Category: Laboratory methods

According to the World Health Organization, iron deficiency is one of the most widespread nutritional deficiencies globally. To accurately address this issue and create effective fortification programs, it is critical to determine iron content in food and fortified products. This involves employing specific analytical methods to measure the precise amount of iron present in a food sample.

According to the U.S. Food and Drug Administration (FDA), accurate food labeling requires precise measurement of fat content, which directly relates to total lipids. Whether in a professional food lab or a home science experiment, understanding how to find the amount of lipids in food is a fundamental aspect of nutritional analysis.

According to food science research, density is a critical physical property used to verify a product's quality, purity, and concentration. Learning how to determine the density of a food sample is a foundational skill in laboratory settings, essential for quality control and nutritional analysis.

Compounds containing two or more peptide bonds, a key characteristic of proteins, give a purple color when treated with dilute copper sulfate in an alkaline solution. This principle is the basis for the Biuret test, which uses an indicator solution to detect proteins, polypeptides, and other compounds containing peptide bonds.

According to Thermo Fisher Scientific, quantifying protein concentration is an essential part of most laboratory workflows involving protein samples. The method for determining total protein varies based on required sensitivity, sample volume, and compatibility with other substances.

Milk typically contains around 3.3% protein, and knowing its concentration is vital for both nutrition and quality control. To determine this, you can learn how would you test milk for protein using a range of methods, from simple at-home observations to sophisticated laboratory procedures, to confirm its content and quality.

According to research, all monosaccharides are classified as reducing sugars due to their free aldehyde or ketone groups. Using a combination of the Benedict's and iodine tests, you can leverage this chemical property to accurately identify monosaccharides in an unknown sample by observing distinct color changes.

Developed by chemist Theodor Seliwanoff, Seliwanoff's test is a specific qualitative biochemical procedure used to differentiate between ketose and aldose sugars. It operates on the principle that ketoses, such as fructose, dehydrate much faster than aldoses, like glucose, when heated with a strong acid.

According to biochemical research, the iodine test is the classic and most well-known method for detecting the presence of polysaccharides like starch. This simple colorimetric reaction relies on iodine-potassium iodide, commonly known as Lugol's solution, to produce a dramatic color change in the presence of certain complex carbohydrates. However, other reagents are also used depending on the specific type of carbohydrate and the analysis required.

While both starch and cellulose are polysaccharides made of glucose monomers, their structural differences lead to profoundly distinct properties and functions. This is most easily demonstrated through a simple chemical test involving iodine, which produces a striking color change with starch but not with cellulose.