Functional grease and preparation method thereof

Abstract

The preparation method comprises the following steps: adding mulberry leaf powder into raw material oil of the functional grease with the acid value lower than 1.0 mgKOH / g, carrying out heat preservation incubation under the protection of nitrogen, and then carrying out decoloration treatment, filtration and recovery to obtain the functional grease. According to the method, a proper amount of mulberry leaf powder is added into the raw oil, incubation is performed for a certain period of time at a proper temperature, then decoloration treatment is performed, and deodorization treatment is performed or not performed, so that the oxidation stability and the digestion and absorption rate of the obtained refined oil are remarkably improved, and the method has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of food science and technology, and more specifically, relates to a functional oil capable of improving oxidation stability and digestion and absorption rate and a preparation method thereof. Background Art

[0002] Polyunsaturated fatty acids are essential fatty acids that the human body cannot synthesize by itself or has a very low efficiency. The human body must obtain enough polyunsaturated fatty acids from food to maintain health. The main source of polyunsaturated fatty acids is edible oils with high content of polyunsaturated fatty acids, such as marine fish oil, linseed oil, silkworm pupa oil, etc. Oils rich in polyunsaturated fatty acids are easily oxidized. When polyunsaturated fatty acids come into contact with oxygen or strong oxidants, they will be oxidized and produce harmful free radicals. In order to avoid this situation, it is necessary to reduce the chance of contact with oxygen during processing and storage as much as possible. The most commonly used method in industry is to add antioxidants.

[0003] Mulberry leaves are a common medicinal and edible resource. They are rich in phenolic substances, which have antioxidant, antibacterial, and anti-inflammatory effects and are widely used in the pharmaceutical and food industries. These phenolic substances have a good antioxidant effect in oils and fats, which can prevent oils and fats from being oxidized and deteriorating, and maintain the stability and nutritional value of oils and fats.

[0004] Pancreatic lipase is a key digestive enzyme that can break down fat into fatty acids and glycerol, which can then be absorbed and utilized by the human body. However, studies have found that when mulberry leaf phenolics are simply added to oils and fats, the mulberry leaf phenolics will bind to the active center of pancreatic lipase, resulting in a significant decrease in enzyme activity and a decrease in the digestion and absorption rate of oils and fats. Therefore, although the phenolics in mulberry leaves have an antioxidant effect in oils and fats, they will have a certain impact on their digestion and absorption rate during the digestion of oils and fats. In practical applications, it is necessary to pay attention to offsetting its shortcomings and adopt some methods to maximize its antioxidant effect while avoiding it from causing a decrease in the digestibility of functional fat components. Summary of the invention

[0005] Based on this, the object of the present invention is to provide a functional oil and a preparation method thereof.

[0006] The technical solutions for achieving the above-mentioned invention objectives include the following.

[0007] The first aspect of the present invention provides a method for preparing a functional oil, comprising the following steps: adding mulberry leaf powder to a raw material oil of a functional oil having an acid value lower than 1.0 mgKOH / g, incubating under nitrogen protection, decolorizing, filtering and recovering, so as to obtain the functional oil.

[0008] The second aspect of the present invention provides a functional oil prepared by the above preparation method.

[0009] In the present invention, by adding an appropriate amount of mulberry leaf powder to the raw material, incubating at a suitable temperature for a certain period of time, and then performing a decolorization treatment, and then performing or not performing a deodorization treatment, the oxidation stability and digestion and absorption rate of the obtained refined oil are significantly improved, and the refined oil has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 The following are the oxidative stability results of the refined silkworm pupa oils in Example 1 of the present invention.

[0011] Figure 2 The digestibility results of each refined silkworm pupa oil in Example 1 of the present invention are shown.

[0012] Figure 3 The following are the oxidative stability results of the refined sardine oils in Example 2 of the present invention.

[0013] Figure 4 The digestibility results of each refined sardine oil in Example 2 of the present invention are shown.

[0014] Figure 5 The oxidative stability results of refined silkworm pupa oil at various incubation temperatures in Example 3 of the present invention are shown.

[0015] Figure 6 The oxidative stability results of refined silkworm pupa oil at various incubation times in Example 4 of the present invention are shown.

[0016] Figure 7 The oxidative stability results of refined sardine oil at various deodorization temperatures in Example 5 of the present invention are shown.

