Method for preparing functional edible oil rich in phytosterol esters and diglycerides

Abstract

A method for preparing functional edible oil rich in phytosterol esters and diglycerides includes steps of: 1) adding a raw material: adding phytosterol, triglyceride and a molecular sieve into a reactor, wherein a ratio of the phytosterol and the triglyceride is 1:2-1:4, a molecular sieve amount is 50 g/L; heating to 50-60° C. and stirring for 30-60 min, for obtaining a pre-mixture; 2) providing non-aqueous enzymatic transesterification: adding 5-20 g/L lipase into the pre-mixture, adding 100-200 ppm antioxidant, stirring and reacting for 8-12 h with a temperature of 50-60° C. and an atmospheric pressure, stopping heating and naturally cooling to a room temperature; and 3) post-treating: after reaction, removing the lipase and the molecular sieve by centrifugation, for obtaining the functional edible oil. The functional edible oil rich in two nutritional active components is obtained by the one-step method. Products of the present invention do not need separation and purification, and operation is simple.

Claims

1. A method for preparing functional edible oil rich in phytosterol esters and diglycerides, comprising steps of: 1) adding a raw material: adding phytosterols, triglyceride, a reaction solvent and a molecular sieve into a reactor, wherein a mole ratio of the phytosterols and the triglyceride is 1:2-1:4, a ratio of the phytosterol and the reaction solvent is 100-200 mmol:1 L, and a molecular sieve amount is 50 g/L; heating to 50-60° C. and thoroughly stirring, for obtaining a pre-mixture; pre-treating the raw material: vacuum-drying the phytosterol at 80° C.-120° C. for 8-12 h, using refined vegetable oil as a source of the triglyceride; controlling a water content in the reaction solvent less than 1 wt %, controlling a water content in the phytosterol less than 1 wt %, and controlling a water content in the triglyceride less than 0.2 wt %. 2) providing non-aqueous enzymatic transesterification: adding 5-20 g/L lipase into the pre-mixture, adding 100-200 ppm antioxidant, stirring and reacting for 8-12 h with a temperature of 50-60° C. and an atmospheric pressure, then stopping heating and naturally cooling to a room temperature; wherein the lipase is Candida rugosa lipase, Candida lipolytica lipase, Candida antarctica lipase or Pseudomonas cepacia lipase obtained by microbial fermentation; 3) post-treating: after reaction, removing the lipase and the molecular sieve by centrifugation, and removing the reaction solvent by vacuum distillation, for obtaining the functional edible oil with the phytosterol esters of 10 wt %-33 wt % and the diglycerides of 10 wt %-30 wt %, wherein a product acid value is less than 1.0 mgKOH/g, and a peroxide value is less than 5.0 meq/kg.

2. The method, as recited in claim 1, wherein the functional edible oil has the phytosterol esters of 28.6 wt %-32.4 wt % and the diglycerides of 25.6 wt %-29.6 wt %, the product acid value is less than 0.7 mgKOH/g, and the peroxide value is less than 4.0 meq/kg.

3. The method, as recited in claim 1, wherein the phytosterols is selected from a group consisting of sitosterol, brassicasterol and campesterol.

4. The method, as recited in claim 2, wherein the phytosterols is selected from a group consisting of sitosterol, brassicasterol and campesterol.

5. The method, as recited in claim 1, wherein the triglyceride is selected from a group consisting of rapeseed oil, flaxseed oil, soybean oil, sunflower seed oil, corn oil, tea seed oil and microbial oil.

6. The method, as recited in claim 4, wherein the triglyceride is selected from a group consisting of rapeseed oil, flaxseed oil, soybean oil, sunflower seed oil, corn oil, tea seed oil and microbial oil.

7. The method, as recited in claim 1, wherein the reaction solvent is selected from a group consisting of isooctane, cyclohexane and n-heptane.

8. The method, as recited in claim 6, wherein the reaction solvent is selected from a group consisting of isooctane, cyclohexane and n-heptane.

9. The method, as recited in claim 1, wherein the antioxidant is natural vitamin E, fat-soluble tea polyphenols or L-ascorbyl palmitate.

10. The method, as recited in claim 8, wherein the antioxidant is natural vitamin E, fat-soluble tea polyphenols or L-ascorbyl palmitate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a schematic diagram of preparing functional edible oil rich in phytosterol esters and diglycerides of the present invention.

[0022] FIG. 2 is chromatograms of sunflower seed oil (A) and corn oil (B), and two corresponding functional edible oil of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] Preferred embodiments of the present invention as shown in the drawings and described are exemplary only and not intended to be limiting.

