In my thesis, I studied various food products, e.g. sweeteners, baking powder, decorative products for pastries, etc. I used the X-ray powder diffraction method. This method is based on the reflection of X-rays on crystalline substances, i.e. substances with an ordered internal structure, the motif of the unit cell is periodically repeated in all three directions of space. We therefore need solid crystalline samples for analysis. The resulting image is called a diffractogram and is characteristic of every crystalline substance, like fingerprints for people.
In the qualitative analysis, I used the X'pert HighScore Plus program to convert the files into a readable format and Crystallographica Search-Match to identify the phases. Then I determined the mass fractions of the identified components of the sample using the Rietveld method in the TOPAS program. I found that most of the samples tested contained at least one type of sugar, usually sucrose. Another common ingredient is sodium bicarbonate. Both ingredients are cheap, so the majority of products contain them. Unfortunately, I was unable to identify quite a few ingredients from the ingredients list, either because they were added to the product in very small quantities and their diffraction peaks were hidden in the background, or because they are amorphous substances or maybe even because their standards are not included in the PDF database.
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