By Dr Namrata Jain*

The Indian food market size is more than USD 300 Billion and growing with a CAGR of ~10%. Food analysis is one of the major concerns with a prerequisite for assuring the best product quality. This interdisciplinary field of research aims to characterize food products in terms of their composition, structure, physicochemical and phytochemical properties. The information is critical for understanding the factors that determine the food properties, as well as the ability to economically produce food materials that are consistently safe and nutritious. HORIBA Scientific aims to be a part of this continuous and demanding research effort of the food industry through high-performance and cost-effective analytical solutions ensuring rapid analysis with high accuracy. HORIBA holds over 200 years of experience in developing a wide range of cutting-edge technologies to support areas impacting human lives. In this context, we hereby introduce the analytical instruments from HORIBA Scientific for particle size characterization that ensures handling food safety and quality control parameters with precision and care.

PARTICLE SIZING

The particle size distribution of particulates has been studied for a wide variety of food and beverages, such as coffee, sugar, flour, chocolate, milk powder, flavours, and spices. The grain size of the raw ingredients not only affects the taste, but also affects the appearance, stability, processability, and functionality of the finished product. Horiba Scientific offers high precision particle size measurement instruments for suspensions, emulsions, powders, pastes, creams, and gels. To determine the sizes of small particles or nanomaterials, such as colouring and flavouring agents, the HORIBA nanoPartica SZ-100V2 is the instrument of choice. It works on the principle of Dynamic Light Scattering (DLS) and is an ideal technology to study particle sizes in the range of 0.3 nm to 10 µm. Larger particles or microparticles can be characterized using HORIBA Partica LA-960V2 Laser Diffraction (LD) system, the most advanced laser scattering particle size distribution analyzer. Two important particle sizing tests carried out by the food industry using HORIBA instruments are discussed below.

Flavour Emulsion sizing with Dynamic Light Scattering

Flavour emulsion is one of the products that is primarily used in many food products including carbonated beverages and dairy products. A typical flavour emulsion contains essential oils, emulsifiers, and stabilizers in an aqueous continuous phase. One of the major concerns related to the use of emulsions is their colloidal stability. Monitoring the particle size of an emulsion has a direct effect on the ease of maintenance of a uniform suspended phase. Reduced particle size allows more particles to be distributed on the interface, resulting in a more stable emulsion. Given the sub-micron size range of the most flavour emulsions, the size analysis can be performed using HORIBA SZ-100V2 system (figure 1). Figure 1 shows the intensity-weighed particle size distribution of flavour emulsion with an average size of 250 nm obtained using SZ-100V2 system.

In addition to the particle sizing, the system also supports zeta potential (surface charge of particles) measurement. The parameter is indicative of the interfacial properties and the continuous solution near the interface within an emulsion system. The magnitude of zeta potential gives an indication of the potential stability of the colloidal system. SZ-100V2 system, therefore, supports the food production process through analysis of two stability parameters, particle size and zeta potential, that helps in improving the shelf life of the manufactured products.

FLOUR Particle Size Analysis with Laser Diffraction

Flour can be produced from different cereals with a large variety of grinding degrees that are optimized for specific applications, like baking bread or cake. Controlling the size of the granules is of primary importance and one of the essential parameters to be continuously monitored during the production process. Along with the texture and appearance of the final product, the grain size of the milled flour also influences the batter or dough properties such as density and viscosity. Considering the grain size in the range of several micrometres, Laser Diffraction (LD) technology has emerged as one of the most important and effective techniques for particle size analysis in the food industry. HORIBA Partica LA-960V2 (figure 2) particle size distribution analyzer’s innovative design advances the scientific knowledge for tomorrow’s world through intuitive software, unique accessories, and high performance.

Wheat flour is one such giant industry where optimization of the particle size is an essential parameter to be monitored at different milling stages. Figure 2 shows the volume-based particle size distribution of wheat flour with a size range of 20 µm to 250 µm. The instrument delivers reproducible and reliable data in less than one minute for a wide size range from 10 nm to 5 mm.

CONCLUSION

The above particle sizing studies clearly indicate the proficiency of both LA-960V2 and SZ-100V2 technologies in supporting the food industry to enhance their productivity in a short span of time.

Further to particle size characterization, HORIBA Scientific is the world leader in Raman spectroscopy which is a novel method of food analysis and inspection. It enables fast and non-destructive chemical analysis of solids, powders, liquids, and gases. The technique allows the determination of composition via quantitative methods, quality control, and identification of impurities or undesired material. The particle finder feature of Raman microscopy also supports study of particle size and particle shape parameters. More information on the importance of the technology in the investigation and monitoring of food processing will be shared in the November 2023 edition of the magazine.

About the author:

* Application Scientist, HORIBA India Scientific Email: namrata.jain@horiba.com