Abstract:

This proposal is an extensive academic work of professors in all five semesters; since its implementation, we have taught the subject of Food Laboratory I, which is one of the pillars in the formation of Food Chemistry students. It seeks to correct the weaknesses identified during the course, while retaining the strengths of experimental education now being carried out.
More than 500 students have developed the experience, confronted with some methodological problems that have impeded the full acquisition of essential concepts.
The three most important issues are:
* In the determination of dietary fiber, the formal methodology requires the use of a series of enzymatic preparations with specific temperatures and pH for each one, which causes much manipulation of the solutions, increasing uncertainty about the outcome.
* In the characterization of the compounds associated with lipids, the diversity of lipid components that are found in food systems does not allow students to reach conclusions regarding the way of optimum extraction of these compounds for a given food with the common/usual techniques available in the laboratory.
* The evaluation of the functional properties of proteins present in food, according to its structural characteristics, requires the use of procedures that use large amounts of solutions and reagents, generating concerns about the validity of the results and producing a large amount of waste.
It is intended that with experimental education, the student can throughly understand some theoretical concepts by using, analyze and evaluate them in a practical experimental exercise, acquire skills to manipulate substances, instruments and equipment, as well as handle actual data and interpret what happens in a phenomenon, operation or process; therefore the raised experiences should be conclusive.

This project, in addition to reviewing the activities currently being carried out, proposes rethinking those procedures, at least in the three issues raised, so the activities carried out make sense to the training that is intended to be taught, and also integrate the experimental aspects with which all professionals dedicated to the Food Chemistry major should be familiar.
- In the quantification of Dietary Fiber, pancreatin is used as an alternative for the determination. Six commercial preparations accessible nationwide were studied and two of them were selected, characterized and applied to three foods, obtaining results that were not significantly different from those obtained with the official/formal kit, without changes in pH and/or temperature.
- Using two different food sources (coffee residue and pork rind), the amount of extracted fat with two different polarity solvents was quantified. Four chromatographic methods were tested to identify terpenes, carotenes, tocopherols and sterols, from unsaponifiable matter, and found that those systems are different depending on the origin of the food (vegetable or animal).
- Using the coffee residue from its process as a model, protein extracts were obtained in which several procedures were implemented to evaluate the functional properties of Water Holding Capacity (WHC), Oil Retention Capacity (ORC), Emulsifying Capacity (EC) and Foaming Capacity (FC), and its stability thereof. The coffee residue's proteins presented ORC and WHC similar to gluten and zein. The EC was considered high and was determined by using a method with very low amounts of oil.

Keywords:

Food, Dietary fiber, Unsaponifiable matter, Functional properties of preoteins.