1. OBJECTIVE
Routinely, the media highlights the antioxidant capacity of foods, portraying them as essential tools for protection and cell regeneration against damage caused by free radicals in our body. The analysis of the chemical composition of fruits, vegetables and greens plays an essential role in scientific research, helping science to find powerful allies for improving the cardiac and immune systems, among others, in the area of ​​medicine. However, knowledge about the properties of each food requires studies and calculations that involve different areas.

Do you know how you can classify the antioxidant capacity of each food?


At the end of this experiment, you should be able to:

relate scientific content involving medicine and chemistry in applications on the properties of food in everyday life;

evaluate the performance of each food regarding its antioxidant capacity;

organize and prepare samples for analysis in the laboratory, using a scientific protocol;

interpret the results obtained after analysis on equipment and perform calculations on the observed values.

2. WHERE TO USE THESE CONCEPTS?
Within the food industry, there is quality control over the products to be supplied to society. Such control encompasses the measurement of several parameters to ensure that the characteristics of the food supplied correspond to what is described in the sale. Therefore, professionals working in this field must have knowledge of the laboratory practices involved in analyzing the chemical composition of foods and the correct interpretation of the results obtained.


3. THE EXPERIMENT
The experiment presented here focuses on detailing the laboratory analysis process for determining antioxidant capacity, through the use of a commonly applied reagent: DPPH (2,2-diphenyl-1-picrylhydrazyl). This compound reacts with the antioxidant molecules present in food, allowing them to be quantified based on the colored compound formed. Using equipment called a UV-VIS spectrophotometer, the amount of this compound is related to the total antioxidant activity (AAT).


4. SECURITY
In this practice, laboratory personal protective equipment (PPE) will be used, which includes a lab coat, mask, gloves and protective glasses. In addition, long pants and closed shoes must be worn. The handling of reagents such as DPPH must be carried out in hoods with exhaust ventilation on.

Remember that, after the analysis, there is a residue that is toxic to the environment, which should not be discarded down the sink.


5. SCENARIO
The experiment will be carried out within a chemical analysis laboratory of a food supplying institution, in its quality control sector. The physical structure is adequate, and the laboratory has all the necessary reagents, glassware and analytical equipment. After the analyses, it is up to you to carry out the calculations and issue a technical opinion on the AAT of the food supplied to the sector.