CN101974593B - Method for producing pea peptide through enzyme method - Google Patents
Method for producing pea peptide through enzyme method Download PDFInfo
- Publication number
- CN101974593B CN101974593B CN 201010540579 CN201010540579A CN101974593B CN 101974593 B CN101974593 B CN 101974593B CN 201010540579 CN201010540579 CN 201010540579 CN 201010540579 A CN201010540579 A CN 201010540579A CN 101974593 B CN101974593 B CN 101974593B
- Authority
- CN
- China
- Prior art keywords
- enzymolysis
- pea
- enzyme
- raw material
- peptide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Coloring Foods And Improving Nutritive Qualities (AREA)
Abstract
The invention discloses a method for producing a pea peptide through an enzyme method, comprising the following steps of: blending screened and edulcorated pea protein powder used as main raw materials with water, ethanol and sodium sulfite to react for 3-5 hours; filtering and cooling to 50-60 DEG C; then sequentially adding two proleases for enzymolysis; modifying; inactivating enzyme; decoloring; separating a membrane; and carrying out spray drying on obtained filter liquor to obtain the pea peptide. The method acquires the pea peptide through a biological double enzyme method, has the advantages of simple production process, short production period, low cost, easy and convenient operation, moderate reaction condition, environmental protection and high safety performance and can be widely used in the fields of drugs, health care products, and the like.
Description
Technical field
The inventive method relates to the deep process technology field of Semen Pisi sativi protein powder; Be specifically related to a kind of method of Production by Enzymes pea peptide; Be a kind of be raw material with the Semen Pisi sativi protein powder; Utilize enzyme enzymolysis Semen Pisi sativi protein powder, utilize the enzyme modification technique that protein peptide is modified again, thereby extract the method for pea peptide.
Background technology
The pea seed contains protein 15.5%-39.7%, and fat is about 2%, also rich vitamin B1, B2 and nicotinic acid.The Semen Pisi sativi protein resource of China is extensive, low price, and Semen Pisi sativi protein is hydrolyzed can obtain the pea peptide, and it is neutral that the pH value is.Research shows, contain in the pea peptide human body can not self synthetic 8 in amino acid, and their ratio approaches the recommendation pattern of FAO/WHO.
But, have a strong impact on absorption and the utilization of human body to them because these amino acid are gone up basically with the polymeric form and are present in the protein.Research shows that protein mainly absorbs with the form of small-molecular peptides after the digestive enzyme effect, bigger than amino acid whose specific absorption through the specific absorption of the low peptide of evidence, more is prone to be absorbed by the body sooner, utilize than amino acid.Based on this theory, the pea polypeptide that utilizes biotechnology pacemaker enzyme incision technology to develop is with a wide range of applications.
The pea polypeptide can not only provide the human body required nutritive substance that grows, and has good physical and chemical index and functional performance simultaneously.Through functional experiment to the pea polypeptide; The researchist finds that the pea polypeptide has better solvability, water-retentivity, oil absorbency, whipability, emulsifying property, gelation etc. than pea protein; And with regard to several kinds of factors the influence of pea polypeptide functional performance is proved, for the application of pea polypeptide provides theoretical foundation.
Pea polypeptide favorable effects and good functional property; Make the pea polypeptide can be widely used in food and the healthcare products; The pea polypeptide has quite high water-retentivity, oil absorbency and good gel formation property, can be used for meat products such as ham sausage, as good additive; The pea polypeptide has certain lathering property and froth stability, can partly replace eggs to add in the cake product; The pea polypeptide has extraordinary emulsifying property and emulsifying stability, can be used as the emulsifying agent of varieties of food items; The pea polypeptide is emulsifying fat rapidly, the good sausage of modulation emulsifying property, and the sausage that makes is very good to eat, is of high nutritive value; The pea peptide is used for biscuit can strengthen fragrance, strengthens protein, and can be developed into the protective foods of difference in functionality; The pea peptide can also be used for the Noodles goods, as can improve nutritive value, intensity and the biceps of noodles in the face with the pea peptide, can improve the outward appearance and the mouthfeel of cereal preparation.
From Semen Pisi sativi protein powder, extract the pea peptide and adopt following method mostly: Semen Pisi sativi protein powder → alkaline purification → high temperature steaming → enzymolysis → filtration → concentrate → spraying drying.Use a large amount of alkaline purifications in the leaching process, both environment was polluted and there is potential safety hazard in human body, destroyed proteinic composition again; And concentrate the article phase of destroying product easily, and do not use membrane separation technique in the prior art, influenced the quality of product.
