Preparation method of novel decolorized sesame oil

Abstract

The present invention discloses a novel decolorized sesame oil production method, and relates to the technical field of food processing, and the method comprises the following steps: raw material pretreatment: sesame seeds are screened and graded, and are circularly cleaned to remove impurities; washing for the first time: cleaning the sesames, and removing surface dust and light impurities; primary stir-frying: stir-frying sesame until the inside is purplish red and the outside is frosted; washing and decolorizing for the second time: putting the sesame into a washing tank, injecting warm water, and mechanically stirring, so that epidermis cells of the sesame are broken, and brown pigment and bitter substances in the sesame are hydrolyzed and dissolved out; dehydrating and stir-frying: performing gradient heating stir-frying, evaporating water in stages, promoting oil release and terminating enzyme activity; and cooling and ripening. Through an innovative process design and a multi-technology synergistic effect, remarkable progress is made in the aspects of decolorization efficiency, nutrition retention, safety, production efficiency and the like.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, in particular to a novel method for preparing decolorized sesame oil. Background Art

[0002] As a traditional edible oil, sesame oil is highly valued for its unique flavor and nutritional value. However, the brown pigments and Maillard reaction products produced during deep processing cause the oil to darken in color, becoming a key issue restricting its application in the high-end market. Existing decolorization processes mainly include physical adsorption and chemical refining.

[0003] The existing pressing process requires high-temperature frying at 180-200°C, which triggers lipid oxidation and the formation of benzopyrene, with a peroxide value as high as 2.5meq / kg. At the same time, traditional acid clay bleaching results in residual aluminum ions.

[0004] To address the above problems, a new method for producing decolorized sesame oil was designed. Through a three-stage decolorization system of water washing decolorization-enzymatic hydrolysis-ultrasonic enhancement, precise separation technology of gradient centrifugation and molecular distillation, and low-temperature control throughout the entire process, a synergistic improvement in decolorization efficiency, nutrient retention, and safety was achieved to solve the above-mentioned technical problems. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a novel method for producing decolorized sesame oil, which solves the technical problems raised in the above background technology.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A novel method for producing decolorized sesame oil, comprising the following steps:

[0007] (1) Raw material pretreatment: After sesame seeds are screened and graded, they are circulated and cleaned to remove impurities;

[0008] (2) First washing: Wash the sesame seeds to remove surface dust and light impurities;

[0009] (3) Primary frying: frying sesame seeds until the inside is red and the outside is frosted;

[0010] (4) Second water washing and decolorization: Place the sesame seeds in a water washing tank, add warm water and mechanically turn them over to rupture the epidermal cells of the sesame seeds, thereby promoting the hydrolysis and dissolution of the internal brown pigments and bitter substances;

[0011] (5) Dehydration and frying: Gradient temperature rise is used to fry, evaporating water in stages, promoting oil release and terminating enzyme activity;

[0012] (6) Cooling and maturation: air the sesame seeds to 35-45°C and maintain a low humidity environment for 1-2 hours;

[0013] (7) Fine grinding: Grind sesame seeds at low temperature to obtain a paste with a fineness of ≤20 μm;

[0014] (8) Dynamic oil separation: Add hot water to the sauce and separate the oil with the help of stirring;

[0015] (9) Gradient centrifugation: multi-stage centrifugation to separate oil and liquid;

[0016] (10) Finished product refining: centrifuge the oil and filter it before canning.

[0017] Preferably, in the second water washing and decolorization in step (4), the water washing temperature is 35-65° C. and the water washing time is 20-70 minutes;

[0018] The bitter substances include Maillard reaction products and free polyphenols.

[0019] Preferably, in step (4), a composite hydrolysis promoter is added to the water washing solution, wherein the composition comprises: 0.01-0.1 wt % of L-cysteine;

[0020] Carbonate 0.05-0.5g / L;

[0021] Metal chelating agent 0.001-0.05g / L;

[0022] And the redox potential is controlled in the range of -100mV to +100mV.

