How many times have you recalled some products,when they were already moldy, and already had to throw them away? I used to often buy an unripe avocado, leave it for a couple of days to make it tastier, but ... in the end I remembered about a week later, when the fruit was already unsuitable for putting it on a toast or just to eat it. The problem is that most products - in particular fruits, have a very short shelf life. In stores, they often trick and try to extend this period by waxing the fruit, and it really helps, but not much. However, recently, scientists were able to develop a new substance that allows fruits to remain fresh for more than one week. Moreover, it has no taste or smell.
How to keep fruits fresh
An article on Advanced Materials Biologiststell how they managed to achieve such results. They took the usual egg white as the basis of the substance, adding curcumin and small crystals of cellulose. According to the results of the study, such a coating is easily washed off with plain water without the use of detergents. Moreover, in terms of effectiveness, it significantly exceeds the existing methods of “preserving” fruits.
Why do apples wax?
Scientists have long been trying to find a way to increase the termshelf life of food. The bottom line is to develop a coating that will inhibit the evaporation of water and, at the same time, the growth of microbes. The most common way to extend the life of fruits is wax - the fruits coated with them really remain fresh longer and at the same time begin to look brighter and more appetizing. However, this method is by no means ideal. Firstly, the wax is washed off very poorly from fruits - you probably noticed how difficult it is to remove it from apples, you even have to rub it with a sponge to wash dishes. In addition, when wax enters the body, it breaks down and can affect some metabolic processes and destroy cell membranes. Not to mention that such processing takes extra time, and many in our Telegram chat said that wax strongly affects the taste of fruits.
Another substance that is used for the same purpose is chitosan. This is one of the most common organic compounds in nature, which refers to natural polymers.
Chitosan obtained using chitin, which is obtained from the shell of crustaceans (crabs, shrimp). Sometimes it is obtained from the cuticle of insects and the cell wall of fungi.
Like wax, chitosan forms a film on products that inhibits the evaporation of water and inhibits the formation of bacteria. It is also washed off poorly, although harm from it is considered less.
What is rubbed with fruit
A new substance developed by scientists consists ofegg white - due to its good biocompatibility, it has become an ideal base. Dry egg yolk was added to it to repel water, glycerin to improve the elasticity of the mixture, as well as curcumin. The latter has antimicrobial and antioxidant properties. The mixing of the ingredients was carried out at a temperature of 80 degrees Celsius. After it was cooled to room temperature, fruits were immersed there and the reaction was monitored.
The study was conducted on four fruits: avocado, strawberries, banana and papaya. While uncoated foods were unsuitable for food after a week, the fruits with the new substance remained fresh for up to 7 days, and only then they began to deteriorate. For example, strawberries have lost only 35% moisture in 5 days with a new coating, whereas usually losses are up to 60%.
In addition, all the fruits were subsequently cut,to look at their elasticity and internal state. Covered products were not only more resilient, but also fresh. Also, scientists were able to confirm the antibacterial properties of the new composition. They laid E. coli bacteria on the surface lubricated with it, and after a night the germs disappeared.
In the future, this discovery may help.cope with global hunger - WHO estimates that around 1 billion people were starving in 2019. A lot of food is wasted and not consumed, because the products often go bad until they get to the shops with farms (and under the scorching sun of Africa this is not surprising).
About half of all fruits and vegetables in the world go bad before consumption.
Now scientists need to spread their find,and since this method is not costly, many farms can soon adopt such a method of processing products. So we will eat more fruits! No wonder they are referred to products that improve brain function. But it is better to use them as early as possible, of course.