GB25535 For Gellan Gum

NATIONAL STANDARD FOR FOOD SAFETY

FOOD ADDITIVE GELLAN GUM

ISSUED ON DATE OF 21TH,DEC. 2010 CARRIED OUT ON 21TH, FEB. 2011.

Issued by MINISTRY OF HEALTH OF PEOPLE’S REPUBLIC OF CHINA

GB25535-2010

FOREWORD

Appendix A of this STANDARD is normative Appendix; Appendix B is illustrative Appendix.

FOOD SAFETY NATIONAL STANDARD

FOOD ADDITIVE GELLAN GUM

1. SCOPE

This standard complies with FOOD ADDITIVE GELLAN GUM produced by fermentation of Psudomonas elodea and carbohydrate.

2. NORMATIVE QUOTED DOCUMENTS

Quoted documents are requisite for carrying out this standard.Any documents marked with Date, only the version with the same date is applicable; any without mark of Date, its newest version is applicable.

3.MOLECULAR STRUCTURE AND RELATIVE MOLECULAR WEIGHT

3.1 MOLECULAR STRUCTURE

The repeating unit of the polymer is a tetrasaccharide, which consists of two residues of D-glucose and one of each residues of L-rhamnose and D-glucuronic acid.

3.2 RELATIVE MOLECULAR WEIGHT

4X10⁵-6X10⁵(ACCORDING TO 2007 WORLD RELATIVE MOLECULAR WEIGHT)

4.TECHNICAL STANDARD

4.1 SENSORY INDEX:SHOULD COMPLY WITH REGULATION OF SHEET 1.

SHEET 1: SENSORY INDEX

ITEM

STANDARD

TEST METHOD

COLOR

LIKE WHITE

PUT SAMPLES INTO

WHITE PORCELAIN, AND

APPEARANCE

POWDER

INSPECT UNDER NORMAL

DAYLIGHT.

4.2 PHYSICAL INDEX: SHOULD COMPLY WITH REGULATION OF SHEET 2.

SHEET 2: PHYSICAL INDEX

ITEM	STANDARD	TEST METHOD
Gellan Gum, w/%	85.0-108.0	APPENDIX A, A.3
Loss on Drying, w/% ≤	15.0	GB5009.3-2010,DIRECT DRYING a
Lead(Pb)/(mg/kg) ≤	2	GB5009.12
Isopropanol/(mg/kg)b ≤	750	APPENDIX B
a.Drying temp. and time is: 105。C And 2.5h. b.Only applicable for non-alcohol processing gellan gum.

4.3 MICROORGANISM INDEX: SHOULD COMPLY WITH REGULATION OF SHEET 3.

SHEET 3: MICROORGANISM INDEX

ITEM		STANDARD	TEST METHOD
Total Plate Count/(CFU/g)	≤	10000	GB4789.2
Coli Group/(MPN/100g)	≤	30	GB4789.3
Salmonella		0/25g	GB4789.4

Mould and Yeast/(CFU/g) ≤		400	GB4789.15

APPENDIX A

(NORMATIVE APPENDIX)

TEST METHOD

A.1 GENERAL PROVISIONS

Unless there’s additional clarification,only pure reagents or water which is regulated by GB/T6682-2008 can be applied for analysis.All volumetric solutions,impurity test solutions,preparations and materials, if no extra requirements market, should be prepared according to GB/T601,GB/T602,GB/T603.All solutions in this test, if not marked the exact type of mixture, are water.

A.2 IDENTITY TEST

A.2.1 SOLUBILITY TEST

Soluble in water, become viscous solutions; Not soluble in alcohol.

A.2.2 GEL TEST WITH Ca ION

Dissolve 1g sample into 99ml water for a 1%solution. Stir the solution for 2hours(Keep some solution for test in A.2.3).Take some solution with wide bore straw and add them into CaCl2 solution(100g/L),gels formed immediately.

A.2.3 GEL TEST WITH Na ION

Add 0.5g NaCl to the 1% solution prepared in A.2.2, heat to 80℃, keep stirring and make sure the temperature be at 80 ℃ for at least 1minutes. Then stop heating and stirring, cooling down to room temperature, finally hard gels formed.

A.3 TEST OF GELLAN GUM CONTENT

A.3.1 PREPARATIONS AND MATERIALS

a) diatomite earth: chromatographic pure.

b) absolute ethyl alcohol.

c) alcohol solution:78+22.

