Potentially Hazardous Foods Temperature Management:
The Importance of Blast Chillers
Food safety should be of the utmost importance for every company in the food industry. All Businesses serving food as Cafes, Restaurants, Clubs, Hospitals, Schools, are aware they need to apply HACCP requirements to keep their food safe.
In Australia you are required to keep all potentially hazardous food under temperature control, to comply with HACCP food safety standards. Temperature Control is related to Parasite Destruction, Cooling, Freezing, Thawing, and Reheating Foods. But what foods are potentially “hazardous foods”? They might contain the types of food poisoning bacteria that can multiply to a large number and cause food poisoning. Bacterial such as Salmonella, Anisakis, Escherichia Coli multiply seriously quickly over just a short amount of time if left in inadequate conditions. However, they can be controlled and destroyed if the correct freezing, cooling and cooking methods are used.
- Raw and cooked meat, including poultry and game, food containing raw or cooked meat such as casseroles, curries, lasagne, meat sauces. Small meat goods such as ham, chicken loaf, Strasbourg, burgers
- Raw and cooked fish, including Sushi and all kind of raw fish meals, salads, patties, stews, fish stocks, fish balls and seafood.
- Dairy products like milk, custard and dairy-based dessert such as tarts, cheesecakes, gelato and ice cream, some types of cheeses
- Cooked pasta and rice
- Processed fruits and vegetables, for example, salads and cut melons
- Food containing eggs, beans, nuts or other protein-rich foods such as quiche, fresh pasta, and soybean products.
- All foods that contain the foods above, such as rolls, sandwiches, uncooked pizza, patisserie and many bakery products
So what foods are not hazardous? Some foods if they have been processed by the manufactures are not listed as hazardous: canned and bottled food, breads and dried foods, dried fruit, fermented dried meats, hard cheeses, spreads, dried foods: raw whole fruits and vegetables are not potentially hazardous because they do not allow any food poisoning bacteria to multiply, but they need to be stored in a properly refrigerated environment to minimise or prevent spoilage and meet their shelf life indicated by the use or by best-before date on the label. It is an offense to sell food that is mouldy or spoilt and even that not potentially hazardous foods can become dangerous if you alter them in some way. For example, custard powder isn’t hazardous because it’s too dry for bacteria to multiply, but it becomes hazardous when milk is added.
In Australia, Parasite Destruction is compulsory when it comes to “ready to eat” form, raw, raw marinated, partially cooked, or marinated-partially cooked fish. Before service or sale, these foods must be chilled throughout to a temperature of:
- -20C° or below for 168 hours (7 days) in a freezer
- -35C° or below for 15 hours in a blast freezer.
It’s already clear that the use of blast chiller is quicker, safer, cheaper and it helps to maintain a better quality of the products. As known, frozen food isn’t the same as fresh; you will lose some texture and nutrients, you also need to be very careful when thawing because the ice crust formation takes a long time to disappear and thawing. Deep Freezing with a blast chiller doesn’t result in ice crust formations; the larger the ice crystals the more damage they do to the cell walls of the food, so when the large water crystals melt, it causes your frozen food, cell molecules to rupture. The texture and taste of your food will deteriorate. As the food thaws, liquid pours out of the collapsed cells. When using the deep freezing function with controlled temperature and ventilation, the water contained in fish solidifies into microcrystals that do not tear its cell membranes, while keeping organoleptic properties, flavour, and texture unchanged. Every premise in general that sell raw meat, raw fish or sushi should use a blast chiller to avoid food poisoning and preserve the quality. Food that is blast-chilled and thawed is as good as a fresh product. This is a huge benefit because it means that restaurants can take advantage of the abundance of seasonal products and preserve them with minimal losses in quality and outcome.
The standard requires you to ensure that the temperature of potentially hazardous food is 5C° or colder, or 60C° or hotter when you receive the potentially hazardous food into your business and store, display and transport this food. Remember that only at 3C° the proliferation of bacteria is very low and the food is basically safe. When preparing food you should keep it at room temperature for a short time as possible and then you must cool the food down according to the law. You cannot leave food cooling down unless you are sure that the temperature of the food is at least above 60C°. There might be poisoning bacteria even in the cooked food because some type of bacteria can survive the cooking process. To check the temperature you must use a sanitised thermometer, kept at your food premises. You may be surprised how long it takes for the food to cool down even if in a cold room or refrigerator! It may take hours to cool at 5C° or less. The longer the food takes to cool the greater the number of bacteria in the food.
With a Blast Chiller, it’s possible to lower the temperature of foods you have just cooked. You can reduce the temperature of cooked food to +5 °C or below within 90 minutes.
Practically, the Blast Chiller does exactly what it sounds like: It cools things down quickly, using fast-moving cold air. While in Europe the use of blast chiller is compulsory when serving raw meat and fish, in Australia it is been making its way into the commercial kitchens. In the past, blast chillers would have been only associated with large manufacturers but the scientific research in food safety and the technology development suggests and supports the use of blast chillers in all food service businesses, from small cafes to larger fine restaurants, to large volume catering companies. Blast Chillers are essential part in any food safety management and HACCP plan. Not only do Blast Chillers ensure that the foods are not at risk of bacteria proliferation, they also prolong the life of products and reducing waste. The temperature range between +65°C and +10°C provides the ideal conditions for bacterial growth, which is precisely what happens when we let cooked products cool at room temperature. The longer the exposure of food to risky temperatures, the faster the growth of bacteria. Rapid cooling of cooked foods extends their shelf life and at the same time reduces the weight loss due to evaporation, preserving their original quality. Every time you cook, your food releases water by evaporation. When you put your food in a Blast Chiller as soon as cooked, the evaporation stops. So you reduce the loss of moisture and its weight. If you sell your food by weight, then your profit will increase. You can take hot dishes straight from the oven and pull their temperature down to perfectly preserve their texture. For example, the rapid cooldown helps bakery products to retain the crisp texture of their crust. Rapid cooldown is wonderful as well for baked pasta as well as fresh homemade pasta and its wonderful silky texture.
It has been proved that a Blast Chiller can increase the Shelf life of food up to 70%
Food quality is dramatically improved with the rapid chilling processing capturing & preserving the organoleptic qualities. Food that has been blast chilled will taste like it’s been freshly cooked. Also with the efficiencies and time savings created by the Blast Chiller, chefs can look to organise a wider menu and make savings on the ingredient purchases.
The thawing of hazardous food is one of the slower and more delicate processes in the kitchen and very often it is not carried out safely due to fast-paced schedules. Some professionals use running water or the microwave as a shortcut to save time, but direct contact with water is not recommended by health standards, while the microwave cooks the food and changes its protein content, inevitably compromising quality. According to the Australian Law, you are allowed to carry out the thawing process in different ways, but what’s the best method not to lose quality and safety? As seen before, the larger the ice crystals the more damage they do to the cell walls of the food. All the liquid that seeps out of your defrosted food is a loss of weight, flavour, texture, and nutrients. A Blast Freezer promotes rapid freezing (the faster the freezing the smaller the crystals) and some blast chillers are equipped with ALL IN ONE technology to support you not on only in Blast Chilling but also in Thawing and Proving. Thawing food in the refrigerator at +2° is certainly effective and safe, but it is very slow and often clashes with the needs of a modern catering business. The blast chiller manages the thawing cycle with different phases and temperatures, speeding up the process considerably. An initial temperature of +20°C is combined with high humidity and reduced air circulation. As time elapses, temperature and humidity inside the compartment decrease progressively until the product is thawed completely in total safety.