of the globe finds its way to another end. Different processing methods affect processed food, hence

instrumentation techniques such as the use of SEM and NMR comes in handy. The major limiting factor in

their use and installation is cost because they are expensive equipment but have high level of accuracy. SEM

and NMR are nondestructive analytical technique. The two Technology have been adopted in the investigation

of microstructure of food. SEM has been used to view Salmonella biofilm, interaction between some fish

products and the inner part of the packaging material. NMR instrumentation was first used for moisture

measurement in foods.

A scanning electron microscope is an instrument that produces images of a sample by scanning the surface of

SEM has enabled the food industry to broaden possible analysis to which samples can be subjected to and this

has improved quality control techniques. Different food processing conditions affect the microstructure of food

and this can be investigated using SEM. SEM is used to identify the structure of food which includes the

intercellular spaces (Jarzębski et al., 2017; Karim et al., 2018). SEM can play a significant role in investigating

the microstructure of agricultural products during drying or cooking as this affects the behaviour of the

product, for example, a product with a porous microstructure will behave differently from one with a compact

microstructure and this goes a long way in providing information on the nature of processing to be given to

such a product (Xiao and Gao, 2012). Live and dead spores of microbial cells, food spoilage organisms and the

extent of thermal damage to these cells could be viewed using SEM (Rozali et al., 2017). SEM can be used to

investigate disease-causing microbial cells on food samples (Gatti and Montanari, 2018). Ultrastructural

important as it helps in determining its functional properties such as rheology and water holding capacity

(Wang et al., 2018). Kaláb et al. (1995) reported that food microstructure evaluation is most appropriate with

microscopy and imaging techniques because images are formed which can be converted to numerical data if

there is a need. Some other techniques used in different investigations in the food industry include X-ray

microtomography (Tan et al., 2016), fourier transform infrared spectroscopy (FTIR) (Jiao et al., 2018), SDS-

PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) ( Liu et al., 2019), mercury intrusion

porosimetry (Kassama and Ngadi, 2005), differential scanning calorimetry/calorimeter (DSC) (Farah et al.,

2018), X-ray diffractometry/diffractometer (XRD) (Mondal et al., 2015), atomic force microscopy (AFM) (Shi

et al., 2018), Laser scanning confocal microscopy (LSCM) (Corradini and McClements, 2017). The properties

and technological benefits of nanomaterials has necessitated its inclusion in food products, consequently,

subjected to food authentication testing such as tomatoes, vinegar and milk (Sobolev et al., 2016). Detecting

complex samples in food accurately and promptly is necessary for human health safety (Gu et al., 2018). NMR

can be used to determine the dynamics of protein (Wu et al., 2019). Borthakur et al. (2016) reported that

nanoemulsions used in food industries are characterized using NMR. Verboven et al. (2018) defined food

microstructure as the arrangement and interaction in food constituents which results in a microscopic matrix.

Textural and structural changes usually lead to changes in the innate properties of food hence the need to

investigate the structure of processed food. Processing methods requiring high temperature such as extrusion

cooking (Fellows, 2017) and deep-fat frying (Kerr, 2016) could transform proteins and polysaccharides in

foods. Extrusion cooking is a technology which involves high temperature in most cases and would likely

result in microstructural changes. Most researchers have investigated the microstructure of foods with the aid

Reference Manager was used to insert in-text references and the list of Bibliography.

Dhowlaghar et al. (2018) used SEM to view Salmonella biofilm from catfish mucus formed on several food-

contact surfaces. Kontominas et al. (2006) used SEM to investigate the interaction between some fish products

and the inner part of the packaging material (which is a metal). dos Santos Rodrigues et al. (2017) observed

the ultrastructure of cells in Staphylococcus aureus biofilm. Nowacka et al. (2018) investigated the suitability

(level of penetration of substances such as moisture) of some packaging materials (paper and cardboard) used

in food. Liu et al. (2018) determined the different microstructures of milk proteins printed with 3D printer

system for food. Liu and Lanier (2015) characterized the microstructure of ground meat. Nguyen et al. (2018)

analyzed the structure of potato slabs during drying. Ray et al. (2015) examined the structure of the shell of

exopolysaccharides and proteins in milk. Hondoh et al. (2016) observed the movement of oil into chocolate.

