Saturday, August 29, 2009

Understanding acidifiers

Common additives that increase the acidity (lower the pH) of foods and beverages. Acidifiers provide tartness and enhance flavors of processed foods. The increased acidity inhibits the growth of microorganisms; thus acidifiers act as preservatives. Certain acidifiers can also retard spoilage by acting as antioxidants, preventing chemical changes due to oxygen. This group of additives includes ADIPIC ACID (adipate), TARTARIC ACID (tartrate), benzoic acid (benzoate), and CITRIC ACID (citrate).

Understanding acid-forming foods

Foods that create acidic residues after they have been broken down by the body. Protein-rich food, such as EGGS, MEAT, and poultry, produce acidic residues when oxidized for energy. The combustion of sulfur-containing amino acids tends to acidify the body (acidic residue). In contrast, fruits and vegetables make the body more alkaline or basic. They contain magnesium, calcium, and potassium salts of organic acids, which yield an alkaline residue when oxidized. Fruits are accordingly classified as alkali-forming foods, even though juices and fruit taste acidic (sour). Excretion of organic acids (potential renal acid load) can be calculated for various foods based on their content of sodium, potassium, calcium, magnesium, chloride, phosphorus, and sulfur. Choosing more alkaline foods may ameliorate osteoporosis, autoimmune conditions such as rheumatoid arthritis, and chronic inflammation.

Acid and human health

A large family of compounds that taste sour and can neutralize bases to create salts. Strong acids like hydrochloric acid (STOMACH ACID) and sulfuric acid (battery acid) give up all of their protons in water and lower the pH, the effective hydrogen ion concentration. A pH of 7.0 is neutral, that is, neither acidic nor basic, while pH values less than 7.0 are considered acidic. Exposure to strong acids tends to damage cells and tissues. The stomach is the only organ normally exposed to strong acids, but it is protected from injury by a heavy mucous layer.
In contrast to strong acids, organic acids are classified as weak acids because they donate only a portion of their hydrogen ions, lower the pH to a lesser degree, and are less dangerous to tissues.
Many compounds in foods are weak acids, including CITRIC ACID, ACETIC ACID, and TARTARIC ACID. Several weak acids are used as FOOD ADDITIVES, including benzoic acid, CARBONIC ACID, and alginic acid. As food additives and recipe ingredients, weak acids add tartness to foods. Weak acids are common intermediates, products of cellular processes that sustain life, including LACTIC ACID, KETONE BODIES, PYRUVIC ACID, acetic acid, FATTY ACIDS, SUCCINIC ACID, citric acid, even the nucleic acids DNA and RNA. GLUTAMIC ACID and ASPARTIC ACID (two common AMINO ACIDS) are classified as acidic amino acids, and are more acid than most.
In the body, weak acids characteristically have lost all their hydrogen ions and exist as a family of anions (negatively charged ions) classified as “conjugate bases” because they have been completely neutralized by the buffer systems of blood. In the blood, lactic acid exists as its anion, lactate; acetoacetic acid (a ketone body) as acetoacetate; citric acid as citrate, and so on. Often the names of acids and their anions are interchanged in nutrition literature.