Food Additives and Preservatives: Types, Functions, Examples microbiologystudy

A food additive is any substance that is added intentionally to foods to manipulate the appearance, taste, texture, and odor of foods. It aims to increase the shelf life of foods. It inhibits the growth of pathogens and also alters the other properties.

• It is not considered a regular food ingredient or is typically not consumed as food. Food additives are assessed for pernicious effects on human health before they are allowed for use. 
• According to the Codex Alimentarius Commission (a joint FAO/ WHO organization involved in preparing food standards) and EEC Commission, food additives are any substance not consumed as food by itself and not used as a typical ingredient of food whether or not it has nutritional value.
• During the manufacture, processing, preparation, treatment, packing, packaging, and transport, the addition of substances plays a crucial role in food. E numbers- found in food labels- are code for substances allowed to be used as food additives within the European Union and EFTA.

The most common food additives are:

a. Monosodium glutamate (MSG)- used in packaged Asian foods

b. Artificial sweeteners such as aspartame, saccharine, and sodium cyclamate

c. Antioxidants in oily or fatty foods

d. Benzoic acid in fruit juices

e. Sulfites in packaged vegetables

f. Nitrates and Nitrites- hot dogs and other meat products

g. Antibiotics to food-producing animals

h. Lecithin, gelatins, corn starch, waxes, gums, and propylene glycol- used in food stabilizers and emulsifiers.

The FDA ensures that food additives used by food manufacturers are safe and approved for regulated use.

Food additives play a crucial role in food processing. They are added to foods in such amounts during processing. It improves the appearance, flavor, and nutritional value. It also helps to maintain the nutritional quality of food. It supports the quality and stability of food and reduces food wastage. It makes the food attractive to consume.

Sources of Additives

There are three types of additives:

• Natural additives
• Man-Made additives
• Artificial additives

Natural additives: Natural additives are obtained naturally from plants and animals, such as extracts from beetroot juice used as coloring agents.

Man-made versions: Man-made additives are synthetic identical copies of natural substances, such as benzoic acid, used as a preservative.

Artificial additives: Artificial additives, such as sulfur dioxide or sorbic acid, are produced synthetically but do not occur naturally. It is utilized in certain dairy products, as well as in semolina and tapioca puddings.

Functions of Food Additives

• It helps to maintain product consistency.
• An emulsifier helps to prevent the separation of ingredients.
• Stabilizers and thickeners help to provide even textures.
• Anti-caking agents help to keep ingredients free-flowing.
• It helps to improve or preserve the nutritional value.
• It maintains the wholesomeness of foods.
• Preservatives help to reduce spoilage and rancidity.
• It helps to control the acidity and alkalinity in foods and provides leavening.
• It helps to change the acid-base balance of foods to require a desired taste, color, flavor, or leavening.
• It helps to give the desired color and enhance the flavor of food.
• Anti-caking agents help to prevent the lumping or clumping of fine, powdery substances.

Classification of Food Additives

The classification of food additives is intentional and unintentional food additives.

Intentional Food additives

• Intentional food additives are additives intentionally added to foods to help with processing and act as preservatives. It enhances the quality of food. It helps to prevent spoilage. 
• It includes Anti-caking agents, Antimicrobial agents, Antioxidants, Colours, Curing and pickling agents, Emulsifiers, Enzymes, Firming agents, Flavour enhancers, Flavouring agents, Humectants, Leavening agents, Release agents, Non-nutritive sweeteners, Nutrient supplements, Nutritive sweeteners, Oxidizing and reducing agents, pH control agents, Propellants and gases, Sequestrants, Solvents and vehicles, Stabilizers and thickeners, Surface-active agents, and Texturizers.

Un-Intentional food additives

• They are not added intentionally to the food; however, they may incidentally enter into foods during food production, agricultural production, raising animals, food processing, packaging, and storage of food products. 
• They are food contaminants. Examples are insects or herbicides from the field when processing grains, pesticides to prevent infestations, hair from unsanitary processing conditions, and wax from products stored in wax-coated packaging. 
• It includes Processing Aids, Food Contact Materials, Packaging Materials, Cleaning Agents, Ion-exchange resins, filter aids, Enzyme preparations, microorganisms, Solvents, lubricants, release agents, Specific function additives, Utensils, Working surfaces, Equipment, Metal, plastic, paper, wood, etc., Detergents, and Sanitizers.

