NUTR 2150 Lecture : Lectures6&7handout.pdf
Document Summary
Matching the supply of food with! the demand in both time and space. Goals: safety - eliminating food hazards, adequate shelf-life - limiting spoilage, days to months, quality - nutritional and aesthetic (ensuring that the process doesn t affect the quality), availability and variety, convenience, favourable economics! With respect to prevention of microbial hazards and microbial food spoilage, preservation processes are intended to: (1) Decrease the rate of microbial growth (e. g. , refrigeration) Restrict access of microorganisms to the food (e. g. , packaging) (2) (3) (4) High temperature (canning, aseptic processing, pasteurization, blanching)! Low temperature (refrigeration, freezing): reduction of water content! Dehydration (spray drying, freeze drying) : oxygen control (packaging), radiation, chemical preservation, solute addition; water activity control (sugar, salt), ph control (acids), preservative"s (nitrate, benzoate, sorbate), biological preservation, fermentations, objectives:, food safety, preservation, sensory quality, enhanced nutritional quality (bioavailability)! Types of heating processes:: blanching ! vegetables! Wilt vegetables to facilitate packaging prior to freezing or canning: pasteurization!
