tower.

(1) The mass ratio of maltodextrin to glycine chelated iron is 1.25:1-1:1.25;

(2) Antioxidant selects ascorbic acid for use, and its consumption is 1.15%-1.35% of the quality of glycine chelated iron;

(3) anticaking agent selects microcrystalline cellulose for use, and its consumption is 1% of glycine chelated iron quality;

(4) The selected solid content based on the total mass of glycine chelated iron and maltodextrin is 20%-30%;

(5) Homogenization pressure is 20-30MPa, homogenization twice;

(6) Spray drying: the inlet air temperature is 170-190°C, and the outlet air temperature is 80-90°C.

The research on the spray drying method of water-soluble glycine chelated iron includes the selection and determination of the amount of filler, the selection of the amount of antioxidant, the selection of the amount of anti-caking agent, the selection of solid content, the selection of air inlet temperature, and the homogeneous pressure ok.

Spray-dried fillers are chosen between cyclodextrins and maltodextrins with low DE values (DE values 8-15). From the appearance point of view, the dry product of glycine chelated iron with cyclodextrin as a filler is earthy yellow in color and has good fluidity, and the dry product of glycine chelated iron with maltodextrin as a filler is also earthy yellow in color and slightly poor in fluidity. However, the water solubility test found that the former has poor water solubility and is easily hydrolyzed in water, while the aqueous solution of maltodextrin as a filler is transparent and clear, and the solution property is very stable. Therefore, choose maltodextrin with a DE value of 8-15 as filler, and consider adding some anti-caking agents to improve the fluidity of the product.

To determine the amount of maltodextrin used as a spray-dried filler, the mass ratios of maltodextrin and glycine chelated iron (based on dry basis determined by oven drying method) are respectively 1:2, 1:1.5, 1:1, and 1.5. :1, 2:1. It was found that when the maltodextrin: glycine chelated iron is less than 1:1, the color of the product is darker, which brings inconvenience to the application; when the maltodextrin: glycine chelated iron is 1:1, the color is lighter and the water solubility is good, which is ideal Product; Maltodextrin: Glycine chelated iron is more than 1.5:1, although the color is light, it is easy to hydrolyze and cannot be used as an additive. Considering the actual utilization value of the product simultaneously, the product with higher iron content is selected, so the preferred maltodextrin: the mass ratio of glycine chelated iron is 1:1.

Antioxidant is selected ascorbic acid for use, and the selection of its consumption, in the process that antioxidant dosage (accounting for the ratio of glycine chelated iron mass) changes from 0.5% to 2%, when antioxidant dosage is less than 1.25%, ferrous iron/total iron The value is lower, and after 1.25%, ferrous iron/total iron is not very different, and the preferred antioxidant dosage is 1.25% of the mass of glycine chelated iron.

The anti-caking agent is selected from microcrystalline cellulose, and its dosage is 1% of the mass of glycine chelated iron, which is more suitable.

The determination of solids content, the lower the solids content, the lower the retention rate of ferrous iron in the product. When the solids content is higher, the degree of oxidation of ferrous iron is lower, but there will be wall sticking phenomenon. Taking various factors into consideration, it is preferable to have a solid content of 20% based on the total mass of glycine chelated iron and filler.

The choice of inlet air temperature, when the inlet air temperature is too low, the wall sticking phenomenon is serious due to insufficient heating of the feed liquid, and the product yield is low; when the temperature is too high, it will affect the stability of ferrous iron, reduce the content of ferrous iron, and optimize the inlet air The temperature was 180°C.

The optimized water-soluble glycine chelated iron spray drying method of the present invention is: the mass ratio of maltodextrin and glycine chelated iron is 1: 1, the antioxidant consumption is 1.25% of the glycine chelated iron quality, and the anticaking agent is The mass of glycine chelated iron is 1%, the solid content is 20%, the homogenization pressure is 30MPa, homogenization is performed twice, the air inlet temperature is 180°C, and the air outlet temperature is 80°C-90°C.