They are the following ways:

• Preservatives
• Antioxidants
• Sequestrants
• Humectants
• Bleaching and maturing agents, starch modifier
• Emulsifiers, stabilizers, gelling agents and thickeners
• Surface Active agents
• Anti-caking agents, anti-foaming agents
• Colors
• Flavor enhancers
• Acids, bases, and buffers
• Glazing agents
• Nutrient supplements
• Enzyme Preparations

Preservatives

• Preservatives prevent or retard the growth of organisms that can cause food spoilage and lead to food poisoning. 
• It extends the shelf-life of products. 
• Examples are bacon, ham, corned beef, and other ‘cured’ meats treated with nitrite and nitrate (E249 to E252) during the curing process.

Antioxidants

• Antioxidants prevent oxidation of food containing fat or oil. It prevents rancidity, which means developing an unpleasant odor or flavor. 
• Moreover, it prevents spoilage of animal fat caused by oxidation. It prevents the browning of cut fruit, vegetables, and fruit juices (and so prolongs the shelf life and appearance). 
• For example, vitamin C (ascorbic acid), or E300, is one of the most used antioxidants.

Sequestrants

• A Sequestrant is a chemical that combines with a substance and then sets aside so it can be replaced from the food. 
• These are food additives that prevent metal ions from oxidizing fats in foods. Examples are sorbital and phosphoric acid.

Humectants

• Humectants can able to bind moisture and lower water activity. It is a moisture retention agent. 
• It helps to control the viscosity, texture, crystallization, and bulking. 
• The oldest humectants are Honey, salt, and sugar used in food. 
• The four polyols such as sorbitol (E420), Mannitol (E4210), Glycerol- E422 (glycerine), and Propylene glycol (E1520) are used to improve texture and retain moisture in food such as coconut and food products.

Bleaching and maturing agents, starch modifier

• Bleaching and maturing agents are chlorine dioxide, bromate, Iodate, and chlorine used in flour. 
• These chemicals help to reduce the time required for natural aging. In cheese, the bleaching agent is used to impart a white color. 
• Benzoyl peroxide and hydrogen peroxide are used to bleach tripe (meat).

Emulsifiers, stabilizers, gelling agents, and thickeners

• Ingredients are combined with the help of Emulsifiers (Lecithins (E322)). Stabilizers prevent ingredients from separation, e.g., locust bean gum (E410). 
• Emulsifiers and stabilizers provide food with a consistent texture- they can be found in low-fat spreads. It inhibits crystallization. 
• It stabilizes emulsion and foams. It also reduces the stickiness of icings on baked products and encapsulates the flavor. 
• Gelling agents help to improve food consistency, e.g., pectin (E440) used to make jam. Thickeners help give proper structure to food (found in most sauces).

Surface Active Agents

• Lecithin, an emulsifier, is an example of surface active agent. 
• It is added to baked goods, makes the dough easier to work with, and enhances the appearance of bread.

Anti-caking agents, anti-foaming agents

• Anti-caking agents provide mobility or flow of particles from adhering to each other, e.g., in dried milk or table salt. 
• Anti-foaming agents prevent or disperse frothing (bubbles in liquid), e.g., in the production of fruit juices. 
• Silicon dioxide (E551) is an important anti-caking agent. Moreover, Other anti-caking agents contain calcium silicate (E552), sodium aluminosilicate (E554), and dicalcium phosphate (E341). Natural products contain talc, kaolin, potato starch, and microcrystalline cellulose (E460).
• Anti-caking agents listed by their E-numbers are E341 tricalcium phosphate, E460(ii) powdered cellulose, E470b magnesium stearate, E500 sodium bicarbonate, E535 sodium ferrocyanide, E536 potassium ferrocyanide, E538 calcium ferrocyanide, E542 bone phosphate, E550 sodium silicate, E551 silicon dioxide, E552 calcium silicate, E553a magnesium trisilicate, E553b talcum powder, E554 sodium aluminosilicate, E555 potassium aluminum silicate, E556 calcium aluminosilicate, E558 bentonite, E559 aluminum silicate, E570 stearic acid, and E900 polydimethylsiloxane. 
• The permitted anti-caking agents are Calcium Aluminum Silicate, Calcium Phosphate tribasic, Calcium Silicate, Calcium Stearate, Cellulose, Magnesium Carbonate, Magnesium Oxide, Magnesium Silicate, Magnesium Stearate, Microcrystalline Cellulose, Propylene Glycol, Potassium Ferrocyanide, Trihydrate, Silicon Dioxide, Sodium Aluminum Silicate, Sodium Ferrocyanide, decahydrate.

