Codex Œnologique International

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SUCRE DE RAISIN

COEI-1-SUCRAI Grape sugar (rectified concentrated grape musts)

  1. Objective, origin and scope of application

Grape sugar is obtained exclusively from grape musts.  The addition of grape sugar to wine is subject to regulation.

The label, or, when this is absent, the documentation accompanying the containers of grape sugar, must cite the sugar percentage.

  1. Properties

Syrupy, milk-white or slightly yellowish liquid with a sugary flavor.

Refraction index at 20 °C

1.42410-1.46663

Total sugar in terms of invert sugar

63% (m/m) minimum

Absorbance at 425 nm under 1 cm at 25° Brix

maximum 0.100

pH at 25° Brix

maximum 5 *

Titration acidity in mEq/kg of sugar

maximum 15 *

Sucrose by recommended method

negative

Sulfur dioxide in mg/kg of sugar

maximum 25

Folin-Ciocalteu index at 25° Brix

maximum 6

Total cations in mEq/kg of sugar

maximum 8

Conductivity at 25° Brix in Micro-Siemens/cm (μScm-1)

maximum 120

5-(hydroxymethyl)furfural in mg/kg sugar

maximum 25

Residual ethanol in g/kg sugar

maximum 8

Heavy metals in mg/kg grape sugar expressed in terms of lead

less than 10

No antiseptics and anti-fermenting agents

1° Brix = 1 g of sugar in 100 g of solution

* after vacuum removal of the carbon dioxide

  1. Tests

 

3.1.         Preparing the Sample

Drawing samples for the various different analyses is difficult; therefore. the following two dilutions are recommended:

3.1.1.  Principal Solution I - for the following tests: titration acidity, total sulfur dioxide and total cations

Weigh exactly 200 g of grape sugar.  Fill to 500 ml with water.

3.1.2.  Principal Solution II - necessary for the following tests: Folin-Ciocalteu index, pH, conductivity, sucrose test and absorbance at 425 nm.

Dilute the grape sugar with water until it has a concentration of 25° ± 0.5° Brix (25 g of sugar in 100 g of solution).

3.2.         Refraction Index at 20 °C (total sugars)

3.2.1.  Equipment:

The refractometer used gives the following, based on type of graduation:

  • 0.1% by mass of sucrose (or dry matter or Brix degrees)
  • the 5th decimal of the index of refraction

The refractometer used should be equipped with a thermometer (+ 10 °C at + 30 °C).

3.2.2.  Procedure Method:

Place two drops of grape sugar on the surface of the fixed prism.  Lower the moving prism and point the instrument toward a light source that illuminates the graduated scale. Observe the line of separation on this scale between a lower clear zone and an upper dark. Read the graduation line at which this line of separation occurs and record the temperature in °C.

3.2.3.  Calculation:

If the device is graduated in percentage (m/m) of sucrose (or dry matter or Brix degrees), the measurement converted to 20 °C using Table 2 is recorded in Table 1 which provides (Column 3) total sugar content in percent (m/m) expressed in terms of sugar.

If the device is graduated by refraction index, the index measured at t °C is used to obtain the corresponding value in percent of sucrose (m/m) at t °C in Table 1 (Column 1).  This value as expressed at 20 °C using the temperature correction table N° 2, transferred to Table 1, which, in Column 3, gives the total sugar number in percent (m/m) of invert sugar.

To obtain the refraction index at 20 °C, refer to the total sugar content expressed in terms of invert sugar in Table 1.

3.2.4.  Recording the Findings:

Total sugar content is expressed parts per 100 by mass of sucrose and is recorded with a decimal.

The refraction index at 20 °C is expressed to 5 decimal places.

3.3.         Absorbance of a 25° Brix Solution at 425 nm (Chromatic characteristics)[1]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-08).

3.4.         Measuring pH[2]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-06).

3.5.         Titration Acidity[3]

Place 10 ml of Principal Solution I in a cylindrical vessel (3.1.1).  Add Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-05).

3.6.         Sucrose Test by HPLC[4]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-04).

3.7.         Sulfur Dioxide[5]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-07).

3.8.         Folin-Ciocalteu Index of the 25° Brix Solution

Place the following, in order, in a 100 ml volumetric flask:

  • 5 ml of Principal Solution II
  • 50 ml water
  • 5 ml Folin-Ciocalteu reagent (R)
  • 20 ml of sodium carbonate solution (R)

Fill to the 100 ml level with water.  Stir to homogenize.  Wait 30 minutes for the reaction to stabilize.

Determine absorbance at 750 nm in 1 cm as compared with a control prepared with water instead of Principal Solution II.

