Fat composition and method for its preparation

Abstract

The application discloses an oil and fat composition and a preparation method thereof. The oil and fat composition is prepared by using a mixed oil of camellia seed oil and silkworm chrysalis oil as raw material and by using immobilized lipase to perform an interesterification reaction. The volume percentage of the camellia seed oil in the mixed oil is 84% to 96%. The oil and fat composition has excellent oxidation stability, and the antioxidation efficiency and the bioavailability of the oil and fat composition are obviously improved, so the oil and fat composition has a wide application prospect.

Description

Technical Field

[0001] This invention belongs to the field of food technology, specifically to the field of food oil technology, and more specifically, to an oil composition and its preparation method. Background Technology

[0002] Camellia seed oil, a unique woody plant oil native to my country, is hailed as the "olive oil of the East" and has been recognized by the Food and Agriculture Organization of the United Nations as a top-recommended health-promoting edible oil. Rich in unsaturated fatty acids, carotene, vitamins, squalene, camellia glycosides, saponins, tea polyphenols, and minerals, camellia seed oil possesses antioxidant, anti-tumor, blood pressure-lowering, blood sugar-lowering, anti-inflammatory, antibacterial, and drug-enhancing properties, as well as the ability to prevent obstructive jaundice and protect the liver. It can be used for nutritional purposes, regulating immune function, preventing obesity, aiding postpartum recovery, and preventing cardiovascular and dermatological diseases.

[0003] Camellia seed oil has an excellent overall fatty acid composition, with unsaturated fatty acid content exceeding 90%. Oleic acid accounts for 75% to 83%, linoleic acid (a polyunsaturated fatty acid) accounts for about 8% to 10%, and linolenic acid accounts for about 1%. The n-6 / n-3 ratio is close to 8:1. However, the bioavailability of camellia seed oil is not high. Its digestibility is only about 20% after 60 minutes and only slightly more than 50% after 120 minutes.

[0004] Furthermore, camellia seed oil contains only 0.51% to 0.87% alpha-linolenic acid (an n-3 essential fatty acid), a severe deficiency that constitutes a structural nutritional deficiency. This makes it difficult for camellia seed oil to independently achieve its complete functions of blood lipid regulation, anti-inflammatory protection, and neurodevelopmental support, limiting its application in areas such as infant nutrition, maternal and child health, brain health in the elderly, and intervention for fatty liver disease. To achieve a balanced diet of fatty acids, camellia seed oil is not suitable as a single long-term edible oil and must be combined with oils rich in alpha-linolenic acid to meet the health needs of all age groups and all physiological stages.

[0005] Silkworm pupa oil is a unique animal-derived (insect-derived) alpha-linolenic acid (ALA) edible oil in my country, with an unsaturated fatty acid content exceeding 70% and an ALA content of 28%–35%. It is a scarce high-n-3 type animal-derived functional oil that can compensate for the insufficient ALA supply in traditional oils, making it an ideal raw material for functional oil blends. However, directly mixing silkworm pupa oil with camellia seed oil significantly reduces the oxidative stability of the camellia seed oil and offers limited improvement in bioavailability. Summary of the Invention

[0006] Therefore, the purpose of this invention is to provide an oil composition that, while ensuring excellent oxidative stability, can also significantly improve bioavailability.

[0007] The technical solutions for achieving the above-mentioned objectives include the following.

[0008] In a first aspect, the present invention provides an oil composition which is obtained by transesterification of a mixture of camellia seed oil and silkworm pupa oil using an immobilized lipase; wherein the volume percentage of camellia seed oil in the mixture is 84% ​​to 96%.

[0009] A second aspect of the present invention provides a method for preparing the above-mentioned oil and fat composition, comprising the following steps:

[0010] (1) Take the camellia seed oil and silkworm pupa oil, mix them together to obtain a mixed oil;

[0011] (2) Add the immobilized lipase to the mixed oil, carry out transesterification reaction, and recover the transesterification reaction product to obtain the product.

[0012] The inventors of this invention discovered that by adding a certain volume ratio of silkworm pupa oil to camellia seed oil and then using immobilized lipase to perform a transesterification reaction on the mixed oil, the resulting oil composition not only maintains the excellent oxidative stability of camellia seed oil but also significantly enhances its antioxidant effect, which is beneficial for storage and processing stability. Furthermore, the bioavailability of the oil composition is greatly improved, with a digestibility of over 30% at 60 minutes and over 85% at 120 minutes. Therefore, the oil composition of this invention has broad application prospects. Detailed Implementation

[0013] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0014] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0015] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0016] In some embodiments of the present invention, an oil composition is disclosed, which is obtained by transesterification of a mixture of camellia seed oil and silkworm pupa oil using an immobilized lipase; the volume percentage of camellia seed oil in the mixture is 84% ​​to 96%.