A.3.2 EQUIPMENTS AND INSTRUMENTS

a) glass fabric filter.

b) drier(180mm).A.3.3TESTPROCEDURE

Take1.0g chromatographic pure diatomite earth and put into a glass fabric filter , paved and dried for 5hours under 105℃. Weigh it after cooling down in the drier. Get 0.2g dried (105℃， 2.5h) samples (accurate to 0.001g), add 50ml water, stirring for 30minutes under 80 ℃ temperature. Add 200ml absolute ethyl alcohol which has been pre-heated to 60℃-70℃, mixing and putting for 12hours. Filter with the above glass fabric filter which is filled with diatomite earth. Wash and filter for 5times with alcohol solution:20mL solutions should be used for first 3times while only 10mL for last two times. Dry the filter residue for 5hours under 105℃ and weigh it after cooling in drier.

A.3.4 CALCULATE RESULT

Gellan Gum X1 is calculated by following formula (A.1)

X1=

X100%............................

(A.1)

Explanation:

X1-------Gellan Gum Content, %

m1------------Weight of filter residue, g

m0--------Weight of sample, g

Test result is determined by arithmetic mean value of parallel determination result.Under repeated test condition, absolute value difference of two independent test result should be less than 2% of arithmetic mean value.

APPENDIX B

(ILLUSTRATIVE APPENDIX)

TEST OF ISOPROPANOL

B.1 REAGENTS AND MATERIALS

a) isopropanol: chromatographic pure.

b) tert.-butyl alcohol:chromatographic pure.

B.2 EQUIPMENTS AND INSTRUMENTS

a) gas chromatograph: equipped with flame ionization detector.

b) chromatographic column:1.8mx2.3mm(inner diameter) stainless stell column or equivalent effect column, filled with 0.2mm-0.15mm PORAPAK QS fillings or other equivalent fillings.

B.3 see Chromatographic conditions

a) carrier gas: helium. b)velocity of flow:80mL/min.. c)injection port temperature:200℃. e)column temperature:165℃. f)detector temperature:200℃. g)sample amount:5μL.

H)isopropanol remaining time is 2min, tert.-butyl alcohol remaining time is 3min.

B.4 PROCEDURE

B.4.1 STANDARD SOLUTION PREPARATION

B4.1.1 ISOPROPANOL (IPA) STANDARD SOLUTION

Weigh 500.0mg isopropanol,and put into a 50mL volume flask, add water to dilute and reach to certain measurement, mix together. Take 10mL this solution, put into a 100mL volume flask, add water to dilute and reach to certain measurement, mix together.

B.4.1.2 TERT.-BUTYL ALCOHOL (TBA) STADARD SOLUTION

Weigh 500.0mg tert.-butyl alcohol, and put into a 50mL volume flask, add water to dilute and reach to certain measurement, mix together. Take 10mL this solution, put into a 100mL volume flask, add water to dilute and reach to certain measurement, mix together.

B4.1.3 MIX STANDARD SOLUTION

Take 4mL isopropanol (IPA) standard solution and 4mL tert.-butyl alcohol (TBA) standard solution, put into a 125mL conical flask, add water and dilute to 100mL, mix together. For 1mL solution, there’s 40μg isopropanol and 40μg tert.-butyl alcohol. B.4.2 TEST LIQUID PREPARATION

Add1mL de-foaming agent(such as DOW-CORNING G-10) into the 1000mL distilling flask with 200mL water inside, make them dissolve. Put 5g gellan gum sample into the solution, shaking for 1hour.Linked a dephlegmator to the flask, adjust the temperature, make to foams impossible to enter the dephlegmator, get about 10mL distillate. Add 4.0mL tert.-butyl alcohol (TBA) standard solution to the distillate to get the TEST LIQUID.

B.4.3 TEST

Inject 5μL mixed standard solution, to test under chromatograph condition, record peak area of isopropanol as AIPA, tert.-butyl alcohol peak area as ATBA. Work out the relative correction factor f (f=AIPA/ATBA).

As the same, Inject 5 μL mixed standard solution, to test under chromatograph condition, record peak area of isopropanol as aIPA, tert.-butyl alcohol peak area as aTBA.

B.5 CALCULATE THE RESULT

Isopropanol Content X is calculated by following formula (B.1):

aIPA X 4000