19Mar 2014 by Vincent Summers No Comments

Food Chemistry: What is a Glycol?

Food
[caption id="attachment_5892" align="alignright" width="440"] Propylene Glycol[/caption] In our food, we expect to find ingredients of the earth, sea, and air—ingredients that occur naturally without any finagling from humans. Grains, vegetables, fruits, meats, fish, fowl, and cheese are all welcome. But go to your neighborhood grocery and pick up any package of prepared food product, and you are likely to be assaulted with a huge array of substances that sound nothing like these ingredients. That array will include thickeners, anti-caking agents, preservatives, fungus preventatives, and so forth. Yet another ingredient may be some form or other of glycol. What is that? Simply put, a glycol is a double alcohol—two adjacent carbon atoms each has a pendant hydroxyl group. The structure is seen to the right, below: [caption id="attachment_20003" align="alignright" width="304"] glycol…
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04Feb 2013 by Vincent Summers 2 Comments

Epoxide Ring Preparation by Oxidation of Alkenes

Chemistry
How many have purchased a 2-tube pack of epoxy at their local hardware or grocery store? It’s a routine item we use to repair a variety of objects. But what is it that makes epoxy glue so strong? Its name gives it away. Epoxy glues use epoxy compounds. Epoxides. What is an epoxide? It’s Simple? Yes An epoxide is a molecule with a tiny 3-member ring in its structure. One atom is oxygen. Two are carbon. The epoxy link is illustrated in Figure 1. R₁, R₂, R₃, and R₄ are pendant groups. How is such a 3-member ring created? Often by the oxidation of an alkene. The reader may appreciate an example.1 Propene Let's try the oxidation of propene, CH3CH=CH2.2 What would be a suitable oxidizing agent for the reaction?…
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03Dec 2012 by Vincent Summers No Comments

Why are Some Bananas Sweeter than Others

Food
Some bananas are sweeter than others. How is that? Having purchased the golden fruit many times, I asked myself, why are some bananas sweeter than others? You pick up a bunch of small, curly, bright yellow fruits.¹ You take them home. On the way, you remove the one with the label. You peel it most of the way down. With a few quick bites, you finish it off. You go shopping again. Displayed are large, straight bananas. You note some bananas are sweeter, while others are starchier. Banana Varieties Each variety of banana is grown for a specific end use. Some (plantains) are fried in a skillet. They are starchy. Others are raised for sweetness and aroma. Those are called dessert bananas. The most popular form of dessert banana is…
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