[0017] Figure 8 The digestibility results of refined sardine oil at various deodorization temperatures in Example 5 of the present invention are shown. DETAILED DESCRIPTION

[0018] In order to facilitate the understanding of the present invention, the present invention will be described more fully below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0019] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in the present invention includes any and all combinations of one or more of the related listed items.

[0020] The experimental methods in the following examples where specific conditions are not specified are generally carried out under conventional conditions, such as those described in Green and Sambrook et al., Molecular Cloning: A Laboratory Manual (2013), or according to the conditions recommended by the manufacturer. The various commonly used chemical reagents used in the examples are all commercially available products.

[0021] Oil raw material oil generally needs to be deacidified, decolorized and deodorized to meet the edible requirements. The inventor of the present invention has found through a large number of studies that the oxidation stability and digestibility of the refined oil obtained by deacidifying the crude oil of functional oil as raw material oil, adding an appropriate amount of mulberry leaf powder to the raw material oil, and incubating it for a certain period of time under nitrogen protection (mulberry leaf powder can play a certain role as an oxidation stabilizer and antioxidant, reducing the possibility of oxidation of refined oil during the production process, and will not affect the activity of pancreatic lipase), and then decolorizing it, and then with or without deodorization, the oxidation stability and digestibility of the obtained refined oil are significantly improved.

[0022] In some embodiments of the present invention, a method for preparing a functional oil is disclosed, comprising the following steps: adding mulberry leaf powder to a raw material oil of a functional oil having an acid value lower than 1.0 mgKOH / g, incubating under nitrogen protection, decolorizing, filtering and recovering, thereby obtaining the functional oil.

[0023] In some embodiments, the decolorization step further includes a deodorization step, and the oxidative stability and digestibility of the refined oils and fats obtained are further improved.

[0024] In some embodiments, the temperature of the deodorization treatment is 120°C to 150°C, and the time of the deodorization treatment is 1 to 2 hours. Preferably, the temperature of the deodorization treatment is 140°C, and the time of the deodorization treatment is 2 hours.

[0025] In some embodiments, the added amount of the mulberry leaf powder is 1% to 2.5% by weight of the functional oil raw material oil, preferably 1.5% to 2.5%, more preferably 2% to 2.5%, and most preferably 2%.

[0026] In some embodiments, the temperature of the incubation is 30°C to 60°C, and the incubation time is 1 to 4 hours. Preferably, the temperature of the incubation is 40°C to 50°C, and the incubation time is 1 to 2 hours. More preferably, the temperature of the incubation is 40°C, and the incubation time is 2 hours.

[0027] In some embodiments, the mulberry leaf powder is one or more of Yueshen No. 10, Yuesang No. 11, Yuesang No. 51, and Kangqing No. 10. More preferably, the mulberry leaf powder is Yueshen No. 10 and / or Yuesang No. 11.

[0028] In some embodiments, the functional oil is an oil rich in polyunsaturated fatty acids.

[0029] In some embodiments, the functional oil is marine fish oil, linseed oil, silkworm pupa oil or polyunsaturated fatty ethyl ester.

[0030] In some embodiments, the marine fish oil is tuna oil, sardine oil or anchovy oil.

[0031] In other embodiments of the present invention, functional oils and fats prepared by the above preparation method are disclosed.

[0032] In the following embodiments of the present invention, the deacidification treatment method refers to the deacidification treatment method of "Study on the effect of deacidification process of rice bran mixed oil alkali refining".

[0033] The oxidation stability test method is as follows:

[0034] The Rancima method described in BS EN ISO 6886:2016 Determination of the oxidative stability of animal and vegetable fats and oils (accelerated oxidation test) was used to detect the oxidative stability of oils and fats, and the induction time was used as an indicator to characterize the oxidative stability of the sample. 3.0 g of sample was placed in a Rancimat 743 test tube, and the test tube was placed in a constant temperature electric heating block, set to a constant temperature of 110 ° C, and the air flow rate was 10 L / h. The time when the oxidation product appears is the oxidation induction time of the sample.