Expressing the results:

Express the results in the form of an index obtained by multiplying the absorbance by 16 in order to obtain a scale comparable to that used for wines.

3.9.         Total Cations

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-09).

3.10.     Conductivity of the Solution at 25° Brix[6]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-01).

3.11.     5-(Hydroxymethyl)furfural(HMF)[7]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-02)

3.12.     Heavy Metals

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-10; Method OIV-MA-F1-11).

 (Heavy metal content, expressed in terms of lead, should be less than 10 mg/kg).

3.13.     Lead

Using the method set forth in the Compendium, quantitatively analyze lead in the Principal Solution I (3.1.1). (Lead content should be less than 1 mg/kg.)

3.14.     Mercury

Using the method set forth in the annex, quantitatively analyze mercury in the Principal Solution I (3.1.1). (Mercury content should be less than 0.3 mg/kg.)

3.15.     Arsenic

Using the method described in the annex, quantitatively analyze arsenic in the Principal Solution I (3.1.1). (Arsenic concentration should be less than 0.5 mg/kg.)

3.16.     Ethanol[8]

Proceed to the analysis according to the method described in the Compendium of international methods of wine and must analysis (Method OIV-MA-F1-03).

3.17.     Meso-Inositol

Gas phase chromatography of a silyl-containing derivative.

N.B. : The information given above is provided for informational purposes. There are other techniques for deriving sugars and polyhydroxy alcohols, and chromatographic methods for determining meso-inositol concentrations

3.17.1.                      Preparing the sample:

Dilute 5 g of grape sugar in 50 ml of water. Dry 50 μl of the dilution and 50 µl of a methyl D-glucopyranoside solution in a concentration of 1 g/liter, (internal standard) under a vacuum in a small 2 ml flask.

Dissolve the residue with 100 μl of pyridine. Add 100 μl of trimethylchlorosilane. Seal the small flask with a teflon stopper and heat at 80 °C for 1 hour. Inject 1 μl with division of the injected volume to 1/60.

3.17.2.                      Separation

Column: apolar capillary type of fused silica 25 m long and inner diameter of 0.2 mm.

Supporting Gas: helium, 1 ml/minute

Injector and detector: 280 °C

Column temperature: 60-250 °C, at 4 °C per minute, then isothermal at 250 °C.

3.17.3.                      Expressing the results: g per kg of sugar

  1. Storage

Grape sugar must be stored in impermeable containers and at ambient termperature from the time it is made.

Annex 1 (sugars)

Table 1 : Sugar content in musts using refractometry

Sucrose % (m/m)

