Food Safety and Food Quality Control

by:

 lim ju boo BSc, Postgrad Dip Nutrition, MD, MSc, PhD (Med), FRSPH, FRSM  

A friend on my WhatsApp group sent me a video of a woman using her foot to step on every dough before steaming them into pau (Chinese pie). 

Other videos from Google showed other food handlers and food sellers stepping on flour and dough with their feet before making them into bread or roti canai (Indian bread).  

Many other videos showed food vendors, hawkers, food stalls, or in restaurants urinating or spitting inside food to make the food culturally, socially or religiously "clean" and "acceptable" for consumption or for other reasons best known only to them before serving to

unaware customers. 

I shall not show them here as these videos are revolting, but they are easily available from Google or from Tik Tok videos. You may check them out yourself.  

All these food preparations are illegal practices not allowed in manufactured food products. After seeing some of these videos sent to me, it spurred me to write this short article on Food Quality Control - an area I am familiar with - by training and qualification at the University of Reading, England. 

At the University of Reading, National College of Food Science and Technology (NCFST) in Weybridge, Surrey, in England in the mid 1960's there was an Applied MSc course in Food Quality Control (QC) that I also studied, other than other different courses I underwent in other universities. NCFST is no longer there at Weybridge.  The college has shifted to the main campus at Reading. 

Let me give a very short summary - just a glimpse - what was taught there on Food QC in the mid 1960's.

In Food Quality Control postgraduate course, a variety of tests and analyses are taught in theory in the lecture rooms, and in the practical classes, they are done in the QC analytical laboratories to ensure that food products are safe, hygienic, meet regulatory standards, and are consistent in quality.  

Here are some examples. Food microbiology and chemical food analysis were taught. 

 1. Microbiological assays were done in practical classes.  The purpose is to detect harmful microorganisms (e.g., Salmonella, E. coli as a fecal indicator, Listeria, yeast, mold). The common tests are total plate count, Coliform count and pathogen detection tests (e.g., PCR or ELISA for Salmonella) 

2. Chemical Analysis. The purpose is to ensure the food’s composition is safe, legal, and matches labeling claims. The common analysis taught and done were:

1. pH measurement as it affects flavor and microbial stability, - Moisture content – relates to shelf life.  Additives & preservatives, e.g., nitrites, sulfides.  Nutritional content such as fat, protein, sugar, vitamins,  

2. Contaminants for heavy metals (e.g., lead, mercury), pesticide residues   

3. Physical Tests. The purpose is to check for defects or contamination that affects safety or quality. Common checks are for foreign object detection (metal, glass, plastic). 

4. Texture analysis, color analysis (spectrophotometry or colorimetry), size, weight, shape conformity.   

5. Sensory Evaluation (Organoleptic Testing):  The purpose is to assess product appeal to consumers. The common attributes tested are for appearance, flavor. aroma and texture. 

6. Shelf-Life Testing:  The purpose is to determine how long a product remains safe and retains desired qualities. This includes microbiological stability, oxidation (rancidity), texture changes, etc.

7. Allergen Testing:  The purpose is to confirm absence or proper labeling of allergens (e.g., peanuts, gluten, milk). The common method used is ELISA tests or PCR7. 

8. Packaging Integrity Tests: The purpose here is to ensure the package protects the product from contamination or spoilage. The tests may include seal strength, leak detection and vacuum / gas composition analysis (in modified atmosphere packaging). 

In chemical analysis for food quality control, a wide range of analytical techniques is used depending on the analyte (e.g., fat, sugar, preservatives) and the required precision.  Here are some of the main types of chemical analysis used: 

1. Wet Chemistry Methods. Examples are, gravimetric analysis (e.g., ash content) and classical titrations (e.g., acid-base, redox, complexometric). It is used for, determining moisture, acidity, salt, and vitamin C. 

Analyzing total fat by extraction followed by evaporation and weighing 

2. Titration. Here are some types done. Acid-base titration.  e.g., measuring acidity in juices Redox titration, e.g., vitamin C (ascorbic acid) quantification.  Complexometric titration. e.g., calcium or magnesium using EDTA. The purpose is for the quantification of specific food components with high accuracy 

3. Spectroscopy / Spectrometry.  Common Techniques - UV-Vis Spectrophotometry – e.g., colorants, protein (via Biuret method), antioxidant activity.  Atomic Absorption Spectroscopy (AAS) – for metals like lead, cadmium. Inductively Coupled Plasma (ICP-OES/MS) – trace metal analysis. Infrared (IR/FTIR) Spectroscopy – for fingerprinting food components (e.g., fats, oils). NIR (Near-Infrared) – rapid, non-destructive testing of moisture, fat, protein 

4. Chromatography types:  Gas Chromatography (GC) – volatile compounds, pesticide residues, flavors. 

5. High-Performance Liquid Chromatography (HPLC) – vitamins, preservatives, sugars, amino acids. Thin Layer Chromatography (TLC) – quick qualitative tests.

