Food Adulteration Detection: Electronic Nose and Optoelectronic Sensing

This article explores food adulteration, its definition, and popular detection methods like the electronic nose and optoelectronic sensing. We’ll also discuss the advantages and disadvantages of each method.

Introduction

Adulteration is a widespread problem affecting various commodities due to corruption. It’s found in foods, fuels, clothing, construction materials, and more. Tragically, this can lead to loss of life due to food poisoning or structural failures of bridges and buildings. Because of this, quality control and commodity checking is essential. This necessitates the use of quality control instruments.

Food Adulteration Definition

Food adulteration refers to the intentional addition or substitution of substances that degrade or lower the quality of food items. Biological and chemical contamination of food also falls under the umbrella of food adulteration.

Food adulteration detection system

Food adulteration can occur at any stage: before preparation, during preparation, after preparation, during storage, during transportation, and at the distribution level. This directly impacts consumer health. Traditional methods for checking food adulteration often rely on chemical and thermal techniques. These methods can be cumbersome and may not always detect adulteration effectively.

Thanks to advancements in cutting-edge technologies and the availability of sensors, modern electronic methods now enable quality checks on food items. Figure 1 illustrates the processes involved in electronic sensing, which mirrors human olfaction.

Food Adulteration Detection Using Electronic Nose (E-nose)

electronic nose

• E-noses offer a high level of reliability in detecting and recognizing odors and flavors.
• They utilize an array of electronic sensors to differentiate between volatile and non-volatile compounds in mixtures.
• These sensors (ranging from one to 32) employ various technologies like organic polymers, metal oxides, and microbalances.
• The technology can be applied to detect various aromas in food and materials, as well as plant diseases and pests.

Advantages

• High level of reliability.

Disadvantages

Limitations of e-noses include:

• Loss of sensitivity in the presence of water vapor or high concentrations of single components like alcohol.
• Sensor drift.
• Short sensor lifespan.
• Inability to offer absolute calibration.
• Lack of quantitative data for aromatic differences.

Food Adulteration Detection Using Optoelectronic Sensing

• Optoelectronics deals with light emission and detection.
• It encompasses the creation, manipulation, and detection of radiation for purposes such as x-rays, infrared, gamma rays, UV, and visible light.
• Optoelectronic devices are used in telecom, military, medical, food adulteration detection, and other fields.
• Optoelectronic devices are more sensitive, reliable, and suitable for detecting different types of adulterants.
• Optoelectronic methods include photovoltaic, photoconductivity, stimulated emission, etc.

Adulterants alter the refractive index of food, resulting in a corresponding phase change. These changes are detected to determine the presence of adulterants in the food.

Other Food Adulteration Detection Methods

The electronics field has spurred research into other food adulteration detection methods, including:

• IR spectroscopy with chemometrics
• Biosensors for urea detection in milk
• Fiber optics based optoelectronic sensing systems
• Surface Plasmon resonance