Some ingredients were benign, such as citric acid and instant coffee.
He then ran the extracts through a gas chromatograph and a mass spectrometer, to see what was in them.The crucial giveaways of Kopi Luwak turned out to be four substances: citric acid, malic acid, pyroglutamic acid and inositol.
Last year Belgian researchers tested a shoebox-sized IVF laboratory built from cheap glass tubes that uses baking soda and citric acid to create the carbon dioxide needed for fertilisation to occur.
They contribute the sugar fructose and citric acid to the semen but do not serve as sperm reservoirs.
Other compounds giving a beer its character include: esters such as isoamyl acetate (banana), ethyl hexanoate (apple), and ethyl acetate (solvent); higher alcohols such as isoamyl alcohol and 2-phenyl ethanol; acids such as octanoic, acetic, isovaleric, butyric malic, and citric; dialkyl sulfides such as dimethyl sulfide; and diketones such as diacetyl.
The fatty acids are broken down into smaller molecules that can enter the citric acid cycle for the synthesis of ATP by oxidative phosphorylation.
In protozoans and eukaryotes in general, metabolism and respiration occur stepwise via three specific pathways: the Embden-Meyerhof-Parnas pathway (glycolysis), the tricarboxylic acid cycle (also known as the Krebs cycle, or citric acid cycle), and the electron transport chain, which uses cytochromes, flavins, and quinones as electron carriers.
The products are of many types: alcohol, glycerol, and carbon dioxide from yeast fermentation of various sugars; butyl alcohol, acetone, lactic acid, monosodium glutamate, and acetic acid from various bacteria; and citric acid, gluconic acid, and small amounts of antibiotics, vitamin B12, and riboflavin (vitamin B2) from mold fermentation.
The ingredients used in curing and pickling are sodium nitrate, sodium nitrite, sodium chloride, sugar, and citric acid or vinegar.
First isolated from lemon juice by a Swedish chemist, Carl Wilhelm Scheele, in 1784, citric acid is manufactured by fermentation of cane sugar or molasses in the presence of a fungus, Aspergillus niger.
About 0.01 percent of citric acid is commonly added to deodorized oils to inactivate trace-metal contaminants such as soluble iron or copper compounds that otherwise would promote oxidation and the development of rancidity.