Summary of the invention
To the deficiency that exists in the prior art; The object of the present invention is to provide a kind of method of Production by Enzymes pea peptide, this method is utilized enzyme enzymolysis Semen Pisi sativi protein powder, and further modifies the peptide bond debitterize; With membrane separation technique desalination and concentrated, finally extract highly purified pea peptide again.
To achieve these goals, the inventive method adopts following technical measures:
A kind of method of Production by Enzymes pea peptide, its step is following:
1, with the Semen Pisi sativi protein powder be raw material, cross earlier 40 mesh sieve removal of impurities, the 5-7 that adds raw material weight doubly, zero(ppm) water, 95wt% ethanol and the sodium sulphite anhydrous 99.3 of 5-10% and 1-2% stir, in 90-95 ℃ of refluxed reaction 3-5h, filtered while hot after react;
2, cooling is filtrated to 50-60 ℃, and adjust pH is 7-8, and the 2-4% that presses raw material weight adds Sumizyme MP, stirs enzymolysis 4-6h, keeps stablizing the pH value stabilization in the enzymolysis process; The 1-2% of raw material weight adds flavor protease again, stirs enzymolysis 5-8h, keeps stablizing the pH value stabilization in the enzymolysis process; The enzymolysis solution that obtains is warming up to 90-100 ℃, keeps the 10-20min enzyme that goes out;
3, with the centrifugal after-filtration of enzymolysis solution, remove proteolytic enzyme, add powdered active carbon and decolour, use the membrane sepn means to separate then, concentrate, promptly get pea peptide dry product after the liquid concentrator drying.
The Sumizyme MP that uses in the inventive method and the vigor of flavor protease are respectively 25U/mg and 30U/mg.
Compared with prior art, advantage of the inventive method and beneficial effect are following:
1, adopt the purity of the pea peptide product that the inventive method produces high, the peptide content of molecular weight below 1000 dalton reaches more than 98% in its total protein, not only improved the nutritive value of pea, brought economic benefit for society simultaneously;
2, the pea peptide that adopts the inventive method to produce, molecular weight is little, and human body is prone to absorb, and specific absorption reaches more than 90%;
3, the present invention adopts activated carbon decolorizing, residues in the product injury to human body when effectively having avoided using the hydrogen peroxide decolouring, and has guaranteed the natural colored degree of product;
4, adopt membrane separation technique of the present invention, the liquid towards material separates, concentrates and purifying, all operates, does not have phase-state change, energy-efficient at normal temperatures, and do not produce pollution in the production process;
5, the inventive method is with short production cycle, cost is low, do not produce any hazardous and noxious substances, and safety has no side effect, and can be widely used in fields such as makeup, food, medicine.
Embodiment
Through concrete embodiment the inventive method is done further detailed description below.
Embodiment 1:
A kind of method of Production by Enzymes pea peptide, its step is following:
Took by weighing commercially available Semen Pisi sativi protein powder behind 40 mesh sieves (crude protein＞61wt% wherein, moisture content＜10wt%, the 1kg of ash＜3wt%); Add 7kg zero(ppm) water, 50g 95wt% ethanol and 10g sodium sulphite anhydrous 99.3; After stirring, be warming up to 90 ℃ of backflow 5h, reacted the back filtered while hot; Cooling filtrating is transferred pH to 7-8 to 50 ℃ with the food grade hydroxide flake sodium solution of 0.1M again, adds the 20g Sumizyme MP then, and 50 ℃ are stirred enzymolysis 6h, and the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; The flavor protease that adds 10g again, 50 ℃ of enzymolysis 8h, the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Be warming up to 90 ℃ then, the insulation 20min enzyme that goes out; Then enzymolysis solution is filtered, get supernatant; Add the 20g powdered active carbon in the supernatant, 55 ℃ of whip attachment 1h decolourings, filtering gac; The filtrating via hole diameter is that the nanofiltration membrane separation system of 1nm separates, and desalination also concentrates; Liquid concentrator is spray-dried, obtains the Powdered pea peptide of 386g white (adopt activated carbon decolorizing among the present invention, the color and luster of products obtained therefrom is a white, is superior to the faint yellow of national Specification), and the examining report of products obtained therefrom is seen table 1.