Colors

• It helps to restore color lost during processing or storage, e.g., marrowfat peas. It ensures that each batch produced is similar in appearance or does not appear off. It enhances the color of foods, e.g., the yellowness of a custard. 
• It provides color to foods that otherwise would be colorless (e.g., soft drinks) and makes them more attractive. 
• Some artificial colors, such as sunset yellow (E110), quinoline yellow (E104), carmoisine (E122), Allura red (E129), tartrazine (E102), and ponceau 4R (E124) show a negative impact on children’s behavior. These colors are applied in soft drinks, sweets, and ice cream. 
• According to the Food Standards Agency, These additives should be avoided if a child shows signs of hyperactivity or Attention Deficit Hyperactivity Disorder.

Flavor enhancers

• Flavor enhancers provide flavor in foods without imparting their taste. In processed foods, Monosodium glutamate (E612) is added. Examples are soups, sauces, and sausages. Flavorings are added to foods, usually in small amounts, to give a particular taste. Amyl acetate (for bananas) and Methyl anthranilate (for grapes) are synthetic flavor enhancers.

Acids, bases, and buffers

• They maintain the acidity or alkalinity of food for the safety and stability of flavor.

Glazing agents

• Glazing agents provide a protective layer or sheen on the food surface, e.g., confectionary (for appearance and shelf-life).

Sweeteners

• There are two types of sweeteners: Intense sweeteners and Bulk sweeteners. Saccharin and Aspartame are non-nutritive sweeteners.

Nutrient supplements

• Vitamins, minerals, and amino acids help to improve nutritional quality. It helps to restore the values lost during processing and storage. 
• It provides high nutritional value. Examples are the use of Vitamin C in canned fruits and the use of thiamine, niacin, and iron in cereal products.

Enzyme Preparations

• Enzyme preparations are additives that may or may not end up in the final food product.
• Enzymes are naturally occurring proteins obtained from plants, animal products, or micro-organisms such as bacteria and are used as alternatives to chemical-based technology. 
• It breaks down larger molecules into their smaller building blocks. It stimulates biochemical reactions.
• They are mainly used in baking (to improve the dough), manufacturing fruit juices (to increase yields), winemaking, and brewing (to improve fermentation), as well as in cheese manufacturing (to improve curd formation).

Regulation of Food Additives

• Food and Drug Administration (FDA): It monitors all foods except meat, poultry, and eggs for consumer consumption. It regulates and permits the use of food additives.
• United States Department of Agriculture (USDA): The Food Safety and Inspection Service (FSIS) monitors added growth hormone levels in animals.
• Food, Drug, and Cosmetic Act- 1938: It gives authority to the Food and Drug Administration to regulate food and its ingredients, including proper labeling.
• Food Additives Amendment-1958: Manufacturers must provide evidence of the additive safety and get FDA permission before the additive can be used in foods or food processing.
• GRAS List: According to scientific evidence, approximately 300 additives are (GRAS) Generally Regarded As Safe. 
• Color Additives Amendment: It is necessary to certify colors as safe for usage. Only 30 color additives are approved for safe use.
• Delaney Clause: If additives are found to produce cancer when ingested by man or animals or found to cause cancer in man or animals, they would not be considered safe. Since the improved technology can determine a higher risk of cancer, an FDA-safe additive can now have a one in a million or less cancer risk.
• Food Labeling: Food manufacturers must list all ingredients (including additives) on the label. The arrangement of ingredients should be according to the weight of the ingredients. Labels containing “artificial colors” or “artificial flavors” signify chemically produced colors or flavors, so make informed decisions accordingly.
• International Regulation (under the United Nations): The food and Agriculture Organization (FAO) ensures food security for all peoples and access to plentiful, innocuous food. World Health Organization (WHO) focuses on international leadership on critical health issues and trends.

Introduction of Food Preservatives

Food preservation is the addition of any chemical or substances to the food. Food products can deteriorate due to enzymatic, physical, chemical, or microbiological processes, which lower their quality, safety, and nutritional value and leads to undesirable changes in their physicochemical and sensory properties. 

