Reducing sugars relative stability

That summary is based on the reports of a well-conceived and carefully executed research program carried out by Rohan. Mohr et al. (7) extended these studies and was able to draw additional conclusions. First, without exception, free amino acids are much more sensitive to destruction in this system than the peptide-bound amino acids. Second, differences in the stability of amino acids under these conditions are not great —from 25% loss for isoleucine to 68.5% for lysine, over a relatively short period of time. In this system the reducing sugars must be the limiting factor, since the glucose and fructose are completely destroyed or removed. Third, neither cystine nor cysteine are reported to be present, and the only other sulfur-containing amino acid, methionine, is present at a much lower concentration than any other amino acid. Clearly, as we shall see later, cocoa would probably have a considerably different flavor if cysteine or cystine were present in the fermented beans. 

Because of the danger of bacterial destruction, as for milk, other foodstuffs that are in liquid solution or in the form of a slurry or a paste have limited shelf life. Similar to refrigeration or the addition of preservatives, the removal of liquid reduces this bacterial activity. Foods that are free (or relatively free) of liquid can be stored for an almost unlimited time if kept dry and cool. Such products may contain proteins, carbohydrates (including the most important one, starch), fat, and other ingredients such as vitamins, flavorings, including salts and sugars, emulsifiers, stabilizers, colors, and chemicals. 

Fig. 2. Schematic of track of an Argon ion-beam in DNA. A high-energy density core is generated by deposition of ca. 50% of the energy of the ion in a relatively small volume. At 77 K, neutral sugar radicals are stabilized largely in the core. A much larger region of space formed by delta rays from the core is characterized by low LET-like spurs. Ion base radicals are stabilized in the spurs, with one-electron-reduced cytosine actually existing as a protonated species.

---