[0017] In one embodiment, the camellia seed oil in the mixed oil is 84% ​​to 95% by volume.

[0018] In one embodiment, the camellia seed oil in the mixed oil is 84% ​​to 90% by volume.

[0019] In one embodiment, the camellia seed oil in the mixed oil is 84% ​​to 86% by volume.

[0020] In one embodiment, the camellia seed oil in the blended oil is 85%, 90%, or 95% by volume.

[0021] In one embodiment, the immobilized lipase is immobilized lipase Lipozyme TL IM, immobilized lipase Novozyme 435, or immobilized lipase Lipozyme RM IM.

[0022] In one embodiment, the immobilized lipase is immobilized lipase Lipozyme TL IM.

[0023] In one embodiment, the immobilized lipase Lipozyme TL IM is dried to constant weight at 25-30°C and 4.5 Pa under vacuum before use.

[0024] In one embodiment, during the transesterification reaction, 20 U to 30 U of enzyme is added per gram of mixed oil.

[0025] In one embodiment, during the transesterification reaction, 24 U to 26 U of enzyme are added per gram of mixed oil.

[0026] In one embodiment, the transesterification reaction is carried out at 150 rpm to 250 rpm and 38°C to 42°C for 7 to 9 hours.

[0027] In other embodiments of the present invention, a method for preparing the above-mentioned oil and fat composition is disclosed, comprising the following steps:

[0028] (1) Take the camellia seed oil and silkworm pupa oil, mix them together to obtain a mixed oil;

[0029] (2) Add the immobilized lipase to the mixed oil, carry out transesterification reaction, and recover the transesterification reaction product to obtain the product.

[0030] In the following embodiments of the present invention, the camellia seed oil used was purchased from Guangdong Wujifeng Agricultural Technology Co., Ltd., the silkworm pupa oil (APO) was purchased from Nantong Fuer Biotechnology Co., Ltd., and the immobilized lipase Lipozyme TL IM was purchased from Novozymes.

[0031] The present invention will be described in detail below with reference to specific embodiments.

[0032] Example 1: Oil and fat composition and its preparation method

[0033] This embodiment provides an oil composition prepared by enzymatic transesterification using camellia seed oil and silkworm pupa oil in a volume ratio of 85:15.

[0034] This embodiment also provides a method for preparing the above-mentioned oil and fat composition, including the following steps:

[0035] (1) Take camellia seed oil and silkworm pupa oil at a volume ratio of 85:15, mix them, and obtain a mixed oil;

[0036] (2) The immobilized lipase Lipozyme TL IM was dried at low temperature (25-30℃) under vacuum (4.5Pa) until constant weight for later use;

[0037] (3) Add the mixed oil to a 100 mL stoppered Erlenmeyer flask, add immobilized lipase Lipozyme TL IM at a ratio of 25.00 U / g mixed oil, and then place the stoppered Erlenmeyer flask in a heat-collecting constant temperature magnetic stirrer with a rotation speed of 200 rpm and a temperature of 40℃. React for 8 h. After the reaction is completed, remove the immobilized lipase Lipozyme TL IM and recover the transesterification oil. The transesterification oil is then stored in a -4℃ refrigerator.

[0038] Example 2 Performance determination of oil and fat composition

[0039] The properties of the oil composition prepared in Example 1 were tested as follows (using camellia seed oil and oil composition of camellia seed oil and silkworm pupa oil physically mixed (85:15) as control oil samples):

[0040] 1. Oxidative stability

[0041] The oxidation stability of the sample was characterized by induction time. Specifically, 3.0 g of the oil composition sample (or control oil sample) was placed in a test tube, which was then placed in a constant temperature electric heating block. The temperature was set to 110℃ and the air flow rate was 10 L / h. The time when the oxidation products appeared was the oxidation induction time (OSI value) of the oil composition sample (or control oil sample).

[0042] 2. Antioxidant Efficacy: The antioxidant efficacy of the oil composition was evaluated using DPPH and ABTS free radical scavenging abilities. The DPPH free radical scavenging method was as follows: Trolox standard was prepared into a 5-25 μg / mL standard solution using methanol. 0.5000 g of the oil composition (or control oil sample) was accurately weighed and placed in a 5 mL centrifuge tube. 2 mL of methanol was added, the mixture was vortexed for 30 s, centrifuged at 7000 g for 5 min, and the supernatant was collected for testing. 100 μL of the supernatant (or Trolox standard solution) was mixed thoroughly with 500 μL of 0.1 mmol / L DPPH methanol solution, and the mixture was reacted in the dark for 30 min. The absorbance of 200 μL of the reaction solution was measured at 517 nm using a microplate reader. All samples were measured in triplicate, and the results were calculated based on the standard curve and expressed as μmol TE / 100 g. The method for determining the ABTS free radical scavenging ability was as follows: 7 mmol / L ABTS solution and 4.9 mmol / L potassium persulfate solution were prepared separately, mixed in equal volumes, and reacted at 4℃ in the dark for at least 14 h to obtain the ABTS stock solution. The stock solution was diluted with methanol and adjusted to an absorbance of 0.7 ± 0.02 at 734 nm, which became the ABTS working solution. 0.5 mL of the supernatant of the oil composition (or control oil sample) (or Trolox standard solution) was added, along with 2.5 mL of the ABTS working solution. After mixing, the solution was reacted in the dark for 10 min, and the absorbance was measured at 734 nm using a UV-Vis spectrophotometer. All samples were measured in triplicate. The ABTS free radical scavenging ability was calculated based on the standard curve, and the results were expressed as μmol TE / 100 g.