Preferred Embodiment 1

[0024] A method for preparing functional edible oil rich in phytosterol esters and diglycerides (a reaction formula thereof is shown in FIG. 1) comprises steps of:

[0025] (1) pre-treating a raw material: drying a reaction solvent (n-hexane) by anhydrous sodium sulfate (with a water content less than 0.1 wt %), vacuum-drying sitosterol (phytosterol) at 80° C. for 12 h (with a water content less than 1 wt %), and using refined sunflower seed oil (with a water content less than 0.2 wt %) as triglyceride;

[0026] (2) adding the raw material: adding 5 L isooctane, 207 g phytosterol (100 mM), 880 g sunflower seed oil (200 mM), and a molecular sieve (50 g/L) into a reactor, heating to 50° C. and stirring, for obtaining a pre-mixture;

[0027] (3) providing non-aqueous enzymatic transesterification: adding 25 g (5 g/L) Candida antarctica lipase into the pre-mixture, adding 200 ppm natural vitamin E antioxidant, stirring and reacting for 12 h with a temperature of 50° C. and an atmospheric pressure, then stopping heating and naturally cooling to a room temperature; and

[0028] (4) post-treating: after reaction, removing the lipase (the Candida antarctica lipase) and the molecular sieve by centrifugation, and removing the n-hexane by vacuum distillation, wherein a total yield is more than 88%, a phytosterols esters content is about 31.6 wt %, a diglycerides content is about 27.7 wt %, a sunflower seed oil content is about 40.7 wt %, a product acid value is less than 1.0 mgKOH/g, and a peroxide value is less than 5.0 meq/kg, which illustrates that a product obtained according to the present invention is rich in two active functional components: phytosterols esters and diglycerides; wherein spectrograms of the sunflower seed oil and corresponding functional edible oil are shown in part A of FIG. 2.

Preferred Embodiment 2

[0029] A method for preparing functional edible oil rich in phytosterol esters and diglycerides comprises steps of:

[0030] (1) pre-treating a raw material: drying a reaction solvent (isooctane) by anhydrous sodium sulfate (with a water content less than 0.1 wt %), vacuum-drying stigmasterol (phytosterol) at 100 ° C. for 10 h (with a water content less than 1 wt %), and using refined rapeseed oil (with a water content less than 0.2 wt %) as triglyceride;

[0031] (2) adding the raw material: adding 5 L isooctane, 310.5 g phytosterol (150 mM stigmasterol), 2616 g rapeseed oil (600 mM), and a molecular sieve (50 g/L) into a reactor, heating to 55° C. and stirring;

[0032] (3) providing non-aqueous enzymatic transesterification: adding 50 g (10 g/L) Candida antarctica lipase, adding 150 ppm fat-soluble tea polyphenols antioxidant, stirring and reacting for 10 h with a temperature of 55° C. and an atmospheric pressure, then stopping heating and naturally cooling to a room temperature; and

[0033] (4) post-treating: after reaction, removing the Candida antarctica lipase and the molecular sieve by centrifugation, and removing the isooctane by vacuum distillation, wherein a total yield is more than 85%, a phytosterols ester content is about 17.4 wt %, a diglyceride content is about 15.2 wt %, a rapeseed oil content is about 67.4 wt %, a product acid value is less than 1.0 mgKOH/g, and a peroxide value is less than 5.0 meq/kg, which illustrates that a product obtained according to the present invention is rich in two active functional components: phytosterols esters and diglycerides.

Preferred Embodiment 3

[0034] A method for preparing functional edible oil rich in phytosterol esters and diglycerides comprises steps of:

[0035] (1) pre-treating a raw material: drying a reaction solvent (n-heptane) by anhydrous sodium sulfate (with a water content less than 0.1 wt %), vacuum-drying brassicasterol at 120° C. for 8 h (with a water content less than 1 wt %), and using refined flaxseed oil (with a water content less than 0.2 wt %) as triglyceride;

[0036] (2) adding the raw material: adding 5 L n-heptane, 414 g phytosterol (200 mM brassicasterol), 5232 g rapeseed oil (1200 mM), and a molecular sieve (50 g/L) into a reactor, heating to 60° C. and stirring;

[0037] (3) providing non-aqueous enzymatic transesterification: adding 200 g (20 g/L) Candida lipolytica lipase, adding 100 ppm L-ascorbyl palmitate antioxidant, stirring and reacting for 12 h with a temperature of 60° C. and an atmospheric pressure, then stopping heating and naturally cooling to a room temperature; and (4) post-treating: after reaction, removing the lipase (the Candida lipolytica lipase) and the molecular sieve by centrifugation, and removing the n-heptane by vacuum distillation, wherein a total yield is more than 84%, the phytosterol esters content is about 12.0 wt %, the diglycerides content is about 10.5 wt %, the flaxseed oil content is about 77.5 wt %, a product acid value is less than 1.0 mgKOH/g, and a peroxide value is less than 5.0 meq/kg.

