Japan Researchers Say Ozone Effective in Neutralising COVID-19
RECENTLY, a Kedah restaurant operator who flouted the mandatory home quarantine rule after returning from India tested positive for Covid-19 – resulting in the Sivaganga cluster, involving employees and patrons of his food outlet. Health Director-General Datuk Dr Noor Hisham Abdullah said the Kedah cluster has a faster rate of transmission compared with nine other clusters in other states, possibly due to a “super-spreader” strain of the Covid-19 virus. This begs the question: how safe is it for us to dine out? How can we protect ourselves, not just as consumers but also as food handlers and operators?
According to the World Health Organisation (WHO), US Centres for
Disease Control and Prevention (CDC) and many other public health organisations, there is currently no evidence that the virus can be transmitted through food or food packaging. Covid-19 is a respiratory illness and it spreads mainly through person-to-person contact and direct contact with respiratory droplets generated when an infected person coughs or sneezes. According to a published WHO document, the coronavirus and other viruses cannot multiply in food; they need an animal or human host to multiply.
The Food and Agriculture Organisation (FAO) added that consumption of cooked meat (of domestic or wild origin), eggs and milk are not considered a means for acquiring the disease. However, contamination of the food supply with other pathogens, such as Salmonella spp, Campylobacter spp, Escherichia coli, and Listeria monocytogenes, represents a major concern for food safety worldwide. Food can become contaminated with microorganisms that can cause human illness from multiple sources along the entire food chain, starting from infections in live animals up to the point of consumption. Preventing such contamination will reduce foodborne illness and decrease the likelihood of new viruses emerging in the food chain.
The WHO puts particular emphasis on good hygiene practices when handling fresh foods that may be consumed raw and/or without any further processing. Examples include fresh fruits and vegetables and ready-to-eat (RTE) foods for consumption without further heat treatment. These foods are mostly prone to contamination from the environment and food handlers. Generally, it is crucial to keep food contact surfaces, equipment, and tools clean, observe good handwashing practices, separate the raw and cooked foods, and use clean water to reduce risk of exposure to any foodborne bacteria and viruses.
While foodborne transmission of Covid-19 has not been reported, avoiding raw and undercooked food of animal origin (meat, eggs, milk products) will reduce exposure to all viruses and other foodborne pathogens. This is advisable for high-risk populations such as the elderly, children aged five and below, pregnant women, and patients with weakened immune system caused by medical treatments. Cooking food to an internal temperature of 70°C is adequate to kill the virus and any other pathogens in meat and other raw food, because the virus is not heat resistant. Always remember that viruses cannot reproduce and grow
in numbers in foods.
However, whether before or after cooking, meats should always be stored in a way that ensures that they do not contaminate other foods and will not be re-contaminated after cooking. Sufficient cooking of frozen food is also encouraged as studies reveal that viruses resist freezing and can be found in frozen food for up to two years at -20°C.
Theoretically, the coronavirus can spread directly from person to person when an infected person coughs or sneezes, producing droplets that reach the nose, mouth, or eyes of another person. Alternatively, as the respiratory droplets are too heavy to be airborne, they deposit on objects and surfaces surrounding the infected person. Thus, potentially, the virus can also spread when a person touches contaminated surfaces and then touch their eyes, nose, or mouth.
Therefore, proper cleaning and sanitising is essential to prevent cross-contamination – this involves sanitisation of inanimate objects such as knives, saws, transport containers and conveyer belts made of metal, plastic and wood.
FAO revealed that most pathogens, including coronaviruses, can be destroyed with most common disinfectants and sanitisers used in food processing. A 0.05% hypochlorite solution, equivalent to a 1:100 dilution of household bleach, is effective at killing most pathogens and can be used to disinfect surfaces after cleaning.
It is important to follow manufacturers’ recommendations regarding disinfectant use, notably the need to first remove organic matter that can inhibit contact and neutralise the efficacy of disinfectants, dilution of the disinfectant, and the contact time required to be effective. If alcohol is used as a disinfectant, it should contain a final concentration of between 60 to 85%. However, all chemical-related disinfectants or sanitisers might leave a residue on the surfaces, and an unintentional overdose of chemicals could be of particular concern.
Alternatively, food business operators can consider a greener and more sustainable way of cleaning and sanitising by using ozonised water – a disinfecting method using water infused with ozone that effectively destroys the cells of viruses, bacteria, and other pathogens. Since ozone rapidly reverts to oxygen, it does not leave any residue after cleaning.
Currently, an industry and academic collaboration between Taylor’s University’s Culinology programme and Medklinn International Sdn Bhd will facilitate research, promote and increase awareness on the application of ozone technology food safety as an alternative disinfectant solution without using chemicals – a useful addition to Medklinn’s ongoing research on the effect of ozone technology on Covid-19.
The food industry should not overlook the importance of food handlers in managing the transmission of viruses. Historically, scientists have discovered that insufficient handwashing by food handlers is responsible for many foodborne disease outbreaks. Typhoid Mary (Mary Mallon), who was attributed with infecting over 50 individuals during her work as a cook while asymptomatically shedding Salmonella Typhi, is the most remarkable example of poor personal hygiene.
Personal protective equipment such as masks and gloves can be effective in reducing the spread of viruses and disease within the food industry, but only if used properly.Additionally, the food industry is strongly advised to introduce physical distancing and stringent hygiene and sanitation measures and promote frequent and effective handwashing, in compliance with government enforced standard operation procedures (SOPs). SOPs are crucial at every step, from food preparation to serving.
Food handlers experiencing clinical gastrointestinal or respiratory disease symptoms should not participate in food processing or preparation. Ultimately, food safety practices in food premises should continue to be delivered to the highest hygiene standards in accordance with established food safety assurance systems.
Despite the fact that the Covid-19 pandemic jeopardised many food businesses due to temporary closures, there were some unexpected positive impacts. The Finnish Institute for Health and Welfare has noted a significant drop in the number of foodborne illnesses in Finland between March and May this year. The institute believes this is because the coronavirus pandemic resulted in various restrictions and recommendations for food businesses. Since there was frequent handwashing and food was prepared for smaller groups, there were fewer foodborne illnesses.
Perhaps the pandemic has made us more aware of the critical importance of food safety and environmental sanitisation to our well-being? Will we adapt to the “new normal” and live healthier lives? Only time will tell.
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