[0043] 3. Digestibility: The bioavailability of the oil composition was assessed using the standardized in vitro food digestion simulation method of INFOOGS 2.0. Specifically, 1 g of the oil composition (or control oil sample) was weighed, and 2.5 mL of SSF digestion solution (containing salivary amylase, 75 U / mL) was added to a 50 mL centrifuge tube. The tube was placed in a 37°C constant-temperature magnetic stirrer to simulate oral digestion for 3 min. Then, 3 mL of SGF digestion solution was added, and the pH was adjusted to 3.0 with 6 mol / L HCl solution. 2 mL of pepsin solution (2000 U / mL) and 15 μL CaCl2 solution were added, and the digestion was simulated in the stomach for 120 min. Finally, 4 mL of SIF digestion solution was added, and the pH was adjusted to 7.0 with 4 mol / L NaOH solution. 5 mL of pancreatic lipase solution (100 U / mL), 1 mL of bile salt solution (133.6 mg / mL), and 20 μL CaCl2 solution were added, and the digestion was simulated in the small intestine for 60 min and 120 min. After digestion, all samples were immediately inactivated by high-temperature enzyme inactivation and stored at -20°C. The oil phase of the digested oil composition was extracted using a chloroform-methanol mixture (chloroform:methanol = 3:1). After the solvent was dried under nitrogen, the oil composition was analyzed by liquid chromatography. The digestibility of the oil composition is calculated using the formula shown below.

[0044]

[0045] In the formula, D is the digestibility of fat (%), FFA is free fatty acid, MAG is monoglyceride, DAG is diglyceride, and TAG is triglyceride.

[0046] The results are shown in Table 1.

[0047] Table 1

[0048]

[0049] Note: Different lowercase letters in the same column indicate significant differences compared with camellia seed oil (control) (p<0.05).

[0050] The results in Table 1 show that:

[0051] 1. Compared with camellia seed oil, the oxidative stability of the oil composition obtained by physically mixing camellia seed oil and silkworm pupa oil, as well as the oil composition obtained by enzymatic transesterification in Example 1, both decreased. However, the decrease in oxidative stability of the oil composition in Example 1 was significantly smaller than that of the physically mixed oil composition, and its oxidative stability was not significantly different from that of camellia seed oil.

[0052] 2. Compared with camellia seed oil, the antioxidant effects of the oil composition obtained by physically mixing camellia seed oil and silkworm pupa oil, and the oil composition obtained by enzymatic transesterification in Example 1, were significantly improved, and there was no significant difference between the two.

[0053] 3. Compared with camellia seed oil, the digestibility of the oil composition obtained by physically mixing camellia seed oil and silkworm pupa oil was slightly improved at 60 min and significantly improved at 120 min. In contrast, the digestibility of the oil composition obtained by enzymatic transesterification in Example 1 was significantly improved at both 60 min and 120 min. Moreover, compared with the physically mixed oil composition, the digestibility of the oil composition in Example 1 was significantly higher at both 60 min and 120 min.

[0054] The results of this embodiment show that the oil composition obtained by enzymatic transesterification of camellia seed oil and silkworm pupa oil can maintain the good oxidative stability of camellia seed oil, while significantly improving its antioxidant efficacy and bioavailability.

[0055] Example 3: Comparison of the effects of different transesterification treatment methods on the properties of oil compositions

[0056] This embodiment compares the effects of different transesterification methods (enzymatic and chemical methods) on the properties of the resulting oil and fat compositions.

[0057] The oil composition obtained by enzymatic transesterification is the oil composition of Example 1.

