Processing Flashcards
Simultaneous addition of sensible heat and water vapor resulting to increase in dry bulb temperature and humidity ratio of air
Heating and dehumidification
Adiabatic process (no heat gain or heat
loss) and follows a constant wet-bulb temperature line; sensible heat in the air is converted to latent heat in the
added vapor
Evaporative cooling
Angle of repose of corn cob and rice hull
Corn cub - 30° to 36°
Rice hull - 35° to 50°
The greatest amount of moisture which can be held by dry air occurring at saturation
Water Vapor Saturation Partial Pressure
Universal gas constant in solving specific volume
287.055 Pa-m³/kg-K
Slope of the sides of the grain mass when poured to rest by gravity
Angle of repose
Bulk density of paddy and corn
Paddy- 576 Kg/m³
Corn- 720 kg/m³
Different angle of repose
Very free flowing - 30°-38°
Free flowing - 39° to 45°
Cohesive or non easy flowing - 46° and above
Measure the moisture content of air measured by a thermometer whose bulb is covered with a wet wick
Wet bulb temperature
Point where drying ceases to be constant
Critical moisture content
Used where rests or tempering periods allow the moisture to equalize throughout the grain; gives higher
heated air utilization per exposure and lower actual drying time
Intermittent drying
Most widely used sorting device used in conjunction with air blast that will satisfactory clean and sort granular products
Screening
Finely ground sample is placed near a desiccant in a closed container
Drying with desiccant
Addition or removal of heat without exchange in moisture content of air
Sensible cooling or heating
Lowers both dry bulb temperature and humidity ratio of air both sensible and latent heat are removed from the air
Cooling and dehumidification
Angle of friction of rise in different surface
Steel surface - 26° to 28°
Wood along the grain - 29° to 30°
Wooden across the grain - 31°
The handling of crops as raw material for food seeds fiber and chemical production
Post-production
Angle of friction of rise in different surface
Steel surface - 26 to 28°
Wood along the grain - 29 to 30°
Wooden across the grain - 31° above
Concerned with the changes in sound transmitted through the material
Acoustic Property
The handling of crops as raw material for food, seeds, fiber and chemical production
Postproduction
Optimum moisture content of grain at harvest
21-24%
Moisture content determination where the sample is allowed to equilibrate with the atmosphere with known relative humidity and temperature in the container
Hygrometric Method
Refers to a sample of matter with definite and constant composition
Substance
Deal with the characteristics of light reflected from or transmitted through an object as affected by the different constituents of the object
Optical properties
Optimum moisture content for milling
11%
Mass per unit volume, including the pore spaces; dependent on the grain moisture content foreign matter present and variety of grain sample
Bulk density
Temperature measured by an ordinary thermometer at thermal equilibrium with air
Dry bulb temperature
Impurities present in the body which can be separated through sieves and other cleaning devices
Dockage
Mixture of dry air and low pressure water vapor
Moist air
Describe the movement of heat into or out of a material and how much it it can contain
Thermal Properties
Change in transmittance of electromagnetic radiation, ratio frequency, and electrical energy that can be measured as crops undergo changes during maturation
Concerned with the strength or resistance of a particular crop when placed under stress
Mechanical properties
Maximum angle at which the grain remains in equilibrium on an inclined surface dependent on moisture and type of surface
Angle of friction
An optimal pre-milling treatment given to paddy to its milling to achieve maximum recovery of head rice and to minimize breakage
Parboiling
Used to determine the state of the moist air when at least two psychrometric properties are known
Psychrometric chart
Temperature at which water vapor condenses when moist air is cooled sufficiently
Dew point temperature
Mass per unit volume, excluding the pore spaces, measured using water displacement method and is dependent on moisture content and variety of grain sample
Particle density
Water is removed by adding a chemical that combines with water
Chemical method
Post harvest losses in paddy in the philippines according to BPRE(1996)
Piling - 0.54
Harvesting - 1.81
Threshing/Cleaning - 2.17
Storage - 2.72
Milling - 3.10
Drying - 4.50
Operation or series of operation in which various properties of the crop are intentionally altered through the process
Crop processing
Separation of clean product into various quality fractions defined on the basis of size, shape, density, texture and color
Sorting
Disagreeable change or departure from the food’s normal state and such change can be detected with the sense of smell, taste, touch or vision.
Food spoilage
Shortcut formula for change in weight
W1(1-MC1)=W2(1-MC2)
W1-W2= change in weight