• Different food preservation techniques have been employed to counteract this problem. So, during food processing, preservatives are one of the food preservation techniques that help to maintain the quality of food and control contamination. 
• It inhibits or retards the undesirable growth of organisms that causes food spoilage. It leads to food poisoning. 
• It increases the shelf-life of products. It keeps the food safe and makes it better for consumption.

Examples of selected preservatives are:

a. Salt, Sugar, vinegar, and pepper

b. Saltpeter or sodium nitrate- meat curing

c. sulfur dioxide (sulfurous acid) and sulfide (inhibit discoloration -of cut fruits and serve as anti-browning agent).

d. Benzoic acid or sodium benzoate (for fruit juice, jellies, margarine, and catsup)

e. Citric and Tartaric acids (provide the acid in syrups, drinks, and jellies for flavor improvement)

f. Alum and soaked lime or apog (such as a firming agent for pickles and fruit preserves).

Types of Food Preservatives

There are two types of preservatives: Natural or Artificial Preservatives.

Natural Preservatives: Natural Preservatives are naturally obtained from a natural source like plants. Examples are sugar, salt, and citric acid made from citrus fruits.

Artificial Preservatives: Artificial Preservatives are man-made preservatives synthesized in a lab. 

Examples are:

• Sodium benzoate- in soft drinks, salad dressings, and canned tuna
• Calcium propionate- in baked goods, processed meats, and dairy products.
• Potassium sorbate- in cheese, wine, and dried meats
• BHA and BHT- used in margarine and potato chips
• TBHQ- used in pasta, cereals, and nuts

They are divided into sub-groups: antimicrobials, antioxidants, and anti-browning agents. 

A. Antimicrobials

• Antimicrobial compounds, either natural or synthetic, can be naturally present in foods or added to inhibit the growth of natural microorganisms (bacteria, yeasts, and molds) and control contamination caused by pathogenic organisms in foods, thus ensuring food safety and quality. 
• Antimicrobials with E and INS numbers ranged from 200 to 290. It extends the shelf life of food. A higher amount of addition of these compounds leads to unpleasant taste, potent odor, altered viscosity, and color retention. 
• Synthetic preservatives are substances of chemical origin that prevent or inhibit the proliferation and growth of bacteria, yeasts, and mold. 
• It has been officially recognized by the regulatory community to be used as food antimicrobials. Inorganic acids and their sodium salts, such as nitrite and sulfate, and weak organic acids, such as benzoic acid, sodium benzoate, sodium propionate, etc., are approved for food applications. 
• Benzoic acid disrupts cell membrane function and inhibits enzymes (molds, yeasts, some bacteria). Propionic acid disrupts cell membrane function (molds, some bacteria).
• Although having beneficial effects, chemical antimicrobials are always controversial. Examples are acetic, benzoic, lactic acids, Malic (E296), fumaric (E297), citric (E330), and other organic acids. Sodium sorbate and parabens are harmful to human health.
• Instead of synthetic preservatives, Natural preservatives are in demand because they are safer for humans and the environment. 
• They are derived from plants, bacteria, fungi, and animals.

The classification of Natural antimicrobials is:

a) Plant-based antimicrobials 

b) Animal and Microbial-based antimicrobials

Plant-based antimicrobials

• Many plant extracts (e.g., herbs and spices) have preservative properties, with antimicrobial activity against various microorganisms that depend on the type, nature, and concentration, and can increase the storage life of foods. 
• Plant-based antimicrobials include essential oils, phenolic compounds, polypeptides, lectins, alkaloids, polyamines, organic acids, glycosides, and glucosinolates.
• Essential oils (EO), bioactive and complex liquid volatile compounds, are produced by aromatic plants. So, In the food industry, it is used as a flavoring agent. It acts as a natural antioxidants and antimicrobial in food preservation.

Animal and Microbial-based antimicrobials

They are isolated from natural sources such as plants, insects, amphibians, crustaceans, and marine organisms. Animal-based antimicrobials of origin are Lysozyme, lactoferrin, ovotransferrin, pleurocidin, defensins, chitosan, etc. 

