Working with edible food and inedible chemicals (or vice versa!) can be challenging, so we have two areas where food analysis is conducted. The first is the “normal” chemistry lab, and this is where “normal” lab rules are enforced. Most important – no food or drink allowed! Once food comes into this lab, it is no longer considered edible, and we’ll be wearing our gloves, eye protection and a lab coat when handling it. It may start out as food, but after it has been dissolved in sulfuric acid, cooked to boiling (we call it ‘reflux’) and diluted with organic solvents, eating it is the last thing on our minds!
Our second lab is the “food” chemistry lab, which allows us to manipulate food in a non-toxic environment. We have a precision balance, a syringe pump, a blender, food grade alcohol, food grade chemicals and all sorts of sterile equipment.
We are lucky enough to share this space with The Cooking Lab, a team dedicated to advancing the state of culinary arts through the creative application of scientific knowledge and experimental techniques. This is where the creators of Modernist Cuisine: The Art and Science of Cooking and Modernist Cuisine at Home do their culinary research. Their kitchen is kind of like your kitchen, except that it is equipped with a complete suite of high-tech gear such as rotor-stator homogenizers, a rotary evaporator, an ultracentrifuge, and a pharmaceutical-grade freeze dryer! This team has shared their knowledge with IV Lab to help us create all kinds of food inventions, and they’ve been instrumental in helping us approach some problems in developing countries.
Between these two labs, we can identify and measure essential food properties like:
- Moisture and fat content
- Solution viscosity
- Titratable acid/base
- Antioxidant activity
- Volatile organic compounds by GC/MS (e.g. isoamyl acetate, methyl salicylate, etc.)
- Sugars, vitamins and other organic species by HPLC (glucose, tocopherol, caffeine, etc.)
We add capabilities as the needs arise, and we also work with external vendors to expand our utility. For example, we might send a sample outside for dietary fiber analysis, but bring in the enzymes and reagents to determine which portion of that is soluble fiber.
A recent project included a measurement of caffeine content in a food. The food source was measured very precisely on the food laboratory balance and diluted into alcohol and water. Once prepared, the sample was transferred to a sonicating bath in the chemistry lab. After sonicating the sample, the contents were transferred into a high speed centrifuge tube and spun at high speed, which packed all of the solids into the bottom of the vial. A sample of the liquid could then be analyzed by HPLC (high performance liquid chromatography). We prepared a series of standard caffeine-containing solutions from pure caffeine to analyze alongside of our test sample. With all of the data in hand, we could report the concentration of caffeine in the sample to the nearest tenth of a milligram (0.0001 grams).
As each new technique is developed and reduced to practice, a standard operating procedure (SOP) document is prepared. Each month our list of SOPs grows a little longer, and represents more of the useful tools which chemistry can provide to the kitchen, the laboratory and the spaces in between.