Food preservation using chemicals

Traditional food preservation techniques have undesirable effects on the appeal of fresh products and artificial preservatives are increasingly being banned. The practice of preserving food by the addition of chemical is quite old, and ordinary table salt (sodium chloride) has been used as a preservative for centuries.

It might be surprising to think of naturally occurring substance as a chemical preservative, but it will be seen that many chemicals substance use in the preservation of foods occur naturally.

When they are used with the proper intend, they can be used to preserve foods that cannot be easily preserved by other means.

They should not be used as a substitute for sanitation and proper handling procedures. Sometimes chemicals are used together with other processes, such as holding at refrigerator temperatures above freezing.

Chemicals preservatives such as sorbate, benzoate, etc, have been used as reliable preservative factors to control a number of micobial hazards, However, such compounds do not satisfy the concept of ‘natural’ and ‘healthy’ food consumers prefer and that the food industry, consequently needs to manufacture.
Food preservation using chemicals

Sulfur dioxide as food additive

Sulfur dioxide has been used since olden times in the form of 1-2% aqueous solutions as a disinfectant for equipment, barrels, bottles, corks and other ancillary items for the wine, drinks and food industries.

Fumes of burning sulfur were used as a sanitizing agent in wine-making by the ancient Egyptians and Romans. The practice is continued by the modern wine industry.

The compound is a colorless, nonflammable gas or liquid under pressure, with a suffocating, pungent odor.

Sulfur dioxide is used to prevent browning in certain dried fruits and to prevent wild yeast growth in wines used to make vinegar.

Sulfur dioxide also is used to control the growth of undesirable microorganism in soft fruits, fruit juices, wines, sausages, fresh shrimp, and acid pickles and using extraction of starches.

It is added to expressed grape juices used for making wines to inhibit molds, bacteria, and undesirable yeasts.

The most obvious drawback of sulfur dioxide is its intense pungent odor, which may be apparent in foods it is used to treat.
Sulfur dioxide as food additive

The advantages of using food irradiation

*Food radiation is an alternative to fumigation of food. Irradiation has been demonstrated as an effective alternative to the fumigants. Unlike fumigation, irradiation does not leave any residues in the products.

*A method to ensure hygienic quality of solid food.

*Improve public health

*Increased confidence in irradiated foods.  Food irradiation is particularly effective in controlling foodborne spoilage microorganisms and decontaminates food form pathogenic bacteria, yeast, molds and insects. This decontamination can improve the hygienic quality of the food and prevent potential health hazards and thus improve public health concerns.

*Reduce shrink and minimal food losses. It is significantly reduced ‘in-system’ physical losses or ‘shrink’ experienced whenever a product with improved shelf life improved. Disinfestations and shelf-life extension improvements provided by irradiation can be used to control and minimize the post-harvest losses caused by insect infestation in grain, pulses and fruits. This point is more important for the developing countries where the losses during the post-harvest stage are high.

*Increase energy savings

*Greater international trade

*Reduced government inspection. The government, itself under public pressure to reduce the incidents of foodborne disease will be reluctant to diminish its inspection function unless it is confident that adequate procedures are in place. Irradiation thus has the desirable effect of reducing unwanted and government interference in the operation of manufacturers and processors.
The advantages of using food irradiation

Vinegar as food additive

Vinegar of acetic acid is a colorless, waterlike liquid that has a piercingly sharp, vinegary odor and a burning taste.

In United States vinegar and acetic acid are generally recognized as safe for use in foods and are classified as GRAS under the Federal Regulations.

Some countries outside specially exclude vinegar from the categories of food additives and preservatives and it is considered to be a food ingredient.

Vinegar, its dilute aqueous solution, has been used since the earliest recorded human history. Vinegar made from palm wine was known in the East as long as 5000 BC.

Vinegars are produced from cider, grapes, sucrose, glucose or malt by successive alcoholic and acetous fermentation.

