Citric Acid In Use

Citric Acid anhydrous appears as an odorless white crystalline granule with a strong acidic taste. It is very soluble in water, freely soluble in alcohol and slightly soluble in ether.
Citric Acid is a constituent of fruit and soft drinks and other food products. Uses include flavor enhancement, bacterial inhabitant, pH adjustment, and as an anti oxidant.

In food application:

-Beverage
Citric acid is the acidulant of choice in the beverage industry. Citric acid is used extensively in carbonated beverage for flavoring and buffering properties.. Their high solubilities make them ideal for syrup concentrates. Citric acid is also used in non-carbonated beverages as flavoring agents and buffers. They also increase the effectiveness of anti-microbial preservatives. Modifications such as juice-added beverages, low calorie beverages, and thirst quenchers use citric acid alone and in combinations with citrate salts.

-Canning Industry
Citric acid lowers the pH to reduce heat processing, chelates trace metals to prevent enzymatic oxidation and color degradation, and enhances the flavor.

-Confections
Citric acid is utilized in the confection industry. Citrates control sugar inversion, optimize gel-setting characteristics, provides tartness and enhance flavor.

-Coffee Creamers
Sodium citrate is used in dairy and non-dairy creamers to stabilize the casein. This prevents feathering of the creamers when added to hot beverages.

-Dietary Calcium Supplements
Citric acid in the from of calcium citrate is used as a dietary calcium supplement. Studies have shown that calcium citrate is more bio-available than calcium carbonate.

-Dry Beverage
Citric acid is used in dry powder beverages for flavor and pH control.
In artificially sweetened beverages citric acid add the bulk and mouth feel normally obtained from the sucrose.

-Jams & Jellies
Citric acid used in jams and jellies to provide tartness and to control the product pH for optimum gelation.

-Fruit and Vegetable Processing
Citric acid is used to inhibit enzymatic and trace metal-catalyzed oxidation reactions which can cause color and flavor deterioration it is often used with ascorbic acid for this purpose. The stability of frozen foods is optimized by the presence of citric acid.

-Oil
Citric acid is utilized in Canola oil de-gumming. Citric acid is also used in the deodorization and hydrogenation steps in oil processing to chelate trace metals which can catalyze rancidity reactions.

-Pudding/Pie Fillings
Fumaric Acid is used in pudding and pie fillings to provide pH control. The non-hygroscopic nature of Fumaric acid lends itself to the less expensive packaging of these product.

-Process Cheese
Sodium Citrate is used in the process cheese industry. Sodium citrate functions as an emulsifying salt to stabilize the water and oil phases of the cheese and improves body and texture.

In industrial applications:

-Algicides
Citric Acid is used to chelate copper in formulations used to kill algae in reservoirs and natural waters. The citric acid chelates the copper, then slowly releases it resulting in extended time of effectiveness.

-Animal Feed
Citric acid is used in animal feeds to form soluble, easily digestible chelates of essential metal nutrients, enhance response to antibiotics, enhance flavor to increase food uptake, to control gastric pH and improve the efficiency of the feed.

In the slaughter operation, sodium citrate is used to prevent the coagulation or clotting of fresh blood. Calcium is an essential mineral for the clotting mechanism to occur. Citrate chelates the calcium, thus preventing the coagulating from taking place.

-Cigarettes
Air-cured tobacco smoke is often alkaline, giving harsh and irritating flavors. Citric acid and other components are added to balance the flavors. Citric acid is also used in cigarette paper to control the burn rate. This ensures the tobacco and paper burn at the same rate.

-Circuit Boards
Citric acid can be used to clean circuit boards prior to soldering. Although more costly than mineral acids, citric acid has the advantage of being environmentally friendly.

-Concrete Admixture
Citric acid is added to concrete formulations to retard the set rate and reduce the amount of water required. In the retarding the set rate, the Citrate interferes with the hydration of portland cement. In its role as a water reducer, citrate acts as a dispersants, reducing the viscosity of the cement slurry so less water is needed to make a workable mixture.

-Detergents
The largest industrial application for citrates is the detergent industry. In liquid detergents, sodium citrate is used as a builder, to increase the effectiveness of the surfactants, due to its high solubility and bio-degradability.
In powder detergents, sodium citrate is used as a co-builder and processing aid. Sodium citrate also contributes alkalinity to enhance surfactant performance. The environmentally friendly nature of sodium citrate is a major factor in the use of citrates in the detergent industry.