[0023] Preferably, the washing tank in step (4) is equipped with an ultrasonic generator to apply 15-50kHz ultrasonic waves with an ultrasonic power density of 0.3-1.5W / cm 3 .

[0024] Preferably, step (4) further comprises enzymatic treatment after washing and decolorization:

[0025] Add neutral protease or cellulase, the enzyme dosage is 0.01% to 0.1% of the sesame mass;

[0026] Enzymatic hydrolysis at pH 6.0-7.5 and temperature 40-55°C for 10-50 minutes;

[0027] After enzymatic hydrolysis, the temperature is raised to 80-90°C to inactivate the enzyme.

[0028] Preferably, the gradient centrifugation in step (9) is performed under the protection of an inert gas, and the dissolved oxygen content is ≤2.0 mg / L.

[0029] Preferably, the method is applicable to a water-substitution process for extracting sesame oil from small-milled sesame oil or a pretreatment process for pressing sesame oil;

[0030] In the pressing process, the bitter substances removed in step (4) account for more than 70% of the total bitter substances in the pressed oil.

[0031] Beneficial effects

[0032] The present invention provides a novel method for producing decolorized sesame oil. The decolorized sesame oil production method of the present invention achieves significant progress in decolorization efficiency, nutrient retention, safety and production efficiency through innovative process design and the synergistic effect of multiple technologies. Through a three-stage decolorization system of water washing decolorization-enzymatic hydrolysis-ultrasonic enhancement, precise separation technology of gradient centrifugation and molecular distillation, and low-temperature control throughout the entire process, a synergistic improvement in decolorization efficiency, nutrient retention and safety is achieved. DETAILED DESCRIPTION

[0033] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0034] The present invention provides a technical solution: a novel method for producing decolorized sesame oil, comprising the following steps:

[0035] (1) Raw material pretreatment: After sesame seeds are screened and graded, they are circulated and cleaned to remove impurities;

[0036] (2) First washing: Wash the sesame seeds to remove surface dust and light impurities;

[0037] (3) Primary frying: frying sesame seeds until the inside is red and the outside is frosted;

[0038] (4) Second water washing and decolorization: Place the sesame seeds in a water washing tank, add warm water and mechanically turn them over to rupture the epidermal cells of the sesame seeds, thereby promoting the hydrolysis and dissolution of the internal brown pigments and bitter substances;

[0039] (5) Dehydration and frying: Gradient temperature rise is used to fry, evaporating water in stages, promoting oil release and terminating enzyme activity;

[0040] (6) Cooling and maturation: air the sesame seeds to 35-45°C and maintain a low humidity environment for 1-2 hours;

[0041] (7) Fine grinding: Grind sesame seeds at low temperature to obtain a paste with a fineness of ≤20 μm;

[0042] (8) Dynamic oil separation: Add hot water to the sauce and separate the oil with the help of stirring;

[0043] (9) Gradient centrifugation: multi-stage centrifugation to separate oil and liquid;

[0044] (10) Finished product refining: centrifuge the oil and filter it before canning.

[0045] This embodiment is further configured such that, in the second water washing and decolorization in step (4), the water washing temperature is 35-65° C., and the water washing time is 20-70 minutes;

[0046] The bitter substances include Maillard reaction products and free polyphenols.

[0047] This embodiment is further configured such that step (4) adds a composite hydrolysis promoter to the water washing solution, the composition of which comprises:

[0048] L-cysteine ​​0.01-0.1wt%;

[0049] Carbonate 0.05-0.5g / L;

[0050] Metal chelating agent 0.001-0.05g / L;

[0051] And the redox potential is controlled in the range of -100mV to +100mV.

[0052] This embodiment is further configured such that in step (4), the water washing tank is equipped with an ultrasonic generator to apply 15-50kHz ultrasonic waves with an ultrasonic power density of 0.3-1.5W / cm 3 .

[0053] This embodiment is further configured such that step (4) further comprises enzymatic hydrolysis after water washing and decolorization:

[0054] Add neutral protease or cellulase, the enzyme dosage is 0.01% to 0.1% of the sesame mass;

[0055] Enzymatic hydrolysis at pH 6.0-7.5 and temperature 40-55°C for 10-50 minutes;

[0056] After enzymatic hydrolysis, the temperature is raised to 80-90°C to inactivate the enzyme.