Index of refraction at 20°C

Density at 20°C

Sugars in g/l

Sugars in g/kg

50.0

1.42008

1.2342

627.6

508.5

50.1

1.42029

1.2348

629.3

509.6

50.2

1.42050

1.2355

630.9

510.6

50.3

1.42071

1.2362

632.4

511.6

50.4

1.42092

1.2367

634.1

512.7

50.5

1.42113

1.2374

635.7

513.7

50.6

1.42135

1.2381

637.3

514.7

50.7

1.42156

1.2386

638.7

515.7

50.8

1.42177

1.2391

640.4

516.8

50.9

1.42198

1.2396

641.9

517.8

51.0

1.42219

1.2401

643.4

518.8

51.1

1.42240

1.2406

645.0

519.9

51.2

1.42261

1.2411

646.5

520.9

51.3

1.42282

1.2416

648.1

522.0

51.4

1.42304

1.2421

649.6

523.0

51.5

1.42325

1.2427

651.2

524.0

51.6

1.42347

1.2434

652.9

525.1

51.7

1.42368

1.2441

654.5

526.1

51.8

1.42389

1.2447

656.1

527.1

51.9

1.42410

1.2454

657.8

528.2

52.0

1.42432

1.2461

659.4

529.2

52.1

1.42453

1.2466

661.0

530.2

52.2

1.42475

1.2470

662.5

531.3

52.3

1.42496

1.2475

664.1

532.3

52.4

1.42517

1.2480

665.6

533.3

52.5

1.42538

1.2486

667.2

534.4

52.6

1.42560

1.2493

668.9

535.4

52.7

1.42581

1.2500

670.5

536.4

52.8

1.42603

1.2506

672.2

537.5

52.9

1.42624

1.2513

673.8

538.5

53.0

1.42645

1.2520

675.5

539.5

53.1

1.42667

1.2525

677.1

540.6

53.2

1.42689

1.2530

678.5

541.5

53.3

1.42711

1.2535

680.2

542.6

53.4

1.42733

1.2540

681.8

543.7

53.5

1.42754

1.2546

683.4

544.7

53.6

1.42776

1.2553

685.1

545.8

53.7

1.42797

1.2560

686.7

546.7

53.8

1.42819

1.2566

688.4

547.8

53.9

1.42840

1.2573

690.1

548.9

54.0

1.42861

1.2580

691.7

549.8

54.1

1.42884

1.2585

693.3

550.9

54.2

1.42906

1.2590

694.9

551.9

54.3

1.42927

1.2595

696.5

553.0

54.4

1.42949

1.2600

698.1

554.0

54.5

1.42971

1.2606

699.7

555.1

54.6

1.42993

1.2613

701.4

556.1

54.7

1.43014

1.2620

703.1

557.1

54.8

1.43036

1.2625

704.7

558.2

54.9

1.43058

1.2630

706.2

559.1

55.0

1.43079

1.2635

707.8

560.2

55.1

1.43102

1.2639

709.4

561.3

55.2

1.43124

1.2645

711.0

562.3

55.3

1.43146

1.2652

712.7

563.3

55.4

1.43168

1.2659

714.4

564.3

55.5

1.43189

1.2665

716.1

565.4

55.6

1.43211

1.2672

717.8

566.4

55.7

1.43233

1.2679

719.5

567.5

55.8

1.43255

1.2685

721.1

568.5

55.9

1.43277

1.2692

722.8

569.5

56.0

1.43298

1.2699

724.5

570.5

56.1

1.43321

1.2703

726.1

571.6

56.2

1.43343

1.2708

727.7

572.6

56.3

1.43365

1.2713

729.3

573.7

56.4

1.43387

1.2718

730.9

574.7

56.5

1.43409

1.2724

732.6

575.8

56.6

1.43431

1.2731

734.3

576.8

56.7

1.43454

1.2738

736.0

577.8

56.8

1.43476

1.2744

737.6

578.8

56.9

1.43498

1.2751

739.4

579.9

57.0

1.43519

1.2758

741.1

580.9

57.1

1.43542

1.2763

742.8

582.0

57.2

1.43564

1.2768

744.4

583.0

57.3

1.43586

1.2773

745.9

584.0

57.4

1.43609

1.2778

747.6

585.1

57.5

1.43631

1.2784

749.3

586.1

57.6

1.43653

1.2791

751.0

587.1

57.7

1.43675

1.2798

752.7

588.1

57.8

1.43698

1.2804

754.4

589.2

57.9

1.43720

1.2810

756.1

590.2

58.0

1.43741

1.2818

757.8

591.2

58.1

1.43764

1.2822

759.5

592.3

58.2

1.43784

1.2827

761.1

593.4

58.3

1.43809

1.2832

762.6

594.3

58.4

1.43832

1.2837

764.3

595.4

58.5

1.43854

1.2843

766.0

596.4

58.6

1.43877

1.2850

767.8

597.5

58.7

1.43899

1.2857

769.5

598.5

58.8

1.43922

1.2863

771.1

599.5

58.9

1.43944

1.2869

772.9

600.6

59.0

1.43966

1.2876

774.6

601.6

59.1

1.43988

1.2882

776.3

602.6

59.2

1.44011

1.2889

778.1

603.7

59.3

1.44034

1.2896

779.8

604.7

59.4

1.44057

1.2902

781.6

605.8

