Bensor test (benzoic/sorbic acid)

BENSOR TEST

PREPARED BY: SITI RUBIAH MOHAMAD

• Benzoic Acid

• Sorbic Acid

WHAT ARE THEY??

Type of chemical preservatives

According to Food Act & Regulations 1983 (Regulation 20) preservative means any substance that, when added to food , is capable of inhibiting, retarding or arresting the process of decomposition, fermentation or acidification of such food but shall not include herb, spices, vinegar or wood smoke.

BENZOIC ACID

Commonly found in most fruits especially berries

(naturally)

Compounds-Benzoic acid, benzoates (Na/K)and

benzoic acid esters

For commercial purposes, it is prepared chemically

from toluene (synthetic)

High concentration give sour taste thus limits it

application

Usually used in fruit juices, pickles, carbonated

beverages.

SORBIC ACID

This family of compounds is available as sorbic acid

potassium sorbate (much more soluble in water than the acid)

sodium sorbate or calcium sorbate.

Give no taste or flavor to products

Highly preferred as it are physiological

harmlessness and organoleptic neutrality

Used in beverages, dairy products, fish and

seafood, fat-based products, baked goods and

confectionery products.

METHOD OF BENSOR EXTRACTION

Weighed sample (spike:1mL)

Extraction buffer added until 40 mL

Vortex and checked pH to 4.6

Marked up until 50 mL with extraction buffer and

centrifuged

Filtered into vials and sent to HPLC for analyse

REFERENCES METHOD:

1) Chapter 29(non-alcoholic beverages and

concentrates) AOAC 16th Edition (1995),

Method 978.08

2) Pearson’s Composition and Analysis of

Foods, pg 89.

MOBILE PHASE OF BENZOIC / SORBIC ACID

1. Weighed and dissolved ammonium acetate in 1000 mL of

deionized water.

2. Adjust pH of the solvent to 4.6.

3. The solvent was filtered

4. Sonicate the solvent.

EXTRACTION BUFFER BENZOIC/SORBIC ACID

1. Step 1-3 as prepare for its mobile phase.

2. 300 mL from solution were removed and replaced by 300

mL of methanol to get ratio 70: 30 (ammonium acetate :

methanol).

SERIAL DILUTION

Blank = buffer solution

Standard 1 = 100 ppm

Standard 2 = 50 ppm

Standard 3 = 25 ppm

Standard 4 = 2.5 ppm

Standard 5 = 0.25 ppm (0.1 ml standard 4 + 0.9 mL buffer)

Quality check (QC) = 10 ppm (0.1 stock marked up in 10

ml)

Figure 1: A basic HPLC system configuration

min0 2 4 6 8 10 12 14

mAU

0

5

10

15

20

25

VWD1 A, Wavelength=230 nm (C:\CHEM32\1\DATA\140625-BENSOR\140625 2014-06-25 12-19-59\027-0801.D)

Area: 606.357

Area: 718.841

QC

6.101

- Sod

ium Ben

zoate

9.528

- Potassiu

m Sorba

te

Figure 2: Example of chromatogram for quality check (QC)

(QC recovery range = 80~120)

min0 2 4 6 8 10 12 14

mAU

0

5

10

15

20

25

30


sample not detected with benzoic & sorbic acid

Figure 3: Example of chromatogram for sample product

min0 2 4 6 8 10 12 14

mAU

0

10

20

30

40

50


Area: 1144.94

Area: 1399.33sample spike with benzoic & sorbic acid

6.026 - Sodium

Benzoate

9.359 - Potassium

Sorbate

Figure 3: Example of chromatogram for sample spike

CALCULATION INVOLVED

1) conc. of sodium benzoate in sample

=HPLC reading x dilution factor x final volume

sample weight

2) conc. of benzoic acid

= conc. of sodium benzoate x conversion factor

Molecular weight of acid/ molecular

weight of it salt

According to Food Act and Regulation 1983 :

SCHEDULE SIXTH (REGULATION 20)

Food

Preservative

[Maximum permitted proportion in milligram per

kilogram (mg/kg)]

Benzoic acid (or sodium

benzoate calculated as

benzoic acid)

Sorbic acid (or its sodium,

calcium or potassium salts

calculated as sorbic acid)

Soya sauce, oyster

sauce, fish sauce, etc

1000 Nil

Fruit- candied, dried,

dried candied etc

350 500

Table 1: Maximum rate of preservatives that allowed in certain food products that

contain in schedule sixth (regulation 20)

Nil means the substance is prohibited in that food

SCHEDULE SIXTH (REGULATION 20)

Table 2: The substances specified in table II schedule sixth (regulation

20)

Food Preservative

Bread Propionic acid and its sodium,

potassium , calcium salts.

Flour confection Benzoic acid

Sorbic acid and its sodium,

potassium and calcium salts

Propionic acid andt its sodium,

potassium and calcium salts

EXAMPLES OF SAMPLES THAT DONE BENSOR

TEST

ND= Non Detected

Benzoic acid

Sorbic acid and its salts

Propionic and its salts

IMPLICATION OF BENZOIC/SORBIC

Good effect:

Shelf life of product more longer

Inhibit microorganism from growth easily

Bad effect:

Allergic reaction, nausea, diarrhea

Change taste and flavor to product

In some people benzoic acid may liberate histamine

and thus cause pseudo-allergic reactions.

Affect liver and kidney

THANK YOU FOR

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Bensor test (benzoic/sorbic acid)

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