Nowadays acetic acid continues to occupy a firm place in food preservation and in some countries synthetic acetic acid has acquired considerable importance alongside vinegar produced by fermentation. Vinegar is used as an acidifier, flavor enhancer, boiler water additive, flavoring agent, pH control agent, pickling agent, solvent and for its antimicrobial properties.
Vinegar as food additive

Gum karaya

It is the dried exudate from the tree, Sterculia urens, tall bushy tree, native to India, where it grows in forests of the eastern and central mountains.  

Chemically, karaya is a complex, particular acetylated polysaccharide with an extremely high molecular weight, consisting of L-rhamnose, D-galactose, and D-galacturonic acid.

Food grade gum is usually a white to pinkish-gray powder. The gum has a high acetyl content and has a tendency of splitting off free acetic acid on aging, the rate of splitting depending on temperature, humidity and particle size.

Gum karaya absorbs water to form viscous colloidal sols. The particle size of the powder determines the types of dispersion.

Gum karaya is the least soluble gum exudate; it is used in foods as a thickening and suspending agent and as a stabilizer in salad dressing, ice cream, sherbets and frozen desserts, in which prevents the formation of large ice crystals.

Gum karaya is also used in cheese spread, sausages, and bakery products sometimes in combination with carrageenan.

Other usages of gum karaya are:
*protective colloid: stabilizer, viscosity control agent, thickener, emulsifier in cosmetics, pharmaceuticals;
*Thickener for textile dyes
*Binder for pulp in the preparation of long fibered, lightweight papers
*Textile coating, denture adhesive, binder in paper manufacturing
*Pharmaceutical (tablet excipient, bulk laxative)
*Substitute for gum tragacanth
Gum karaya

Xanthan gum in food

Xanthan gum is widely used in food applications, but it also extensively used in pharmaceutical, cosmetic and other technical application.

Following its approval as a food additive, xanthan gum found man uses in the food industry, since at low concentrations it provides storage stability, water-binding capacity and esthetic appeal.

Xanthan gum is an anionic branched polyelectrolyte. The backbone consists of α (1-4) D-glucopyranose glucan.

The unique physical and physiological properties of xanthan gum make it one of the most versatile hydrocolloids for use in a host of food.

These properties result in products with longer shelf life, improved flow, consistently, viscosity, better texture and a pleasing appearance.

It is used as a stabilizer for dressings. Ideally the product has high yield value and strong pseudoplasticity.

In syrup and toppings, the rheological properties of xanthan gum provide ease of pouring and excellent cling.

The uniform viscosity of xanthan from 5 to 70° also helps yield a uniform texture and good stability. Xanthan gum can be used to control the rheological properties of mayonnaise.

In chocolate syrups, the cocoa powder remains uniformly suspended, eliminating settling and ensuring consistency.

The xanthan gum also used in sauces, relishes, canned soups and dairy product. Its heat stability and excellent stabilizing and suspension properties are important in canned foods. Typically, xanthan gum is used in fruit juices to help to suspend the fruit particles, to prevent oil ringing and to provide good viscosity without masking the natural flavor of the fruit.

In gravy or sauces, xanthan gum binds the water so strongly that it helps to delay the formation of a surface skin.
Xanthan gum in food 

Food Additives as Preservatives and Appearance Additives

Food Additives as Preservatives and Appearance Additives
Preservatives are added to food substance to slow spoilage and deterioration. Some sources estimate that there are about 100 common preservatives being used by the food industry.

Preservatives are specific to the food being preserved; antioxidants are used in fatty products, for example, while breads often have “mold inhibitors.”

Other common multipurpose preservatives are familiar ingredients such as salt, sugar and vinegar. All of these extend the shelf life of food products and reduce the risk of food related disease.

Some preservation techniques , such as irradiated food, aseptic processing and microwave pasteurization, reduce the need for conventional food additives used to reduce spoilage, but their safety is sometimes debated.

Appearance additives include texturizers, coloring agents and flavorings. These additives enhance the look, mouthfeel or taste of foods without changing other characteristics.