[0057] This embodiment is further configured such that the gradient centrifugation in step (9) is performed under the protection of an inert gas, and the dissolved oxygen content is ≤2.0 mg / L.

[0058] This embodiment is further configured such that the method is applicable to a small-milled sesame oil water-substitution process or a pressed sesame oil pretreatment process;

[0059] In the pressing process, the bitter substances removed in step (4) account for more than 70% of the total bitter substances in the pressed oil.

[0060] The detailed connection means are well-known technologies in this field. The following mainly introduces the working principle and process. The specific operations are as follows.

[0061] Example:

[0062] Embodiment 1: small grinding sesame oil process (water substitution method)

[0063] step:

[0064] Raw material pretreatment:

[0065] Take 100 kg of Henan white sesame, remove branches, leaves, sand and gravel through a vibrating screen, and rinse in reverse current for 3 times (water temperature 25°C).

[0066] Primary stir-fry:

[0067] The sesame seeds were fried in a tilting wok until they were red inside and frosted outside (about 22 minutes), and hot air with a moisture content of 2.8% was introduced.

[0068] Hydrolysis decolorization:

[0069] First water washing: rinse with 40℃ tap water for 5 minutes to remove floating dust (turbidity drops from 150NTU to 20NTU);

[0070] Second water washing and decolorization: inject 50°C softened water, add composite hydrolysis promoter (L-cysteine ​​0.03wt%, sodium bicarbonate 0.2g / L, disodium EDTA 0.02g / L), and mechanically turn for 45 minutes (redox potential controlled at -30mV).

[0071] Dehydrated stir-fry:

[0072] Three-stage gradient frying (150℃×15min→170℃×10min→180℃×5min).

[0073] Cooling and maturation:

[0074] Dry in a negative pressure warehouse to 40°C (humidity 35%) and maintain for 1.5 hours.

[0075] Fine grinding:

[0076] Basalt stone mill ≤ 45℃ grinding, paste D50 = 18μm.

[0077] Dynamic oil separation:

[0078] Add 80°C hot water (liquid-to-solid ratio 2:1) to the sauce, stir at 200 rpm, and simultaneously add 0.7 wt% of diatomaceous earth-activated carbon (3:1).

[0079] Gradient centrifugation:

[0080] 1500g×20min→3000g×15min→5000g×10min (nitrogen protection, dissolved oxygen 0.8mg / L).

[0081] Finished product refining:

[0082] Place in the dark at 12°C for 8 days, filter through a 0.22 μm membrane and can.

[0083] Effect:

[0084] The oil color is translucent (Lovibond colorimetric: yellow 35 / red 3.2, compared to traditional craft yellow 30 / red 8.5);

[0085] Bitterness value reduced by 82% (ISO sensory score: bitterness intensity 1.2 vs traditional 6.8);

[0086] The oil yield is 48.5% (45.1% for traditional process).

[0087] Example 2: Sesame oil pressing process (hot pressing)

[0088] step:

[0089] The raw materials were subjected to hydrolysis and decolorization: the same as steps 1-4 of Example 1 (the second water washing was changed to 60° C., 0.03 wt % neutral protease was added, and the enzymatic hydrolysis was carried out at 50° C. for 30 min).

[0090] Pre-pressing treatment:

[0091] After dehydration and frying, the moisture content of sesame is less than 5%, and the oil is extracted by a screw press (temperature 110° C., pressure 60 MPa).

[0092] Crude oil refining:

[0093] The crude oil was molecularly distilled (evaporation temperature 90°C, vacuum degree 8kPa, scraping speed 300rpm), and the light phase with an acid value of 0.4mgKOH / g was collected.

[0094] Effect:

[0095] Bitter substance removal rate was 78.3% (HPLC detection: sesamolin decreased from 920 mg / kg to 200 mg / kg, chlorogenic acid decreased from 350 mg / kg to 75 mg / kg);

[0096] The oil yield from pressing increased to 42.6% (38.9% for traditional hot pressing process);

[0097] Peroxide value 1.2meq / kg (traditional process 4.5meq / kg).

