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Volume IV - 10.2 Food and Color Additives

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Orientation and Training

Food and Drug Administration

DOCUMENT NO.:
IV-10
VERSION NO.: 1.6

Section 10 - Food Standards & Additives

EFFECTIVE DATE: 09-01-05REVISED: 02-14-13

Food and color additives are defined in the Act in Sections 201(s) and 201(t), respectively. However substances generally recognized as safe (GRAs) under proposed conditions of use, sanctioned prior to the 1958 Food Additives Amendment, or subject to the provisions of Section 408 (Pesticide Chemicals) of the Act, are exempt from the definitions.

 10.2.1  Introduction

In 1958, the Food Additives Amendment became Section 409 of the Act. This section requires that safety be established on a proposed additive. The use of any food additive--direct, indirect, or GRAS--must be authorized by regulation in 21 CFR 170. Within Section 409 is the so called "Delaney clause," which restricts use of cancer inducing substances (carcinogens) in food: " . . . no additive shall be deemed to be safe if it is found to induce cancer when ingested by man or animal, or if it is found, after tests which are appropriate for the evaluation of the safety of food additives  to induce cancer in man or animal. . . ."

There are exceptions to this restriction on the use of carcinogens, which relate to their use in animal feeds for food producing animals.

In 1960, the Color Additive Amendment became Section 706 of the Act. It established the same safety criteria for proposed color additives as for food additives. Regulations for enforcement are in 21 CFR Parts 70-82.

In 1990, the Nutrition Labeling and Education Act (NLEA) was passed. It requires the declaration of all certifiable color additives on the product label with a few exceptions; for example butter, cheese, and ice cream are exempt from certified color labeling requirements except for FD&C Yellow No. 5 and No. 6. See CFR 101.22(k)(1).

Analytical exercises are included under this topic for food and color additives in consumer products.

Before beginning the exercises, the trainee should review the pertinent sections of the Act and the regulations to become familiar with the types of analyses that may be needed.

 10.2.2  Food Additives Exercises

This section includes exercises for food additives, salt (sodium chloride), sodium nitrite in smoked fish, sulfites in dried fruit, monosodium glutamate, artificial sweeteners (saccharin & cyclamates) and borates in caviar.

 10.2.2.1  Salt and Sodium Nitrite in Smoked Fish

A.  Introduction

This exercise has been developed to provide an introduction to food additives, food additive regulation, and the principles of analysis for common chemical preservatives such as sodium chloride and sodium nitrite.

B.  Assignment

The trainer will provide a sample of smoked fish. Determine water phase salt and nitrites as described:

  1. Sample Preparation

    Prepare each subsample separately for analysis according to AOAC 937.07(e), except take the loin muscle as defined in 21 CFR 161.190(a)(3) for the sample portion. i.e.. "the longitudinal quarter of the great lateral muscle (loin muscle) freed from skin, scales, visible blood clots, bones, gills and viscera and from the nonstriated part of such muscle." Grind the loin muscle according to AOAC 937.07(a), paragraph 2. Store the sample as directed in AOAC 937.07, first paragraph, and use for analysis in parts 2 and 3, below.

  2. Water Phase Salt
    1. Analyze each of the prepared subs by AOAC 952.08A for moisture content (total solids) and AOAC 937.09 for salt content. (See 21 CFR 172.177.)
    2. Calculate salt content in the water phase of the loin muscle according to the formula: 
      % Salt in water phase of loin muscle = [% NaCl (NaCl + % moisture)] x 100
  3. Sodium Nitrite

    Analyze each of the prepared subs for nitrite using AOAC 973.31. Report nitrite as ppm sodium nitrite in loin muscle.

C.  References

  1. Code of Federal Regulations. (2003). Title 21,  Pts. 110-Current Good Manufacturing Practice in Manufacturing, Packing, or Holding Human Food,  170-Food Additives, and Section 172.177-Sodium nitrite used in processing smoked chub. Washington DC: Office of Federal Register National Archives and Records Administration.

