Extending Shelf Life 3.0 / 5 based on 1 rating ? Design & Technology: Food TechnologyPreserving and processingGCSEAQA Created by: zoeCreated on: 23-03-14 10:22 What are the four methods of extending shelf life at low temperatures? chilling, cook-chilling, freezing, AFD 1 of 22 What is AFD? accelerated freeze drying 2 of 22 What is meant by quick frozen? food is reduced from 0*c- -18*c in 12 minutes 3 of 22 What does quick freezing reduce? cell damage in the food 4 of 22 What is AFD a combination of? freezing and drying 5 of 22 What happens during AFD? the food is quick frozen then placed in a vacuum under reduced pressure, before being slightly heated to change ice to vapour and dry the food 6 of 22 What is cook-chilling? when food is cooked then cooled to between 0*c and 3*c in 90 minutes or less 7 of 22 How long do cook-chill products have a shelf life of? 5 days 8 of 22 How hot do cook-chill dishes have to be heated to at least? 72*c 9 of 22 Why is the optimum temperature for chilling foods 4*c? prevents growth of listeria monocytogenes 10 of 22 Once cooked how long do you have to heat cook-chill products? 2 hours 11 of 22 What does chilling cause? enzyme activity to be reduced 12 of 22 What are the five high-temperature methods of extending shelf-life? pasteurisation, sterilisation, ultra-heat treatment, canning, irradiation 13 of 22 What is pasteurisation? liquid is heated and held at a temperature for a short time (HTST) 14 of 22 What is sterilisation? food is heated to high temperatures for a longer period than in pasteurisation 15 of 22 What is ultra-heat treatment? when liquid is heated to a very high temperature for a short time 16 of 22 What do radicals do during irradiation? destroy the bacteria 17 of 22 Where does irradiation use ionising radiation from? electron beams or gamma rays 18 of 22 What is canning a form of? sterilisation 19 of 22 How do radicals form in irradiation? the food absorbs the energy 20 of 22 How long do baked beans have to be heated at 120*c for until being quickly cooled? 33 minutes 21 of 22 What is irradiation NOT the same as? radiation 22 of 22
There are a number of methods of preservation, the chosen one just depends on cost, commercial use and type of product. 5.0 / 5 based on 1 rating
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