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MPM: V-5. Miscellaneous and Multiple Food Products

Macroanalytical Procedures Manual (MPM) Main Page

A. Method for Plant Gums (V-24)

(1) Scope

This method describes procedures for detecting and measuring contamination caused by gross extraneous filth and/or decomposition in plant gums and for determining the percent of reject product material due to insect damage, mold or other adhering filth. The method involves direct visual examination and separation of contaminants.

Gums are hydrocolloids (hydrophilic colloids). Their water-binding properties make them an important ingredient for improving the texture of foods. The method is applicable, but not limited, to the "natural" gums listed in Table V-1.

(2) Applicable Documents

(3) Defects

Plant gums are subject to contamination by field and storage insects, birds, rodents, and other animals. Mold growth can also result from improper drying or storage conditions.

(4) Procedure: Determination of Extraneous Material Caused by Mold, Insect, and Rodent or Other Animal Contamination in Plant Gums

  1. Sample Preparation -- Sample a representative or selective number of analytical units of the product, depending on the history of the lot. Weigh each analytical unit or subsample. Sift a minimum of 100 g from each subsample on appropriate size sieve(s) to separate whole insects, rodent excreta, and other extraneous material. State sieve size and method of use in report of results.
  2. Visual Examination and Report -- Examine "throughs" and "overs" on the sieve(s). Follow Chapter V, Section 8A(4)b. through d. for examination, classification, and reporting of contaminants.

(5) Procedure: Determination of Insect-Damaged, Moldy, and Otherwise Reject Product Material in Plant Gums

  1. Sample Preparation -- From each subsample weigh 100 g of material remaining from Procedure (4) as the analytical unit. Depending on the size of gum pieces, the sieve "overs" may provide this analytical unit. Alternatively, draw a separate analytical unit of 100 g from the original subsample. State how analytical unit is taken.
  2. Visual Examination and Report -- Follow Section 8.A(5)b. through d. for examination, classification, and reporting of reject product material.


Light Filth in Crude Plant Gums, AOAC 969.45

Type Name of Gum Source Production
Plant Exudates Arabic Acacia species, trees Africa
Tragacanth Astragalus species, shrubs Asia Minor, Iran, Syria, Turkey
Karaya Sterculia urens Roxb., tree India
Ghatti Anogeissus latifolia Wall., tree India and Ceylon
Plant Extracts Pectins Citrus species, peel, and Malus sylvestris Mill., apple, pomace United States
Arabinoga- lactan (larch gum) Larix species, larch trees United States
Plant Seed Flours Locust bean (carob bean) Ceratonia siliqua L., carob tree Near East and Mediterranean
Guar Cyamopsis tetragonoloba, (L.) Taub., guar plant India and Pakistan
Psyllium Seed Plantago species, plantain India and Mediterranean
Quince Seed Cydonia oblonga, Mill., quince tree Iran
Seaweed Extracts Agar Gelidium species and other red algae Japan
Alginates Macrocystis pyrifera (L.) C.A. Agardh. and other brown algae (kelp) United States
Carrageenan Chondrus species, Gigartina species, and other red algae Maine and Europe
Furcellaran Furcellaria fastigiata (Hudson) Lamouroux, a red alga Denmark and Norway
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