Amino acid
Amino acids are organic compounds containing amine (-NH) and carboxyl (-COOH) functional groups, along with a side chain (R group) specific to each amino acid. The key elements of an amino acid are carbon (C), hydrogen (H), oxygen (O), and nitrogen (N), although other elements are found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known (though only 20 appear in the genetic code) and can be classified in many ways. They can be classified according to the core structural functional groups' locations as alpha- (α-), beta- (β-), gamma- (γ-) or delta- (δ-) amino acids; other categories relate to polarity, pH level, and side chain group type (aliphatic, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid residues form the second-largest component (water is the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis.
Orange juice
For Canadian markets, orange juice must be the fruit juice obtained from clean, sound, and mature oranges. The juice must also contain a minimum of 1.20 milliequivalents of free amino acids per 100 millilitres, contain a minimum of 115 milligrams of potassium per 10 milliliters, and possess a minimum absorbance value for total polyphenolics of 0.380. Sweeteners such as sugar, invert sugar, dextrose or glucose solids may be added. The orange juice must have a Brix reading of at least 9.7, excluding the sweetening ingredients, and contain between 0.5 and 1.8 percent of acid by weight calculated as anhydrous citric acid. Added orange essences, orange oils and orange pulp adjusted in accordance with good manufacturing practice is permitted. Orange juice is also permitted to contain sugar, invert sugar, dextrose in dry form, glucose solids, a Class II preservative, amylase, cellulase and pectinase.