Plant crude oil compound enzyme degumming method and application thereof

Abstract

The invention discloses a compound enzyme degumming method for crude plant oil and application of the compound enzyme degumming method. Quara Boost and Quara LowP are adopted for compound enzyme method degumming, phospholipase C can hydrolyze phospholipids, degummed foots are reduced, and the loss of neutral oil in the grease separation process is reduced. The content of diglyceride can be remarkably increased by degumming through a compound enzyme method, so that the yield of grease is increased. Meanwhile, excessive generation of free fatty acid is avoided, the increase of acid value is inhibited, and the quality of the degummed oil is improved. The degumming reaction time of the single phospholipase A1 is shortened, and the defect that the degumming effect of the single phospholipase C is not thorough is overcome.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil processing, in particular to a composite enzyme degumming method for crude vegetable oil and application thereof. BACKGROUND

[0002] The crude vegetable oil obtained by mechanical pressing or solvent extraction without refining is called crude vegetable oil, and phospholipid is the core component of colloidal impurities therein. The presence of phospholipid will affect the sensory and nutritional value of oil and fat, and even may cause food safety problems. The essence of industrial "degumming" is the directional removal of phospholipid. High-quality edible oil meeting the standards cannot be obtained without oil refining processing, and degumming as a key step of refining effectively removes phospholipid to facilitate the subsequent refining process and obtain more clarified, more stable and safer vegetable oil. The phospholipid composition of crude vegetable oil from different sources varies greatly, and the presence of non-hydrated phospholipid brings great challenges to the completeness of degumming. Therefore, the traditional degumming technology cannot meet the refining requirements, and the enzyme degumming has the advantages of high efficiency, high oil yield and green environmental protection, and has become the development trend in the field of crude vegetable oil degumming. The emergence and development of enzyme degumming promote the crude vegetable oil degumming to a new stage of high efficiency, high value and green environmental protection. SUMMARY

[0003] The present application aims to overcome the shortcomings and deficiencies of the prior art, and provides a composite enzyme degumming method for crude vegetable oil.

[0004] Another object of the present application is to provide the application of the composite enzyme degumming method for crude vegetable oil.

[0005] The object of the present application is achieved by the following technical solutions:

[0006] A composite enzyme degumming method for crude vegetable oil, comprising the following steps:

[0007] (1) heating and holding the crude vegetable oil, adding citric acid, homogenizing, stirring for acidification, adjusting the pH after acidification,

[0008] (2) adding phospholipase C and buffer, homogenizing, and performing the first degumming reaction;

[0009] (3) heating and holding the product obtained by the first degumming reaction, adding phospholipase A1, and performing the second degumming reaction;

[0010] (4) heating and holding the product obtained by the second degumming reaction, inactivating, and breaking the emulsion to obtain the degummed crude linseed oil.

[0011] The holding in step (1) is 70-85℃ for 5-100min.

[0012] The plant crude oil in step (1) is a non-refined plant oil obtained by mechanical pressing or solvent extraction; preferably, it is a flaxseed crude oil.

[0013] The mass ratio of the plant crude oil in step (1) to citric acid is 5000:3-12; preferably, it is 5000:6.

[0014] The homogenization in step (1) is performed at 8000-12000 rpm; preferably, it is performed at 10000 rpm.

[0015] The acidification in step (1) is performed at 400-600 rpm for 20-40 min; preferably, it is performed at 500 rpm for 30 min.

[0016] The pH adjustment in step (1) is performed by adjusting the pH to 6-8.

[0017] The phospholipase C in step (2) is Quara Boost produced by Novozymes.

[0018] The phospholipase C in step (2) is added in an amount of 500-800 U / kg; preferably, it is added in an amount of 690 U / kg.

[0019] The buffer in step (2) is added in an amount of 2-4 wt% of the total water content.

[0020] The buffer in step (2) is a sodium citrate buffer.

[0021] The homogenization in step (2) is performed at 8000-12000 rpm; preferably, it is performed at 10000 rpm.