    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfrv2_01.html  and from
    http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfrv3_01.html

  2. Official Methods of Analysis of AOAC International, AOAC International, (current ed.). Gaithersburg MD.
  3. U.S. Food & Drug Administration, Office of Enforcement. Compliance policy guides manual. Compliance Police Guide 7308.15, Chubs, Hot Process Smoked with Added Nitrite, p. 276.
  4. U.S. Food & Drug Administration, Office of Enforcement. Compliance policy guides manual. Compliance Policy Guide 7308.18, Tuna, Sable, Salmon, Shad--Smoked Cured. Adulteration Involving Food Additives, Sodium Nitrite, p. 283.
  5. (1987). Food additive analytical manual.  (Vol. 2, Sodium Nitrate, Sodium Nitrite). Arlington, VA: Association of Official Analytical Chemists.
  6. Food chemicals codex (current edition). Washington. DC: National Academy of Sciences Press.
  7. U.S. Food & Drug Administration, Center for Food Safety and Applied Nutrition. Everything Added to Food in the United States (EAFUS): A Food Additive Database. Food Ingredients and Packaging. Retrieve from http://www.fda.gov/Food/FoodIngredientsPackaging/ucm115326.htm

D.  Questions

  1. What are the three conditions that are to be met for a preservative to be used according to good manufacturing practices?
  2. List 10 standardized foods for which the addition of chemical preservatives has been permitted by regulation.
  3. Which fish or fish products may legally contain nitrates or nitrites? List the maximum legal level for each product and describe how the retail container must be labeled.
  4. Where is "water phase salt" defined? How does water phase salt vary with moisture content? Write the equation used for calculating the salt concentration in the water phase. 
  5. Why is water added to the portion taken for analysis by AOAC 952.08A?
  6. How would one show that all the volatile components had been evaporated from the tissue?
  7. Show the reactions involved in the titrimetric analysis for total chloride. 
  8. Why is the HNO3 solution boiled before the indicator is added?
  9. AOAC 937.09B(b) states "With 10g sample each mL 0.1N AgNO3 = 0.058% NaCl." How is this factor obtained?
  10. What is the structure of the colored product formed during the nitrite analysis? Show the reactions involved.
  11. How has the order of addition of reagents been shown to affect this type of analysis?
  12. What is the correlation between pH and color stability?

 10.2.2.2  Sulfites

A.  Introduction

Sulfur dioxide and sodium and potassium bisulfites and metabisulfites are used in foods as antioxidants and bleaching agents. Sulfites are commonly used as preservatives in dried fruits and as bleaching agents in the processing of maraschino cherries.

This exercise instructs the trainee to determine the amount of sulfite, calculated as sulfur dioxide, present in a preserved food.

B.  Assignment

The trainer will provide a sample of dried fruit preserved with sulfites. Determine the amount of sulfite present as sulfur dioxide using AOAC 990.28 Sulfites in Foods Optimized Monier-Williams Method. Report both the titrimetic and gravimetric results.

C.  References

  1. Code of Federal Regulations. Title 21, Pt. 130.9-Sulfites in standardized foods. Washington DC: Office of Federal Register National Archives and Records Administration.

    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfr130_01.html.

  2. Official Methods of Analysis of AOAC International, AOAC International, (current ed.). Gaithersburg MD.

D.  Questions

  1. Why doesn't the HCl distill into the U tube or sulfur dioxide absorber? What is an azeotrope?
  2. What reaction occurs in the distilling flask? In the U tube? In the sulfur dioxide absorber?
  3. What is the purpose of the gravimetric determination? 

 10.2.2.3  Monosodium Glutamate

A.  Introduction

Any substance used in food must be of a food grade quality. The "Food Chemicals Codex" as initiated in 1958 to compile standards for food grade chemicals. In 1971, FDA officially recognized the Codex in the regulations. (See 21 CFR 170.30(h)(1) and 570.30.)

This exercise has been developed to test a common food additive for conformity with certain Codex specifications.