The examining report of table 1 embodiment 1 products obtained therefrom
| Test item | National Specification | Detected result |
| Form | Powdered, no caking phenomenon | Powdered, there is not caking |
| Color and luster | Yellow or faint yellow | White |
| Flavour and smell | The flavour and the smell that have product to have | Do not have |
| Impurity | The visible tramp material of no twenty-twenty vision | Inclusion-free |
| Gross protein | ≥80.0％ | 95.6％ |
| (the molecular weight 1000 of peptide in the total protein | ≥75.0％ | 98.3％ |
| Below the dalton) content | ||
| PH value (the 10wt% aqueous solution) | 7.0-8.0 | 7.3 |
| Moisture | ≤7.0％ | 1.5％ |
| Ash content | ≤10.0％ | 2.1％ |
| Arsenic content (in the As element) | ≤0.5mg/kg | 0.22mg/kg |
| Lead content (in the Pb element) | ≤0.5mg/kg | 0.16mg/kg |
| Total plate count | ≤30000cfu/g | 1000cfu/g |
| Coliform | ≤40MPN/100g | ＜20MPN/100g |
| Mould and yeast | ≤50cfu/g | ＜10cfu/g |
| Pathogenic bacterium | Must not detect | Do not detect |
Embodiment 2:
A kind of method of Production by Enzymes pea peptide, its step is following:
Took by weighing commercially available Semen Pisi sativi protein powder behind 40 mesh sieves (crude protein＞61wt% wherein, moisture content＜10wt%, the 2kg of ash＜3wt%); Add 10kg zero(ppm) water, 200g 95wt% ethanol and 30g sodium sulphite anhydrous 99.3; After stirring, be warming up to 92 ℃ of backflow 4h, reacted the back filtered while hot; Cooling filtrating is transferred pH to 7-8 to 55 ℃ with the food grade hydroxide flake sodium solution of 0.1M again, adds the 60g Sumizyme MP then, and 55 ℃ are stirred enzymolysis 5h, and the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Add the 30g flavor protease again, 55 ℃ of enzymolysis 7h, the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Be warming up to 94 ℃ then, the insulation 16min enzyme that goes out; Then enzymolysis solution is filtered, get supernatant; Add the 45g powdered active carbon in the supernatant, 55 ℃ of whip attachment 1h decolourings, filtering gac; The filtrating via hole diameter is that the nanofiltration membrane separation system of 1nm separates, and desalination also concentrates; Liquid concentrator is spray-dried, obtains 800g white powder pea peptide, and the examining report of products obtained therefrom is seen table 2.
The examining report of table 2 embodiment 2 products obtained therefroms
Embodiment 3:
A kind of method of Production by Enzymes pea peptide, its step is following:
Took by weighing commercially available Semen Pisi sativi protein powder behind 40 mesh sieves (crude protein＞61wt% wherein, moisture content＜10wt%, the 10kg of ash＜3wt%); The ethanol and the 200g sodium sulphite anhydrous 99.3 that add 60kg zero(ppm) water, 700g 95wt%; After stirring, be warming up to 93 ℃ of backflow 4h, reacted the back filtered while hot; Cooling filtrating is transferred pH to 7-8 to 55 ℃ with the food grade hydroxide flake sodium solution of 0.1M again, adds the 400g Sumizyme MP then, and 55 ℃ are stirred enzymolysis 5h, and the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Add the 200g flavor protease again, 55 ℃ of enzymolysis 6h, the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Be warming up to 96 ℃ then, the insulation 14min enzyme that goes out; Then enzymolysis solution is filtered, get supernatant; Add the 250g powdered active carbon in the supernatant, 55 ℃ of whip attachment 1h decolourings, filtering gac; The filtrating via hole diameter is that the nanofiltration membrane separation system of 1nm separates, and desalination also concentrates; Liquid concentrator is spray-dried, obtains 4.01kg white powder pea peptide, and the examining report of products obtained therefrom is seen table 3.
The examining report of table 3 embodiment 3 products obtained therefroms
Embodiment 4:
A kind of method of Production by Enzymes pea peptide, its step is following:
Took by weighing commercially available Semen Pisi sativi protein powder behind 40 mesh sieves (crude protein＞61wt% wherein, moisture content＜10wt%, the 100kg of ash＜3wt%); Add 650kg zero(ppm) water, 8kg 95wt% ethanol and 1600g sodium sulphite anhydrous 99.3; After stirring, be warming up to 95 ℃ of backflow 3h, reacted the back filtered while hot; Cooling filtrating is transferred pH to 7-8 to 60 ℃ with the food grade hydroxide flake sodium solution of 0.1M again, adds the 3000g Sumizyme MP then, and 60 ℃ are stirred enzymolysis 4h, and the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Add the 1600g flavor protease again, 60 ℃ of enzymolysis 5h, the sodium hydroxide solution with above-mentioned 0.1M in the enzymolysis process keeps pH value of reaction system at 7-8; Be warming up to 100 ℃ then, the insulation 10min enzyme that goes out; Then enzymolysis solution is filtered, get supernatant; Add the 2.2kg powdered active carbon in the supernatant, 55 ℃ of whip attachment 1h decolourings, filtering gac; The filtrating via hole diameter is that the nanofiltration membrane separation system of 1nm separates, and desalination also concentrates; Liquid concentrator is spray-dried, obtains 41kg white powder pea peptide, and the examining report of products obtained therefrom is seen table 4.
