HIERARCHY OF ANALYSIS

 

HIERARCHY OF ANALYSIS

Food undergoes a multi-stage journey from production, processing, distribution, and retail shops or restaurants before it reaches your plate. Throughout this process, food may become unsafe due to various factors, with the most used terms for such issues being 'contamination' and 'adulteration.' Both contamination and adulteration involve the presence of substances unintended in the food product, but the key distinction lies in their intent.

Contamination is typically unintentional and can result from natural causes, such as the uptake of heavy metals from the soil by plants, or from lapses in quality control during food production, like the introduction of foreign materials like hair or glass.

Adulteration, on the other hand, is often economically driven, involving the deliberate substitution or dilution of high-quality ingredients with cheaper alternatives. For example, diluting milk with water to increase its volume. Adulteration may not always lead to immediate health risks, but it invariably introduces unknown hazards and associated risks to the food product.

Food spoilage occurs when there is an undesirable alteration in the food's normal characteristics, affecting its smell, taste, texture, or appearance. Bacteria, molds, and yeasts are common culprits of spoilage, as seen in the appearance of green fuzzy patches on bread, for instance.

Detecting unsafe, adulterated, or spoiled food can be accomplished using our senses, including sight, smell, touch, and hearing. For example, fuzzy and discoloured mold growth, a soft and mushy texture, and a foul odor are signs of spoilage in fruits and vegetables. In canned foods, bulging cans, strong odors upon opening, gas or spurting liquids, and cloudy, mushy food are indicative of spoilage. Sensory examination can also uncover common adulterants, such as visually identifying the addition of papaya seeds to black pepper.

However, it's important to note that not all unsafe or adulterated foods may exhibit poor quality, making it necessary to conduct different levels of analysis to distinguish between safe and unsafe food. Basic analysis can be performed at home or in a school laboratory using minimal equipment, chemicals, and labware. These tests often indicate the presence or absence of negative attributes in a food sample.

Intermediate tests require slightly more advanced equipment and skills and provide quantitative information, revealing the quantity of specific attributes in a food sample. For example, the "Food Safety on Wheels" mobile lab can perform 23 tests to detect adulteration in milk and milk products, including the values of Fat, Solids-Not-Fat, Protein, and the detection of common adulterants.

Advanced analysis, conducted in specialized laboratories by highly skilled technicians using state-of-the-art equipment, is necessary to detect very low levels of negative and positive attributes or obtain specific information about a food's origin. Techniques like inductively coupled plasma mass spectrometry (ICP-MS) can detect heavy metal contaminants, while High Performance Liquid Chromatography (HPLC) is used to analyse organic compounds. Gas Chromatography/Mass Spectrometry (GC/MS) separates and identifies chemical mixtures at the molecular level, while Liquid Chromatography-Mass Spectrometry (LC/MS) combines the separating power of HPLC with mass spectrometry for analysis.

In summary, food safety and quality assessment can be performed at various levels of analysis, ranging from basic sensory examination to advanced laboratory techniques, to ensure the safety and integrity of our food supply.

Reference : fssai