B.  Assignment

Perform these monograph tests: identification, assay specific rotation, pH (of 1 in 20 solution), and loss on drying. Do single determinations for identification and duplicate determinations for the others. If the laboratory does not have a mercury lamp, determine the specific rotation using the sodium D line only.

C.  References

  1. Food Chemicals Codex (current edition).
  2. Code of Federal Regulations. Title 21, Sects. 182.1-Substances that are generally recognized as safe (as food additives), and 582.1-Substances that are generally recognized as safe (for drugs).
    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfr182_01.html
    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfrv6_01.html 

D.Questions

  1. What other names are used for "monosodium glutamate"? What name must be used on a food label? Cite the regulation that supports the answer.
  2. How much monosodium glutamate is permitted in foods?
  3. Why is monosodium glutamate titrated in a non-aqueous solvent system and not in water? Show the chemical reactions involved.
  4. Define optical activity, optical rotation, angular rotation, and specific rotation.

 10.2.2.4  Artificial Sweeteners

A.  Introduction

Based on a Canadian study, which showed that saccharin was the cause of bladder cancer in rats, FDA banned all uses of saccharin except as a tabletop sweetener in 1977. A two year moratorium was declared under the Saccharin Study and Labeling Act which lifted the ban and required any food containing saccharin to carry a warning statement on the label. This moratorium has been extended until 2002.

Cyclamate was banned for use in 1970 by FDA due to studies linking the sweetener to bladder cancer.

B.  Assignment

This exercise has been developed to test a food for the presence of saccharin and cyclamates.

C.  References

  1. Code of Federal Regulations. Title 21, Sections 180.37-Saccharin, ammonium saccharin, calcium saccharin, and sodium saccharin, 189.135-Cyclamate and its derivatives. Washington DC: Office of Federal Register National Archives and Records Administration.

    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfr180_01.html 
    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfr189_01.html

  2. Official Methods of Analysis of AOAC International, AOAC International, (current ed.). Gaithersburg MD.
  3. HPLC determination of selected food additives. Laboratory Information Bulletin, LIB No. 3053.
  4. HPLC determination of saccharin, benzoate, sorbate, and dulcin. Laboratory Information Bulletin, LIB No. 3140.

D.  Questions

  1. The referenced TLC method is for beverages, what modification would be made for a non-liquid sample?  What potential problems may be incurred using a modified method?
  2. In terms of the TLC extraction procedure, what is the purpose of adding 5 ml of 50%  NaOH solution?
  3. In terms of HPLC, what may occur if there is a change in the composition of the mobile phase?
  4. In terms of HPLC how critical is the detection wavelength?
  5. What is the salt of benzoic acid?  What pH does sodium benzoate optimally function?   Which is more soluble, sodium benzoate or benzoic acid?
  6. What is meant by a regulated food additive?  Provide examples.

 10.2.2.5  Borates

A.  Introduction

Boric Acid has been prohibited for use in foods as a preservative.

B.  Assignment

This exercise has been developed to test food products, such as caviar, for the  presence of boric acid.

C.  References

  1. Official Methods of Analysis of AOAC International, AOAC International, (current ed.). Gaithersburg MD.
  2. Determination of boron in caviar by inductively -coupled argon plasma- atomic emission spectrophotometry. Laboratory Information Bulletin, LIB No. 3843.
  3. U.S. Food & Drug Administration, Office of Enforcement. (2000, August). Compliance policy guides manual. Compliance Policy Guide 540.150: Caviar, Use of Term-Labeling, p. 275. Retrieve version from http://www.fda.gov/ ICECI/ ComplianceManuals/ CompliancePolicyGuidanceManual/ucm119194.htm

D.  Questions

  1. "Caviar" is made from what type of fish?
  2. When the roe of other fish types are used, what labeling requirement must be followed?
  3. What is the purpose of adding boric acid?

 10.2.3  Color Additives Exercises

A.  Introduction

The purpose of this exercise is to introduce the trainee to the regulations for color additives.