[0035] The in vitro digestion experiment method is as follows:

[0036] The bioaccessibility of refined oils was investigated by referring to the standardized method of in vitro simulated food digestion of INFOGEST 2.0. The specific method is as follows: weigh 1g of oil sample, add 2.5mL SSF digestion solution (containing salivary amylase, 75U / mL) in a 50mL centrifuge tube, place it in a 37℃ constant temperature heated magnetic stirrer to simulate oral digestion for 3min, then add 3mL SGF digestion solution, adjust the pH to 3.0 with 6mol / L HCl solution, and then add 2mL pepsin solution (2000U / mL), 15uL CaCl 2 Solution, simulate gastric digestion for 120 min. Finally, add 4 mL of SIF digestion solution, adjust the pH to 7.0 with 4 mol / L NaOH solution, add 5 mL of pancreatic lipase solution (100 U / mL), 1 mL of bile salt solution (133.6 mg / mL), 20 uL of CaCl 2Solution, simulated small intestinal digestion for 0min, 30min, 60min, 90min, 120min. After digestion, all samples were immediately inactivated by high temperature and stored in a -20℃ refrigerator. A chloroform and methanol mixed solution (chloroform: methanol = 3:1) was used to extract the oil phase in the digested samples. After nitrogen was blown to dry the solvent, the oil composition was analyzed by liquid chromatography. The oil digestibility calculation formula is shown below.

[0037]

[0038] Wherein, D is the digestibility of fat (%), FFA is free fatty acid, MAG is monoglyceride, DAG is diglyceride, and TAG is triglyceride.

[0039] For the deodorization treatment method, please refer to "Li Zimu. Influence of refining process conditions on the quality and composition changes of DHA algae oil [D]. Henan University of Technology, 2022.".

[0040] In the following examples, the raw materials and reagents used were all commercially available.

[0041] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Example 1 Preparation method of refined silkworm chrysalis oil

[0043] The following steps are involved:

[0044] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0045] 2. Add 10 g of mulberry leaf dry powder of Yueshen No. 10, Yuesang No. 11, Yuesang No. 51 and Kangqing No. 10 respectively to 1.0 kg of raw material oil, place in a 2 L stoppered flat-bottom flask, fill with nitrogen and seal, place in a constant temperature magnetic stirrer at 40 ° C, and stir for 2 h;

[0046] The preparation method of mulberry leaf dry powder refers to "Kuang Zheshi, Huang Jing, Liao Sentai, et al. Effects of mulberry leaf powder and fermented mulberry leaf powder on slaughter performance, meat quality and cecal flora of bearded chickens [J]. Chinese Journal of Animal Husbandry and Veterinary Medicine, 2016, 43(08): 1989-1997.".

[0047] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover to obtain refined silkworm pupa oil.

[0048] Sampling was performed to test its oxidation stability and digestibility. The results of oxidation stability and digestibility were as follows: Figure 1 and Figure 2As shown in the figure. Adding four different mulberry leaf powders to the deacidified silkworm pupa oil and then bleaching it to obtain refined silkworm pupa oil, the oxidative stability OSI and digestibility of the oil were improved; Yuezhen No. 10 had the best effect.

[0049] Example 2 Preparation method of refined sardine oil

[0050] The following steps are involved:

[0051] 1. Deacidify the crude sardine oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0052] 2. Add 5g, 10g, 15g, 20g and 25g of mulberry leaf dry powder of Yueshen No. 10 to 1.0kg of raw oil respectively, place in a 2L stoppered flat-bottom flask, fill with nitrogen and seal, place in a constant temperature magnetic stirrer at 40°C, and stir for 2h;

[0053] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover to obtain refined sardine oil.

[0054] Samples were taken to test their oxidation stability and digestibility. The results of oxidation stability and digestibility were as follows: Figure 3 and Figure 4 As shown. After adding Yuezhen No. 10 mulberry leaf powder to the deacidified sardine oil and then bleaching, the oxidative stability OSI and digestibility of the refined sardine oil were improved. When the addition amount of mulberry leaf powder was above 10g / kg of fish oil, the oxidative stability OSI did not increase significantly, while the digestibility of the refined sardine oil had an obvious dose effect.

[0055] Example 3 Preparation method of refined silkworm chrysalis oil

[0056] The following steps are involved:

[0057] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0058] 2. Add 10 g of mulberry leaf dry powder of Yueshen No. 10 to 1.0 kg of crude oil, place in a 2 L stoppered flat-bottom flask, fill with nitrogen and seal, place in a constant temperature magnetic stirrer at 30°C, 40°C, 50°C, 60°C, 70°C, respectively, and stir for 2 h;

[0059] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover to obtain refined silkworm pupa oil.