• Lysozyme- Lysozyme is an enzyme used as a preservative in meat, fish, milk, dairy products, fruits and vegetables. 
• Lactoferrin- Lactoferrin is found in milk and other secretions. It has iron-binding capacity. 
• Cathledicin- Cathledicin is present in mammals and shows activity against bacteria, fungi, and viruses.
• Lactic acid bacteria: LAB generates antibacterial compounds such as bacteriocins, organic acids, reuterin, diacetyl, ethanol, CO2, H2O2, and lactic acid derivatives. Lactic acid bacteria (LAB) have been used as cultures to produce fermented products such as sausages, cheeses, or yogurts.
• Bacteriocins: Bacteriocins are ribosomally synthesized antimicrobial peptides having bactericidal or bacteriostatic effects. Bacteriocins used in food like preservation of meat and vegetable products are synthesized by strains of Carnobacterium, Lactococcus, Lactobacillus, Pediococcus, Leuconostoc, and Propionibacterium and the major bacteriocins include nisin, pediocin, diplococcin, plantaricin, acetylphilin, helveticin, bulgarican, and lactacin. Nisin, an antimicrobial peptide, is the only bacteriocin naturally synthesized by Lactococcus lactis. It disrupts cell membrane function (gram-positive bacteria, lactic acid-producing bacteria). It is the only bacteriocin recommended for global application as an additive in the food industry with GRAS (generally recognized as safe) status. It has excellent antibacterial properties.

B. Antioxidants

• Antioxidants (INS 300-326 and E300-E326) prevent autoxidation and preserve dry and frozen foods.
• During the storage process, two types of oxidations occur in foods. They are lipid peroxidation and rancidification.

Lipid peroxidation

• Lipid peroxidation is a process under which oxidants such as free radicals or non-radical species attack lipids containing carbon-carbon double bonds (polyunsaturated fatty acids (PUFAs)). 
• It involves hydrogen abstraction from carbon, with oxygen insertion resulting in lipid peroxyl radicals and hydroperoxides. The lipid peroxidation process includes initiation, propagation, and termination.

Rancidification

• Rancidity refers to ‘off’ odors and flavors resulting from lipid oxidation or lipolysis (breakdown of oils chemically or by lipase into constituent fatty acids), which occur during storage. 
• When fats and oils are exposed to air, light, moisture, and bacteria, it leads to hydrolysis or oxidation that causes food items unfit for consumption. Rancidity occurs in three steps: initiation reaction, propagation reaction, and termination reaction.

There are two types of rancidity: 

Oxidative Rancidity: 

• Oxidative rancidity is a reaction caused by fat Oxidation. The chemical reaction is catalyzed by heat, ultraviolet light, heavy metals, and oxygen. It forms toxic compounds like peroxides, which can destroy vitamins A and E in foods by causing oxygen damage. 
• Oxidative rancidity of oils and fats such as lard, shortenings, and cooking oils refers to the unwanted odors and flavors that accumulate over time when exposed to the oxygen in the air.

Hydrolytic Rancidity

• Hydrolytic rancidity leads to an unpleasant odor due to the release of free fatty acids from glycerides, which is unsuitable for consumption. It is caused by fat hydrolysis. 
• Triglycerides are a combination of three fatty acids- that undergo oxidative rancidification-present in oil foods.

Antioxidants help to scavenge free radicals and oxygen, stopping peroxidation at the initiation or propagation stages. Therefore, the shelf life of foods increases. It inhibits oxidation of fatty acids, BHA (E320) and BHT (E221).

BHA is used in animal fats than in vegetable fats for foods and coatings. BHT is used in animal fats and dry breakfast cereals. Both of them are pernicious to human health. 

Gallate compounds (E310–E312) are used alone or in combination with BHT and BHA and can be used in dried milk, fats, oils, nut butter, potato products, chewing gums, cereals, meats, nuts, and food supplements. 

EFSA-approved other chemical antioxidants, such as ascorbic acid and derivatives (E300–E304)- dairy products, chewing gums, cereals, meats, desserts, salads, sauces, and others, EDTA (E385), erythorbic acid (E315), sodium erythorbate (E316), citrates (E330–E380), lactates (E325–E327), and tartrates (E334–E354).