Texturizers are put into food products to maintain a desired texture, and sodium nitrate is used to develop and stabilize the pink color in meats.

Coloring agents are used to increase attractiveness of food to consumers; foods that are frequently colored include candy, soft drinks and diary products such as butter, cheese, and cream.

Flavoring additives are the most common type of additive approved for human consumption. If the roughly 3,000 additives approved, about 2,000 are flavorings used to replace the flavors lost during processing.

Hence, this category of additives used mainly to appeal to user tastes and to enhance purchasing of the target food product.
Food Additives as Preservatives and Appearance Additives

Legal Background History of Food Additives

Legal Background History of Food Additives
As with many other elements used in food processing, additives originate very early in human history, For example, people learned in prehistoric times that adding salt to meat would preserve it.

Likewise, smoke which also acts as a preservative might considered an early food additive. Overtime, additives have come to thoroughly influence our eating habits, our taste preferences, and our socio-cultural development.

The earliest legislation controlling the use of food additives took place in Britain in the 19th century, following the work of Frederick Accum, though its original impetus was the prevention of food adulteration.

In the United States, the Food and Drug Administration (FDA) oversees the regulation of ingredients that can be added to food.

It was not until 1958 that registration was adopted requiring food and chemical manufacturers to test their additives before they were submitted to the FDA.

Before the law, the FDA itself was responsible for testing the submitted additive. Thereafter, Congress established a Generally Recognized as Safe (GRAS) list.

This list recognized that many substances that had been added to food for along time were commonly seen as safe by qualified scientists, which exempted them from premarket clearance.

This list was revised in 1969 and as of 1980 contained 415 substances that were originally included in the 1958 project. Today, manufacturers are responsible for demonstrating their GRAS status and providing evidence (such as scientific literature) to support it.

Approximately 100 new substances are presented to the FDA for GRAS certification every year.

Also included in 1958 law was an amendment called the Delaney Act; it stipulated that “no additives may be permitted in any amount of the tests show that it produces cancer when fed to man or animals by other appropriate test.”

Many manufacturers, as well as some FDA commissioners, have criticized this amendment as being unenforceable.

Instead, in 2003, the FDA adopted a “no residue” clause; this clause provided that the FDA could approve an animal feed additive or drug that induces cancer if there is “no residue” of the additive found after slaughter.

The FDA maintains that the risk is slight or nonexistence of humans consume meat or drink milk from an animal with a minuscule amount of a carcinogen present.
History of Food Additives and History of Legal Background

What is Food Additive?

What is Food Additive?
The broadest definition of a food additive is any substance that becomes part of a food product, either directly or indirectly, during some phase of processing, storage or packaging.

The universe of food additives encompasses:
Direct Food Additives
Direct food additives, these that rare intentionally added to food for a functional purpose, in controlled amounts, usually at low levels (from parts per million to 1-2%, by weight.)

Indirect Food Addictive
Indirect or incidental food additives, those entering into food products in small quantities as a result of growing or packaging.

The difference between food ingredients and additives is mainly in the quantity used in any given formulation.

Food ingredients can be consumed alone as food (e.g., sucrose), whole food additive are used in small quantities (usually less than 2%) relative to the total food composition but which nonetheless play a large part in the production of desirable and safe food products.

Food additives may be looked upon as minor ingredients incorporated into foods to affect their properties in some desired way.

Most commonly, the effects desired relate to color, flavor texture nutritive value, or stability on storage.

There is no rigorous definition that meets all needs.

The Codex Alimentarius, which dominates actions in international circles, considers an additive as a ingredient “not normally consumed as a food by itself and normally used as a typical ingredient.”
What is Food Additive?

Food Additives in general

Food Additives in general
Food additives are used as anti-microbial agents, to reduce physical and chemical spoilage and to aid processing.

Their use is as old as cookery. Salting and smoking as preservation techniques and the addition of spices and sweeteners to make food more palatable and introduce a greater variety into eating have been used since prehistoric times.

