Method for preparing feather protein powder by jointly applying sodium phosphate and sodium bicarbonate as catalysts

Abstract

The invention provides a method for preparing feather protein powder by jointly applying sodium phosphate and sodium bicarbonate as catalysts, and belongs to the technical field of biomass resource utilization. The method disclosed by the invention comprises the following steps: dispersing feathers in water, then adding the feathers into a mixed solution of sodium phosphate and sodium bicarbonate, and sequentially carrying out heating, pressurizing and drying treatment to obtain the feather protein powder. According to the method, sodium phosphate and sodium bicarbonate are combined for preparing the feather protein powder, so that the high-alkalinity condition required by hydrolysis of keratin can be considered, the defect of excessive hydrolysis of the feather powder caused by treatment with a strong-alkalinity solvent is overcome, the color and quality of the product are ensured, and the preparation cost of the feather protein powder is reduced.

Description

Technical Field

[0001] This invention relates to the field of biomass resource utilization technology, and in particular to a method for preparing feather protein powder by using sodium phosphate and sodium bicarbonate as catalysts in combination. Background Technology

[0002] The protein in livestock and poultry feathers is mainly composed of keratin, accounting for up to 85%. It also contains abundant 18 amino acids, including lysine, methionine, threonine, tryptophan, histidine, glycine, and cysteine, as well as various macro- and micro-elements, giving it extremely high potential for feed use. Processing feathers into protein powder can not only alleviate the shortage of protein feed ingredients but also reduce the environmental pollution caused by feathers.

[0003] Typically, the feathers of one adult chicken, duck, or goose can be processed into 80-150g of feather meal, while a single pig can produce 500g of pig hair meal. The crude protein content is as high as 85%-90%, and the cysteine ​​content is as high as 4.65%. Except for significantly lower levels of lysine and methionine, the composition of other essential amino acids in feather protein is slightly higher than in fishmeal. However, feather protein is an insoluble protein. The peptide chains within the protein backbone form many cord-like disulfide bonds, hindering the function of proteolytic enzymes. This results in a very low digestibility and absorption rate of feather protein by livestock and poultry, thus impeding its development and utilization.

[0004] Employing scientific processing methods to disrupt the spatial structure of keratin and improve the digestibility and absorption rate of feather protein has significant socio-economic value. Common processing methods for feather powder include enzymatic hydrolysis, acid-base chemical hydrolysis, extrusion puffing, microbial fermentation, and high-temperature, high-pressure hydrolysis. Among these, enzymatic hydrolysis mainly refers to the use of modern hydrolytic enzyme engineering technology, which involves stepwise low-temperature, low-pressure catalysis with the addition of multiple enzymes and catalysts, followed by high-pressure, high-temperature hydrolysis and sterilization. Then, based on a scientifically integrated processing technology and the assistance of various additives, a high-quality, high-efficiency composite enzymatically hydrolyzed feather protein powder is formed. The process of preparing feather protein powder through acid-base chemical hydrolysis typically involves mixing livestock and poultry feathers with a certain concentration and volume of acid or alkali and boiling the mixture while continuously stirring to ensure even heating. The feathers are boiled until they retain their original color and can be easily broken. They are then removed, the liquid is extracted, rinsed with water to remove the acid (or alkali), or neutralized with alkali (or acid), and finally dried, pulverized, and sieved to obtain feather powder. Currently, the selection of acid or alkali solutions mainly focuses on reagents such as sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium sulfite, hydrochloric acid, sulfuric acid, and phosphoric acid. For example, Influence of Process Parameters and Raw Materials on the Characteristics of Hydrolyzed Feather Meal, Waste and Biomass Valorization, DOI: https: / / doi.org / 10.1007 / s12649-020-01203-1. Effects of Autoclaving, Addition of Sodium Hydroxide and Their Combination on Protein Content in Vitro Digestibility of Chicken Feathers, International Journal of Poultry Science, 17(8):356-361, 2018. However, the above-mentioned acid-base chemical hydrolysis methods have certain drawbacks. The main drawbacks are that acid hydrolysis can easily cause equipment corrosion, alkaline hydrolysis usually uses strong alkali sodium hydroxide, which can easily lead to the deterioration of amino acids and excessive color of the product, while enzymatic hydrolysis has poor hydrolytic activity for keratin and is relatively expensive. Summary of the Invention

[0005] In view of this, the present invention provides a method for preparing feather protein powder by using sodium phosphate and sodium bicarbonate as catalysts in combination, comprising the following steps: dispersing feathers in water, adding a mixed solution of sodium phosphate and sodium bicarbonate, and sequentially heating and pressurizing and drying to obtain feather protein powder.

[0006] Preferably, the mass ratio of sodium phosphate to sodium bicarbonate is 1-3:1. More preferably, the mass ratio of sodium phosphate to sodium bicarbonate is 1-2:1.

[0007] Preferably, the feathers are pulverized before use, and the particle size of the pulverized feathers is controlled within the range of 0.5-2 cm. More preferably, the particle size of the pulverized feathers is controlled within the range of 1-2 cm, and even more preferably, the particle size of the pulverized feathers is 1.5 cm.

[0008] Preferably, the total amount of the sodium phosphate and sodium bicarbonate mixed solution is equivalent to 3-5 wt% of the weight of the feathers. More preferably, the total amount of the sodium phosphate and sodium bicarbonate mixed solution is equivalent to 3-4 wt% of the weight of the feathers.