• ascorbic acid- oxygen scavenger
• butylated hydroxyanisole (BHA)- free radical scavenger
• Butylated hydroxytoluene (BHT)- free radical scavenger
• citric acid- enzyme inhibitor/metal chelator
• sulfites- enzyme inhibitor/oxygen scavenger
• tertiary butylhydroquinone (TBHQ)- free radical scavenger
• Tocopherols- free radical scavenger

Applications of Antioxidants

• Calcium ascorbate (E302): It prevents browning in dip freshly cut fruit. Examples are dairy, and cured or cooked meat products. 
• Potassium citrate (E332) and calcium citrate (E333): It helps to change intense flavors. Examples are Jellies, marmalades, pH buffers, sequestrants, antioxidants, and cheese.  
• Tartaric acid (E334) and its derivatives, sodium (E335), potassium (E336), and calcium (E336) salts: chocolates, marmalades, gelatins, canned food, and fresh pasta, as well as in cheeses, fats, oils, meats, and sausages 
• Phosphoric acid (E338) and its salts synergize with citric acid (to prevent fat oxidation) in soft drinks, fruit jellies, cheese, and yeast powders.
• Sodium phosphate (E339): Examples are Pasta, meat, powdered milk, fruit, cheese, snacks, and ready-made desserts. It has chelating and antimicrobial effects, enhanced by synergy with nisin.
• Potassium phosphate (E340): Meats, bread, pasta, powdered juices, eggs, pasta, and sausages 
• Calcium phosphate (E341): Baking industry, fruit preserves, powdered juice flour, cheese, and porridge
• Ammonium phosphate (E342) and magnesium phosphate (E343): Bread, pasta, cookies, and pancakes
• Adipic acid and its salts: Cheeses, jellies, and canned fruit
• Succinic acid: Chicken meat, dairy products, and cooked foods
• Calcium disodium EDTA (E385): Poultry, processed meats, vegetables, fruits and juices, and beer
• Rosemary extract- Natural antioxidant

C. Anti-browning Agents

Anti-browning agents prevent enzymatic and non-enzymatic browning in food products, such as dried fruits and vegetables.

Enzymatic Browning

Enzymatic browning occurs due to the oxidation of polyphenols to quinones, catalyzed by the enzyme polyphenol oxidase (also known as PPO, tyrosinase, o-diphenol oxidase, and catechol oxidase). Then, polymerization of the quinones occurs. These enzymes cause the browning. This discoloration generally occurs in raw fruit and vegetable products rather than blanched or thermally processed products. They are present in nature, like fungi, bacteria, and higher plants (mushrooms, apples, potatoes, pear, bananas, peach, and avocado).

Enzymatic browning occurs from physiological injury, senescence, pre- or postharvest bruising, fruit disruption or vegetable flesh by peeling, coring, slicing, or juicing, tissue disruption from freeze-thaw cycling, and tissue disruption by bacterial growth. 

When phenolic compounds and oxygen come in contact with each other, an enzymatic browning reaction gets triggered. Mechanical injuries and tissue damage decrease the plant cell membrane integrity and thereby cause the improvement of the brown color produced.

The enzymatic browning in fruit and vegetable products can happen due to the loss of ascorbic acid (vitamin C) through a reaction with quinones. Blanching is used to control enzymatic browning.

Non-enzymatic Browning

Non-enzymatic browning reactions may result from the classic Maillard reaction between carbonyl and free amino groups, i.e., reducing sugars and amino acids. 

It produces melanoidin pigments in foods (dairy, cereal, fruit, and vegetable products). 

Due to heat and prolonged storage, discolorations generally occur in food products. Non-enzymatic browning can be controlled by avoiding excessive heat exposure, regulating moisture content in dehydrated products, and using sulfites.

In the food industry, the Browning of food is a concern in the various stages of food production. The cut fruits and vegetables get exposed to oxygen, which results in enzymatic browning. The most common additives are vitamin C (E300), citric acid (E330), and sodium sulfite (E221). Sulfites control enzymatic and non-enzymatic browning, suppression of microbial growth, and bleaching; however, it is unhealthy for human health.

Ascorbic acid (vitamin C) has been used as an antibrowning agent, an alternative to sulfiting agents. Another alternative to sulfite is Kojic acid [5-hydroxy-2-(hydroxymethyl)-γ-pyrone]. The U.S. Food and Drug Administration has banned sulfite usage in certain raw fruit and vegetable products. 

Examples are:

• a. Erythorbic acid (E315), used in beverages for flavor preservation.
• b. 4-hexylresorcinol (E586), an organic compound allowed only in shrimp.
• c. Calcium lactate- inhibits the browning of foods, especially fruits, by maintaining their structure.
• d. Ascorbic acid (Vitamin C- E300), an anti-oxidant, helps to keep fruit from darkening.

