Food Hygiene Silver and H2O2 – Agents for Food Hygiene

Author / Editor: Dev Gupta / Dominik Stephan

Although, many methods are used for reducing the number of microorganisms from food and food products by using both physical and chemical principles, success of any such preservation method is greatly influenced by effective, efficient and ecological plant sanitation methods.

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(Picture: Sanosil)
(Picture: Sanosil)

Microbial contamination and pollution plays a significant role in food, beverage, dairy, breweries and other food processing industries. Micro-organisms are associated in a variety of ways with food and food processing operations followed in industries. The degree of contamination, type, their numbers and source of their entry during different operations in industries significantly influence the quality, availability and quantity of food and food products consumed by mankind.

Naturally occurring foods – such as fruits, vegetables, cereal, milk and related types – normally contain micro-organisms known as Normal Flora and may be further contaminated with additional micro-organisms during handling and processes. Spoilage and failures of preservation are mainly attributed to micro-organisms and their ability to grow in food and food products, as those serve as ideal media for their growth and proliferation. Food may also carry pathogenic micro-organisms and transmit diseases. Toxic compounds formed in food and food products, as a result of heavy growth of micro-organisms, often results into food intoxication disorders after consumption.


Microorganisms: Friends and Enemies

Micro-organisms are versatile in their metabolisms, and thus are used in various industrial applications. Various fermented food products, dairy products, beverages, beer, wine etc., are manufactured by food industries making use of industrially important microbial strains belonging to bacteria, yeast and fungi. How friendly are Saccharomyces cerevisiae and Lactobacillus species to us – are very well known facts to mankind.

Scientists and food technologists are continuously working towards manufacture of fermented food products under absolute hygienic conditions, making use of these beneficial microorganisms. Any contamination during such operations plays a significant role affecting both production as well as spoiling and deteriorating quality of the products.

Microbial Contamination in the Food Industry

The inner tissues of healthy plants and animals are free of micro-organisms, however, the surfaces of raw vegetables, meat and milk are contaminated with variety of micro-organisms. The magnitude of microbial contamination reflects one or more of the following:

  • the microbial population of the environment,
  • from which the food was taken
  • the condition of the raw product
  • the method of handling
  • the time and conditions of storage

It is desirable to maintain a very low microbial level of contamination on raw food. The presence of extremely large number of micro-organisms suggests that some undesirable events have occurred – and that food is indeed, susceptible to further deterioration.

Microbial load in atmosphere, water, surfaces, equipment, pipelines and a high degree of contaminants in raw material – play a vital role in various processes of manufacture in the food industries. Various methods are employed for reducing the number of micro-organisms from food and food products by using both physical and chemical principles. However, success of such preservation methods is greatly influenced by effective, efficient and ecological plant sanitation procedures or methods practised by industries.

Cleaning, disinfection and hygienic operations are the most important and vital aspects for food industries. All these three operations are interlinked and inevitable, any change in these operations leads to poor quality with low shelf-life, and increases possibility of spread of epidemic diseases like gastroenteritis, typhoid, dysentery and food poisoning.

Food Hygiene: Cleaning

Food hygiene depends on water in several important ways. It is the solvent for application of cleaning agents and disinfectants, and the carrier for the removal of soils. Water may contain a variety of impurities from the environment including dissolved gases, inorganic salts, soluble organic substances and micro-organisms. Contaminated water is a common vehicle for the transmission of pathogenic micro-organisms to man – either directly or through food. Micro-flora of water includes food spoiling organisms, such as psychrophilic bacteria, which affects refrigerated foods. Treatment of water supplies to kill these harmful micro-organisms is a prerequisite for food hygiene.

Cleaning is a process that suspends or dissolves dirt, usually in water, from the object being cleaned. Its effectiveness can be enhanced by:

  • 1. application of energy in some form such as
  • 2. scrubbing, spraying or turbulent flow
  • 3. use of chemical additives, known collectively
  • 4. as cleaners or cleaning agents

Food Hygiene: Disinfectants

Disinfectants are chemicals that reduce micro-organisms including pathogens to an insignificant level. Disinfecting chemicals are very important to reduce microbial counts of water, atmosphere and equipments including pipelines and surfaces.

A wide range of chemicals, with moderate to strong germicidal action on micro-organisms, finds application in the food processing industry. These chemicals are:

  • halogen and their deviates
  • quaternary ammonium compounds
  • phenol and its derivatives
  • aldehydes and related compounds
  • oxidising agents
  • salts, acids and alkalies and many more

These conventional chemicals are sold in the market under different trade names. However, these chemicals are not free from their evident disadvantages like:

  • non ecological
  • slow or difficult to decompose
  • their ability to react with basic substances
  • dangerous when overdosed
  • partly carcinogenic and mutagenic with unpleasant taste and odour

Continuous use of these chemicals also leads to development of genetic resistance. Research has been going on for years in this specific field to develop a new product with a broad spectrum, mircobicidal activity, free from genetic resistance, carcinogenicity, mutagenicity and toxicity, to help man fight its smallest yet most dangerous enemies.