Ong et al. (2011) investigated the microstructural changes in milk during cheese manufacture. James and

Smith (2009) characterized the microstructure of chocolate during the processes of heating and cooling.

Jackowiak et al. (2005) characterized wheat kernels which have been damaged by Fusarium. Barron and

Butler (2008) characterized the microstructural properties of bread crumb. Dalgleish et al. (2004) observed

casein micelles. Zhao et al. (2011) characterized powders from soy bean proteins. Taglienti et al. (2011)

investigated the pulp of kiwifruit. Han et al. (2016) investigated Vibrio parahaemolyticus biofilm on the

surfaces of some food and surfaces in contact with food. Oh et al. (2016) used SEM to directly count bacterial

cells on the surfaces of treated and untreated disposable gloves used in food handling. James and Yang (2011)

investigated the tenderness of beef which has been subjected to different processing treatments by observing

probiotic containing cereal-based food product. Wang et al. (2019) investigated microstructure of buckwheat

noodles. Martínez et al. (2015) investigated the microstructure of extruded wheat flour. Kharat et al. (2019)

investigated extrudates from different varieties of whole grain millet flours. Nwadi and Okonkwo (2020)

investigated the effect of extrusion cooking on the microstructure of whole wheat flour using scanning electron

microscope.

One of the most detailed and effective analytical technique used to investigate the structure (such as structure

of proteins) and composition of food without destroying the sample nor producing harmful substances is

(NMR (van Duynhoven, 2017). Callaghan (2017) described NMR microscopy as a Magnetic Resonance

Imaging (MRI) technique which is usually conducted in vertical bore NMR magnets which involves small

samples. Application of NMR in Food Science started in the 1980s (Marcone et al., 2013). In the past NMR

was been used only to determine structure but it is now also been used in chemical fingerprinting and study of

metabolites (Ramakrishnan and Luthria, 2017). Farag et al. (2018) quantified metabolites in two species of

cinnamon. NMR is very efficient in identifying and quantifying substances including metabolites within a

short time. The content, purity and molecular structure of a sample can be determined using NMR. This

NMR technique has been applied include wheat, vinegar, meat, dairy products (milk and cheese), coffee, green

tea, oils (from fish and vegetable), apple juices and more recently wine and beer (Mannina et al., 2012). NMR

have been used to differentiate soluble and insoluble casein phosphate nanoclusters in milk, investigating the

distribution of phosphorus in cheese and detecting the differences in the caseins of different species of milk-

producing animals (Boiani et al., 2017). The advantages of NMR over other physico chemical techniques is

that the sample is not destroyed and there is a wide range of length and time scales from which information is

usually acquired, hence the efficiency of NMR in probing food which is a complex system (Belton et al., 1993;

Watanabe et al. 1995). As a result of consumer consciousness regarding the safety as well as quality of food,

all the food supply chains are ensuring significant concern for food authenticity. NMR and metabolome field

have created great opportunities in the area of food authentication (Lolli & Caligiani, 2024).

thermal attributes of oilseeds. Gresley and Peron (2019) identified chocolates from three different geographical

regions based on the constituents of the chocolate. Pramai et al. (2018) identified metabolites in germinated

rice which may have some health and nutritional benefits. Zhao et al. (2013) detected Cronobacter skazakii in

very low concentration using NMR-based assay. Ishihara et al. (2018) identified the particular metabolites in

cabbage vinegar which differentiates it from other vinegars. Boiani et al. (2017) identified different species of

phosphorus in skim milk so as to investigate ionic changes during microfiltration and diafiltration. Malongane

et al. (2018) identified the compounds in four different South African herbal teas. Soares et al. (2017)

investigated changes (chemical and nutritional) which took place during heat treatment of passion fruit juice.

Rodrigues et al. (2011) monitored the chemical changes in lager beer under forced aging conditions. Martínez-

Yusta and Guillén (2014) determined changes (lipidic composition and Level of degradation) in some fried

cucumber. Xu et al. (2016) investigated the characteristics of solid food sample infused with carbondioxide.

analyses, every required equipment is supposed to be installed before operations begin. Adequate budgeting

should be carried out especially for procurement of expensive equipment such as those for SEM and NMR

techniques. Integrating SEM and NMR with newer imaging techniques or AI-based data analysis for improved

food authentication may also be considered.