Module 1: Principles and Methods of Crop Processing Flashcards
operation or a series of operations in which the properties of the crop is intentionally altered through the process
crop processing
transformation of raw agricultural materials into intermediate or finished products
crop processing
examples of crop processing
- pasteurization of milk
- fermentation of milk to produce cheese
does the degree of alteration in properties vary?
yes
what should not be damaged severely when processing crops?
nutritional properties
processing of crops on the earliest days of man’s history
meat and fish - salted, smoked, dried
herbs - dried as meds
fruits and cereals - fermented for alcohol beverages
in the early days, the aim of traditional food processing was to…?
maintain a supply of wholesome and nutritious food during the year
crop processing efforts contributes to
- food security & stability
- food safety
- variety in diet
- avoiding losses or wastage of supplies
- facilitate handling
crop processing helps to facilitate handling and it makes possible the _________ of produce in other areas
marketing
4 post-harvest activities
- packaging
- storage
- transportation
- marketing
a disagreeable change or departure from the
food’s normal state
food spoilage
change can be detected with the senses of
smell, taste, touch, or vision
they are damaged when food spoilage occurs
- nutritional value
- texture
- flavor
when food spoilage occurs, the food can still be eaten somehow
true or false
false; spoiled food is harmful and unsuitable to eat
degree and rate of spoilage vary
true or false
true
______ moisture content is conducive for microbial growth
high or low
high
3 classification of foods
- perishable
- semi-perishable
- staple or non-perishable
3 classification of foods
lasts several days
perishable
meat, milk, eggs, fruits and veggies
3 classification of foods
can last from 6 months to 1 year
semi-perishable
flour grain products, dried fruits and dry mixes
3 classification of foods
foods lasting for more than 1 year
staple or non-perishable
sugar, dried beans, spices and canned goods
causes of food spoilage
- microbial spoilage
- other factors
- biological and chemical reactions
- infestations of insects and rodents
- low temp injury
microbial spoilage
minor agent, common sa dried fruits and veggies
fungi
microbial spoilage
major agent, especially sa wet or high moisture food
bacteria
examples of microbial spoilage
- blue mould rot and soft rot in tomato
- watery soft rot in apple
steps on how microbial spoilage occurs
microorganisms utilize the food constituents for their metabolic activities resulting in loss of quality
they produce enzymes and other chemicals during metabolic activities to enhance food quality deterioration
techniques to avoid microbial spoilage
1 destroy the microorganisms
2. suppress their growth by modifying their environment
3. deprive them of water
preservation methods
- thermal processing
a. pasteurization
b. sterilization - dehydration and drying
- freezing
- chemical preservation
- fermentation
preservation methods
food is subjected to heat treatment to kill the enzymes and micro-orgs by heating then sealing while still hot
thermal processing
preservation methods - thermal processing
foods are heated below boiling point of water, generally followed by prompt cooling
pasteurization
preservation methods - thermal processing
application of high temp heat to eliminate microorganisms
sterilization
ex: canning
preservation methods
removal of moisture to a safe level
drying
preservation methods
complete removal of moisture
dehydration
removal of water in liquid foods or addition of solid to lower water/solid ratio
concentration
ways of removing water from food
- use of natural agents, i.e. sun, wind
- use of chemicals, i.e. salt, sugar
- use of engineering devices, i.e. heating,freezing
general rule in water removal (or reduction)
reduction of water content in the food retards enzymatic action
preservation methods
combi of beneficial effects of low temps where microorgs cannot grow, chem reactions are reduced, and cellular metabolic reactions are delayed
freezing
preservation methods - methods of freezing
- direct contact with refrigerant (ex: spray freezing)
- indirect contact between food and refrigerant (plate freezing)
- use of refrigerated air (ex: blast freezing)
preservation methods - chemical preservation
commonly used preservatives/practices
- salt and sugar
- wood smoking
- other activities
- sodium benzoate (mayo, pickles)
- propionate (bakery)
- nitrite (cured and fermented meat)
preservation methods - chemical preservation
lowers the water activity of foods therefore inhibiting the growth of microorgs
salt and sugar
preservation methods - chemical preservation
anaerobic breakdown of carbohydrates with or without the production of CO2
fermentation
preservation methods - chemical preservation
by-products of fermentation have a __________ effect in the food by ________ the pH
preserving; lowering
wood smoke contains alcohols, organic acids, phenols, aldehydes, ethers, etc. that when absorbed by water, it provides?
added color and flavor
these are the overruling objectives of the agri sector over the years
- food security
- increasing incomes
a crucial step in converting raw harvested agri products into marketable products
crop processing
these can make a big difference to the financial impact of small-scale agriculture
post-harvest activities
transformation of raw agri mats into intermediate finished products such as animal fee, crude oil extracts for biofuel production, and industrial fibers
crop processing
general term applied to handle crops as raw material for food, seeds, fiber, and chemical production
postproduction
postproduction starts from harvest up to transport only
true or false
false; harvest to retail (final consumer)
postproduction covers primary and secondary processing
true or false
true
secondary processing includes food and non-food crop handling, seed processing and storage
true or false
false; that is primary processing
includes trimming, washing, curing, waxing, disease/pest control, sorting, sizing, cooling and packing
postharvest handling
a processing job consists of series of events or known as?