We have recently introduced a new broad spectrum biocide based on hydrogen peroxide and silver in a complex form. The complex is free from different disadvantages of conventional biocides.

Hydrogen Peroxide (H2O2) – A Clean Solution?

H2O2 is a highly oxidising agent with powerful disinfectant properties. Also, it is a substance which, by the emission of O2, transforms itself into pure H2O, thus leaving no trace of foreign substances in treated water.

H2O2 is used industrially as a food additive, bleaching agent and for carrying out chemical reactions. It is increasingly being used to decontaminate and purify industrial sewage and exhaust air. However, in its concentrated form, hydrogen peroxide is fairly unstable and has a tendency to decompose, so that stabilizing agents have to be added. This marked tendency has been a hindrance in using hydrogen peroxide as a water disinfectant. Further disadvantages of hydrogen peroxide are: high sensitivity to rise in temperature, sensitivity to sunlight and UV-rays, slow, short and limited effectiveness. It is thus not suitable for preventing recontamination.

Silver: Food Hygine Agent Surpreme

The term ‘oligodynamic’ was coined by the Swiss botanist Carl von Nageli in 1880, as he found that highly diluted silver solutions (Ag) have an algicidal effect. He discovered that a silver concentration of 0.01 mg/l had ‘incredible’ effects on vegetation – such as algae etc., and he named this ‘oligodynamic effect.’

Important progress was later made since tests showed that the same low dosage also had a bactericidal effect. Silver proved to have several advantages over the commonly used water disinfectants. ‘Silvered’ water has the following benefits – odourless, causes no eye irritation, does not produce chloramines or other irritating water substances. As Ag–ions can be dosed in minimal quantities – neither the chemical nor physical properties of the treated water are altered; they can be applied in a wide pH-range and do not influence the pH-value of the water. Also, Ag is very potent at high water temperatures. As silver is ‘supreme’ in its long-lasting bacteriostatic effectiveness, it very actively prevents regermination and recontamination.

Combining the Advantages for Food Hygiene

Our above-mentioned formulation is known as Virosil. The advantages of the two main components H2O2 and Ag+ can be found in it, which explains why Virosil is a revolutionary disinfectant.

One advantage very relevant to the food processing industry must be emphasized right away. Combination of oxidation and oligodynamics has resulted in a two-phased (multifaceted) product, which is capable of destroying bio-films. This process is extremely important when attacking higher forms of bacteria and viruses, which have developed a bio-film as a protective coat. H2O2 oxidises the film, thus enabling the Ag+ to penetrate unhindered and remove the bacterium or the virus. In normal concentrations (i.e., without dangerously overdosing), Virosil is one of the far products capable of destroying bio-films.

A brief list of the properties of Virosil, which make it an eco-friendly formulation includes: it can be used universally, its LD50 value is greater than 2000 mg/kg. of animal weight, it offers rapid sterilization or disinfection, it does not form chemical compounds with other basic elements.

Also, Virosil causes no irritation to skin or eyes, the revolutionary disinfectant causes no alteration to taste of food and substances, it remains effective even at high water temperatures, it offers non-pollution and biodegradable properties, it has neutral pH, it is noncarcinogenic and non-mutagenic, it is odourfree, it shows good stability in storage, it gives a long lasting effect and so far no toxic effect has been reported.

Germicidal Effect of Virosil

The complex Virosil was tested for its biocidal activity, and was found to be effective against – bacteriophages, viruses, sporebearing bacteria, yeasts, fungi, mycoderms, amoeba, gram positive and gram negative bacteria. Also, it is effective on HIV, hepatitis hegionella, meningococci, polio-myelitis virus, cholera bacillus and yersinia pestis (plague bacillus) in prescribed dosages.

Applications in Food Hygiene

Virosil finds wide applications in the food and food processing industries. It can be used to remove and kill contaminants found in industrial environments. Some of its typical application areas (industry segment wise) are –

  • Beverage industries: Mineral water factories; Breweries; Juice factories and Soft drink bottling plants,
  • Food industries: Canning factories; Sea food & fisheries; Meat & meat processing; Essence manufacturing; Edible oil & margarine factories, Bakeries, Poultry products and Slaughter houses & abbatoirs,
  • Dairies: Milk packaging factories; Automatic vending machines; Milk powder & Condensed milk factories; Cheese & butter production and Ice cream manufacturing units,
  • Drinking water: General disinfection of drinking water; Cisterns; Containers; Pipes; Wells and Long-term disinfection of emergency water reserves,
  • Animal farms: Poultry farms; Cattle farms; Fish docks and Aqua cultures,
  • Pharma and Chemical industries: Dental products; Mouthwash and Disinfectant materials, and in different areas of Water & waste water plants.

* The author is the CEO of Sanosil Biotech.