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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.

Reference

Light Filth in Crude Plant Gums, AOAC 969.45