Premier Analytical Services

INVESTIGATIVE MICROSCOPY SERVICE

Appearance and texture of foods are key in consumer preference. These are governed by the food’s structure.

Microscopical examination allows food structures to be visualised and thereby gives valuable information regarding the roles of the various raw ingredients and processing regimes on final product structure and attributes.

PREMIER ANALYTICAL'S INVESTIGATIVE MICROSCOPY SERVICE CAN HELP YOU UNDERSTAND THE EFFECTS OF RAW INGREDIENTS AND PROCESSING ON THE APPEARANCE AND TEXTURE OF YOUR PRODUCTS, ENABLING YOU TO IDENTIFY THE CAUSE OF SPECIFIC ISSUES, IMPROVE PRODUCT QUALITY AND DEVELOP NEW PRODUCTS WITH THE DESIRED ATTRIBUTES.

Premier Analytical Services’ Microscopy laboratory can help you to understand your products by providing expert interpretation of a range of complementary structural and compositional analyses:

Optical microscopy – structures and spatial distributions can be elucidated for components such as fat/oil, protein, starch, cellular plant material, muscle fibres, gums and hydrocolloids.

Scanning electron microscopy – original and fracture surfaces of samples can be examined to give structural information relating to product appearance, aeration, density and texture.

Energy dispersive X-ray microanalysis – inorganic elemental composition can be determined to examine the distribution or dissolution of ingredients, such as salt, cocoa powder and fats.

Fourier transform infrared spectroscopy – determines the composition of polymer based packaging materials.

Image analysis – gives quantitative information on structural features, such as particle size / shape and product aeration / density.

SOME EXAMPLES OF THE USE OF INVESTIGATIVE MICROSCOPY IN UNDERSTANDING FOODS AND POLYMER PACKAGING ARE TO BE FOUND BELOW:

RAW INGREDIENT CHARACTERISATION AND EFFECT OF PROCESSING

The structures existing in raw ingredients affect how they process and their contribution to final product attributes. The selected processing regime can have a dramatic effect on the structure of the product components and therefore the texture/appearance of the final product.

Microscopy can aid in understanding raw ingredients and the structural changes they undergo through processing. Such information can then be used to optimise both processing efficiency and product quality. Microscopy can also be used to confirm some supplier’s ingredient claims.

A controlled heating stage allows heating processes to be mimicked on the optical microscope and changes to the sample structure monitored.


Scanning electron micrograph showing emulsifier distribution (palely contrasting material) within powdered ingredient to be well distributed, but not encapsulating the other ingredient components.		Optical micrograph of a stained, pregelatinised, waxy starch ingredient showing retention of some granular nature. Such information is of importance for achieving correct cook and viscosity in sauces.		Polarised light micrograph of processed fat showing different fat crystal sizes and aggregation; this affects subsequent product mixing and final texture		Optical micrograph of aerated water in oil emulsion (left); emulsion structure is important for product stability and mouth feel. Optical micrograph of specifically stained starch, showing granular nature to have been destroyed by processing (right); starch granularity can be key in starch based product texture.

FINAL PRODUCT QUALITY - APPEARANCE AND TEXTURE

An undesirable product appearance or texture, leading to poor product perception, can form during manufacture or develop over shelf-life. Achieving and maintaining the desired product attributes is therefore important. Identifying the cause of an unwanted characteristic is the first step to delaying or inhibiting its formation through reformulation, process changes or storage conditions.

Microscopical examination over the desired product shelf-life can allow the occurrence of undesired structural changes to be identified sooner, shortening the duration of unsuccessful shelf-life trials.


Scanning electron micrograph of dark, dull chocolate surface due to fat migration into product.		Scanning electron micrograph of dull, white, bloomed chocolate surface.		Optical micrograph showing fat aggregate growth in cream filling over storage affecting appearance and mouth feel.		Scanning electron micrograph showing recrystallisation of sugar syrup phase during shelf-life, thereby affecting initial bite texture.

EQUIPMENT ASSESSMENT

The surface structures of processing equipment can affect product adhesion and release and therefore parameters such as process throughput. Examination of such equipment surfaces can help to explain their performance and be useful in the identification, or design, of better alternatives prior to their use / assessment on line.

PACKAGING STRUCTURE AND COMPOSITION

Microscopy can be used to determine the structure of packaging materials, including cross-sectional and surface structures and seal formation. The additional use of Fourier transform infrared spectroscopy determines the composition of polymer type packaging materials. The results obtained can be searched against our libraries of reference spectra to determine the polymer type.


Scanning electron images of the surfaces of two types of conveyor belts (left and centre) and polished plastic process roller (right) affecting product adherence.		Fourier transform infrared spectra allowing identification of polymer type.		Optical microscopy image of cross-section of laminated packaging showing polymer layers present.