Introduction to Food Processing and Food Science
What this domain covers
This opening domain tests whether you can separate two ideas that candidates often blur: food science (the study of the chemistry, microbiology, engineering and nutrition of food) and food processing (the deliberate operations that turn raw agricultural produce into safe, stable, saleable products). The PSEB paper expects definitions, the objectives of processing, the primary/secondary/tertiary classification, and the intrinsic and extrinsic factors that govern spoilage.
Core rules
- Processing objectives: safety, preservation, palatability, convenience, transportability, value addition and waste utilisation - not only longer shelf life.
- Primary processing: cleaning, grading, sorting, milling, hulling, pasteurisation of raw produce. Secondary: jam, biscuits, bread, butter, cheese, pickles. Tertiary: ready-to-eat meals, retort pouches, catering products.
- Spoilage agents: biological (bacteria, yeasts, moulds), chemical (oxidation, enzymatic browning), physical (moisture gain or loss, light, insects).
- Intrinsic factors: pH, water activity, redox potential, nutrient content, antimicrobial constituents. Extrinsic: temperature, relative humidity, gaseous atmosphere.
Worked example
A farmer near Jalandhar has 2 tonnes of surplus tomato in June and cannot sell it fresh. Route: wash → grade and discard bruised fruit → crush → heat to inactivate pectin enzymes → add salt, sugar and citric acid to pH 4.2 → concentrate → hot-fill into sterilised bottles → cool. Reasoning: the product is acidic (pH below 4.6), so a 100 °C hot fill and pasteurisation are sufficient and no pressure retort is needed. Value addition converts a spoiling crop into a stable product.
Traps
Calling simple grading value addition; listing nutrition as a processing objective instead of a food-science discipline; mixing secondary and tertiary examples; forgetting that enzymes, not only microbes, cause spoilage.