Butter production process

3.1 Melting raw butter

Pour the raw butter from the slaughterhouse directly into the melting tank to dissolve it. When the oil temperature reaches 110 degrees Celsius, it is maintained for 30 minutes to remove excess water and remove impurities (grass, wood, packaging fragments, etc.) with the oil. Separate. The impurities floating on the oil surface can be directly salvaged, and the impurities that sink to the bottom of the oil can be removed after the oil is pumped, and the impurities contained in the oil can be removed by filtering during pumping.

3.2 Deacidification process

The deacidification process is a key step in the refined processing of tallow. The deacidification effect is directly related to the quality of refined tallow. There are basically two modern tallow deacidification processes: neutralization and distillation. The neutralization method is a refining method that uses alkali to neutralize the free fatty acids in the oil to generate fatty acid salt (soap) and water. The soap absorbs some impurities and settles and separates from the oil. The precipitate formed is called soapstock. Distillation deacidification method is also called physical refining. This deacidification method does not use lye to neutralize, but uses the difference in relative volatility of triglycerides and free fatty acids to perform steam distillation under high temperature and high vacuum to make free Fatty acids and low molecular weight substances are discharged together with steam. This method is suitable for high acid value oils.

Our company has used these two methods in trial production, but the deacidification effect of distillation method is better than that of neutralization method, but it requires more personnel. Considering that the current general neutralization method is used in production, it is considered. There are many alkalis used in the neutralization method, such as caustic soda, soda ash, etc., but the most widely used in industrial production is caustic soda. Caustic soda can neutralize most of the free fatty acids in the raw oil, and the resulting fat sodium salt (sodium soap) is in It is not easy to dissolve in the oil, it becomes a flocculent gel and settles; the sodium soap produced by neutralization is a surface active substance with strong adsorption and absorption capacity, which can remove a considerable amount of other impurities (such as protein, mucus, pigments with phospholipids and bands). Substances with hydroxyl or phenol groups) are carried into the sediment, and even suspended impurities can be carried down by the flocculent soap mass. Therefore, the neutralization method itself has a comprehensive effect of deacidification, degumming, de-impurity and decolorization. Therefore, caustic soda is also used as a deacidification agent in the company's production, and the hydration process is omitted in the production process.

  3.2.1 Control of the amount of caustic soda in the neutralization method

The deacidification process is the key to refined tallow, but the amount of alkali added is the key to deacidification. If the amount of alkali is insufficient, the fatty acids cannot be completely removed, and if the amount of alkali is excessive, the oil will not be alkaline enough to meet the national standards. . Therefore, it is very important to control the amount of alkali added. When acid-base neutralization, the total amount of alkali consumed includes two parts: one part is the amount of free fatty acid alkali, which is usually called the theoretical alkali amount, which can be obtained by calculation; the other part is the extra excess to meet the process requirements. The alkali is called excess alkali. The theoretical alkali quantity can be calculated by the acid value of the tallow drawn into the deacidification tank. The theoretical alkali quantity calculation formula is:

Theoretical base amount = O. 731×acid value

No matter what kind of butter finishing process, the theoretical alkali quantity is basically this value, so our company also uses this value for calculation. However, the amount of super-alkali is different, because our company uses a batch neutralization method for deacidification, and it has been found in practice that when the amount of super-alkali is controlled at 0.15%. Therefore, the actual amount of alkali used = 0.7325 × acid value

3.2.2 Control of the concentration of caustic soda by neutralization method

The acid value and color of raw tallow is the most important basis for determining the concentration of lye. For raw tallow with high acid value and dark color, use concentrated alkali; for raw tallow with low acid value and light color, use light alkali. Our company uses raw tallow provided by Anhui Fengyang, which has been rough processed in its place of origin before finishing. Therefore, the acid value of raw tallow is not high and the color is relatively light. Therefore, the low-concentration alkali used in the concentration of lye is selected and controlled at about 0.4%.

  3.2.3 Temperature control during neutralization

The temperature of the oil in the neutralization process is an important factor that affects the effect of the deacidification process. During operation, it must be controlled to the temperature when the oil and soapstock are obviously separated, and the heating speed reflects the speed of accelerating the reaction and promoting the flocculation process of soapstock. The deacidification operation temperature is related to the quality of oil production, deacidification process and lye concentration. After trial production, when the oil temperature of the deacidification process is controlled at 80℃-90℃, the deacidification effect is the best.

  3.2.4 Control of stirring speed

During neutralization deacidification, the reaction between caustic soda and free fatty acids occurs on the surface of the alkali droplets. The finer the alkali droplets are dispersed, the larger the total surface area of ​​the lye, which increases the chance of contact between the lye and the free fatty acids and speeds up the chemistry. The reaction speed shortens the neutralization time, which is conducive to the improvement of the refining rate. The purpose of stirring is to highly disperse the lye in the oil phase, but also to control the stirring speed before and after adding the alkali. The speed can be appropriately fast when the alkali is added, but not too fast. The company obtains the stirring speed in actual production, and it is generally controlled at 40-60r/min when alkali is added, and the stirring speed is controlled within 20r/min after alkali addition.

