Food and beverages are processed and presented to consumers in contradiction to legal regulations, leading to health, nutrition and economic deception. It is forbidden to allow unauthorized additives in food and beverages, to use permitted additives on limits and to mix them with other foods or beverages. In this sense, fruit juices are one of the most common counterfeit foods and beverages. It is not easy to avoid this deception as an effective food control cannot be carried out.

Since the natural composition of fruit juices depends on many factors, it is difficult to determine the analytical proof criteria. However, due to the new technological developments, a lot of progress has been made.

Formalin number is a measure of the amino acids present in fruit juices in general. The fruit juices are titrated with sodium hydroxide using formaldehyde solution and the number of formol is determined. Formol number is an analytical criterion used to determine the water additive ratio in the fruit juices offered for consumption. According to the results of different studies, the number of formol is, for example, between 12-29 in orange juice, 11-38 in grapefruit juice, 1-7 in apple juice, 2-19 in strawberry juice and 1-3 in lemon juice.

An inexpensive amino acid or ammonium salt is added to the juice and the formol number is increased. In order to avoid this situation which misleads people, it is necessary to check whether the number of formol is increased with different additives. For these inspections, the number of formol was determined for different fruit juices.

In order to determine whether or not water is added to fruit juices, formol number determination is applied.

In authorized laboratories, determination of formol number is carried out within the scope of chemical tests. In these studies, the standards published by domestic and foreign organizations are complied with. The standard for the determination of formol number is as follows:

 

• TS EN 1133 Fruit and vegetable juices - Determination of formol number