unit operations
the unit operations [processes, devices, and procedures] that appear the most important in agri processing are
- size reduction
- air conditioning
- cleaning and sorting
- steam generation and use
- drying and dehydration
- heat transfer
- concentration by evaporation
- pumps and fans
- refrigeration
- plant layout
- mats handling
- instrumentation
main contributor in food spoilage
[high] moisture content
all cooked foods are considered perishable foods
true or false
true
staple or non-perishable foods won’t lose quality if stored under ideal conditions
true or false
false; it will lose quality even is stored under ideal conditions
is there an exact method to determine how long a food will maintain quality and be safe to eat?
none; because many conditions affect quality
storage life of foods is affected by
- freshness of the food when it reached the grocery store
- length of time and the temperature at which it was held before purchase
- temperature of your food storage areas
- humidity level in your food storage areas
- type of storage container or packaging the food is stored in
- characteristics of the food item
it can be the result of insect damage, physical injury, enzymatic degradation and microbial activity
spoiled food
it accounts for huge losses in food stocks
infestations (invasions) insects and rodents
if uncooked food are not used while fresh, ___________ cause undesirable changes in color, texture and flavor
enzymes
this is known as enzymatic degradation
enzymes are destroyed easily by heat processing
true or false
true
___________ of air causes food spoilage because atmospheric ______ can react with some food components that may cause rancidity or color changes
oxidation; oxygen
microbial spoilage
this causes fermentation, which is the result of its metabolism
yeast
two types of yeast
- true yeast
- false yeast
two types of yeast
metabolizes sugar producing alcohol and carbon dioxide gas (fermentation)
true yeast
two types of yeast
grows as a dry film on a food surface, such as on pickle brine
false yeast
_______ (true/false) yeast occurs in foods that have a high sugar content or high acid environment
false
these form spores which, when dry, float through the air to find suitable conditions where they can start the growth cycle agin
moulds
main symptoms from eating moulds
nausea or vomiting from the bad taste and smell
both yeasts and moulds can thrive in high in high acids foods
true or false
true
both yeasts and moulds are not easily destroyed by heat
true or false
false; they are easily destroyed by heat
how are yeasts and moulds destroyed in high acid foods?
processing them at a temp of 100 degree Celsius in a boiling water canner
round, rod or spiral shaped microorg and grows under a wide variety of conditions
bacteria
bacteria prefer low acid foods like veggies and meat
true or false
true
how is bacteria destroyed in foods?
low acid foods must be processed for the appropriate length of time at 116 degree Celsius in a pressure canner
eating spoiled food caused by bacteria can cause?
food poisoning
pasteurization was developed by _____ ________ in 1864 to improve the keeping qualities of wine
Louis Pasteur
pasteurization is less drastic than sterilization, yet it is already sufficient to inactivate particular diseases-producing organisms
true or false
true
pasteurization inactivates most viable vegetative forms of microorganisms as well as heat-resistant spores
true or false
false; but not heat-resistant spores
preservation methods
main objective of sterilization
to eliminate microorganisms that is, bacteria, yeasts and moulds to prevent decomposition of the food
pathogenic toxins may be produced during _________ of the good if certain organisms are still viable
storage
there is only 1 fixed amount of heating required to kill different organisms
true or false
false; amount of heating required varies across different organisms
which are harder to destroy by heat treatment?
spores or vegetative forms of bacteria
spores forms
effects of the reduction of water in food
- decreased weight
- increase amount of product per container
- decreased shipping costs
preservation methods
considered to be one of the oldest methods of food preservation that have become sophisticated over time
drying
preservation methods
one of the oldest and most widely used methods of food preservation
freezing
freezing is the best in preserving the taste, texture, and nutritional value in foods among the methods
true or false
true
freezing preservation ________(retains/reduces) the quality of agricultural products over long storage periods
retains
freezing is superior to canning and dehydration
true or false
true
factors contributing to the safety and nutrition quality of frozen products
- high quality raw materials
- good manufacturing practices in the preservation process
- products are kept in accordance with specified temperatures
substances which are added in very low quantities (up to 0.2%) and which do not alter the organoleptic and physico-chemical properties of the foods at or only very little.
chemical foods preservatives
preservation of food containing food preservatives is based on
- combined or synergistic activity of several additives
- intrinsic product parameters
- extrinsic factors
conversion of carbohydrates to alcohols and carbon dioxide or organic acids using yeasts, bacteria, or a combination thereof, under anaerobic conditions.
fermentation
the chemical conversion of sugars into ethanol, a process which is used to produce alcoholic beverages such as wine, beer, and cider
fermentation
leavening of bread (CO2 produced by yeast activity) is a process of fermentation
true or false
true
what is produced in sour foods through fermentation?
lactic acid
three stages of fermentation
acidification: bacteria, mold, or yeast start the process by creating an acidic environment, promoting the growth of more microorganisms.
flora proliferation: as acidity increases, beneficial bacteria and other microorganisms thrive.
flavor improvement: the pH continues to drop as remaining proteins, sugars, and starches are fermented, this stage enhances flavor by reducing acidity and bitterness.
the degradation in both quantity and quality of a food production from harvest to consumption
postharvest loss
quality losses include those that affect the….?
