# Learning ultrasound assisted extraction through the use of sugar-coated chocolates

## TL;DR

This paper uses sugar-coated chocolates to demonstrate how ultrasound helps extract substances more efficiently, making it easier to teach the concept to students of all ages.

## Contribution

A novel, intuitive experiment using sugar-coated chocolates to demonstrate ultrasound extraction mechanisms for educational purposes.

## Key findings

- Cavitation and acoustic streaming can be visually demonstrated using sugar-coated chocolates.
- Video analysis provides a quantitative way to observe the extraction process.
- The experiment is suitable for educational use from primary school to university levels.

## Abstract

Extraction of bioactive compounds from vegetal matrices is a dynamic field in pharmaceutical, cosmetic and food industry. Many of these compounds have high medicinal value. Ultrasonic assisted extraction (UAE) becomes an interesting alternative to reduce both the amount of chemical solvents and the processing time.

The aim of the present paper is to introduce, intuitively, the physical mechanisms involved in ultrasonic extraction for non-specialists.

Two different mechanisms, cavitation and acoustic streaming, can be easily experimentally shown. The proposed experiment is the extraction of the sugar cover in sugar-coated chocolates. Extraction is analyzed using video tools to obtain a quantitative evolution of the process. Graphical results and videos are a useful tool for showing the basis of ultrasonic extraction in several levels from primary school to university students. In the event that the necessary ultrasound equipment is not available, we hope that the videos available in the supplementary material will be useful for teaching the topic.