From the beginning of time food has been a crucial part of a healthy and well-functioning society. All kinds of vitamins, micronutrients, and macronutrients are needed for every human being to work efficiently. But to have it you need food in the seasons when it just simply doesn’t grow. This simple fact was well-known by our ancestors and so began our history of food preservation. But how do you even start? Well, since the spoilage of food happens due to bacteria, you simply have to get rid of it or prevent it from multiplying.
The earliest way of preserving food was first recorded as early as 12,000 B.C was drying. This process revolves around a rather simple process of removing moisture from the product, so the microorganisms no longer have water to live in. There are a quite lot of prehistorical ways to do this simple thing: air drying, sun drying, smoking, or wind drying. Of course, nature isn’t exactly the most reliable. Rainy days, high moisture in the air, clouds, and you won’t be able to dry your food.
Nowadays these problems are not so acute since we have all the different ways to dehydrate the product. Solar drying is still used to dry food but is mostly done in greenhouses to protect from birds and insects as well as decrease the time to reach the wanted moisture content thanks to increased temperature.
Lyophilization which is also called freeze drying, is slower and with higher costs, because it involves freezing and the production of a vacuum. Also, equipment is expensive by itself. It’s mainly used to dry products with rich and valuable aromas such as mushrooms, herbs and spices, fruit juices, and seafood. In infrared drying, the solid food is exposed to a source of infrared heating increasing the temperature of its surface. This way of drying is proven to be faster than other methods (up to 20% of drying time according to Raquel P. F. Guiné work “The Drying of Foods and Its Effect on the Physical-Chemical, Sensorial and Nutritional Properties”)
Humanity has come a long way in developing dehydration technologies. Drying increases the shelf life and eases storing and transporting goods, but it has one biggest drawback. The quality of dehydrated food is usually drastically reduced as compared to that of the original foodstuff.
The ideal temperature for bacteria to multiply is from 8°C to 60°C (46.4°F to 140°F). This means that to prevent food from spoilage you need to chill it below 8°C or heat it above 60°C. And chilling does exactly that. Chilling is the application of temperatures in the range of 0°C to 8°C, above the freezing point of the food. It delays the spoilage of the product while retaining its freshness and appeal. This way of preserving the food is great for keeping the texture, flavor, and nutrient content intact. But temperature only slows down the live circle of harmful bacteria and can not last more than 4 days since the risk of food poisoning increases drastically after that (according to Katherine Zeratsky, certified in dietetics by the state of Minnesota and the American Dietetic Association.)
Freezing is a way to preserve the foodstuff by a gradual decrease in temperature below 0°C. This method has a strong preserving effect. Because the multiplication of germs is reduced and also, the water activity is reduced by converting part of the water into ice. The disadvantage of this method is that ice crystals created will enlarge and destroy the food cell wall. It, in turn, will ruin the texture, taste, and aroma of the food. In fact, it’s common knowledge that if you cook previously defrosted food, it will be worse than before. But is there a way to fix that?
Yes, there is. It is called deep freezing. In food, there are ‘antifreeze proteins’ that delay the crystallization of water. It is generally believed that the damage to the texture, taste, and aroma during freezing is significantly reduced by accelerating the freezing rate. This is due to the fact that cells can not break by enlarging over the given volume when the entire mass is frozen. Furthermore, rapid freezing results in the formation of smaller ice crystals, which are less harmful to the texture of cells. But even if we have top-quality frozen foodstuff it’s only half the problem. In frozen food, the shelf life, and bacteria deterioration process is long but inevitable. Thus, what else do you need to make your food last longer?
Extensive studies on the effect of frozen storage on product quality were undertaken in the 1960s by researchers and the Western Research Laboratories (Canet, 1989). A concept known as ‘time–temperature–tolerance’ (TTT) was developed (Van Arsdel et al., 1969). The research showed that a lower temperature in storage will almost always result in higher quality. The quality of the packaging is as important as temperature due to the fact, that airflow can cause a major quality loss.
Preserving the food in its original state is a difficult task that requires not only theoretical but practical knowledge. Ocean Treasure with over 15 years of experience and as the only company in China that holds the three global certificates — BRC, ASC, MSC can guarantee top-quality service. We treasure customer satisfaction above all else and 99.5% of our customers appreciate working with us. Let us show you what it feels like to work with us
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