59.5

1.44079

1.2909

783.3

606.8

59.6

1.44102

1.2916

785.2

607.9

59.7

1.44124

1.2921

786.8

608.9

59.8

1.44147

1.2926

788.4

609.9

59.9

1.44169

1.2931

790.0

610.9

60.0

1.44192

1.2936

791.7

612.0

60.1

1.44215

1.2942

793.3

613.0

60.2

1.44238

1.2949

795.2

614.1

60.3

1.44260

1.2956

796.9

615.1

60.4

1.44283

1.2962

798.6

616.1

60.5

1.44305

1.2969

800.5

617.2

60.6

1.44328

1.2976

802.2

618.2

60.7

1.44351

1.2981

803.9

619.3

60.8

1.44374

1.2986

805.5

620.3

60.9

1.44397

1.2991

807.1

621.3

61.0

1.44419

1.2996

808.7

622.3

61.1

1.44442

1.3002

810.5

623.4

61.2

1.44465

1.3009

812.3

624.4

61.3

1.44488

1.3016

814.2

625.5

61.4

1.44511

1.3022

815.8

626.5

61.5

1.44534

1.3029

817.7

627.6

61.6

1.44557

1.3036

819.4

628.6

61.7

1.44580

1.3042

821.3

629.7

61.8

1.44603

1.3049

823.0

630.7

61.9

1.44626

1.3056

824.8

631.7

62.0

1.44648

1.3062

826.6

632.8

62.1

1.44672

1.3068

828.3

633.8

62.2

1.44695

1.3075

830.0

634.8

62.3

1.44718

1.3080

831.8

635.9

62.4

1.44741

1.3085

833.4

636.9

62.5

1.44764

1.3090

835.1

638.0

62.6

1.44787

1.3095

836.8

639.0

62.7

1.44810

1.3101

838.5

640.0

62.8

1.44833

1.3108

840.2

641.0

62.9

1.44856

1.3115

842.1

642.1

63.0

1.44879

1.3121

843.8

643.1

63.1

1.44902

1.3128

845.7

644.2

63.2

1.44926

1.3135

847.5

645.2

63.3

1.44949

1.3141

849.3

646.3

63.4

1.44972

1.3148

851.1

647.3

63.5

1.44955

1.3155

853.0

648.4

63.6

1.45019

1.3161

854.7

649.4

63.7

1.45042

1.3168

856.5

650.4

63.8

1.45065

1.3175

858.4

651.5

63.9

1.45088

1.3180

860.0

652.5

64.0

1.45112

1.3185

861.6

653.5

64.1

1.45135

1.3190

863.4

654.6

64.2

1.45158

1.3195

865.1

655.6

64.3

1.45181

1.3201

866.9

656.7

64.4

1.45205

1.3208

868.7

657.7

64.5

1.45228

1.3215

870.6

658.8

64.6

1.45252

1.3221

872.3

659.8

64.7

1.45275

1.3228

874.1

660.8

64.8

1.45299

1.3235

876.0

661.9

64.9

1.45322

1.3241

877.8

662.9

65.0

1.45347

1.3248

879.7

664.0

65.1

1.45369

1.3255

881.5

665.0

65.2

1.45393

1.3261

883.2

666.0

65.3

1.45416

1.3268

885.0

667.0

65.4

1.45440

1.3275

886.9

668.1

65.5

1.45463

1.3281

888.8

669.2

65.6

1.45487

1.3288

890.6

670.2

65.7

1.45510

1.3295

892.4

671.2

65.8

1.45534

1.3301

894.2

672.3

65.9

1.45557

1.3308

896.0

673.3

66.0

1.45583

1.3315

898.0

674.4

66.1

1.45605

1.3320

899.6

675.4

66.2

1.45629

1.3325

901.3

676.4

66.3

1.45652

1.3330

903.1

677.5

66.4

1.45676

1.3335

904.8

678.5

66.5

1.45700

1.3341

906.7

679.6

66.6

1.45724

1.3348

908.5

680.6

66.7

1.45747

1.3355

910.4

681.7

66.8

1.45771

1.3361

912.2

682.7

66.9

1.45795

1.3367

913.9

683.7

67.0

1.45820

1.3374

915.9

684.8

67.1

1.45843

1.3380

917.6

685.8

67.2

1.45867

1.3387

919.6

686.9

67.3

1.45890

1.3395

921.4

687.9

67.4

1.45914

1.3400

923.1

688.9

67.5

1.45938

1.3407

925.1

690.0

67.6

1.45962

1.3415

927.0

691.0

67.7

1.45986

1.3420

928.8

692.1

67.8

1.46010

1.3427

930.6

693.1

67.9

1.46034

1.3434

932.6

694.2

68.0

1.46060

1.3440

934.4

695.2

68.1

1.46082

1.3447

936.2

696.2

68.2

1.46106

1.3454

938.0

697.2

68.3

1.46130

1.3460

939.9

698.3

68.4

1.46154

1.3466

941.8

699.4

68.5

1.46178

1.3473

943.7

700.4

68.6

1.46202

1.3479

945.4

701.4

68.7

1.46226

1.3486

947.4

702.5

68.8

1.46251

1.3493

949.2

703.5

68.9

1.46275

1.3499

951.1

704.6

69.0

1.46301

1.3506

953.0

705.6

69.1

1.46323

1.3513

954.8

706.6

