Food Additives and Redox Reactions

True (A)

False (B)

False (B)

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

Substances that bind free metal ions in food systems, forming non-ionized, non-toxic complexes. These complexes prevent reactions that lead to food degradation, such as discoloration, rancidity, and loss of nutritional quality.

Metal ions in food systems can cause various problems like discoloration, rancidity, and loss of nutritional quality.

The formation of a stable compound between a metal ion and a chelating agent, resulting in a complex that is non-ionized and non-toxic.

Chelating agents remove free metal ions from food, preventing them from catalyzing unwanted reactions. This helps to preserve food quality, color, and texture.

The reaction between a metal ion and a chelating agent that forms a stable, non-ionized, non-toxic complex.

Chelating complexes are easily eliminated from the body, making them safe for use in food.

Chelating agents play a crucial role in food preservation by controlling metal ions that can damage food quality.

The ability of a chelating agent to bind to a single metal ion.

Chelating agents are molecules that bind to metal ions, forming a stable complex. They are not antioxidants, but they can act as antioxidants by removing metal ions that catalyze oxidative reactions.

Chelating agents can help stabilize food products by preventing oxidative reactions that can lead to spoilage. They can also prevent discoloration by removing trace metals that contribute to color changes.

Citric acid and its derivatives, phosphates, and EDTA are commonly used in food applications to bind to metal ions.

The solubility of chelating agents is crucial for their effectiveness. For example, citric acid and its esters are soluble in fats and oils, while EDTA salts are effective in emulsions like mayonnaise and salad dressings.

The pH of the environment affects the efficiency of chelating agents. A higher pH generally enhances chelating efficiency because the carboxylate ion, which is formed at higher pH, is a more efficient donor group.

Trace elements like iron, copper, and cobalt can act as catalysts for oxidation, leading to deterioration of food products. For example, copper and iron can destroy vitamins A, E, and thiamine.

Chelating agents are helpful in preventing discoloration in food products. For example, they can prevent pink discoloration in canned pears, blue-green discoloration in shellfish, and clouding in soft drinks.

Chelating agents do not directly scavenge free radicals or delay oxidation. They prevent oxidative reactions by removing metal ions that act as catalysts for oxidation.

Chemicals that bind to metal ions, preventing them from reacting and causing unwanted changes in food.

A condition in beer where particles form and cause cloudiness when chilled.

A reddish pigment that forms in some canned fruits during processing, caused by the breakdown of tannins.

A blue discoloration in crab meat caused by a reaction between copper and a substance called biuret.

The use of EDTA to prevent the depletion of calcium and other essential minerals in the body.

Polyphosphates and EDTA can be used to prevent the formation of glassy crystals in canned seafood by reacting with magnesium in the seafood.

Chelating agents like tartaric acid and its salts can be added to cheese to prevent color loss and rancidity.

Free copper can cause the formation of haze in beer by promoting the oxidation of polyphenolic compounds.

Phytoalexins are antimicrobial compounds produced by plants in response to pathogen attacks. They help defend against fungi and bacteria.

Phytoalexins are often specific to plant families. For instance, legumes primarily produce isoflavonoids as phytoalexins, while Solanaceae plants produce terpenoids.

Essential oils are a type of natural antimicrobial extracted from plants. They're often considered safe for use.

Essential oils work by interfering with the cell membrane of bacteria and fungi. Their lipophilic nature helps them penetrate cell walls.

Essential oils are more effective against Gram-positive bacteria than Gram-negative bacteria. This is because Gram-negative bacteria have an outer membrane that makes them more resistant.

Synthetic antioxidants used to prevent oxidation in food, especially fats. They are more polar than other antioxidants like BHA and BHT.

A specific type of gallate, it is a synthetic antioxidant that is derived from gallic acid. It effectively protects against oxidation in animal fats like lard and tallow.

Two powerful synthetic antioxidants similar in structure and activity. They contain di-tert-butyl groups, making them effective at neutralizing free radicals and slowing down oxidation.

A specific antioxidant used in food to prevent spoilage by delaying oxidation. More effective in short-chain fatty acids like those found in coconut or palm kernel oils.

A common antioxidant often found in food packaging materials and used in conjunction with other antioxidants. BHT is especially good with BHA for a better antioxidative effect.

The ability of an antioxidant to effectively stop oxidation even after the food product has been cooked or heated. This is a desirable trait for synthetic antioxidants.

A type of chemical reaction that involves the loss of electrons. In the context of food, oxidation is the process that causes food spoilage, like rancidity in fats and oils.

These are molecules that can react with free radicals, preventing them from causing damage to the food. Antioxidants donate a hydrogen atom to stabilize free radicals, effectively ending their damaging chain reaction.

A chemical compound that can donate electrons to protect other molecules from damage caused by free radicals. It can also reduce the concentration of reactive oxygen species (ROS) like hydrogen peroxide.

Sulfur dioxide (SO2) and its related compounds, such as sulfites (Na2SO3, NaHSO3, KHSO3), are widely used in food preservation, particularly for fruits and vegetables. They effectively inhibit microbial growth, prevent discoloration caused by enzymatic and non-enzymatic browning, and act as antioxidants.

Sulfur dioxide (SO2) can react with hydrogen peroxide, a reactive oxygen species (ROS), effectively neutralizing it and acting as an antioxidant. It can also reduce quinones (compounds involved in browning reactions) to their phenol form, which are less reactive, and prevent the formation of these quinones by inhibiting polyphenol oxidase enzymes, further protecting from browning.

Sulfite forms, such as bisulfite, exhibit antimicrobial properties. Their effectiveness is influenced by pH conditions, with higher pH favoring activity against bacteria but not yeast. Gram-negative bacteria are more susceptible to sulfite action compared to Gram-positive, making these compounds valuable in food preservation.

Sulfur dioxide (SO2) is a key component in winemaking, acting as a solvent to extract flavors and compounds from grape solids like stems, seeds, and skins. It is also used throughout the winemaking process.

Sulfite filters are commonly used in winemaking to remove excess sulfites. This is done to prevent unwanted sulfite levels in the final product, which can cause adverse reactions in some individuals.

Sulfur dioxide (SO2) is utilized at three stages of winemaking. First, it prevents oxidation during the prefermentation process, ensuring the must (grape juice) remains fresh. Second, it controls microbial growth after fermentation, preventing spoilage. Third, it stabilizes the wine before bottling, preventing any changes or accidents in the bottle.

While its use in food preservation is widespread, SO2 is not advised for foods containing thiamine (Vitamin B1) as it can degrade this essential nutrient.