-Enhanced Oil Recovery
Aluminum citrate is used for in-situ gelling of polymers in polymer flooding operations. The citrate controls the rate of availability of the aluminum ion.

-Environmental Aspects
Many of the following industrial applications utilized citric acid due to its environmentally friendly properties.. Citric acid is found throughout nature in many fruits and vegetables and is a natural component in metabolic processes. Citric acid is highly biodegradable and is an affirmed GRAS food additive.

-Fertilizer Micronutrients
Citric chelates of iron, copper, magnesium, manganese and zinc are used to correct soil deficiencies because they are soluble in water at normal soil pH. Metal sulfates are dissolved in water and citric acid followed by neutralization with ammonia. The soluble citrate chelate promotes the transfer of the metal nutrient into the plant's root or leaf system the biodegradability of citric acid is important for this application.

-Fossil-Fuel Power Plants
Ammoniated citric acid is used to clean metal oxides from the water side of steam boilers with a two-step single-fill operation the resulting surface is clean and passivated. The cleaning solution can easily and safely be disposed of by incineration or liming.

-Hard Surface Cleaners
Citric acid is used in liqued hard surface (floor). Citrate acts as a scale-dissolver, buffer and as an anti-redeposition agent.

-Hair Shampoos and Rinses
Citric acid is added to hair care formulations to adjust the pH, act as a buffer and chelate metal ions to prevent discoloration and decomposition the presence of the citric ion stabilizes the formulation.

-Nuclear Reactors
Citric acid is utilized in nuclear reactors to remove mill scale from welding operations. HC1 cannot be used due to the possibility of chloride stress fracturing of the stainless steel.

-Oil Well Acidizing
Citric acid is used in oil well acidizing to prevent the formation of insoluble gels of iron hydroxide. Wells are typically injected with HC1, oxidation reactions can occur which cause formation of insoluble iron hydroxide gels. These gels interfere with pumping hydroxide gels. These gels interfere with pumping operations. Citric acid is added to the well to chelate the iron thus preventing the gel formation.

-Radiator
Sodium citrate is used in radiator cleaning formulations to chelated metal from the metal oxide scales and to maintain the pH

-Ship Bilge and Reverse Osmosis Cleaning
Citric acid is used as a chelating agent in cleaning bilges and desalination units aboard ships.
In bilge cleaning, citric acid is used for rust removal. In desalination units, citric acid solutions are used to remove iron, calcium and other cations which foul the cellulose acetate membranes used in reverse-osmosis systems. Citric acid will solubilize these ions without damaging the membranes.

-Paint Industry
In the paint industry citric acid is used to retard the setting of titanium dioxide, the most common pigment used in paints and other coatings.

-Paper
Citric acid is added to the pulp slurry prior to bleaching to control paper staining by sequestering metal ions.

-Pet Food
In the animal feed industry, the primary use of citric acid is in pet food, where it is the flavor enhancer of choice. Fumaric acid is also used in this application

-Pharmaceuticals
Citric acid is widely used as a flavoring and stabilizing agent in pharmaceutical preparations. It is used in liquid preparations to enhance fruit flavors and to impart a desirable tart taste that helps mask medicinal flavors.
Citric acid help maintain stability of the active ingredients by buffering aqueous solutions, sequestering trace metals, and assisting in the dispersion of suspensions.
Citric acid in syrups, elixirs, of suspensions and solutions is considered a well established market.
The largest use of citric acid in the pharmaceutical industry is for the effervescent effect it produces when combine with bicarbonates or carbonates in antacids and dentrifices. Effervescence, beside improving palatability, can greatly improve the solubility of co-constituents.

-Plating
Citric acid is used as a chelating agent to control the deposition rate of metals in both electroplating and electroless plating operations. It is also used to buffer the pH of the plating bath.

-Textiles
In textile finishing, citric acid is used to adjust pH, as a buffer and as a chelating agent in dye operations and in durable-press finishes using glyoxal resins. In this application citric acid is easier and sager to work with than acetic acid.

-Water Softener Resin
Citric acid is mixed in the salt to chelate iron from fouled water softener resins in both home and commercial systems.