69.2

1.46347

1.3519

956.7

707.7

69.3

1.46371

1.3526

958.6

708.7

69.4

1.46396

1.3533

960.6

709.8

69.5

1.46420

1.3539

962.4

710.8

69.6

1.46444

1.3546

964.3

711.9

69.7

1.46468

1.3553

966.2

712.9

69.8

1.46493

1.3560

968.2

714.0

69.9

1.46517

1.3566

970.0

715.0

70.0

1.46544

1.3573

971.8

716.0

70.1

1.46565

1.3579

973.8

717.1

70.2

1.46590

1.3586

975.6

718.1

70.3

1.46614

1.3593

977.6

719.2

70.4

1.46639

1.3599

979.4

720.2

70.5

1.46663

1.3606

981.3

721.2

70.6

1.46688

1.3613

983.3

722.3

70.7

1.46712

1.3619

985.2

723.4

70.8

1.46737

1.3626

987.1

724.4

70.9

1.46761

1.3633

988.9

725.4

71.0

1.46789

1.3639

990.9

726.5

71.1

1.46810

1.3646

992.8

727.5

71.2

1.46835

1.3653

994.8

728.6

71.3

1.46859

1.3659

996.6

729.6

71.4

1.46884

1.3665

998.5

730.7

71.5

1.46908

1.3672

1000.4

731.7

71.6

1.46933

1.3678

1002.2

732.7

71.7

1.46957

1.3685

1004.2

733.8

71.8

1.46982

1.3692

1006.1

734.8

71.9

1.47007

1.3698

1008.0

735.9

72.0

1.47036

1.3705

1009.9

736.9

72.1

1.47056

1.3712

1012.0

738.0

72.2

1.47081

1.3718

1013.8

739.0

72.3

1.47106

1.3725

1015.7

740.0

72.4

1.47131

1.3732

1017.7

741.1

72.5

1.47155

1.3738

1019.5

742.1

72.6

1.47180

1.3745

1021.5

743.2

72.7

1.47205

1.3752

1023.4

744.2

72.8

1.47230

1.3758

1025.4

745.3

72.9

1.47254

1.3765

1027.3

746.3

73.0

1.47284

1.3772

1029.3

747.4

73.1

1.47304

1.3778

1031.2

748.4

73.2

1.47329

1.3785

1033.2

749.5

73.3

1.47354

1.3792

1035.1

750.5

73.4

1.47379

1.3798

1037.1

751.6

73.5

1.47404

1.3805

1039.0

752.6

73.6

1.47429

1.3812

1040.9

753.6

73.7

1.47454

1.3818

1042.8

754.7

73.8

1.47479

1.3825

1044.8

755.7

73.9

1.47504

1.3832

1046.8

756.8

74.0

1.47534

1.3838

1048.6

757.8

74.1

1.47554

1.3845

1050.7

758.9

74.2

1.47579

1.3852

1052.6

759.9

74.3

1.47604

1.3858

1054.6

761.0

74.4

1.47629

1.3865

1056.5

762.0

74.5

1.47654

1.3871

1058.5

763.1

74.6

1.47679

1.3878

1060.4

764.1

74.7

1.47704

1.3885

1062.3

765.1

74.8

1.47730

1.3892

1064.4

766.2

74.9

1.47755

1.3898

1066.3

767.2

75.0

1.47785

1.3905

1068.3

768.3

Table 2 Correction of the Conventional Sugar Mass Titer as a Function of Temperature Mass Titer Measured in %

 

(N.B. : In the French original reproduced here, commas should be replaced with decimal points)

Table 3: Conductivity Corrections for Temperatures Other Than

20oC in μ siemens/cm-1

Temperatures

20.2

20.4

20.26

20.8

21.0

21.2

21.4

21.6

21.8

22.0(1)

19.8

19.6

19.4

19.2

19.0

18.8

18.6

18.4

18.2

18.0(2)

Conductivity

0

0

0

0

0

0

0

0

0

0

0

50

0

0

1

1

1

1

1

2

2

2

100

0

1

1

2

2

3

3

3

4

4

150

1

1

2

3

3

4

5

5

6

7

200

1

2

3

3

4

5

6

7

8

9

250

1

2

3

4

6

7

8

9

10

11

300

1

3

4

5

7

8

9

11

12

13

350

1

3

5

6

8

9

11

12

14

15

400

2

3

5

7

9

11

12

14

16

18

450

2

3

6

8

10

12

14

16

18

20

500

2

4

7

9

11

13

15

18

20

22

550

2

5

7

10

12

14

17

19

22

24

600

3

5

8

11

13

16

18

21

24

26

(1) Subtract the correction

(2) Add the correction


[1] Modified by resolution OIV-OENO 419A-2011

[2] Modified by resolution OIV-OENO 419A-2011

[3] Modified by resolution OIV-OENO 419A-2011

[4] Modified by resolution OIV-OENO 419A-2011

[5] Modified by resolution OIV-OENO 419A-2011

[6] Modified by resolution OIV-OENO 419A-2011

[7] Modified by resolution OIV-OENO 419A-2011

[8] Modified by resolution OIV-OENO 419A-2011