Non-enzymic browning
The development of color and aroma was due to the formation of new compounds. A chemical reaction (Maillard reaction) took place between the carbonyl group of glucose and the amino group of the amino acids (1). As sucrose does not contain a free carbonyl group, the Maillard reaction did not take place, and no significant change was observed in the appearance and odor of the mixture. However, when sucrose is hydrolyzed, fructose and glucose are obtained. These in turn react with amino acids and proteins to give colored products. When the concentration of glucose was high, the color and odor of the reaction mixture were darker and more intense, respectively, due to a larger amount of products formed. Glycine, leucine, and methionine formed different products that obviously had different colors and aromas. This is how food technologists develop a combination of aromas and color for the food industry.
Effect of processing, packaging and storage on chocolate
Due to a sugar re-crystallisation process, the appearance and physical property of the chocolate was slightly altered.
The packaging prevented the chocolate from getting in direct contact with humidity. However, when the unwrapped chocolate was exposed to a humid environment, it absorbed water, and some sugar molecules got dissolved in the water. Upon the evaporation of the absorbed water at a lower humidity level, the sugar molecules formed larger crystals and left a dusty rough layer.
Making sweets
The table below gives a list of products that can be made at the indicated temperatures (2).
Crystallisation is a process in which solids are formed from a solution or melt. Crystals are normally formed from supersaturated solutions.
Sweetness
The sweetness of a matrix depends on the type (chemical structure) and concentration of sweetener, its pH, temperature and composition.
The solubility of particular sugar in water depends on its chemical structure, polarity and its ability to form hydrogen bonds with water. The solubility of sugars is also affected by temperature, pH and the presence of other compounds in the medium.
When a sugar is insoluble in a product, a rough texture is obtained, for example, apple crumble.
As the solutions containing the artificial sweeteners were less viscous, they were less palatable than those containing the natural sugars.
Effect of sugar type on hygroscopicity
From the results obtained, it can be concluded that lactose is more hygroscopic than glucose.