[0022] The first degumming reaction in step (2) is performed at 50-60°C at 400-600 rpm for 50-70 min.

[0023] The incubation in step (3) is performed at 60-80°C for 5-10 min.

[0024] The phospholipase A1 in step (3) is Quara LowP produced by Novozymes.

[0025] The phospholipase A1 in step (3) is added in an amount of 80-120 U / kg; preferably, it is added in an amount of 100 U / kg.

[0026] The second degumming reaction in step (3) is performed at 60-80°C at 400-600 rpm for 30-50 min.

[0027] The incubation in step (4) is performed at 80-90°C for 2-10 min.

[0028] The application of the above-mentioned crude plant oil composite enzyme degumming method in oil and fat processing.

[0029] The present invention has the following advantages and effects compared to the prior art:

[0030] (1) When using Quara Boost and Quara LowP for the composite enzyme method, phospholipase C can hydrolyze phospholipids, reduce degumming oil bottoms, and reduce the loss of neutral oil during oil separation.

[0031] (2) Composite enzyme degumming can significantly increase the diglyceride content, thereby improving the oil yield.

[0032] (3) It avoids the excessive generation of free fatty acids, which is beneficial to inhibit the increase of acid value and improve the quality of degummed oil.

[0033] (4) The reaction time of degumming by single phospholipase A1 is shortened, and the defect of incomplete degumming effect by single phospholipase C is also made up. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 The linseed oil residue is obtained after degumming by different treatment methods in the embodiments and comparative examples.

[0035] Figure 2 is the phosphorus content of different treatment methods in the examples and comparative examples.

[0036] Figure 3 is the diglyceride increment of different treatment methods in Examples and Comparative Examples.

[0037] Figure 4 It is the free fatty acid increment of different treatment methods in the examples and comparative examples. DETAILED DESCRIPTION

[0038] The present invention will be described in further detail below with reference to the embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0039] If specific experimental conditions are not specified in the following embodiments, conventional experimental conditions or those recommended by the reagent company will generally be used. Materials and reagents used were commercially available unless otherwise specified.

[0040] The sources of the various enzymes used in the examples are as follows:

[0041] Phospholipase C Quara Boost and Phospholipase A1 Quara LowP were from Novozymes.

[0042] The main detection methods of the present invention are as follows:

[0043] The method for determining the phosphorus content in oils and fats before and after degumming shall refer to GB / T 5537-2008 “Inspection of grains and oils—Determination of phospholipid content”.

[0044] Free fatty acid determination method: Analysis was performed using normal-phase high-performance liquid chromatography (HPLC) equipped with a differential refractive index detector on a Phenomenex Luna column (4.6 mm × 250 mm, 5 μm particle size). The mobile phase consisted of n-hexane, isopropanol, and formic acid (23:1:0.003, v / v / v), with a column temperature of 30°C and a flow rate of 1 mL / min. Dissolve 10 μL of the oil sample in 1 mL of mobile phase. Subsequently, add 0.1 g of anhydrous sodium sulfate to remove moisture. After centrifugation at 10,000 rpm for 1 minute, aspirate the supernatant with a syringe, filter it through a 0.22 μm filter, and prepare for injection. Free fatty acid content was quantified using the area normalization method.

[0045] Diacylglycerol determination: Separation was performed using a Waters high-performance liquid chromatography (HPLC) equipped with an evaporative light detector (EVD) using a silica gel column (4.6 mm × 250 mm, 5 μm particle size). Mobile phase A consisted of n-hexane:isopropanol (99:1, v / v) and mobile phase B consisted of n-hexane:isopropanol:glacial acetic acid (1:1:0.01, v / v / v). The flow rate was 1 mL / min, and the gradient elution program was as follows: 100% mobile phase A (0–10 min); 90% mobile phase A (10–14 min); 70% mobile phase A (14–15 min); and 100% mobile phase A (15–20 min). Detection parameters included a detector gain of 1, a gas pressure of 22.0 psi, a drift tube temperature of 55°C, and a column temperature of 35°C.

