Food additives are substances added to food to preserve flavor or enhance its taste and appearance. Some additives have been used for centuries; for example, preserving food by pickling (with vinegar), salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines. With the advent of processed foods in the second half of the 20th century, many more additives have been introduced, of both natural and artificial origin.
Many food additives absorb radiation in the ultraviolet and / or visible region of the spectrum. This absorbance can be used to determine the concenttration of an additive in a sample using external calibration. However, additives may occur together and the absorbance by one could interfere with the absorbance of another. A prior separation stage is necessary and the additives are first separated by high liquid chromatography (HPLC) and then determined on-line using a UV and/or visible detector.
Cosmetic materials come from a variety of sources but, unlike the ingredients of food, are often not considered by most consumers. Cosmetics often use vibrant colors that are derived from some unexpected sources, ranging from crushed insects to rust. Many new techniques have allowed manufacturers to synthesize such colors and the use of animals (or parts thereof) has been declining for many years and is now virtually eliminated, due in large part to the efforts of Beauty Without Cruelty, PETA and other groups.
Cosmetics in a variety of forms date back to early civilizations, with the need to improve ones personal appearance being an important factor in attracting a mate. Over the years the ingredients have changed dramatically as we discovered how to manufacture our own scents and cosmetic formulas. The realization of the dangers of many common ingredients also greatly affected the growing industry.
More about: Food additive & cosmetic materials sale
Read more: Nano products
No comments:
Post a Comment