[0060] Sampling was performed to test its oxidation stability and digestibility. The results of oxidation stability and digestibility were as follows: Figure 5 As shown. Figure 5 It can be seen that the incubation temperature has a significant effect on the oxidative stability of refined silkworm pupa oil. When treated at 30-40℃ for 2h, its OSI increased significantly with the increase of treatment temperature. When the temperature continued to increase from 40℃ to 60℃, its OSI did not change much with the increase of treatment temperature. Therefore, a constant temperature treatment of 40℃ was used for subsequent experiments.

[0061] Example 4 Preparation method of refined silkworm chrysalis oil

[0062] The following steps are involved:

[0063] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0064] 2. Add 10 g of mulberry leaf powder of Yueshen No. 10 to 1.0 kg of crude oil, place in a 2 L stoppered flat-bottom flask, fill with nitrogen and seal, place in a 40 ° C constant temperature magnetic stirrer, and stir for 0, 1 h, 2 h, 3 h, and 4 h respectively;

[0065] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover to obtain refined silkworm pupa oil.

[0066] Sampling was performed to test its oxidation stability and digestibility. The results of oxidation stability and digestibility were as follows: Figure 6 As shown. Figure 6 It can be seen that after incubation at 40°C for 2h, the OSI can reach a maximum of 4.49h. Further extension of the insulation time has little effect on improving its oxidative stability. Therefore, incubation at 40°C for 2h was used for subsequent experiments.

[0067] Example 5 Preparation method of refined sardine oil

[0068] The following steps are involved:

[0069] 1. Deacidify the crude sardine oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0070] 2. Add 20 g of mulberry leaf dry powder of Yueshen No. 10 to 1.0 kg of crude oil, place in a 5 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0071] 3. Add 2% of crude oil to activated clay, decolorize for 30 minutes at 60°C under a vacuum of -0.08MPa, and filter and recover after cooling to below 40°C;

[0072] 4. The recovered decolorized sardine oil is deodorized at 120°C, 130°C, 140°C, 150°C and 160°C for 1 hour under 200Pa to obtain refined sardine oil.

[0073] Samples were taken to test their oxidation stability and digestibility. The results of oxidation stability and digestibility were as follows: Figure 7 and Figure 8 The oxidation stability of the deodorized sardine oil was significantly improved, and the digestion and absorption rate was also improved to a certain extent. The oxidation stability of the refined sardine oil deodorized at 140°C could reach up to 2.67h. Therefore, the deodorization treatment at 140°C was used for subsequent experiments.

[0074] Example 6 Preparation method of refined silkworm chrysalis oil

[0075] The following steps are involved:

[0076] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0077] 2. Add 20 g of mulberry leaf dry powder of Yueshen No. 10 to 1.0 kg of crude oil, place in a 5 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0078] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover;

[0079] 4. The recovered decolorized silkworm pupa oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined silkworm pupa oil.

[0080] Example 7 Preparation method of refined tuna oil

[0081] The following steps are involved:

[0082] 1. Deacidify crude tuna oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0083] 2. Add 20 g of mulberry leaf dry powder of Yueshen No. 10 to 1.0 kg of crude oil, place in a 5 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0084] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover;

[0085] 4. The recovered decolorized tuna oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined tuna oil.

[0086] Example 8 Preparation method of refined anchovy oil

[0087] The following steps are involved:

[0088] 1. Deacidify the crude anchovy oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0089] 2. Add 20 g of Yueshen No. 10 mulberry leaf powder to 1.0 kg of crude oil, place in a 2 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0090] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover;

[0091] 4. The recovered decolorized anchovy oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined anchovy oil.

[0092] Example 9 Preparation method of refined fish oil ethyl ester

[0093] The following steps are involved:

[0094] 1. Use commercially available fish oil ethyl ester (DHA 50%, EPA 10%, acid value less than 1 mgKOH / g) as raw material oil;

[0095] 2. Add 20 g of Yueshen No. 10 mulberry leaf powder to 1.0 kg of crude oil, place in a 2 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0096] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover;

[0097] 4. The recovered decolorized fish oil ethyl ester is deodorized at 140°C for 1 hour under 200Pa to obtain refined fish oil ethyl ester.