[0046] Example 1

[0047] (1) Before degumming, appropriate crude linseed oil was taken to detect its phosphorus content, diglyceride content and free fatty acid content. The results showed that the phosphorus content was 342.24 mg / kg, the diglyceride content was 2.38%, and the free fatty acid content was 8.58%.

[0048] (2) 100 g of crude linseed oil was weighed and kept at 70°C for 10 min. A 0.12% (w / w) citric acid solution (50 wt%) was added and homogenized at high speed (10,000 rpm) for 1 min. The mixture was then stirred at 500 rpm for 30 min for acidification. After acidification, a 4% NaOH solution was added to adjust the pH of the reaction system to 7.0.

[0049] (3) Add 0.05 M sodium citrate disodium buffer and 690 U / kg Quara Boost to ensure a total water content of 3% (w / w) and homogenize at 10,000 rpm for 1 min. Then, degumming was performed at 55°C and stirred at 500 rpm for 60 min.

[0050] (4) After the first degumming, transfer to 70°C for 10 min, adjust the reaction pH to 4.0, and then add 100 U / kg Quara Low P. Continue to stir at 500 rpm for 40 min.

[0051] (5) After the reaction, heat the mixed oil to 85°C for 5 min to inactivate the enzyme and break the emulsion, and obtain the degummed flaxseed crude oil.

[0052] (6) Take an appropriate amount of degummed flaxseed crude oil for testing. The experimental results show that the phosphorus content decreases from 342.24 to 1.71 mg / kg, the diglyceride content increases by 0.52%, and the free fatty acid content does not change.

[0053] Example 2

[0054] The degumming method is the same as in Example 1, except that the amount of citric acid added is changed from 0.12% to 0.18%. After degumming, the phosphorus content of the flaxseed crude oil is 1.73 mg / kg, the diglyceride content increases by 0.51%, and the free fatty acid content does not change.

[0055] Example 3

[0056] The degumming method is the same as in Example 1, except that the reaction pH of Quara Boost is changed from 7.0 to 6.0. After degumming, the phosphorus content of the flaxseed crude oil is 1.89 mg / kg, the diglyceride content increases by 0.47%, and the free fatty acid content does not change.

[0057] Example 4

[0058] The degumming method is the same as in Example 1, except that the reaction pH of Quara Boost is changed from 7.0 to 8.0. After degumming, the phosphorus content of the flaxseed crude oil is 1.97 mg / kg, the diglyceride content increases by 0.42%, and the free fatty acid content does not change.

[0059] Example 5

[0060] The degumming method is the same as in Example 1, except that the amount of Quara Boost enzyme added is changed from 690 U / kg to 920 U / kg. After degumming, the phosphorus content of the flaxseed crude oil is 1.80 mg / kg, the diglyceride content increases by 0.49%, and the free fatty acid content does not change.

[0061] Example 6

[0062] The degumming method was the same as Example 1 except that the Quara Boost reaction temperature was changed from 55 °C to 50 °C. The phosphorus content of the crude linseed oil after degumming was 1.81 mg / kg, the diglyceride content was increased by 0.46%, and the free fatty acid content was unchanged.

[0063] Example 7

[0064] The degumming method was the same as Example 1 except that the Quara Boost reaction time was changed from 60 min to 80 min. The phosphorus content of the crude linseed oil after degumming was 2.23 mg / kg, the diglyceride content was increased by 0.52%, and the free fatty acid content was unchanged.

[0065] Example 8

[0066] The degumming method was the same as Example 1 except that the Quara Low P reaction temperature was changed from 70 °C to 75 °C. The phosphorus content of the crude linseed oil after degumming was 2.41 mg / kg, the diglyceride content was increased by 0.52%, and the free fatty acid content was unchanged.