B.  Assignment

Perform the following laboratory exercises: analyses of a bakery product (cookie or cake) hard candy or beverage and a lipstick using the appropriate method for the presence of color additives. Review the references and answer the questions that follow.

C. References

  1. Code of Federal Regulations. Pts. 70-Color Additives, 71-Color Additive Petitions, 73-Listing of Color Additives Exempt from Certification, 74-Listing of Color Additives Subject to Certification, and 81-General Specifications and General Restrictions for Provisional Color Additives for Use in Food, Drugs, and Cosmetics. Washington DC: Office of Federal Register National Archives and Records Administration.
    Retrieve from http://www.access.gpo.gov/nara/cfr/waisidx_01/21cfrv1_01.html
  2. Compliance Program Guidance Manual, current programs that direct the analyses of food, cosmetics, and drugs for colors.
    Imported Foods-Food and Color Additives
    http://www.fda.gov/ICECI/ComplianceManuals/ComplianceProgramManual/default.htm
    Domestic Food Safety Program
    http://www.fda.gov/ICECI/ComplianceManuals/ComplianceProgramManual/default.htm
    Imported Cosmetics Program
    http://www.fda.gov/ICECI/ComplianceManuals/ComplianceProgramManual/default.htm
    Domestic Fish and Fishery Program
    http://www.fda.gov/ICECI/ComplianceManuals/ComplianceProgramManual/default.htm
  3. Official Methods of Analysis of AOAC International, AOAC International, (current ed.). Gaithersburg MD.
  4. (1977). Newburger's manual of cosmetic analysis (2nd ed., chap. 19). Arlington, VA: Association of Official Analytical Chemists.
  5. Determination of color additives in food products. Laboratory Information Bulletin, LIB No. 3420. 
  6. Center for Food Safety and Nutrition, Office of Cosmetics and Colors: Color Additives.
    Retrieve from http://www.fda.gov/ForIndustry/ColorAdditives/default.htm

D. Exercise

Discuss with the trainer:

Briefly describe the analysis of a temporary tattoo for colors using Newberger's method of analysis.

E. Questions

  1. What is a color additive?
  2. Define these terms: straight color, lake, diluent.
  3. What are "certified" colors?
  4. Under what conditions may color additives be used in the area of the eye, in injections, or in surgical sutures?
  5. List the restrictions, if any, for the following colors:
    1. Citrus Red No.2
    2. Orange B
    3. Titanium dioxide
    4. FD&C Blue No. 1
    5. FD&C Red No. 3
    6. FD&C Red No. 40
    7. FD&C Yellow No. 5
  6. What are chromophores and auxochromes? Identify the chromophores and auxochromes in two of the colors listed in the previous question.
  7. What is hypochromic shift?  Give the effect of hypochromic shift for two of the colors in question 5.
  8. Give one example of a triphenylmethane color.
  9. List the Colour Index Number (C.l. No.) and common name for FD&C Red No. 1, FD&C Red No. 3, D&C Orange No. 3, FD&C Green No. 3. FD&;C Yellow No. 7, D&C Yellow No. 9, FD&C Blue No. 2, and FD&C Violet No. 1.
  10. A label of a food product declares "...E123..." as an ingredient. Is this product permitted in the U.S.?
  11. A label of a food product declares "...Sunset Yellow FCF, Eythrosine Lake, Allura Red AC." Is this product correctly labeled?  If not, why? If the importer relabels the product, would it be permitted in the U.S.?
  12. How many synthetic colors are approved for use in cosmetics?  Which of these colors are permitted in eye area cosmetics?
  13. A lipstick sample was analyzed using Newburgers, 19.1. One bright pink band of color, exhibiting orange fluorescence, was detected. Using Table 12 in Neuburgers (page 119), what  color(s) was(were) detected? Are the possible color(s) detected, permitted for use? 
  14. Discuss solubility in terms where one would expect to find the following colors:
                         Natural color such as riboflavin or saffron
                         Tartrazine
                         Sudan 1
                         D&C Red 19 or DC Red 28
                         Red #3