The terms food safety and food quality are often taken as the same. However, in principle they are two different concepts. Food quality is a broad term that will vary depending on what the specific consumer wants. On the other hand, food safety has to do with the wholesomeness and fitness of the food for consumption. Therefore, a food can be fit for consumption but is of poor quality. For example, having an undesirable texture and taste. On the other hand, a food can meet these quality characteristics but is not safe to eat due to the presence of hazards (chemical, physical and biological). Food quality characteristics may be divided into physical, chemical, sensory and functional characteristics.
Physical properties are properties of foods that can be observed and measured without changing the chemical nature of the food e.g. size, color, weight, particle size, viscosity and density.
Chemical properties are properties of foods that can only be measured and observed by changing the chemical nature of the food e.g. acidity, pH, moisture, rancidity and nutritional composition (protein, carbohydrates, lipids, vitamins and minerals).
Sensory properties are properties of foods relating to the experience of the consumer while eating the product e.g. appearance, texture, taste, flavor, aroma. Note that taste and flavor are listed separately. There are only five tastes i.e. bitter, sweet, salty, sour and umami. Umami is a savory taste. We taste with our tongue and detect flavors using olfactory nerves in our nasal cavity. Flavors, e.g. onion, ginger, and cinnamon flavor are the result of thousands of volatile flavor compounds present in the food material.
Functional properties are the properties or behaviors of foods that result from the combination of its physical and chemical properties e.g. the ability of carbohydrates to react with proteins to cause Maillard reaction resulting in new colors and flavors; or the ability of gluten proteins to stretch and recoil like elastic.
An understanding of food science principles is key to understanding and knowing how to make foods that will satisfy consumer need for taste, appearance, convenience, shelf life, and nutrition.
Reference: Potter, N. N. & Hotchkiss, J. H. (1998). Food Science, 5th edition. New York, NY: Springer Science+Business Media LLC.