[0067] Example 9

[0068] The degumming method was the same as Example 1 except that the Quara Low P reaction pH was changed from 4.0 to 3.0. The phosphorus content of the crude linseed oil after degumming was 2.50 mg / kg, the diglyceride content was increased by 0.52%, and the free fatty acid content was unchanged.

[0069] Example 10

[0070] The degumming method was the same as Example 1 except that the Quara Low P enzyme dosage was changed from 100 U / kg to 150 U / kg. The phosphorus content of the crude linseed oil after degumming was 2.16 mg / kg, the diglyceride content was increased by 0.52%, and the free fatty acid content was unchanged.

[0071] Example 11

[0072] The degumming method was the same as Example 1 except that the Quara Low P enzyme dosage was changed from 100 U / kg to 200 U / kg. The phosphorus content of the crude linseed oil after degumming was 1.90 mg / kg, the diglyceride content was increased by 0.51%, and the free fatty acid content was unchanged.

[0073] Comparative Example 1

[0074] The degumming method was the same as Example 1 except that the Quara Boost reaction pH was changed from 7.0 to 4.0. The phosphorus content of the crude linseed oil after degumming was 1.72 mg / kg, the diglyceride content was increased by 0.09%, and the free fatty acid content was increased by 0.32%.

[0075] Comparative Example 2

[0076] The degumming method was the same as that in Example 1, except that the pH of the Quara Boost reaction was changed from 7.0 to 5.0. After degumming, the phosphorus content of crude linseed oil was 1.83 mg / kg, the diglyceride content increased by 0.18%, and the free fatty acid content increased by 0.3%.

[0077] Comparative Example 3

[0078] The degumming method was the same as that in Example 1, except that the reaction temperature of Quara LowP was changed from 70°C to 55°C. After degumming, the phosphorus content of crude linseed oil was 7.85 mg / kg, the diglyceride content increased by 0.51%, and the free fatty acid content remained unchanged.

[0079] Comparative Example 4

[0080] The degumming method was the same as that in Example 1, except that the pH of the Quara LowP reaction was changed from 4.0 to 7.0. After degumming, the phosphorus content of crude linseed oil was 11.91 mg / kg, the diglyceride content increased by 0.52%, and the free fatty acid content remained unchanged.

[0081] Comparative Example 5

[0082] The degumming method was the same as that in Example 1, except that the pH of the Quara LowP reaction was changed from 4.0 to 6.0. After degumming, the phosphorus content of crude linseed oil was 8.73 mg / kg, the diglyceride content increased by 0.51%, and the free fatty acid content remained unchanged.

[0083] Comparative Example 6

[0084] Degumming was carried out according to the method of Example 1, except that steps (4) and (6) were omitted and the reaction time in step (3) was adjusted to 100 min.

[0085] The phosphorus content of the degummed flaxseed oil obtained after centrifugation decreased from 342.24 to 17.34 mg / kg, the diglyceride content increased by 0.51%, and the free fatty acid content did not change.

[0086] Comparative Example 7

[0087] The degumming method was the same as that of Comparative Example 6, except that the reaction pH was changed from 7.0 to 4.0. After degumming, the phosphorus content of crude linseed oil was 23.22 mg / kg, the diglyceride content increased by 0.08%, and the free fatty acid content did not change.

[0088] Comparative Example 8

[0089] The degumming method was the same as that of Comparative Example 6, except that the reaction pH was changed from 7.0 to 5.0. After degumming, the phosphorus content of crude linseed oil was 19.41 mg / kg, the diglyceride content increased by 0.19%, and the free fatty acid content did not change.

[0090] Comparative Example 9

[0091] Degumming was performed according to the method of Example 1, except that step (3) was omitted, the reaction pH in step (4) was adjusted to 7.0, and the amount of Quara LowP enzyme added was changed from 100 U / kg to 400 U / kg. After degumming, the phosphorus content of crude linseed oil was 11.98 mg / kg, the diglyceride content increased by 0, and the free fatty acid content increased by 0.11%.