It was during the nineteenth century that the use of food additives proliferated enormously and many of them were highly reprehensible.

Red lead was used to color sweets, alum and copper sulphate to ‘improve’ bread, ground beech leaves to adulterate tea and bone meal to whiten flour.

Today, effective methods of detection and more or less strict food legislation prevent the more glaring transgression in many countries.

Nevertheless, just as the aim of the politician is to attain power, the purpose of business is to make money and for many the temptation to break the law is too great.

A hundred years ago, some manufacturers were prosecuted for cheapening spice with starch of groundnut shells.

Today, some are prosecuted for adding excessive amounts of soya protein to meat products.

The increase use of synthetic food additives also poses health problems but these must be seem in proper perspective.

Some toxins are present in very small amounts but others in such quality that, if they were an ingredient in a new food additive, it would almost certainly be prohibited.

Also, a large number of other toxins have been isolated from seafood and fungi.

Food additives actually are essential to modern living. Without them the world’s population could not be fed adequately and the range and palatability of food could not be maintained.
Food Additives in general

Risks of Food Additive

Risks of Food Additive
Food additives, especially vitamins and minerals the quantity added to a finished food product may not be sufficient to achieve an intended health benefit.

Some foods that are commonly consumed by the majority of the population may be supplemented with various vitamins or minerals.

A single serving of a fortified food may not provide the same health benefit as regular consumption of a fortified food.

For example, iodine is added to table salt to provide a regular source of this important mineral.

Table salt is regularly consumed by most Americans, and iodine is often lacking in typical diets.

The determination of a beneficial, yet safe, quality of iodine to add to table s at must consider the typical consumption of salt over the lifetime of the consumer.

While food additive may provide a benefit to a processor or a consumer when used as intended, the use of an inappropriate quantity may be deleterious to the food or to the consumer.

If an additive is used in excess to process a product, then the desired effect may not be achieved, or else there may be an undesirable quality defect attributed to the product.

For example, of an artificial sweetener such as aspartame is added to a beverage in a high concentration, then the product may be too sweet and rejected by the consumers.

Or an excessively high concentration of a chemical additive may lead to an acute illness or injury to the consumer, such as can occur with sulfiting agents.

People who are sensitive to additive s containing sulfur, especially those with asthma, are at a greater risk to suffer am allergic reaction to high levels of sulfites.

Safety determination of additive use should consider the effects of accidental or intentional consumption of a high quantity of an additive that is beyond its prescribed used level.

Also additive may be injuries to health when consumed in moderate doses over extended time periods.

When the risks or benefits of food additive use are considered, estimation must be made of the long term or lifetime consumption of the additive.

These substances may have cumulative effects in health may interact with other biological or chemical compounds in the body, or may elicit different responses in consumers of different ages or health status.
Risks of Food Additive

Food Additive in General

Food Additive in General
A food additive is a substance (or a mixture of substance) which is added to food and is involved in its production, processing, packaging and/or storage without being a major ingredient.

Additives or their degradation products generally remain in food, but in some case they may be removed during processing.

The following examples illustrate and support the use of additives to enhance the:

Nutritive Value of food
Additive such as vitamins, minerals, amino acids and amino acids derivatives are utilized to increase the nutritive value of food. A particular diet may also require the use of thickening agents, emulsifiers, sweeteners, etc.

Sensory Value of Food
Color, odor, taste and consistency or texture, which are important for the sensory value of food, may decreases during processing and storage. Such decreases can be corrected or readjusted by additives such as pigment aroma compounds or flavor enhancers.
Development of “off flavor” for instance, derived from fat or oil oxidation, can be suppressed by antioxidants. Food texture can be stabilized by adding minerals or polysaccharides, and by many other means.