The examining report of table 4 embodiment 4 products obtained therefroms
Claims (4)
1. the method for a Production by Enzymes pea peptide, its step is following:
A, the Semen Pisi sativi protein powder that takes by weighing after the removal of impurities of sieving are raw material, and the ethanol and the sodium sulphite anhydrous 99.3 of 1-2% that add the 95wt% of doubly water of raw material weight 5-7,5-10% stir, and at 90-95 ℃ of refluxed reaction 3-5h, reacts filtered while hot afterwards;
B, cooling are filtrated to 50-60 ℃, and adjust pH is 7-8, and the 2-4% that presses raw material weight adds the Sumizyme MP of 25U/mg, and constant temperature stirs enzymolysis 4-6h, and the pH value that keeps reaction system with sodium hydroxide solution in the enzymolysis process is at 7-8; The 1-2% that presses raw material weight again adds the flavor protease of 30U/mg, and constant temperature stirs enzymolysis 5-8h, and the pH value that keeps reaction system with sodium hydroxide solution in the enzymolysis process is at 7-8; The enzymolysis solution that obtains is warming up to the 90-100 ℃ of enzyme that goes out;
C, with the centrifugal after-filtration of enzymolysis solution, remove proteolytic enzyme, filtrating is decoloured through powdered active carbon, and then comes desalination and concentrate through membrane sepn, promptly gets the pea peptide after the liquid concentrator drying;
What described membrane sepn operation was adopted is that the aperture is the nf membrane of 1nm.
2. the method for claim 1, it is characterized in that: the time of the described enzyme that goes out is 10-20min.
3. the method for claim 1, it is characterized in that: the consumption of described powdered active carbon is the 2-2.5% of raw material weight.
4. the method for claim 1 is characterized in that: described decolouring is 55 ℃ of following whip attachment 1h decolourings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010540579 CN101974593B (en) | 2010-11-11 | 2010-11-11 | Method for producing pea peptide through enzyme method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201010540579 CN101974593B (en) | 2010-11-11 | 2010-11-11 | Method for producing pea peptide through enzyme method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101974593A CN101974593A (en) | 2011-02-16 |
| CN101974593B true CN101974593B (en) | 2012-07-25 |
Family
ID=43574501
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201010540579 Expired - Fee Related CN101974593B (en) | 2010-11-11 | 2010-11-11 | Method for producing pea peptide through enzyme method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101974593B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015114045A1 (en) * | 2014-01-29 | 2015-08-06 | Upfront Chromatography A/S | Novel separation processes for pea protein |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011122937A1 (en) * | 2010-03-29 | 2011-10-06 | N.V. Nutricia | Pea protein peptides with anti helicobacter pylori activity |
| CN103194519A (en) * | 2013-04-27 | 2013-07-10 | 江南大学 | Method for preparing antioxidative peptide through proteolysis on pea protein and application thereof |
| CN103436580A (en) * | 2013-08-27 | 2013-12-11 | 山东天久生物技术有限公司 | Preparation method of pea polypeptide |
| CN105368905A (en) * | 2015-12-09 | 2016-03-02 | 曾志亮 | Microwave-assisted method for preparing pea protein polypeptides |
| CN106075384B (en) * | 2016-06-17 | 2019-07-19 | 天津科技大学 | Pea active peptide is inhibiting the application and preparation method thereof in growth of cancer cells |
| CN107279458A (en) * | 2017-07-13 | 2017-10-24 | 安徽生物肽产业研究院有限公司 | It is a kind of that there is zinc-rich pea small peptide of enhancing immunity of organisms and preparation method thereof |
| CN108220371B (en) * | 2017-12-29 | 2020-12-25 | 武汉天天好生物制品有限公司 | Preparation method of pea peptide with prebiotic effect and application of pea peptide in food |
| CN109055466A (en) * | 2018-07-30 | 2018-12-21 | 山东理工大学 | A kind of preparation method of pea peptide and its application in whitening field |
| CN111019989B (en) * | 2018-10-09 | 2022-08-05 | 杏辉天力（杭州）药业有限公司 | Pea oligopeptide powder and preparation method thereof |
| CN114410723A (en) * | 2022-02-17 | 2022-04-29 | 漯河永瑞生物科技有限公司 | Pea antioxidant peptide with good emulsibility and preparation method thereof |
