CJW-Food+acidulants

Food Acidulants-- served as pH control agents, preservatives and chelating agent.

**pH control agent** -- needed to maintain acidic fermentation processes. -- citric acid has widest effective buffer range (2.5-6.5) -- tartaric acid can only use at pH 3.0-4.5
 * to obtain certain pH range in product formulation
 * acidulant reaction with baking soda is essential in the leavening action of the CO2
 * maintain acidic pH and the tartness of carbonated beverages
 * benefit products that use preservative e.g sodium benzoate
 * buffering capacity-- provides protection from pH dependent effects like colour or flavor changes.

acidic pH can stop growth or enhance the effectiveness of heat sterilization or the antimicrobial effect of solutes. in extreme cases it may actually destroy the organisms-- consideration for controlled acid fermentation processes. also serve as antibrowning agents to maintain the normal flavor, color and texture.
 * Preservatives **

**Chelating agents/ antioxidant synergists** Trace metals such as iron, nickel, manganese, cobalt, chromium, copper and tin promote oxidative reaction, via catalytic action, produce undesirable reactions such as discoloration, rancidity and instability of nutrients --> this prevent the metal ions from reacting with other materials or from acting as a catalyst for reactions. --> the formation of a stable, water-soluble chelate is referred to as sequestration
 * Citrates & phosphates have the ability to form ring structures with metal ions (chelation)
 * citric acid is the strongest chelating agent. other example are lactic, malic and tartaric acid.
 * chelating function is useful in retarding the enzymatic browning of fruits & vegetables
 * Acidulants are used as synergists for antioxidants (e.g BHA &BHT, ascorbates) in the preservation of fats & oils, and in food products containing fatty compounds.

Can modify or enhance food flavour such as hard candies, gelation desserts, carbonated/noncarbonated beverages, jellies, preserves, toppings, etc Add the tartness required to balance the excessive sweetness Some acids are selected for their ability to modify the sweetness of sugar. Enhancement of certain flavours requires combination of the flavor with appropriate acid. e.g.
 * Flavour Adjuncts **
 * acetic acid gives a distintive vinegar note, it would not enhance a delicately flavoured fruit beverage
 * citric acid gives a sharp, clean bite
 * the acid taste lingers with fumaric acid but it dissipates quickly with citric
 * acidity of malic acid builds slowly but then lingers
 * tartaric acid with grape flavour
 * phosphoric acid with cola flavour
 * others such as citric, fumaric and malic acid are more widely use.

**Control of Gelation & Coagulation** -->using acidulants provides precise pH control.
 * For gelling high methxyl pectin, the pH must be adjusted to 2.5-3.5
 * in the production of direct acidified cheese products, tofu and similar products that require protein coagulation,