3.2.5 Deacidification process operation

The melted raw tallow is filtered and pumped into the deacidification tank, and stirred continuously, and the stirring speed is controlled at 40-60r/min. Because it is an intermittent deacidification, when there is a certain amount of tallow in the deacidification tank, the oil pumping is stopped, but the stirring cannot be stopped. After the oil is pumped, add edible defoamer to the deacidification tank, because foam must be generated during the stirring process, the defoamer is beneficial to eliminate foam, and is beneficial to oil sedimentation and stratification. The amount of defoamer is controlled within 0.05‰-0.1‰ (calculated according to the amount of oil in the deacidification tank). After the defoamer is added, the caustic soda and refined salt can be dissolved. The role of refined salt is mainly to reduce the oil content of saponins and increase the sedimentation rate. The amount of refined salt is controlled within 0.05%-0.1%. The amount of lye added is calculated based on the measured tallow acid value, and the lye concentration is controlled at about 0.4%. Add the dissolved caustic soda and refined salt into the deacidification tank at a flow rate of 0.5-1L/s. During the deacidification process, the oil temperature is controlled at 80℃-90℃. After the lye is dripped, continue to stir at the original speed for 10-15 minutes, then reduce the speed and stir for 5-10 minutes, then stop stirring, and stand still for 30-60 minutes. The defoamer floating on the liquid surface sucks away the deacidified tallow from the upper layer and enters the next process to release the lower layer of saponins to complete the deacidification process.

3.3 Decolorization and deodorization process

Pure butter is colorless when it is liquid, white when it is solid, and has no odor. But the deacidified butter has different colors, which is caused by the different amounts and varieties of pigments in the butter; the deacidified butter also has a bad smell, and these smells are generally caused by Volatile substances are mainly composed of certain traces of non-glyceride components, such as oxides of ketones, aldehydes, and hydrocarbons. In addition, some new odors will be generated during the refined processing of butter, such as the solvent odor in the leached oil, the soapy odor in the neutralization process, and the earthy odor in the decolorizing oil. It is precisely because of these different pigments and odors that affect the appearance and stability of the butter, and also affect the taste, etc., so it must be decolorized and deodorized. The process is only carried out in one tank, first decoloring and then deodorizing, saving one tank.

3.3.1 Decolorization

There are many methods for decolorization of tallow. The most widely used in industrial production is adsorption decolorization. In addition, there are heating decolorization, oxidation decolorization, and chemical reagent decolorization. Adsorption decolorization is a process in which some surface active substances with strong adsorption capacity are added to the oil, under certain process conditions, the pigment and other impurities in the grease are adsorbed, and the adsorbent and impurities are removed by filtration to achieve the purpose of decolorization and purification of the grease. Our company adopts adsorption decolorization method in the production, and the adsorbent selected is activated clay.

(1) Control of the amount of decolorizing agent

  Different types of pigments require different amounts of clay. At present, commercially available activated clay is used for the decolorization of domestic bulk oils. In the company's production, combined with the actual situation, the amount of white clay is controlled to be 1% to 3% of the oil weight.

(2) Control of decolorization temperature

The formation of "adsorbent-pigment" compounds on the surface of the adsorbent requires a certain amount of energy, so there must be a certain temperature to provide enough energy to make them react. The temperature is too high, and the generated heat cannot be released. The temperature is too low and the adsorption reaction cannot proceed. Production experience shows that its temperature is controlled at 85℃-90℃, and the decolorization effect is the best.

(3) Control of decolorization pressure

 Our company uses normal pressure to decolorize in production, so the pressure control requirements are not strict.

(4) Control of decolorization and stirring speed

In the decolorization process, continuous stirring is beneficial to decolorization, but the control of the stirring speed is also very important. In the actual production of the company, the range of the stirring speed is summarized. Generally, it is controlled at 40-60r/min, and the decolorization effect is the best.

(5) Control of decolorization time

Activated clay is acidic. As time goes by, the degree of oxidation of oil and the rate of acid value rise will increase the factors that affect decolorization. Therefore, it is necessary to control the decolorization time, and the production experience knows that the decolorization time is controlled at 15-20min.

(6) Decolorization process operation

The activated clay is first sucked into the decolorization tank, and its dosage is controlled at 1% to 3%, and then the deacidified tallow is pumped into the tank for the decolorization process. In the decolorization process, the decolorization time, temperature, stirring speed, and the amount of activated clay should be controlled. After the decolorization is completed, the next deodorization process is carried out in this tank.

3.3.2 Deodorization

Deodorization is mainly to remove those odorous substances in butter. Deodorization methods include vacuum steam deodorization, polymerization, gas injection, hydrogenation, and chemical deodorization. Among them, the vacuum steam deodorization method is currently the most widely used method at home and abroad with better results. It utilizes the great difference in the volatility of the odorous substances in the tallow and the volatility of the tallow. Under the conditions of high temperature and high vacuum, with the help of the principle of steam distillation, the volatile substances in the tallow that cause the odor are combined with the deodorizer in the deodorizer. Water vapor escapes together to achieve the purpose of deodorization.

(1) Control of deodorization temperature

Deodorization temperature is related to the quality of deodorization effect, so it is necessary to pay attention to temperature control. In actual production, the deodorizing temperature of tallow is controlled at 110°C-115°C.

(2) Control of deodorization pressure

In the deodorization method, vacuum deodorization is used, so the pressure in the tank should be kept in a vacuum, and the vacuum pressure should be controlled -0.08-0.09MPa during production.

(3) Control of deodorization time

In the production process of refined processing of butter, the deodorization time is generally controlled at 30 minutes.

(4) Deodorization process operation

Vacuum the butter processed in the previous step and control the oil temperature. After the deodorization time is reached, open the valve at the upper end of the deodorization tank to take away the odor from the water vapor to achieve the deodorization effect and complete the process.

4 Filter

The processed butter is pumped to the plate filter under pressure for filtering operation. Because activated clay is added during the decolorization process, it must be filtered out. Since decolorization and deodorization are carried out in one tank, it can be filtered only after deodorization is completed. When filtering, control the pressure of the filter well, generally maintain it at about 0.5Mpa, and control the flow rate at 2-5L/s. The filtered butter is cooled, inspected, and packaged into finished products.