6.. Dry Chemistry - Techniques - Reagent strips or dipsticks (e.g., for glucose or pH). Infrared analyzers. Used in on-the-spot or rapid testing, especially in dairy or field testing 

7.  Mass Spectrometry (often coupled with GC or HPLC). Used for highly sensitive analysis of contaminants, drug residues, or precise compositional analysis 

8. Electrochemical methods, for example - pH meters, ion-selective electrodes (e.g., for sodium, nitrate). Conductivity meters - Purpose is to analyze ionic content and electrolyte properties. Each method is chosen based on cost, speed, accuracy, and regulatory requirements. 

When we say food quality control (QC) does that mean QC is done only for the finished food products, or the QC done online, meaning monitoring the food from the farm, handling and delivery of the raw materials all the way to the finished food products?  

This is an excellent question should any readers ask me.  In practice, Food Quality Control includes both finished product testing and in-line or in-process monitoring, but there’s an important distinction to make - traditional Quality Control focuses primarily on the finished food products. The goal is to ensure that the final product meets safety, quality, and labeling standards. Examples are testing a batch of packaged juice for pH, sugar content, and microbial safety. Inspecting a final product for color, weight, and shelf life.   

1. In-Process (Online) - Quality Control focuses on continuous monitoring and control during production. The goal is to prevent defects before they occur and maintain consistency. For example, monitoring temperature and pH during fermentation.  

2. Checking metal detectors on the production line. Online fat or moisture analysis with NIR sensors 

3. Farm-to-Fork Quality Monitoring (More of QA + QC): This involves both Quality Control (QC) and Quality Assurance (QA). QC is part of the overall quality management system that starts from the raw material stage. This includes raw material inspection – checking grains for moisture and aflatoxins and mycotoxins. Handling & storage, controlling temperature, humidity, pest exposure. 

4. Processing controls – hygiene, equipment calibration. Packaging & transportation – integrity, cold chain compliance. 

5. Statistics and analytical data used in QC - for upper and lower limits for safety limits - outside these limits warning bells ring.  

Thus, my answer is, QC is not limited to finished products. It is applied at multiple stages (raw materials, in-process, and final product). 

However, the scope of QC often focuses on measurable, testable outputs, while Quality Assurance (QA) includes systems, procedures, and preventive actions throughout the supply chain. 

What about food legislation? 

Does food QC make sure the finished product complies with the food legislation of a country especially in terms of food additives, food composition, food labelling and food and nutritional claim. 

My answer to this question is - yes.  Food Quality Control (QC) plays a key role in ensuring that finished products comply with food legislation, but it does so as part of a larger quality management system that also includes regulatory compliance and quality assurance (QA). 

Let me explain how food QC helps ensure compliance with food legislation: 

1. Food Additives Compliance QC checks: Type and quantity of additives (e.g., preservatives, colorants, sweeteners). The purpose is to ensure they are permitted, within legal limits, and correctly declared on labels. Example: Sodium nitrite in cured meats must not exceed regulatory limits 

2. Food Composition QC checks: Levels of fat, sugar, protein, fiber, salt, moisture. The purpose is to verify that the product matches legal standards and label declarations. For example, a product labeled "low fat" must meet the national criteria for that claim 

3. Food Labeling QC role: This is to support accurate labeling by providing analytical data. It covers ingredient list order, such as allergen declarations, for example, ensuring declared allergens (like gluten) are truly present or absent. QC also includes net quantity and weight. Storage instructions must be included.  

4. Nutritional Claims - QC tests to validate claims such as: “high in vitamin C” “source of fiber” “sugar-free".  The purpose is to prevent misleading consumers and ensure compliance with legal definitions 

5. Food Safety Legislation. QC helps ensure the product is free from contaminants, pathogens, or unauthorized substances, as required by law. This includes monitoring pesticide residues. heavy metals. mycotoxins.

 

A postgraduate course in food quality control for an analytical chemistry graduate is in very high demand because these food specialists are highly employable in the food manufacturing industry for quality control of their products due to stringent food laws and food legislation in every country. 

 

To summarize - QC directly supports compliance with food legislation in areas like additives, composition, labeling, and claims, but it’s often coordinated with QA, regulatory affairs, and R&D departments to ensure full legal compliance.

These food QC are far, far from those food handling and practices, such as stepping and spitting and urinating inside food for some reasons best known to them, sent to me and also found in Google videos.