[0098] Example 3: Sesame Oil Pressing Process (Cold Pressing Optimization)

[0099] Innovation: Verification of the effectiveness of hydrolysis decolorization under wide parameters

[0100] Step adjustment:

[0101] Second wash: 35°C hard water (calcium ion 150 mg / L), only mechanical stirring (no compounding agent added), the time is extended to 70 minutes;

[0102] Pressing conditions: low temperature pressing at 60℃ and pressure of 80MPa.

[0103] Effect:

[0104] The bitter substance removal rate still reached 71.5% (sesamol was reduced from 920 mg / kg to 260 mg / kg);

[0105] Cold pressed oil retains tocopherol content (112mg / 100g vs 98mg / 100g for traditional cold pressed oil). Key data comparison table

[0106]

[0107] It should be noted that, in this document, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

Claims

1. A novel method for producing decolorized sesame oil, characterized in that: The following steps are involved: (1) Raw material pretreatment: After sesame seeds are screened and graded, they are circulated and cleaned to remove impurities; (2) First washing: Wash the sesame seeds to remove surface dust and light impurities; (3) Primary frying: frying sesame seeds until the inside is red and the outside is frosted; (4) Second water washing and decolorization: Place the sesame seeds in a water washing tank, add warm water and mechanically turn them over to rupture the epidermal cells of the sesame seeds, thereby promoting the hydrolysis and dissolution of the internal brown pigments and bitter substances; (5) Dehydration and frying: Gradient temperature rise is used to fry, evaporating water in stages, promoting oil release and terminating enzyme activity; (6) Cooling and maturation: air the sesame seeds to 35-45°C and maintain a low humidity environment for 1-2 hours; (7) Fine grinding: Grind sesame seeds at low temperature to obtain a paste with a fineness of ≤20 μm; (8) Dynamic oil separation: Add hot water to the sauce and separate the oil with the help of stirring; (9) Gradient centrifugation: multi-stage centrifugation to separate oil and liquid; (10) Finished product refining: centrifuge the oil and filter it before canning.

2. a novel decolorized sesame oil preparation method according to claim 1, is characterized in that In the second water washing and decolorization in step (4), the water washing temperature is 35-65°C and the water washing time is 20-70 minutes; The bitter substances include Maillard reaction products and free polyphenols.

3. A novel decolorized sesame oil preparation method according to claim 1, characterized in that Step (4) adds a composite hydrolysis accelerator to the water washing solution, the composition of which comprises: L-cysteine ​​0.01-0.1wt%; Carbonate 0.05-0.5g / L; Metal chelating agent 0.001-0.05g / L; And the redox potential is controlled in the range of -100mV to +100mV.

4. A novel decolorized sesame oil preparation method according to claim 1, characterized in that In step (4), the washing tank is equipped with an ultrasonic generator to apply 15-50kHz ultrasonic waves with an ultrasonic power density of 0.3-1.5W / cm 3 .

5. A novel decolorized sesame oil preparation method according to claim 1, characterized in that , step (4) also includes enzymatic treatment after washing and decolorization: Add neutral protease or cellulase, the enzyme dosage is 0.01% to 0.1% of the sesame mass; Enzymatic hydrolysis at pH 6.0-7.5 and temperature 40-55°C for 10-50 minutes; After enzymatic hydrolysis, the temperature is raised to 80-90°C to inactivate the enzyme.

6. A novel decolorized sesame oil preparation method according to claim 1, characterized in that , step (9) gradient centrifugation is carried out under the protection of inert gas, and the dissolved oxygen content is ≤2.0 mg / L.

7. A novel decolorized sesame oil production method according to claim 1, characterized in that, The method is applicable to a water-substitution process for extracting sesame oil from small-milled sesame oil or a pretreatment process for pressing sesame oil; In the pressing process, the bitter substances removed in step (4) account for more than 70% of the total bitter substances in the pressed oil.

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