معالجة الفواكه والخضروات

Study Notes

Food preservation methods start by analyzing the entire food chain, including growing, harvesting, processing, packaging, and distribution. This requires an integrated approach.
Identifying the properties needing preservation is crucial, as one property might be beneficial for one product but detrimental to another.
Shelf life is the duration a product can remain stored under specific conditions, maintaining optimal quality for consumption.
Factors affecting shelf life include the processing method, packaging, and storage conditions.
Predicting shelf life is important, especially for new products without established distribution histories. Predictions rely on understanding deterioration mechanisms and rates.
Deterioration mechanisms are categorized into microbiological (microorganism growth, off-flavor, toxin production), enzymatic (browning, color change, off-flavor), chemical (color loss, flavor loss, nonenzymatic browning, nutrient loss, oxidation-reduction, rancidity), physical (collapse, controlled release, crystallization, flavor encapsulation, phase changes, recrystallization, shrinkage, transport of components), and mechanical (bruising, vibration, cracking, damage).

Preservation methods focus on inhibition, inactivation, and avoiding recontamination.
Inhibition methods include low-temperature storage, reducing water activity, decreasing oxygen, increasing carbon dioxide, acidification, fermentation, adding preservatives, antioxidants, controlling pH, freezing, drying, concentration, surface coating, structural modifications, chemical modifications, gas removal, and phase transition changes (Hurdle technology).
Inactivation methods include sterilization, pasteurization, irradiation, electrifying, pressure treatment, blanching, cooking, frying, extrusion, light, sound, and magnetic fields.
Avoid recontamination methods include packaging, hygienic processing, hygienic storage, aseptic processing, HACCP, GMP, ISO 9000, TQM, and risk analysis & management.