Shelf Life of Food
The current forms of food production and distribution, as well as the trend towards convenient foods, have increased the demand for longer shelf life. Furthermore, the world food supply situation requires preservation by avoiding deterioration as much as possible.
The extension of shelf life involves protection against microbial spoilage, for example, by using anti-microbial additives and by using active agents which suppress and retard undesired chemical and physical changes in food.
The latter is achieved by stabilization of pH using buffering additives or stabilization of texture with thickening or gelling agents which are polysaccharides.

It is implicitly understood that food additives and their degradation products should be non toxic at their recommend levels of use. This applies equally to acute and to chronic toxicity, particularly the potential carcinogenic, teratogenic (causing a malformed fetus) and mutagenic (causing a malformed fetus) and mutagenic effects.

It is generally recognized that additives are applied only when required for then nutritive or sensory value of food, or for its processing or handling.
Food Additive in General

Flavoring Agents

Flavoring Agents
Flavoring agents are the largest single group of food additives. Food and beverage applications of flavors include dairy, fruit, nut, seafood, spice blends, vegetables and wine flavoring agents. They may complement, magnify, or modify the taste and aroma of the foods.

There are over 1200 different flavoring agents used in foods to create flavor or replenish flavors lost or diminished in processing, and hundreds of chemicals may be used to simulate nature flavors. Alcohols, esters, aldehydes, ketones, protein hydrolysates and MSG are examples of flavoring agents.

Natural flavoring substances are extracted from plants, herbs and spices, animals, or microbial fermentations. They also include essential oils and oleoresins (created by solvent extract with solvent removed), herbs, spices and sweetness.

Synthetic flavoring agents are chemically similar to natural flavorings, and offer increased consistency in use and availability. They may be less expensive and more readily available than the natural counterpart although they may not adequately simulate the natural flavor. Some examples of synthetic flavoring agents include amyl acetate, used as banana flavoring benzaldehyde, used to create cherry or almond flavor, ethyl butyrate for pineapple, methyl anthranilate for grape, methyl salicylate for wintergreen flavor, and fumaric acid, which is an ideal source of tartness and acidity in dry foods.

Flavor enhancers such as monosodium glutamate (MSG) intensify or “bring out,” enhance or supplement the flavor of other compounds in food; they have a taste outside of the basic sweet, sour, salty or bitter. Monosodium glutamate was chemically derived from seaweed in the early 1900s, but is manufactured commercially by the fermentation of starch, molasses, or sugar.
Flavoring Agents

Coloring Agents as Food Additive

Coloring Agents as Food Additive
A color additive is any die, pigment, or substance that imparts color when added or applied to a food, drug, cosmetic, or human body. The term “FD&C” is applied to ‘food color additive’ approved by the FDA for food, drug and cosmetic usage, “D&C” is used for approved ‘drug and cosmetic coloring agents’, and “external D&C” is granted to approved ‘color additive applied externally.’ The synthetic coloring agents are assigned FD&C classifications by initials, the shade and a number, for example, FD&C Red#40, and FD&C Yellow #5.

Coloring agents are added to foods because of the sensory appeal they provide, for the purpose of making processed foods look more appetizing. For example, colors are used in baked products, candies, dairy products such as butter, margarine and ice cream, gelatin desserts, jams and jellies in order to improve their appearance. It has been said that people “eat with their eyes” as well as their plates.

There are thousands of foods that use colors to maker them looks appetizing and attractive. The primary reasons for adding coloring agents include the following:

• Offsetting color loss due to exposure to air, light, moisture and storage
• To correct natural variations in color or enhance color
• To provide visual appeal to wholesome and nutritious foods
• To provide color to foods that would otherwise be colorless, including “fun foods” and special foods for various holidays
  

Pigment may be derived from natural sources such as plant, mineral or animal sources primarily the former. Some of the same ingredients added to foods for their health benefits, also offer “natural” coloring. These includes anthocyanins, carotenoids, chlorophylls, foods such as beets (betalains), cabbage, tomatoes (lycopene), and number of other flowers, fruits and vegetables.