[0098] Example 10 Preparation method of refined fish oil glyceride

[0099] The following steps are involved:

[0100] 1. Use commercially available concentrated fish oil glyceride (DHA 24%, EPA 36%, acid value less than 1 mgKOH / g) as raw material oil;

[0101] 2. Add 20 g of Yueshen No. 10 mulberry leaf powder to 1.0 kg of crude oil, place in a 2 L stoppered flat-bottom flask, seal with nitrogen, and place in a constant temperature magnetic stirrer at 40 ° C, stirring for 2 h;

[0102] 3. Add 2% activated clay by weight of crude oil, carry out decolorization treatment at 60°C under vacuum of -0.08MPa for 30 minutes with magnetic stirring, cool to below 40°C and filter and recover;

[0103] 4. The recovered decolorized fish oil ethyl ester is deodorized at 140°C for 1 hour under 200Pa to obtain refined fish oil glyceride.

[0104] Comparative Example 1 Preparation method of refined silkworm chrysalis oil

[0105] The following steps are involved:

[0106] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0107] 2. Take 500g of the crude oil, add 2% of the crude oil weight of activated clay, decolorize at 60°C under a vacuum of -0.08MPa with magnetic stirring for 30min, cool to below 40°C and filter and recover;

[0108] 3. The recovered decolorized silkworm pupa oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined silkworm pupa oil.

[0109] Comparative Example 2 Preparation method of refined tuna oil

[0110] The following steps are involved:

[0111] 1. Deacidify crude tuna oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0112] 2. Take 500g of the crude oil, add 2% of the crude oil weight of activated clay, decolorize at 60°C under a vacuum of -0.08MPa with magnetic stirring for 30min, cool to below 40°C and filter and recover;

[0113] 3. The recovered decolorized tuna oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined tuna oil.

[0114] Comparative Example 3 Preparation method of refined anchovy oil

[0115] The following steps are involved:

[0116] 1. Deacidify the crude anchovy oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0117] 2. Take 500g of the crude oil, add 2% of the crude oil weight of activated clay, decolorize at 60°C under a vacuum of -0.08MPa for 30min with magnetic stirring, cool to below 40°C and filter and recover;

[0118] 3. The recovered decolorized anchovy oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined anchovy oil.

[0119] Comparative Example 4 Preparation Method of Refined Fish Oil Ethyl Ester

[0120] The following steps are involved:

[0121] 1. Use commercially available fish oil ethyl ester (DHA 50%, EPA 10%, acid value less than 1 mgKOH / g) as raw material oil;

[0122] 2. Take 500g of the crude oil, add 2% of the crude oil weight of activated clay, decolorize at 60°C under a vacuum of -0.08MPa for 30min with magnetic stirring, cool to below 40°C and filter and recover;

[0123] 3. The recovered decolorized fish oil ethyl ester is deodorized at 140°C for 1 hour under 200Pa to obtain refined fish oil ethyl ester.

[0124] Comparative Example 5 Preparation method of refined fish oil glyceride

[0125] The following steps are involved:

[0126] 1. Use commercially available concentrated fish oil glyceride (DHA 24%, EPA 36%, acid value less than 1 mgKOH / g) as raw material oil;

[0127] 2. Take 500g of the crude oil, add 2% of the crude oil weight of activated clay, decolorize at 60°C under a vacuum of -0.08MPa for 30min with magnetic stirring, cool to below 40°C and filter and recover;

[0128] 3. The recovered decolorized fish oil glyceride is deodorized at 140°C for 1 hour under 200 Pa to obtain refined fish oil glyceride.

[0129] Comparative Example 6: Method of adding mulberry leaf powder after refining silkworm pupa oil

[0130] The following steps are involved:

[0131] 1. Deacidify the silkworm pupa oil to make its acid value reach 1mgKOH / g and then use it as raw material oil;

[0132] 2. Take 1.0 kg of the crude oil, add 2% of the crude oil weight of activated clay, decolorize for 30 minutes at 60°C under a vacuum of -0.08 MPa, and filter and recover after cooling to below 40°C;

[0133] 3. The recovered decolorized silkworm pupa oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined silkworm pupa oil.

[0134] 4. Add 20 g of Yueshen No. 10 mulberry leaf dry powder to the recovered refined silkworm pupa oil, place it in a 1L stoppered flat-bottom flask, fill it with nitrogen and seal it, then place it in a constant temperature magnetic stirrer at 40°C. After stirring for 2 hours, filter and recover the refined silkworm pupa oil.