[0058] The raw materials for chemical transesterification were camellia seed oil and silkworm pupa oil in a volume ratio of 85:15. The chemical transesterification process followed the method described by Dong Zhe (Dong Zhe. Research on the preparation of low-saturated oils by chemical transesterification of high-oleic sunflower seed oil and palm stearin [J]. Grain and Food Industry, 2025, 32(03):19-24.). Specifically, the oil composition was added to a 100 mL stoppered Erlenmeyer flask, and the mixture was vacuum-treated at 105℃ for 0.5 h to remove water and gas. At 80℃, 0.3% sodium methoxide was added as a catalyst, and the reaction was carried out in an oil bath at 500 rpm under vacuum for 30 min. Afterwards, 5% citric acid aqueous solution was added to terminate the reaction. The reaction solution was washed with hot water until neutral, and after vacuum drying, the transesterified oil was obtained and stored at -4℃.

[0059] The oxidative stability, antioxidant efficacy, and digestibility of the oil composition were evaluated using the method described in Example 2, and the results are shown in Table 2.

[0060] Table 2

[0061]

[0062] Note: Different lowercase letters in the same column indicate significant differences (p<0.05).

[0063] As shown in Table 2, compared with the oil composition prepared by chemical transesterification, the oil composition prepared by enzymatic transesterification has significantly better oxidative stability and antioxidant effect, while there is no significant difference in digestibility.

[0064] Example 4: Performance comparison of oil compositions prepared from camellia seed oil and silkworm pupa oil in different volume ratios

[0065] This embodiment compares the oxidative stability, antioxidant efficacy, and digestibility of oil compositions prepared by enzymatic transesterification using camellia seed oil and silkworm pupa oil in different volume ratios (95:5, 90:10, 85:15, 80:20, 75:25) as raw materials. The results are shown in Table 3.

[0066] Table 3

[0067]

[0068] Note: Different lowercase letters in the same column indicate significant differences compared with camellia seed oil (control) (p<0.05).

[0069] As shown in Table 3, when the ratio of camellia seed oil to silkworm pupa oil was 90:10 and 85:15, the OSI (oxidation induction time) of the oil composition was lower than that of pure camellia seed oil, but the difference was not significant. When the ratio of camellia seed oil to silkworm pupa oil was 80:20 or lower, the OSI of the oil composition decreased significantly. Therefore, when the ratio of camellia seed oil to silkworm pupa oil is greater than 85:15, the resulting oil composition can maintain the good oxidative stability of camellia seed oil, which is beneficial to storage and processing stability. In addition, as the proportion of silkworm pupa oil in the oil composition increases, the antioxidant efficacy and digestibility of the oil composition both show a gradual upward trend.

[0070] Based on the results of this embodiment, the oil compositions prepared by enzymatic transesterification using camellia seed oil and silkworm pupa oil in ratios of 95:5, 90:10, and 85:15 can maintain the high oxidative stability of camellia seed oil, while achieving high levels of antioxidant activity and digestibility. This approach balances oxidative stability, antioxidant efficacy, and digestibility. Among these, the camellia seed oil to silkworm pupa oil ratio of 85:15 exhibits the best overall performance.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above 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.

[0072] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An oil and fat composition, characterized in that, It is obtained by transesterification of a mixture of camellia seed oil and silkworm pupa oil using immobilized lipase; the volume percentage of camellia seed oil in the mixture is 84%~96%.

2. The oil composition according to claim 1, characterized in that, The camellia seed oil in the blended oil has a volume percentage of 84% to 95%.

3. The oil composition according to claim 2, characterized in that, The camellia seed oil in the blended oil is 84% ​​to 90% by volume.

4. The oil composition according to claim 3, characterized in that, The camellia seed oil in the blended oil has a volume percentage of 84% to 86%.

5. The oil composition according to claim 1, characterized in that, The camellia seed oil in the blended oil is 85%, 90%, or 95% by volume.

6. The oil and fat composition according to any one of claims 1 to 5, characterized in that, The immobilized lipase is immobilized lipase Lipozyme TL IM, immobilized lipase Novozyme 435, or immobilized lipase Lipozyme RM IM.

7. The oil composition according to claim 6, characterized in that, The immobilized lipase is immobilized lipase Lipozyme TL IM, which is dried to constant weight under vacuum at 25-30℃ and 4.5Pa before use.

8. The oil and fat composition according to any one of claims 1 to 5, characterized in that, In the transesterification reaction, 20 U to 30 U of enzyme is added per gram of mixed oil; preferably, 24 U to 26 U of enzyme is added per gram of mixed oil.

9. The oil and fat composition according to any one of claims 1 to 5, characterized in that, The reaction conditions for the transesterification reaction are: 150 rpm to 250 rpm, 38℃ to 42℃ for 7 h to 9 h.

10. A method for preparing the oil and fat composition according to any one of claims 1 to 9, characterized in that, Includes the following steps: (1) Take the camellia seed oil and silkworm pupa oil, mix them together to obtain a mixed oil; (2) Add the immobilized lipase to the mixed oil, carry out transesterification reaction, and recover the transesterification reaction product to obtain the product.

Images