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Winning words on Hepatitis A in berries

Posted by The Food Chain on December 21, 2015 at 9:30am

3818787293?profile=originalRebecca Jenkinson, a graduate of the Food Quality, Safety and Nutrition course at Queen’s University Belfast, was the 2015 winner of the Student Prize. The prize was awarded to the best essay on the theme of Food: Is it safe to eat?

Below is an excerpt from Rebecca’s essay, which focused on Hepatitis A in frozen berries.

Protective measures to make mixed frozen berries safe for human consumption

The advice given to the public with this particular outbreak [across the EU from January 2013 to September 2014], was to boil mixed frozen berries for one minute before consumption (FSAI, 2014). However, this would significantly compromise the quality of berries. The texture, appearance and taste would all deteriorate.

Consumers have the right to demand frozen berries which are safe, without the annoyance of having to process the berries further, especially if this adversely affects their quality. Additionally, heat-treating products which contain mixed frozen berries, for example ice cream or smoothies, simply isn’t viable.

It is therefore imperative the berry industry introduces protective methods to eliminate or reduce the risk of Hepatitis A Virus (HAV) in frozen berries. Protective measures to prevent contamination by food handlers need to be in place, for example adequate hand washing and toilet facilities. Additionally, berry handlers should wear protective clothing, such as gloves, to prevent contamination (Sprenger, 2012).

It could be suggested that all berry handlers should be vaccinated against Hepatitis A, as often they are the cause of outbreaks. Moreover, HAV is capable of surviving on many different surfaces used in manufacturing, such as stainless steel and copper (Craven et al., 2009). It is therefore vital cleaning is carried out frequently, as HAV can survive on surfaces for long periods of time (Craven et al., 2009).

There are procedures which can reduce the risk of HAV in berry factories. Washing berries in water can result in a 1.1log₁₀ reduction of HAV (Craven et al., 2009). This should be routine. Additionally, washing berries with 200pm of free chlorine can be seen to result in a 2.4log₁₀ reduction of HAV (Craven et al., 2009).

The use of UV radiation for inactivating HAV in strawberries was investigated. The results show that a 2.6log₁₀ reduction of HAV can be achieved by this method (Fino and Kniel, 2008). However, it is thought that the uneven surfaces of various berries can protect some virus particles from the light (Doyle, 2010). In addition, UV light cannot penetrate beyond the surface of the berries (Zuber et al., 2014).

This may not be the most effective method of decontamination of HAV from raspberries or blackberries, as the inside of these fruits are partially exposed. Furthermore, it may be necessary that sample checks are carried out at the production, processing and distribution level of berries. (EFSA, 2014). This may be particularly important in less developed countries, such as Bulgaria.

References:

  • Doyle, M.E. (2010) White paper on effectiveness of existing interventions on virus inactivation in meat and poultry products, Madison, University of Wisconsin.
  • Fino, V. and Kniel, K. (2008) UV Light Inactivation of Hepatitis A Virus, Aichi Virus, and Feline Calicivirus on Strawberries, Green Onions, and Lettuce. Journal of Food Protection, 71, pp908-913.
  • Sprenger, R. (2012) Supervising Food Safety (Level 3). Highfield.co.uk Limited, South Yorkshire. p4.

 

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