[0135] Comparative Example 7 Preparation method of tuna oil with mulberry leaf powder added after refining

[0136] The following steps are involved:

[0137] 1. Deacidify crude tuna oil to make its acid value reach 1 mgKOH / g and then use it as raw material oil;

[0138] 2. Take 1.0 kg of the crude oil, add 2% of the crude oil weight of activated clay, decolorize for 30 minutes at 60°C under a vacuum of -0.08 MPa, and filter and recover after cooling to below 40°C;

[0139] 3. The recovered decolorized tuna oil is deodorized at 140°C for 1 hour under 200Pa to obtain refined tuna oil.

[0140] 4. Add 20 g of Yueshen No. 10 mulberry leaf dry powder to the recovered refined tuna oil, place it in a 1L stoppered flat-bottom flask, fill it with nitrogen and seal it, then place it in a constant temperature magnetic stirrer at 40°C. After stirring for 2 hours, filter and recover the refined tuna oil.

[0141] The functional oils of Examples 6 to 10, Comparative Examples 1 to 5, and Comparative Examples 6 to 7 were sampled to test their oxidative stability and digestibility. The results are shown in Table 1.

[0142] Table 1

[0143]

[0144] As can be seen from the results in Table 1, compared with the functional oils (Comparative Examples 1-5) obtained by the functional oil preparation method without adding mulberry leaf powder to the raw oil, the functional oils (Examples 6-10) prepared by the functional oil preparation method of the present invention, that is, deacidifying the crude oil of the functional oil as the raw oil, adding an appropriate amount of mulberry leaf powder to the raw oil, and incubating it for a certain period of time under nitrogen protection, have significantly improved oxidation stability and greatly improved digestion and absorption rate. In addition, when the functional oil is obtained by the existing refining method, mulberry leaf powder is added to the functional oil (Comparative Examples 6-7), compared with not adding mulberry leaf powder (Comparative Examples 1-2), its oxidation stability will decrease (the possible reason is that some metal ion-type pro-oxidants exist in the mulberry leaf powder, causing the oxidation stability to decrease), and the digestion and absorption rate will also decrease.

[0145] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0146] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing functional oils and fats, It is characterized in that The following steps are involved: The functional oil is obtained by adding mulberry leaf powder to the raw oil of the functional oil with an acid value lower than 1.0 mgKOH / g, incubating the raw oil under nitrogen protection, decolorizing the raw oil, filtering and recovering the raw oil.

2. The method for preparing the functional oil according to claim 1, It is characterized in that The decolorization step also includes a deodorization step.

3. The method for preparing the functional oil according to claim 2, It is characterized in that The temperature of the deodorization treatment is 120° C. to 150° C., and the time of the deodorization treatment is 1 to 2 hours; the temperature of the deodorization treatment is preferably 140° C., and the time of the deodorization treatment is preferably 2 hours.

4. The method for preparing the functional oil according to any one of claims 1 to 3, It is characterized in that The addition amount of the mulberry leaf powder is 1% to 2.5% by weight of the functional oil raw material oil, preferably 1.5% to 2.5%, more preferably 2% to 2.5%, and most preferably 2%.

5. The method for preparing the functional oil according to any one of claims 1 to 3, It is characterized in that The temperature of the thermal incubation is 30°C to 60°C, and the time of the thermal incubation is 1 to 4 hours; preferably, the temperature of the thermal incubation is 40°C to 50°C, and the time of the thermal incubation is 1 to 2 hours; more preferably, the temperature of the thermal incubation is 40°C, and the time of the thermal incubation is 2 hours.

6. The method for preparing the functional oil according to any one of claims 1 to 3, It is characterized in that The mulberry leaf powder is one or more of Yuezhen No. 10, Yuesang No. 11, Yuesang No. 51, and Kangqing No. 10; more preferably, the mulberry leaf powder is Yuezhen No. 10 and / or Yuesang No.

11.

7. The method for preparing the functional oil according to any one of claims 1 to 3, It is characterized in that The functional oil is an oil rich in polyunsaturated fatty acids.

8. The method for preparing the functional oil according to claim 7, It is characterized in that The functional oil is marine fish oil, linseed oil, silkworm pupa oil or polyunsaturated fatty ethyl ester.

9. The method for preparing the functional oil according to claim 8, It is characterized in that The marine fish oil is tuna oil, sardine oil or anchovy oil.

10. The functional oil prepared by the preparation method according to any one of claims 1 to 9.

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