Biomimetics

MeBioS Biosensors: Biomimetics Research

Traditionally, instrumental and sensory techniques are used to determine very important aspects of the food product – taste and aroma. Instrumental analytical techniques such as chromatography techniques give very accurate information on the chemical composition of the sample, but unfortunately they are expensive, time consuming and require skilled people to operate the equipment. In sensory analysis taste is evaluated by trained panels or consumer panels. This analysis is by far the most realistic technique to obtain information on human flavor, but it has some problems including standardization of measurements, correctness of training, taste saturation of the panelist and high cost.

The spectacular capabilities of biological sensory systems inspired scientists to implement their organization principals in artificial sensory devices. The latter were first intended for gas analysis and odor recognition. Such odor detection systems or electronic noses usually provide for the qualitative recognition of gas mixture and/or the identification of certain individual gases. The same principles were applied to the development of multisensor systems for liquid analysis – electronic tongues. The electronic tongue (ET) tries to imitate human taste perception and it can be used as a fast-screening and cheap alternative to traditional techniques. It consists of an array of weakly selective potentiometric chemical sensors that have cross-sensitivity. The electronic tongue has been successfully applied in a wide range of applications and it is able to determine quantitatively the composition of a complex sample and to distinguish, classify and identify liquid samples. The most exciting application area of ET is taste quantification, which is understood as the assessment of taste characteristic of the product using an ET and correlation of its response to human sensory perception.

Another alternative of traditional techniques is Fourier Transform Infrared Spectroscopy (FTIR). Fourier transform infrared spectroscopy is a powerful tool for the identification of chemical components. Chemical bonds (functional groups) in a molecule absorb IR light and produce an IR absorption spectrum which is like a molecular fingerprint. Attenuated Total Reflectance (ATR) is today the most widely used FTIR sampling tool. ATR generally allows quantitative or qualitative analysis of samples with little or no sample preparation.

One more alternative is a novel high throughput system (HTS) accessory for FTIR analysis. The HTS is a microplate module which allows for the measurement of various types of a large number of samples applied on a small (109 mm × 73 mm × 0.675 mm) standardized microtiter plate with 96, 384 or 1536 wells using the infrared spectroscopy. The module increases the sample throughput and allows for a continuous 24-hour-operation of the measurement system.

In current research in cooperation with Center for Malting and Brewery Science of KULeuven (http://www.biw.kuleuven.be/lmt/cmbs/home.htm) and Laboratory of Chemical Sensors of Saint-Petersburg University (http://www.electronictongue.com/) all of these novel analytical techniques are applied for analysis of Belgium beer.