Xylitol, erythritol, corn syrup and high fructose corn syrup can be all made from corn. While corn is admittedly sweet, it doesn't taste sugary. It takes a lot of processing to turn it into this very sweet substances.
My puzzle is, why are the first two regarded as artificial and the latter two, natural? 🤔
From Wikipedia, how each is made:
Industrial production starts with lignocellulosic biomass from which xylan is extracted; raw biomass materials include hardwoods, softwoods, and agricultural waste from processing maize, wheat, or rice. The xylan polymers can be hydrolyzed into xylose, which is catalytically hydrogenated into xylitol. The conversion changes the sugar (xylose, an aldehyde) into the primary alcohol, xylitol. Impurities are then removed.
Erythritol is produced industrially beginning with enzymatic hydrolysis of the starch from corn to generate glucose. Glucose is then fermented with yeast or another fungus to produce erythritol. Other methods such as electrochemical synthesis are in development. A genetically engineered mutant form of Yarrowia lipolytica, a yeast, has been optimized for erythritol production by fermentation, using glycerol as a carbon source and high osmotic pressure to increase yields up to 62%.
First, the enzyme α-amylase is added to a mixture of corn starch and water. α-amylase is secreted by various species of the bacterium genus Bacillus and the enzyme is isolated from the liquid in which the bacteria were grown. The enzyme breaks down the starch into oligosaccharides, which are then broken into glucose molecules by adding the enzyme glucoamylase, known also as "γ-amylase". Glucoamylase is secreted by various species of the fungus Aspergillus; the enzyme is isolated from the liquid in which the fungus is grown. The glucose can then be transformed into fructose by passing the glucose through a column that is loaded with the enzyme D-xylose isomerase, an enzyme that is isolated from the growth medium of any of several bacteria.
Corn is milled to extract corn starch and an "acid-enzyme" process is used, in which the corn-starch solution is acidified to begin breaking up the existing carbohydrates. High-temperature enzymes are added to further metabolize the starch and convert the resulting sugars to fructose. The first enzyme added is alpha-amylase, which breaks the long chains down into shorter sugar chains – oligosaccharides. Glucoamylase is mixed in and converts them to glucose. The resulting solution is filtered to remove protein, then using activated carbon, and then demineralized using ion-exchange resins. The purified solution is then run over immobilized xylose isomerase, which turns the sugars to ~50–52% glucose with some unconverted oligosaccharides and 42% fructose (HFCS 42), and again demineralized and again purified using activated carbon. Some is processed into HFCS 90 by liquid chromatography, and then mixed with HFCS 42 to form HFCS 55. The enzymes used in the process are made by microbial fermentation.