[0092] Comparative Example 10

[0093] Degumming was performed according to the method of Example 1, except that the order of steps (3) and (4) was changed, i.e., Quara LowP degumming was performed first, followed by Quara Boost degumming. The pH in step (2) was changed to 4.0, and the reaction pH in step (3) was 7.0. After degumming, the crude linseed oil had a phosphorus content of 1.81 mg / kg, a diglyceride content increased by 0, and a free fatty acid content increased by 0.38%.

[0094] Table 1 Parameter comparison of different degumming conditions and the phosphorus content, diglyceride content and free fatty acid content of the products

[0095]

[0096]

[0097] Note: “ / ” means not setting the condition, and “-” means not detected.

[0098] As shown in Table 1, the combined enzymatic degumming method using Quara Boost and Quara LowP in this example achieved excellent results, thoroughly hydrolyzing phospholipids and reducing phosphorus content to between 1.21 and 2.50 mg / kg, meeting refining requirements. This process, with a short reaction time of 100 minutes and excellent results, also generated additional diacylglycerol, increasing its content by approximately 0.42 to 0.52%. This method avoids the acid value increase associated with degumming using only phospholipase A1, Quara LowP, and addresses the incomplete degumming problem associated with using only phospholipase C, Quara Boost.

[0099] Furthermore, during the combined enzyme degumming process, while Quara Boost can reduce phosphorus content to below 5 mg / kg at a reaction pH of 4.0-5.0, the diacylglycerol increase is only 0.09-0.18%, far lower than the diacylglycerol increase in the examples. At a reaction pH of 6.0-7.0, Quara LowP's degumming effect is poor and falls short of refining requirements. In particular, the degumming effects of Quara Boost and Quara LowP alone fall far short of refining requirements, and the Quara LowP degumming process produces no diacylglycerol at all.

[0100] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A plant crude oil composite enzyme degumming method, characterized in that The steps include: (1) Heat the crude vegetable oil and keep it warm, add citric acid, homogenize, stir and acidify, and adjust the pH after the acidification is completed. (2) adding phospholipase C and buffer, homogenizing, and performing the first degumming reaction; (3) heating the product obtained from the first degumming reaction and keeping it warm, adding phospholipase A1, and performing a second degumming reaction; (4) heating the product obtained from the second degumming reaction and keeping it warm, inactivating it, and breaking the emulsion to obtain the degummed linseed crude oil.

2. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The heat preservation in step (1) is 70-85° C. for 5-100 minutes; The crude vegetable oil in step (1) is unrefined vegetable oil obtained by mechanical pressing or solvent extraction.

3. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The mass ratio of the crude vegetable oil to the citric acid in step (1) is 5000:3-12; The acidification condition in step (1) is stirring at 400-600 rpm for 20-40 minutes.

4. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The homogenization condition in step (1) is 8000-12000 rpm; The pH adjustment in step (1) is to adjust the pH to 6-8.

5. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The amount of the buffer solution added in step (2) is such that the total water content reaches 2-4 wt%; The buffer solution in step (2) is disodium hydrogen citrate buffer solution; The homogenization condition in step (2) is 8000-12000 rpm.

6. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The amount of phospholipase C added in step (2) is 500-800 U / kg; The conditions of the first degumming reaction in step (2) are 50-60° C. and 400-600 rpm for 50-70 min.

7. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The insulation condition of step (3) is insulation at 60-80° C. for 5-10 minutes.

8. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The amount of phospholipase A1 added in step (3) is 80-120 U / kg; The second degumming reaction in step (3) is carried out at 60-80° C. and 400-600 rpm for 30-50 min.

9. The plant crude oil composite enzyme degumming method according to claim 1, wherein: The insulation condition of step (4) is insulation at 80-90° C. for 2-10 minutes.

10. Use of the composite enzymatic degumming method for crude plant oil according to any one of claims 1 to 9 in oil and fat processing.

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