Comparison of Oxidation Stability of Glycine Chelated Iron Prepared under Different Drying Process Conditions

The composite glycine chelated iron prepared by the spray drying process and the pure glycine chelated iron prepared under vacuum drying conditions were subjected to storage experiments to observe their stability, and the results are shown in Figure 1. As can be seen from Figure 1, the composite glycine chelated iron is due to the addition of a certain amount of maltodextrin as a filler, and this part of the filler has played a certain role in oxygen barrier, and also because a certain amount has been added before spray drying. Antioxidants, so the oxidation stability of compound glycine chelated iron is better than that of pure glycine chelated iron.

Comparison of moisture absorption and moisture return of products prepared by different drying processes

The composite glycine chelated iron prepared by the spray drying process and the pure glycine chelated iron prepared under vacuum drying conditions were exposed to the air, and their moisture absorption was observed. The result is shown in Figure 2. As can be seen from Figure 2, compared with the pure glycine chelated iron product obtained by vacuum drying, the hygroscopic phenomenon of the composite glycine chelated iron product produced by the spray drying process has been significantly improved. Placed in the open for 1 hour, the moisture absorption weight gain rate of the composite product is 63.46% smaller than that of the pure product, and the moisture absorption weight gain rate of the composite product is 47.64% smaller than that of the pure product at the 10th hour. The shape of the anti-hygroscopicity curve is similar, and it shows a linear upward trend at the beginning. After the 10th hour, the weight gain decreases significantly, and the curve tends to be stable. It may be that the moisture absorption weight gain is close to saturation at this time. After standing for 48 hours, the moisture absorption weight gain rate of the final composite product is 41.81% smaller than that of the pure product. This shows that the maltodextrin and a very small amount of anti-caking agent added in the spray drying have played a very good anti-hygroscopic effect, so that glycine chelated iron can be better applied to food fortification carriers (such as flour) and prolong its life. shelf life.

Comparison of water solubility of products prepared by different drying processes

The water solubility of glycine chelated iron directly affects its application in flour, so the solubility of the compound glycine chelated iron obtained by spray drying and the pure product of glycine chelated iron obtained by vacuum drying are compared here. The result is shown in Figure 3. As can be seen from Figure 3, in 100mL of water, the water solubility of the products prepared by two different drying processes is almost the same. The solubility of the pure glycine chelated iron prepared by the vacuum drying method is about 9.73g/100mL, and the compound glycine prepared by the spray drying method is about 9.73g/100mL. The solubility of chelated iron is about 9.05g/100mL. It can be seen that the complex glycine chelated iron has good solubility, is very suitable for adding to food, and is well utilized as an iron fortifier.

Beneficial effects of the present invention: adopting the glycine chelated iron spray drying method of the present invention can obtain products with excellent color, water solubility, oxidation resistance and moisture absorption resistance. After the product is spray-dried, the amino acid content is 31.30%, the total iron content is 7.17%, the ferrous iron content is 5.89%, and there is almost no free iron. The comprehensive consideration of the oxidation resistance, moisture resistance and water solubility of the product is better than that of the glycine chelated iron product after vacuum drying. The water content in the spray-dried product is 3.1%, and the content of other components (dextrin, composite antioxidant, etc.) is 58.43%. The method of the invention has the advantages of continuous production on an industrial scale, simple operation process, low processing cost, stable product quality, convenient long-term preservation, convenient application and the like. The obtained compound glycine chelated iron product has the characteristics of stable chemical performance, high biological potency, non-toxic and non-irritating, good palatability, and enhancement of human immune function. The amino acid chelate has little effect on active ingredients such as vitamins and antibiotics. It can also reduce the antagonism with other trace elements, and can be used as feed additives, nutritional enhancers, pharmaceutical preparations, and for the prevention and treatment of iron and zinc and other trace element deficiencies.

Description of drawings

Fig. 1 compares the oxidation stability of spray-dried compound glycine chelated iron and glycine chelated iron pure product.

Fig. 2 Changes of hygroscopicity (moisture absorption weight gain) of two products with standing time.

