DDHK. ORG - Results research and the latest discoveries from Lecturers of the School of Science and Technology Hayati Bandung Institute of Technology or ITB, Maya Fitrianti, has succeeded in developing sterilization technology with ultrasonic waves.
ITB's latest discovery is not only able to kill bacteria, but also makes sterilized food items last longer.
"Started his research when he went to doctoral school in the United States in 3," said researchers at the Center for Bioscience and Biotechnology Research ITB it was reported by Tempo.co, Thursday, October 13, 2022.
Maya is interested in ways to kill microorganisms such as bad bacteria in food, as well as ways to preserve food.
Other researchers are also looking for alternative technologies, such as ultrasonic waves.
According to him, this is because there are certain limitations to conventional or common methods.
Maya said sterilization usually uses chemicals, sanitizers, antibiotics, or by heating. The old method can make microorganisms mutate and even develop to become more resistant. Different when using ultrasonic waves.
“If you apply pressure from ultrasonic waves, mechanically the bacterial cell walls will be destroyed. We use that principle,” explained Maya.
Already Known in the Hospital
Ultrasonic sterilization is well known and is used in hospitals to clean surgical instruments, as well as in eyewear shops.
Maya started her research at ITB in 2020, involving lecturers and students, to develop it on fresh food products such as milk, fruit and vegetables, namely spinach, cherry tomatoes, strawberries.
In addition to bacteria, in fruits such as strawberries found there are fungi that make it runny quickly. While in spinach, bacteria make the leaves quickly wither to rot and smell.
An introductory journal on the ultrasonic sterilization of milk and juice has been made. "The result can kill microbes in food, it can run out up to 99,9 percent," continued Maya.
Milk and carrot juice can be stored for up to 10 days in the refrigerator compared to heating. The results of further research studies are currently being written with a target to be published by the end of this year.
"Ultrasonic sterilization can make fresh products such as fruits and vegetables look beautiful, safe to eat, and maintain their nutrition," Maya hoped.
Ultrasonic Instrument Prototype
In the laboratory, the research team used a prototype ultrasonicator made by a Mechanical Engineering lecturer at ITB. Adjusting for a wide ultrasonic sound range, it can be set to multi-frequency.
Milk and juice are put into a vessel and then sterilized for a few minutes with ultrasonic waves. During testing, the frequencies were tested from 20-22 kilohertz, 47-50 kilohertz, and 100 kilohertz.
The mechanism, the ultrasonic waves propagate to the milk or juice and create cavitation bubbles.
"At some point the bubble bursts and creates a lot of energy, so it can destroy bacteria," explained Maya.
The number of bacteria in a cup of juice or milk there is a total of 10 to the sixth power so that it can be reduced to 99,9 percent. After that, the milk and juice are stored in plastic packaging or bottles and then put in the refrigerator.
The research identified three types of bacteria for the model, namely Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. All three have different shapes and cell wall thicknesses and play a role in food contamination.
Beyond bacteria, the research team wants to test ultrasonic waves on yeast, viruses, and microscopic fungi such as mold, and the surfaces of medical devices. [DDHK News]
