Safety Note
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In cases where special safety instructions are not given, use common safety precautions, especially when working with hot, sharp, or breakable items. Be sure to read and follow warning labels on household chemicals.
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Lesson List
Analysis of the Sugars in Soft Drinks
Bradford Protein Determination of Milk Protein
Infrared Analysis of Piperine in Black Pepper
Soxhlet Extraction of Fat from French Fries
Lesson Descriptions |
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| Analysis of the Sugars in Soft Drinks |
Why analyze the sugars in soft drinks? "Sugar" is a loosely used term, which can mean many distinctly different chemicals. Labels on soft drink cans and bottles are a good example of this murky terminology—"high fructose corn syrup and/or sugar."
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Bradford Protein Determination of Milk Protein
It is often necessary to quantitate protein in a biochemistry or biotechnology laboratory. In 1976 Bradford published a rapid and sensitive method for determining the amount of protein in a sample, which has revolutionized protein chemistry. The method had several advantages over previous methods of protein quantitation. The Bradford method is quite fast and convenient and has few of the interferences that many of the older methods were subject to.
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Infrared Analysis of Piperine in Black Pepper
Piperine 1-[5-(1,3-Benzodioxol-5-yl)-1-oxo-2,4-petadienyl ]piperidine C 17 H 19 NO 3 (see Figure 1)can be isolated from black pepper (Piper nigrum)and other Piper species.Black pepper contains 6 -9% piperine by weight.Piperine is tasteless,but its stereoisomer,chavicine,is the active ingredient in black pepper that provides its characteristic taste.Loss of pungency during storage of black pepper is attributed to the slow isomerization of chavicine into piperine. Piperine is extracted from black pepper by ethanol using a soxhlet extraction apparatus.The piperine is purified by recrystallization and then characterized by IR spectroscopy.
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Soxhlet Extraction of Fat from French Fries
An accurate and precise quantitative analysis of lipids in foods is important not only for nutritional labeling, but also for determining whether the food meets the standards for identity and uniformity, and for understanding the effects of fats and oils on the functional and nutritional properties of foods. The validity of the fat analysis of a food depends on many factors, including proper sampling and preservation of the sample before the analysis. The Soxhlet procedure allows for the calculation of total lipid (fat) content in french fries or other food substances. In many of its published methods, the U.S. Environmental Protection Agency requires Soxhlet extraction of components from a variety of sample matrices including foods and soils. This experiment involves the extraction of fat from commercial (fast-food) french fries by an exhaustive extraction with solvent using a Soxhlet extractor apparatus.