Fig. 3 Solubility of chelated iron in 100mL water of two different drying processes.

Detailed ways

Example 1

Weigh 50g water-soluble glycine chelated iron, dissolve in 500mL deionized water, add 50g maltodextrin, 0.65g antioxidant, 0.5g anti-caking agent, solid content is 20%, homogenization pressure 20MPa, homogenization two Second, the inlet air temperature is 180°C, the outlet air temperature is 80°C-90°C, and spray-dried in a spray drying tower.

Take 5g of the product and dissolve it in 100ml of ultra-pure water, the system is transparent without precipitation, the content of ferrous iron accounts for 81.77% of the total iron content, the product is relatively dry and has good solubility.

Example 2

Weigh 50g water-soluble glycine chelated iron, dissolve in 1000mL deionized water, add 50g maltodextrin, 0.625g antioxidant, 0.5g anti-caking agent, solid content is 10%, homogenization pressure 20MPa, homogenization two Second, the inlet air temperature is 180°C, the outlet air temperature is 80°C-90°C, and spray-dried in a spray drying tower.

Take 5g of the product and dissolve it in 100ml of ultrapure water, the system is transparent without precipitation, the content of ferrous iron accounts for 79.10% of the total iron content, the product is dry and has good solubility.

Example 3

Weigh 50g water-soluble glycine chelated iron, dissolve in 500mL deionized water, add 50g maltodextrin, 0.625g antioxidant, 0.5g anti-caking agent, solid content is 20%, homogenization pressure 20MPa, homogenization two The second time, the air inlet temperature is 160°C, and the outlet air temperature is 80°C-90°C, and it is spray-dried in a spray drying tower.

Take 5g of the product and dissolve it in 100ml of ultra-pure water. The system is transparent without precipitation. The content of ferrous iron accounts for 84.12% of the total iron content.

Example 4

Weigh 50g of water-soluble glycine chelated iron, dissolve in 500mL of deionized water, add 50g of maltodextrin, 0.625g of antioxidant, 0.5g of anti-caking agent, the solid content is 20%, the homogenization pressure is 30MPa, and the homogenization pressure is 20%. Second, the inlet air temperature is 180°C, the outlet air temperature is 80°C-90°C, and spray-dried in a spray drying tower.

Take 5g of the product and dissolve it in 100ml of ultra-pure water. The system is transparent without precipitation. The content of ferrous iron accounts for 82.03% of the total iron content. The product has good solubility and the solution is clear.

Claims (2)

1, a kind of spray drying process of water-soluble iron chelate of glycine, it is characterized in that in water-soluble glycin chelated iron, adding maltodextrin, anti-caking agent and composite antioxidant, homogeneous under certain pressure, spray-drying in spray drying tower at last, process conditions are:

(1) mass ratio of maltodextrin and glycin chelated iron is 1.25: 1-1: 1.25;

(2) antioxidant is selected ascorbic acid for use, and its consumption is the 1.15%-1.35% of glycine chelate weight of iron;

(3) anti-caking agent is selected microcrystalline cellulose for use, and its consumption is 1% of a glycine chelate weight of iron;

(4) selected solid content in glycin chelated iron and maltodextrin total quality is 20%-30%;

(5) homogenization pressure is 20-30MPa, twice of homogeneous;

(6) spray-drying: EAT is 170-190 ℃, and leaving air temp is 80-90 ℃.

2, the spray drying process of water-soluble iron chelate of glycine according to claim 1 is characterized in that process conditions are:

(1) mass ratio of maltodextrin and glycin chelated iron is 1: 1;

(2) antioxidant is selected ascorbic acid for use, and its consumption is 1.25% of a glycine chelate weight of iron;

(3) anti-caking agent is selected microcrystalline cellulose for use, and its consumption is 1% of a glycine chelate weight of iron;

(4) selected solid content in glycin chelated iron and maltodextrin total quality is 20%;

(5) homogenization pressure is 20-30MPa, twice of homogeneous;

(6) spray-drying: EAT is 180 ℃, and leaving air temp is 80 ℃-90 ℃.

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