Flashcards
Instant Coffee Processing
Flashcards do conjunto (17)
- 13 types of coffee from a process viewRoast & Ground
Instant
Single Portioned - 22 types of coffee bean & describeARABICA:
- South America & Africa
- Expensive- premium
- Low caffeine but high coffee solubles – lipid content/essential oils and total polysaccharides/sugar = sweet and floral coffee.
- Much higher lipid content and higher total polysaccharide than Robusta.
ROBUSTA
- Can grow everywhere- South America, Africa, Malaysia, Columbia
- Cheap
- Strong and bitter – ‘caffeine shot’ & lower lipid content and total polysaccharides.
- Double the caffeine content of Arabica
- No difficult processing conditions - 3Describe Coffee cherriesGrow in clumps
Deep red colour when ripe
2 coffee beans/seeds in pulp surrounded by mucilage (sugary, sweet tasting membrane)
Processed to separate beans from pulp, wash & dry - 4What is Green Coffee?the form in which coffee is internationally distributed -> beans that have been hulled and cleaned
- 5Draw the processing flow for Green Coffee, including 'wet' and 'dry' processing
- 6Give process flow for Instant coffee production, from green coffee beans.
- 7What is the importance of roasting as a CCP in coffee production?80% of roasting time is moisture removal -> green beans change colour to straw coloured, then to light brown.
Pyrolysis takes place - bean swells and undergoes rapid darkening by maillard reaction, as well as changes to chemical composition of bean.
Swelling takes place due to increased porosity & popping of beans.
Cell structure softens = coffee can be extracted - 8What is the specific heat (Cp) of: 1. dry green Arabica bean? 2. Normal 12% moisture of green coffee bean?1. 0.39
2. 0.47 - 9Degree of roasting is affected by:Time, temp, flow rate of heating air, roasting rate
Degree of roasting measured by:
Colour – visual or quantitative (colour reflectance reading)
Density – monitor before and after
Roasting time – fixed time for well controlled temp - 105 types of roaster:Fluidised bed
Pressure roaster
Horizontal rotating drum – perforated or solid walls
Vertical rotating bowl
Vertical static drum - 11Describe grinding step in coffee productionthrough rollers. Can adjust the number of rollers, the speed of the rollers and the grooves around the rollers to change the particle size achieved. Particle size reduces as goes through the grinder, enables more efficient extraction of soluble solids and volatile flavour substances.
- 12Describe extraction step in coffee productionKey operation for the extraction of soluble solids and volatile aroma/flavour compounds. (by heat and mass transfer into coffee)
Extraction by percolation or infusion (injected steam into coffee)
Percolation extraction:
- Column batteries
- Continuous screw counter clockwise
Infusion extraction:
- Open tanks with agitator
- Closed tanks/reactors, with/without agitators - 13Describe Concentration in coffee productionVacuum concentration – if to spray dry: ~50%TS, if to freeze dry: ~45% TS.
- Maintains aroma and saves money
Freeze concentration
- Water removed as ice crystals
- Maintains aroma
Membrane filtration
- Reverse Osmosis used to pre-concentrate aroma fraction of extract. - 14Drying in coffee productionto achieve low moisture (2-5%) coffee granules from coffee extract.
Spray drying: Very high inlet temperature; can be at a very large scale
Freeze-drying: Temp can be as low as -40oC; expensive, small scale; creates good aroma.
(freeze and then remove ice crystals by sublimation) - 15What is agglomeration used for in coffee processing?Using fluidised bed dryer to improve the reconstitutability of the powder.
- 16Aromatisation of coffeeDried coffee usually doesn’t have an aroma. Larger manufacturers recover the aromatic volatiles during the grinding/extraction process and then spray them back on prior to filling = consumers can open pack to coffee-like fragrance.
Volatiles carried by coffee oil so filling needs to take place under blanket of inert gas like CO2 in order to reduce risk of oxidation. - 17Filling and packingSealed packaging necessary to prevent loss of volatiles and prevent moisture pick-up.
Instant coffee can cake at 7% moisture.
Dehumidifiers used to supply dry air to packing room.
Instant coffee processing conditions: 26oC, 25%RH
Informações
- Descrição
- 4 th yr Food Science SEM 1 (5. Instant Coffee Processing) FlashCards sobre Instant Coffee Processing, criado por Lizzy Cottam em 10-01-2017.
- Criado por
- Lizzy Cottam
- Visualizações
- 2
- Avaliação