[0009] Preferably, the total amount of water used is equivalent to 40-50 wt% of the weight of the feathers. More preferably, the total amount of water used is equivalent to 40-45 wt% of the weight of the feathers.

[0010] Preferably, the heating temperature is controlled within the range of 130-140°C, and more preferably, the heating temperature is 130°C.

[0011] Preferably, the reaction time under heating and pressurization is controlled within the range of 30-60 minutes.

[0012] Preferably, the drying temperature is controlled within the range of 75-85°C, and the drying process is carried out until constant weight is achieved.

[0013] Preferably, the feathers include, but are not limited to, the feathers of poultry such as chickens, ducks, and geese.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] This invention combines sodium phosphate and sodium bicarbonate, achieving a balance between reaction speed, product color and quality, and reduced production costs for feather protein powder. Feather hydrolysis involves the conversion of proteins into peptides, which are further hydrolyzed into feather protein powder primarily composed of amino acids and short peptides.

[0016] The sodium phosphate used in this invention undergoes hydrolysis upon dissolving in water, producing a strong alkalinity. This alkalinity allows for high reactivity in the crystalline regions of feather keratin and a strong decomposition effect on the low-activity keratin in the initial stages of the reaction. As the reaction progresses, short peptides and some amino acids are produced, preferentially consuming sodium phosphate and causing a decrease in alkalinity. Subsequently, sodium bicarbonate is dissolved in water, also reaching a pH of approximately 8.7. This slight alkalinity promotes further peptide hydrolysis at high temperatures, but the mild alkaline environment prevents amino acid degradation. The resulting feather protein powder is lighter in color than when using strong alkaline sodium hydroxide as a hydrolysis promoter. The synergistic effect of sodium phosphate and sodium bicarbonate achieves the high alkalinity required for keratin hydrolysis while also addressing the drawback of excessive hydrolysis of feather powder caused by using strong alkaline solvents. Attached Figure Description

[0017] Figure 1 This is a picture of the feather protein powder from Embodiment 1 of the present invention.

[0018] Figure 2 This is a picture of the feather protein powder from Embodiment 2 of the present invention.

[0019] Figure 3 This is a picture of the feather protein powder of Comparative Example 1 of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0021] Unless otherwise specified, the test methods or experimental methods described in the following examples are all conventional methods; unless otherwise specified, the raw materials and additives are obtained from conventional commercial sources or prepared by conventional methods.

[0022] Example 1

[0023] Take 100g of white duck feathers, crush them to 1.5cm, add 40mL of water, add 3g of Na3PO4 and 3g of NaHCO3, and put them into a 1L stainless steel pressure reactor. Turn on the jacket electric heating and control the temperature inside the reactor to 130℃ for half an hour. Turn off the heating power, slowly depressurize, and release the exhaust gas into the fume hood. Dry the water-containing powder inside the reactor in a vacuum drying oven at 80℃ to obtain light yellow feather protein powder.

[0024] Example 2

[0025] The difference from Example 1 is that the amount of NaHCO3 added is 5g.

[0026] Comparative Example 1

[0027] The difference from Example 1 is that 6g of NaOH was used instead of 3g of Na3PO4 and 3g of NaHCO3. Test results showed that the resulting feather protein powder was significantly darker in color than that of Example 1.

[0028] Comparative Example 2

[0029] The difference from Example 1 is that the temperature inside the reactor was controlled at 120°C. Test results showed that the color of the obtained feather protein powder was significantly lighter than that of Example 1, but the powder contained clearly visible stiff feather shafts, indicating that the reaction was not complete.

[0030] Comparative Example 3

[0031] The difference from Example 1 is that the temperature inside the reactor was controlled at 150°C. Test results showed that the resulting feather protein powder turned a lighter brown color.

[0032] Comparative Example 4

[0033] The difference from Example 1 is that sodium carbonate is used to replace Na3PO4 in an equal amount.

[0034] The absorbable protein components in the feather protein powder prepared in the detection examples and comparative examples were analyzed. The method and procedure for determining the test protein in the experiment are in accordance with GB / T17811-2008. The results are shown in Table 1.

[0035] Table 1

[0036] project Absorbable protein content, % Example 1 90 Example 2 91 Comparative Example 1 87 Comparative Example 2 85 Comparative Example 3 83 Comparative Example 4 88

[0037] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing feather protein powder by jointly using sodium phosphate and sodium bicarbonate as catalysts, characterized in that, Includes the following steps: After dispersing the feathers in water, a mixed solution of sodium phosphate and sodium bicarbonate is added, followed by heating, pressurization, and drying to obtain feather protein powder.

2. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The mass ratio of sodium phosphate to sodium bicarbonate is 1-3:

1.

3. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The feathers are pulverized before use, and the particle size of the pulverized feathers is controlled within the range of 0.5-2cm.

4. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The total amount of the sodium phosphate and sodium bicarbonate mixed solution used is equivalent to 3-5 wt% of the weight of the feathers.

5. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The total amount of water used is equivalent to 40-50 wt% of the weight of the feathers.

6. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The heating temperature is controlled within the range of 130-140℃.

7. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The reaction time under heating and pressurization is controlled within the range of 30-60 minutes.

8. The method for preparing feather protein powder by combining sodium phosphate and sodium bicarbonate as catalysts according to claim 1, characterized in that, The drying temperature is controlled within the range of 75-85℃, and the drying process is carried out until constant weight is achieved.

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