In the enforcement of Division 17 of the Food and Agricultural Code relating to fruits and vegetables, except for those commodities wherein the specific commodity section of the law or a specific section of the California Administrative Code describes a method of determining waste, the method of arriving at a percentage of waste by weight for the purpose of determining compliance shall be as follows:

The percentage of waste by weight on an individual specimen, by defects so listed in the law, shall be determined by removing the affected parts of such specimen as would be done in the normal and practical preparation for use, and weighing such parts against the original weight of the fruit or vegetable. When weighing defective parts, include only that skin or peel that is removed with the defective portions.