[0038] Preferred Embodiment 4

[0039] A method for preparing functional edible oil rich in phytosterol esters and diglycerides comprises steps of:

[0040] (1) pre-treating a raw material: vacuum-drying sitosterol (phytosterol) at 100° C. for 12 h (with a water content less than 1 wt %), and using refined tea seed oil (with a water content less than 0.2 wt %) as triglyceride, wherein no solvent is added, which means the tea seed oil is used as a reaction solvent;

[0041] (2) adding the raw material: adding 207 g phytosterol (100 mM), 2612 g tea seed oil (600 mM), and a molecular sieve (50 g/L) into a reactor, heating to 50° C. and stirring;

[0042] (3) providing non-aqueous enzymatic transesterification: adding 25 g (5 g/L) Candida antarctica lipase, adding 200 ppm natural vitamin E antioxidant, stirring and reacting for 12 h with a temperature of 50° C. and an atmospheric pressure, then stopping heating and naturally cooling to a room temperature; and

[0043] (4) post-treating: after reaction, removing the lipase (the Candida antarctica lipase) and the molecular sieve by centrifugation, wherein a total yield is more than 83 %, the phytosterol esters content is about 29.8 wt %, the diglycerides content is about 24.7 wt %, the tea seed oil content is about 45.5 wt %, the product acid value is less than 0.6 mgKOH/g, and the peroxide value is less than 5.0 meq/kg.

[0044] Preferred Embodiment 5

[0045] The preferred embodiment 5 is almost the same as the preferred embodiment 1, differences are: the Candida antarctica lipase is replaced by Candida antarctica immobilized lipase which is immobilized by ion exchange resin, wherein the immobilized lipase is prepared by dissolving the Candida Antarctica lipase in a disodium hydrogen phosphate solution and reacting with the ion exchange resin under stirring at 30° C. for 8 h. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 92%, the sterol ester content is about 32.5 wt %, the diglyceride content is about 29.6 wt %, the sunflower seed oil content is about 37.9 wt %, the acid value is less than 0.8 mgKOH/g, and the peroxide value is less than 5.0 meq/kg.

[0046] Preferred Embodiment 6

[0047] The preferred embodiment 6 is almost the same as the preferred embodiment 1, differences are: in the step (1), the sunflower seed oil is replaced by soybean oil; the sitosterol is replaced by brassicasterol; and a reaction time is 8h. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 85%, the phytosterol esters content is about 20.2 wt %, the diglyceride content is about 18.9 wt %, the soybean oil content is about 60.9 wt %, the acid value is less than 0.8 mgKOH/g, and the peroxide value is less than 5.0 meq/kg.

Preferred Embodiment 7

[0048] The preferred embodiment 7 is almost the same as the preferred embodiment 1, differences are: in the step (1), the sunflower seed oil is replaced by corn oil; the sitosterol is replaced by a mixture of brassicasterol and sitosterol with a ratio of 1:1. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 88%, the sterol ester content is about 30.2 wt %, the diglyceride content is about 28.4 wt %, the corn oil content is about 41.4 wt %, the acid value is less than 0.8 mgKOH/g, and the peroxide value is less than 5.0 meq/kg. Chromatograms of the corn oil and corresponding functional edible oil are shown in part B of FIG. 2.

Preferred Embodiment 8

[0049] The preferred embodiment 8 is almost the same as the preferred embodiment 1, differences are: in the step (1), the sunflower seed oil is replaced by microbial oil rich in DHA; the phytosterol is a mixture of stigmasterol and sitosterol with a ratio of 1:1. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 84%, the sterol ester content is about 31.4 wt %, the diglyceride content is about 25.6 wt %, the microbial oil content is about 43.0 wt %, the acid value is less than 0.7 mgKOH/g, and the peroxide value is less than 4.0 meq/kg.

Preferred Embodiment 9

[0050] The preferred embodiment 9 is almost the same as the preferred embodiment 1, differences are: the Candida antarctica lipase is replaced by Candida hpolytica lipase, an amount of the natural vitamin E antioxidant is changed to 100 ppm. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 85%, the sterol ester content is about 29.8 wt %, the diglyceride content is about 27.6 wt %, the sunflower seed oil content is about 42.6 wt %, the acid value is less than 0.8 mgKOH/g, and the peroxide value is less than 5.0 meq/kg.

Preferred Embodiment 10

[0051] The preferred embodiment 10 is almost the same as the preferred embodiment 1, differences are: the Candida antarctica lipase is replaced by Pseudomonas cepacia lipase, the flaxseed oil is replaced by a mixture of soybean oil and sunflower seed oil with a ratio of 1:1. Functional edible oil rich in pohytosterol esters and diglycerides is obtained, wherein a total yield is more than 85%, the sterol ester content is about 28.6 wt %, a diglyceride content is about 27.4 wt %, the soybean oil content is about 20.2 wt %, the sunflower seed oil content is about 23.8 wt %, the acid value is less than 0.8 mgKOH/g, and the peroxide value is less than 5.0 meq/kg.

[0052] All raw materials according to the present invention, upper and lower limits as well as intervals according to the present invention, and upper and lower limits as well as intervals of technical parameters (such as temperature and time) are able to achieve the object, and no further embodiment will be provided.