In newer packaging, such as that used to prevent browning of precut vegetables and fruits used in supermarket salad bars, the atmosphere has been modified. Chemists must be concerned with the public's fear of food additives, which is tied to a fear of chemicals, even though additives are used to improve the quality, variety, convenience, and nutritive value of our food and have been determined to be safe. At the same time, chemists guard against adulteration of food. Over the past two centuries, concern about adulteration of the food supply in the US has been almost eliminated, but food processors must be vigilant in ensuring the purity, safety, and quality of ingredients supplied to them. Ensuring the safety of food means that chemical and microbiological aspects must be monitored.
Chemical safety is ensured primarily by analyzing food for trace residues of pesticides.
The most common way to provide microbiological safety, other than thermal processing, is by reducing water activity or lowering the pH, but both influence other attributes such as flavor, color, and texture. Biostatic agents may also be added. There is a definite relationship between the composition of the product and processing conditions, applicable chemistry, product texture, cost, and any subsequent preparation required. Thus, food product formulations are extremely important. Team approaches are most often used in problem solving.