Follow Workplace Hygiene Procedures Case Studies Case study 1... 2 Preparation... 2 Cross contamination and food handling practices... 2 How to stop the spread... 3 Temperature control... 3 What can you do to manage temperature control?... 3 Cooking... 3 Temperature control during food preparation... 4 Case Study 2... 5 Spreading food poisoning bacteria with a food slicer... 5 Food safety controls... 5
Case study 1 Though most people have a good understanding of the importance of hand washing, it continues to be one of the key actions individuals often forget. We would usually expect every kitchen that we work in to have a hand wash basin and a towel, soap and warm water. While we might be pretty quick to report a basin that isn't working, many food handlers and chefs can be observed working away on a range of different tasks without taking the time to wash their hands. A couple of years ago there was an incident where several people reported that they were sick after eating lunch or dinner at a particular café. The café served approximately 100 meals from a Bain Marie each day and was open for lunch and dinner. One of the most popular menu items was chicken schnitzel. The staff prepared the dish from scratch and took great pride in the quality of the food they served. They did not use pre-prepared food as they liked to cook and see their customers enjoy the food. On the day of the complaints 25 schnitzels were served and it was the one food choice that all of the people who complained had eaten. All of those who complained were served between 11.30am and 12.30pm. One customer was treated at the outpatients at a local hospital and tests confirmed that they had salmonella food poisoning. How could a chicken schnitzel be the source of food poisoning? Let's take a look at preparation process and see if we can find some things that may have gone wrong to allow salmonella bacteria to contaminate the schnitzel and multiply. Preparation The schnitzels are made from fresh chicken breast fillets that are flattened on a board using a small meat mallet. This takes about an hour depending on interruptions, and after this they are refrigerated until they are ready to be crumbed, usually in the afternoon. The chicken is crumbed using egg wash made from fresh eggs and crumbs that are freshly made at the café. Once crumbed, the schnitzels are placed on trays in the cool room until they are needed and cooked on a grill in batches of 5. After cooking, they are placed in the Bain Marie and usually only remain there for approximately 1 hour before they are sold. Approximately 40 schnitzels were prepared on the day of the incident but there were 8 uncooked schnitzels left over from the previous day. These were used first and cooked in 1 batch at 11am. Batch 2 was cooked at 11.30am but no one can remember whether all of the first batch had been sold by then. So where could food safety issues arise during this process? Cross contamination and food handling practices There are a lot of opportunities in this process for Mr Salmonella to contaminate the schnitzel. Spotless Follow Workplace Hygiene Procedures Workbook 2 of 5
Raw chicken is a source of salmonella and while most of us understand that chicken needs to be thoroughly cooked, if food poisoning bacteria multiply to great enough numbers even cooking may not make the food safe. Every time we touch raw chicken, the shell of an egg or raw egg liquid we have the potential to get salmonella on our hands. Wiping our hands on an apron, picking up a tea towel or touching a box of food handling gloves can all provide Mr Salmonella and his offspring with opportunities to populate every surface you touch. How to stop the spread The simplest thing you can do to is to wash your hands THROUGHLY every time you handle raw chicken or eggs BEFORE you touch anything else. Hand wash basins aren t there for decoration - use them! Use food handling gloves but remember you still need to wash your hands. Temperature control If the chicken was contaminated with salmonella, the next thing that can make the schnitzels unsafe is time. Making schnitzels takes time and in a busy kitchen it is easy to get interrupted mid task and leave food sitting on the bench for too long. This gives the bacteria the opportunity to multiply. Sometimes batches of egg wash are made up that are used for a couple of days. This can be contaminated and every time it is in the temperature danger zone bacteria multiply. Once prepared and before cooking the schnitzels might sit on a tray in the kitchen or beside the grill. This also provides more time for bacteria to grow. What can you do to manage temperature control? To manage temperature control, be aware of temperature when you are preparing food. When you are flattening chicken it is getting warm. The crumbing process takes time during which the chicken stays in the temperature danger zone. The time and temperature between when you start preparing and when you finish and the schnitzels are returned to the cool room and chilled to below 5 C is important. Bacteria are multiplying all of the time that the food is in the danger zone. Think about egg wash. This is a good place for bacteria to grow, especially if you use the same batch for a couple of days or add fresh eggs to a batch where bacteria can multiply. Cooking It is absolutely critical that the chicken is cooked through the centre in the thickest part. There can be no short cuts, even if you re busy and customers are waiting you need to check and be sure. You should use a thermometer to find out how long and at what temperature you need to cook the schnitzels, but because the schnitzels are different thicknesses you will still need to check that they are cooked all the way through. Remember, cooking does not destroy spores and toxins; if there are enough bacteria in the food even cooking won't make it safe. Spotless Follow Workplace Hygiene Procedures Workbook 3 of 5
Temperature control during food preparation The following has been taken from the Food Safety and Personal Hygiene Manual, page 51: The control of time and temperature is critical in controlling the growth of pathogens in potentially hazardous foods. The goal must be to minimise the time that potentially hazardous foods are at a temperature between 5 C and 60 C. Bacteria can grow rapidly when the environment suits them. Most food preparation areas have a room temperature of between 20 C and 40 C, which is an ideal temperature for bacteria to multiply. It is, therefore, important to minimise the time that food is in the food preparation area. It is also important that all food handlers have a good understanding of the temperature danger zone. Spotless Follow Workplace Hygiene Procedures Workbook 4 of 5
Case Study 2 Spreading food poisoning bacteria with a food slicer Food slicers are use in many kitchens and most of the food that is sliced does not go through a cooking step; it is ready to eat". We especially use slicers to slice sandwich filling, sliced tomatoes and other vegetables, and cooked meats. An incident of food poisoning was confirmed when a person reported that they were sick after eating a sandwich. The person was treated by a doctor who, following tests, notified the health department that the person had listeriosis. Listeriosis is caused by eating food contaminated with the bacteria Listeria monocytogenes. Listeria bacteria are widespread and commonly found in soil. They have also been found in many different foods, especially fruits and vegetables that may have contact with soil. It is not always possible to identify which particular food caused an illness as symptoms might not appear for 3 to 70 days after eating the contaminated food. An investigation by the health department confirmed the presence of Listeria in sliced roast beef, sliced tomato and sliced turkey, all of which had been sliced on the slicer. The slicer at this site was used to slice a range of meats and vegetables. It was a busy site making about 100 serves of sandwiches and rolls each day. The slicer was cleaned at the end of food preparation each day. It was clear that the slicer was the source of the contamination. The problem seemed to be that the tomatoes and capsicum that were sliced were not washed properly (double) but rinsed in a colander under running water. The vegetables were always sliced first and then the meats. The slicer was wiped down between products, not broken down and cleaned. Following the Health Department investigation Food Act orders were made requiring the site to do a full chlorine clean down of the kitchen, retrain all food handlers in cross contamination management and cleaning, and provide separate slicers for meats and vegetables. Food safety controls Do not prepare, process or handle cooked foods with the same equipment or utensils (tongs, knives, and cutting boards) that are used on raw foods, unless they have been thoroughly washed with hot soapy water and sanitised between uses. Spotless Follow Workplace Hygiene Procedures Workbook 5 of 5