| CN114315970B (en) * | 2022-03-15 | 2022-07-19 | 中食都庆（山东）生物技术有限公司 | Pea peptide with muscle increasing effect, and preparation method, medicament and application thereof |
| CN115590069A (en) * | 2022-10-14 | 2023-01-13 | 海南华研胶原科技股份有限公司（Cn） | Composition containing pea peptide and preparation method and application thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101731444B (en) * | 2009-12-30 | 2012-06-27 | 陕西天宝大豆食品技术研究所 | Pea peptide nutriment and preparation method thereof |
-
2010
- 2010-11-11 CN CN 201010540579 patent/CN101974593B/en not_active Expired - Fee Related
Non-Patent Citations (2)
| Title |
|---|
| 吴泽柱.玉米蛋白肽的生产加工研究现状.《中国食品添加剂》.2009, * |
| 李志平.木瓜蛋白酶水解豌豆蛋白的工艺研究.<食品研究与开发>.2010, * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015114045A1 (en) * | 2014-01-29 | 2015-08-06 | Upfront Chromatography A/S | Novel separation processes for pea protein |
| EA030803B1 (en) * | 2014-01-29 | 2018-09-28 | Апфронт Кроматографи А/С | Separation processes for pea protein |
Also Published As
| Publication number | Publication date |
|---|---|
| CN101974593A (en) | 2011-02-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101974593B (en) | Method for producing pea peptide through enzyme method | |
| CN101974590B (en) | Method for extracting rice peptides | |
| CN104531817B (en) | A kind of hyaluronic acid, chondroitin sulfate, collagen peptide, bone powder fodder and the method for soap coproduction | |
| CN101974591B (en) | Enzymatic method for extracting soy peptide | |
| CN102550797B (en) | Production method of sea cucumber peptide extract | |
| CN100464643C (en) | Composite silkworm feed stuff and its producing method | |
| CN101886106A (en) | Method for extracting collagen peptide from fish scales | |
| CN101965898B (en) | Method for extracting peanut peptide | |
| CN104726527A (en) | Preparation technology for producing collagen through enzymolysis of fish scales | |
| CN103937865A (en) | Peony polypeptide as well as preparation method and application thereof | |
| CN108103131A (en) | A kind of preparation process of ocean fish collagen oligopeptide powder and its application | |
| CN102367465A (en) | Extraction method of pig blood protein peptide | |
| CN101974592B (en) | Extraction method of wheat gluten peptide | |
| CN108902676A (en) | Wheat-based polypeptide and modified starch compounding wheat analogies and preparation method thereof | |
| CN101979655B (en) | Enzyme method for producing mung bean peptide | |
| CN103652314B (en) | Microencapsulated walnut peptide and preparation method thereof | |
| CN102987275B (en) | A kind of preparation method of the soy oligosaccharides glycopeptide of high biological value | |
| CN103030645A (en) | Method for preparing high-purity heme on large scale and application of heme | |
| CN102021216B (en) | Extraction method of antialcoholism peptide | |
| CN106509799A (en) | Method for preparing seafood seasoning from clam cooking liquor and prepared seafood seasoning | |
| CN101974597B (en) | Method for extracting ovalbumin peptide | |
| CN104262132A (en) | Method for preparing calcium propionate from eggshell | |
| CN105029572B (en) | A kind of black soya bean antioxidation polypeptide beverage and preparation method thereof | |
| CN105018557A (en) | Preparation method of pumpkin seed meal small peptides | |
| CN109221597A (en) | A kind of preparation method of river Puffer fish low fat albumen powder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| DD01 | Delivery of document by public notice |
Addressee: Hubei far Cheng Cheng Chong Technology Co., Ltd. responsible person Document name: Notification that Application Deemed not to be Proposed |
|
| C56 | Change in the name or address of the patentee |
Owner name: HUBEI YUANCHENG SAICHUANG TECHNOLOGY CO., LTD. Free format text: FORMER NAME: HUBEI YUANCHENG PHARMACEUTICAL CO., LTD. |
|
| CP01 | Change in the name or title of a patent holder |
Address after: 430064 No. 496, Wuchang, Wuhan District, Hubei, Zhongshan Road Patentee after: HUBEI YUANCHENG PHARMACEUTICAL CO., LTD. Address before: 430064 No. 496, Wuchang, Wuhan District, Hubei, Zhongshan Road Patentee before: Hubei Yuancheng Pharmaceutical Co., Ltd. |
|
| CP01 | Change in the name or title of a patent holder | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120725 Termination date: 20141111 |
|
| EXPY | Termination of patent right or utility model |