Flashcards
Food Processing & Preservation
Flashcards do conjunto (42)
- 1what is food processing?The conversion of raw animal and plant tissue into forms that are convenient and practical to consume. e.g Wheat flour.
- 2What can processing food remove?Substances such as: phyphate, polyphenols and oxalate which can affect nutrient utilization.
- 3Advantages of food processing.Mechanical processing, soaking, fermentation and germination/malting- can increase bio-availability of some nutrients. E.g. phytate inhibits iron, zinc, and calcium absorption.
- 4what is food preservation?Prevents food from being spoiled by the action of enzymes and micro-organisms.
- 5How do enzymes affect food?The alter texture, taste & colour.
E.g. Apples browning when cut
Fat/oil becoming rancid. - 6how do micro-organisms and yeast affect food?Microorganisms and yeast cause mould to grow, due to the nutrient and water content of food.
- 7Advantages of food preservation:INCREASES:
1)safe storage of food
2) availability- out of season foodstuff.
3)availability- Transportation easier
4) shelf life and reduces production costs. - 8Definition of food preservation:Use of specific thermal & non thermal techniques to:
* Minimize the # of spoilage microbes in food.
* make food safe- extended shelf life. - 9What should be maintained in food preservation?Nutritional value
Texture
Flavor of food. - 10What are methods of preservation & storage?Heating
cooling
reducing water content
irradiation
chemical preservatives
novel Techniques - 11What are 2 types of heating methods?Pasteurizing & heat sterilizing.
- 12What are 2 types of cooling?Freezing & Refrigeration.
- 13What are 5 types of reducing water content?Sugaring (Jam)
Salting
Pickling
Drying
Smoking. - 14What are 3 other types of preserving food methods?Irradiation, chemical preservatives & Novel techniques.
- 15What is pasteurization and what effect does it have on food?Mild treatment (Temp between 80 °C-90 °C)
Minimizes pathogenic microbes.
Effect on food:
Minor changes to nutritional & sensory characteristics of foods. Shelf life extended by a few days or weeks. - 16What are some foods that are pasteurized and how is this done?Milk
Heated for 15 sec @ 72 °C
Destroys pathogenic organisms. - 17What are some public health concerns with raw/unpasteurized milk?Banned in Scotland. In the UK 0.01% of raw milk.
Associated with food borne diseases.
mishandled raw milk= 3x more hospitalization than other food borne diseases. - 18What is heat sterilization?Complete destruction of organisms
Effect on food: Increases shelf life up to 6 months @ ambient temperature. - 19What is an example of food that is heat sterilized and how?Milk
-Heated for 15mins @ 12 °C
-destroys all contaminating bacteria
-causes flavour changes
Loss of Vit c & B Vitamins. - 20What is UHT?UHT= Ultra heat Treated/ Ultra High Temperature processing.
-Higher processing temperatures for a shorter time.
Shelf life @ least 6 months (No Fridge) - 21example of UHT food and how.UHT Long life milk, juice, yogurt, wine
Heated for 1 sec @ 135 °C
-destroys all bacteria
tastes better than sterilized
more widely available- abroad. - 22What is Blanching?Blanching= heating food to 75 °C-85 °C for 1-8 Minutes.
Food heated rapidly to a pre-set temperature, held for a pre-set time , cooled rapidly to near ambient temperatures. - 23What happens in blanching? What are Nutrient losses/gains in Blanching. Examples?It inactivates autolytic Enzymes.
It is a pre-treatment before canning/freezing.
There are minimal losses.
Examples: Vegetables. - 24What is canning?Food heated and sealed in an air tight container.
Destroy microbes + prevent re entry
2 ways of processing:
*Boiling- Water bath *Pressure canner. - 25What foods can be canned?Vegetables, meat, pasta.
- 26Are there any gains or losses in canning?Texture + taste changes
Longer shelf life
Nutritional losses- Vit C
Nutr Gains: Lycopene + Dietary fiber. - 27What is freezing?Food frozen below -18 °C
Domestic freezers (-6 °C to -12 °C) Preserves food for months/years if properly stored.
Stored in bulk- cost effective. - 28Are there any changes in freezing?minimal change 2 flavour + Nutrient loss Emulsions= destabilized
Damage to cells by ice crystal growth - 29What is refrigeration?House hold fridges = 2-8C
T > 10 C avoided - 30Are there changes in refrigeration?Reduces rate of biochemical + microbiological changes
Extends shelf life of fresh + processed food Biochem & Physical changes during Fridge storage= loss of quality- limit shelf life - 31What is sugaring?Creates hostile environment- water removed.
Food= heated with sugar
= packed in sugar - 32Changes in sugaring?Sugar attracts water= fermentation Increased Energy content.
- 33Examples of foods that are sugared.Jam.
- 34What is salting?Addition on NACL
1 of the oldest methods of preservation Most bacteria, fungi, pathogenic organisms cannot survive in high salt environment – hypertonic nature - 35Changes in salting?Increases sodium content of food which has health implications- High blood pressure.
- 36What is pickling?Anaerobic fermentation = produce lactic acid (Salt in water=brine)
Marinating + stored in acidic solution usually vinegar (acetic acid) pH <5 - 37Changes in pickling?Increases sodium- Health implications.
- 38What is drying?Moisture removed- heat.
Moisture content too low for microbes to grow.
Sun, air/wind + freeze dry
UNLIMITED SHELF LIFE IN PROPER STORAGE - 39Changes in drying?Nutrients + flavour concentrate
Texture changes
Chem changes to chlorophyll + carotenoid pigments.
Prevented by treatment with ascorbic acid/ or SO2 VITAMIN LOSS - 40What is smoking?Process of flavoring, cooking or preserving food by exposing to smoke from burning or smoldering plant materials e.g. wood.
- 41Smoking Health concerns?Polycyclic aromatic hydrocarbons (PAH) - production of heterocyclic amines & polycyclic aromatic hydrocarbons that can cause colon cancer
- 42Changes in smoking?Removes water (nutrients concentrate) Forms surface layer
Vitamin loss Addition of flavour
Informações
- Descrição
- O usuário eliminou as informações de disciplina FlashCards sobre Food Processing & Preservation, criado por Usuário eliminado em 03-10-2016.
- Criado por
- Usuário eliminado · out 2016
- Atualizado
- 20 dez 2016
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- 67
- Histórico
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- Criado por Cleo Smiley · 6 mai 2015
- Copiado por Adi Woolner · 3 out 2016
- Avaliação