Synthetic coloring agents are generally less expensive than the natural colorants, are more intense, and have better coloring power, uniformity, and stability when exposed to environmental conditions such as heat and light. They may be water soluble or made water insoluble by the addition of aluminum hydroxide. Only small quantities of granules, a paste, a power or solution are needed in foods to achieve the desired color effects.
Coloring Agents as Food Additive

Food Additive: Acidulants

Food Additive: Acidulants
From the root word, acid, in acidulants, one can conclude that this class of compounds tends to lower pH of any food in which the compounds are incorporated. They also enhance desirable flavors, and in many cases, such as in pickled products, are the major taste component. Vinegar (acetic acid) is added to relishes, chili sauce, ketchup and condiments as a flavor component and to aid in the preservation of these products. Since the microbial spoilage of food is inhibited as the pH of a food is lowered, acidulants are used for that purpose in many cases. Many acidulants occur naturally in foods (e.g., citric acid in citrus fruits, malic acid in apples, acetic acid – the major component of vinegar). Tartaric acid is widely used to lend tartness and enhance flavor. Citric acid is widely used in carbonated soft drinks. Phosphoric acid is one of the very few inorganic acids used as an acidulants in foods. Citric acid accounts for 60% of all acidulants used in foods.

In addition to their preservative and flavor enhancing effects, acidulants are used to improve gelling properties and texture. Acidulants are also used as cleaners of dairy equipment.

Acidulants may be used in the manufacturer of processed cheese and cheese spread for the purpose of emulsifications as well as to provide a desirable tartness.

Acid salts may be added to soft drinks to provide a buffering action to prevent excess tartness. In some cases, acid salts are used to inhibit mold growth.
Food Additive: Acidulants

Flavoring as Food Additive

Flavoring as Food Additive
Flavorings are compound, many of which are natural, although there are also many synthetic ones that are added to foods to produce flavors or to modify existing flavors. In early days of human existence, salt, sugar, vinegar, herbs, spices, smoke, honey and berries were added to foods to improve their taste or to produce a special, desirable taste.

The range of natural and synthetic flavoring available to the modern food technology is very large. Essential oils form a major source of flavorings. Essential oils are odorous component of plants and plant material that are characteristic odors of the material from which they are extracted, because of the large production of orange juice, quantities of essential oil or orange are produced as by products. For this reason there is little need for the production of synthetic orange flavoring.

Fruits extract have been used as flavorings, but these are relatively weak when compared to essential oils and oleoresins. An oleoresin is a solvent extract of spices from which the solvent, usually a hydrocarbon, has been removed by distillation. Because of their weak effects, fruit extracts may be intensified by combining them with other flavorings.
Flavoring as Food Additive

Nutrients Additive

Nutrients Additive
The need for a balanced and ample nutrient intake by the human body is well known. Although nutrients are available in foods, losses of fractional amounts of some of them through processing, and increasing frequencies of improper dieting, have led to the practice of adding minimum daily requirements nutrients to popular foods, such as breakfast cereals, baked goods, pasta products, and low calorie breakfast drinks. Nutrients additives include mainly vitamins, proteins, and minerals.

Vitamin D is an exceptional example of the value of the food additive concept. The major source of vitamin D for human lies in the existence of a precursor compound lying just under the skin that converts to the vitamin form when we are exposed to the radiant energy of the sun. However, in many cases, exposure to the sun is sporadic and insufficient, especially in areas where there is normally insufficient sunshine or in cases where outdoor activities are of sufficient duration. Thus, vitamin D is added to nearly all commercial milk in a ration of 400 U.S.P units per qt (0.95).

The additive of protein concentrate to components of diet of inhabitants of underdeveloped countries has been used successfully to remedy the high incidence of protein malnutrition. It should be noted that soybean is incomplete and requires the addition of some amino acids in which it is deficient. Children, especially, succumb in large numbers to the disease, kwashiorkor that results from insufficient protein intake.

Among minerals, iron has received major attention as a food additive, mainly because of its role in preventing certain anemias.
Nutrients Additive