Common food preservation techniques

The common food preservation techniques are:

a. Refrigeration

b. freezing

c. drying and curing

d. Vacuum and oxygen-free modified atmosphere packaging

e. Lactic fermentation

f. sugar preservation

g. Ethanol preservation

h. Addition of weak acids such as sodium lactate

i. Carbon dioxide-enriched atmosphere packaging

j. Emulsification

k. Pasteurization

l. Food irradiation

m. Addition of preservatives such as nitrite or sulfite ions

n. Application of high hydrostatic pressure

o. Pulse electric field processing

References

1. Leek, T. K. V. (2023). Food additives and reactions: Part 2: Antioxidants, benzoates, parabens, colorants, flavorings, natural protein-based additives. In Elsevier eBooks. https://doi.org/10.1016/b978-0-323-96018-2.00049-3
2. Krishnan, P. S. (2017, October 5). Food additives and preservatives [Slide show]. SlideShare. https://www.slideshare.net/PopurisaiKrishnan/food-additives-and-preservatives
3. Malacas, B. A. (2012, July 29). Food additives ppt [Slide show]. SlideShare. https://www.slideshare.net/slideshow/food-additives-ppt/13790666
4. Anand, A. (2019, March 19). Food additives and preservatives [Slide show]. SlideShare. https://www.slideshare.net/slideshow/food-additives-and-preservatives-137143681/137143681
5. Enhancers, D. (n.d.). FOOD ADDITIVES. https://slideplayer.com/slide/12556625/
6. Sandman. (2022, February 16). What are humectants in foods? The Food Untold. https://thefooduntold.com/food-additives/what-are-humectants-in-foods/
7. World Health Organization: WHO. (2023, November 16). Food additives. https://www.who.int/news-room/fact-sheets/detail/food-additives
8. Garone, S. (2024, September 13). The impact of food additives on health: What you need to know. EverydayHealth.com. https://www.everydayhealth.com/diet-nutrition/how-safe-are-food-preservatives/
9. Novais, C., Molina, A. K., Abreu, R. M. V., Santo-Buelga, C., Ferreira, I. C. F. R., Pereira, C., & Barros, L. (2022). Natural Food Colorants and Preservatives: a review, a demand, and a challenge. Journal of Agricultural and Food Chemistry, 70(9), 2789–2805. https://doi.org/10.1021/acs.jafc.1c07533
10. Davidson, P. M., & Singh, R. P. (2024, September 26). Food additive | Definition, Types, Uses, & Facts. Encyclopedia Britannica. https://www.britannica.com/topic/food-additive/Preservatives
11. Ayala, A., Muñoz, M. F., & Argüelles, S. (2014). Lipid peroxidation: production, metabolism, and signaling mechanisms of malondialdehyde and 4-Hydroxy-2-Nonenal. Oxidative Medicine and Cellular Longevity, 2014, 1–31. https://doi.org/10.1155/2014/360438
12. Anand, J. (2024, March 11). What is rancidity? ScienceABC. https://www.scienceabc.com/pure-sciences/what-is-rancidity.html
13. Preserving color and preventing browning of foods. (n.d.). https://extension.psu.edu/preserving-color-and-preventing-browning-of-foods
14. Petric, D. (2018, May 23). Types of food additives [Slide show]. SlideShare. https://www.slideshare.net/slideshow/types-of-food-additives/98273425
15. Anti-browning/Bleaching agents and anti-caking or free-flow agents for the food industry. (n.d.). https://epgp.inflibnet.ac.in/epgpdata/uploads/epgp_content/Food_Technology/Food_Additives/17.Anti-browning/bleaching__agents_and_anti-caking_or__free-flow_agents_for_the_food__industry/et/2692_et_m17.pdf.
16. Hamdan, N., Lee, C. H., Wong, S. L., Fauzi, C. E. N. C. A., Zamri, N. M. A., & Lee, T. H. (2022). Prevention of Enzymatic Browning by Natural Extracts and Genome-Editing: A review on Recent progress. Molecules, 27(3), 1101. https://doi.org/10.3390/molecules27031101
17. ShaikhSaniya. (2019, July 24). Food preservatives [Slide show]. SlideShare. https://www.slideshare.net/slideshow/food-preservatives-157541752/157541752