lesson 3

hazard analysis and critical control points

systematic approach—identify hazards, determine CCPs, set critical limits, monitor, corrective actions, verification, record-keeping.

microbiological control

indicator organisms vs pathogens — testing regimes for total plate counts, coliforms, Salmonella, Listeria, E. coli O157:H7.

traceability

lot coding, blockchain pilots for entire supply chain trace-back

good manufacturing practices

facility design, personnel hygiene, equipment maintenance

chemical hazard

pesticides, mycotoxins (aflatoxin), veterinary

drug residues, allergens, migration from packaging.

sanitation standard operating procedures

cleaning schedules, detergents, ATP testing.

physical hazards

glass, metal, stones — detection by sieves,metal detectors, X-ray.

quality assurance

ensures products meet sensory, nutritional, and functional specification

log reduction

measure of microbial reduction. 1-log = 90%, 3-log = 99.9%, etc.

d value

time at a certain temperature to reduce a microbial population by 1 log (90%)

z value

temperature change needed to change the D-value by a factor of 10

pasteurization

reduces non-spore-forming pathogens (e.g., Listeria)

high pressure processing

400–600 MPa for seconds to minutes —inactivates vegetative pathogens while preserving flavor.

pulsed electric field

short high-voltage pulses disrupt cell membranes — used for liquid foods

fermentation

uses beneficial microbes (lactobacilli, yeasts) to preserve food and add flavor — e.g., yogurt, kimchi

packaging

reduce oxygen, increase CO₂ relative to O₂ to slow respiration in fresh produce; oxygen scavengers extend shelf life

trade offs

thermal sterilization ensures shelf stability but degrades heat-sensitive vitamins and alters sensory attributes. HPP preserves quality but may not inactivate spores and is capital intensive

free drying

preserves structure and nutrients but is costly

control of water activity

reducing aw below certain thresholds prevents microbial growth (e.g., aw < 0.6 prevents bacterial growth

proximate analysis

moisture (oven drying), ash (muffle furnace),

crude protein (Kjeldahl or Dumas), crude fat

(Soxhlet), carbohydrate by difference

chromatography

HPLC for vitamins and sugars; GC for volatile flavor compounds and fatty acids (after derivatization)

spectrophotometry

color, TBARS for lipid oxidation

molecular method

PCR for species identification, DNA barcoding to detect adulteration

immunoassay

allergen detection, mycotoxin screening

mass spectrometry

coupled with GC or HPLC for powerful identification

fortification

adding micronutrients to staple foods (iodization of salt, vitamin A in sugar or oil, iron in flour) to reduce deficiencies.

reformulation

reducing sodium, sugar, trans fats; replacing trans fats with healthier lipids.

life cycle assessment

cradle-to-grave analysis quantifying environmental impacts (global warming potential, eutrophication, water footprint). LCA compares alternative processes (e.g., plant-based vs. animal proteins).

circular economy

minimize waste by reusing or upcycling by-products (e.g., fruit pomace → fiber ingredients; whey → protein isolates)

sustainable packaging

reduce material, choose recyclable/biodegradable options, optimize for preservation to reduce food

risk assessment process

hazard identification, hazard characterization (dose-response), exposure assessment, risk characterization

food fraud and adulteration

intentional deception for economic gain - substitution, dilution, mislabeling.

processed food and public health

Ultra-processed foods (UPFs) are formulations of industrial ingredients with additives; often energy-dense with poor nutritional profiles.

packaging and plastic pollution

conventional single-use plastics pollute ecosystems and contribute microplastics to food chains.

functional food

whole or processed foods that contain biologically active components which provide health benefits beyond basic nutrition (e.g., probiotic yogurt

precision nutrition

tailor dietary advice or products to an individual's genetic makeup, metabolic markers, microbiome profile, lifestyle, and preferences