- nutrient/caloric composition
- acceptability
- edibility of a given product
cutting postharvest losses does what?
add a sizable quantity to the global food supply, thus reducing the need to intensity production in the future
postharvest activities include the following
- handling
- storage
- processing
- packaging
- transpotransp
6, marketing
according to the World Resources Institute, ______________ _______ of horticultural produce are a significant problem
these losses can occur due to various factors throughout the supply chain, from _______ to _______
this results in wasted food, resources, and human effort, however, accurately measuring these losses is challenging
post-harvest losses; farming to retail
these can provoke losses of products even before their harvest
- poor quality seeds
- inadequate farming practices
- insect attacks
from the harvest onward, the grain undergoes a series of operations during the course of which quantitative and qualitative losses can occur
true or false
true
it determines the time time of harvesting
degree of maturity
risks of extended pre-harvest field drying
- losses due to attacks by pests
- moulds
- theft
risk of harvesting before maturity
mould development leading to decay of seeds
what can cause quantitative loss of product during transport?
- transport conditions
- defective packaging
insufficient drying can cause losses from the development of which things during storage
- moulds
- insects
- rot
excessive drying of grain causes the grain to become too dry and becomes ________ and can crack after threshing, during hulling or milling
brittle
if harvest is threshed before it is dry enough, the operation will most probably be incomplete
true or false
true
if grains are threshed when too damp, it will be more susceptible to?
micro-organisms
art of keeping the quality of agricultural materials and preventing them from deterioration for specific period of time, beyond their normal shelf life.
storage
excessive hulling can case cracks and lesion, and it also becomes vulnerable to insects such as the….?
rice moth (Corcyra cephalonica)
final and decisive element in the post-harvest system
marketing
in 2010, a total of ___% palay grain losses incurred during postharvest activities
16.47%
drying and milling recorded the highest losses with 34% and 36% respectively
true or false
false; 36% and 34% share respectively
(2018) an average of 7.8 percent was lost in the cost postharvest system, of which 4.54% was due to milling loss
true or false
false; it was due to drying loss
these types of crops account for 44% of total volume of food crops
high-value crops
average post-harvest losses are 42% for vegetables and 38% for fruits
true or false
false; it was 28% for fruits
(2005) a loss reduction of 1% is equivalent to Php ____ million gain in productivity
Php 355.2 million gain
constraints in the PH post-harvest industry
- wide economic gap between farmers and businessmen
- low adoption of improved post-harvest facilities
- technical inefficiencies
- insufficient post-harvest training and extension activities
- weak information system
- cooperative capacity
- resource constraints
(Kader, 2005) strategies for reducing postharvest losses include
- applying current knowledge to improve handling systems, especially packaging and cold chain maintenance, to ensure quality and safety of horticultural perishables
- overcoming socioeconomic constraints, such as infrastructure inadequacies, poor marketing systems, and weak research and development capacity
- encouraging consolidation and vertical integration among producers and marketers of crops
choice of technology package depends on the circumstances such as
- scale of production
- crop type
- prevailing climatic conditions
- farmer’s affordability and willingness to pay
the logical first step in identifying an appropriate strategy for reducing postharvest losses
systematic analysis of each commodity production and handling system
in PH, most grains have a single annual harvesting season
true or false
true
grains should be dried in such a manner that damage to the grain is minimized and moisture levels are lower than those required to support mold growth during storage
what percentage
(usually below 13-15%)
quality can be improved after harvest
true or false
false; it cannot be improved, only maintained
post-harvest losses at storage are associated with?
- poor conditions
- lack of storage capacity
storage should be constructed possessing these qualities
- dry, well-vented conditions
- protection from rain and drainage of ground water
- protection from entry of rodents and birds and minimum temp fluctuations
main causes of loss of in roots and tubers are associated with
- mechanical damage
- physiological condition (maturity, respiration, water loss, sprouting)
- diseases
- pests
root and tuber crops are still living organisms after they have been harvested
true or false
true
losses that occur during storage of roots and tubers arise mainly from?
their physical and physiological condition
REVIEW QUESTIONS (no answer in the flashcard)
- Define the following crop processing activities:
a. Cleaning
b. Sorting
c. Grading - Suggest ways to prevent postharvest losses.
- How is giving priority in increasing agricultural produce may alleviate poverty?
EXPLAIN
