2. Introduction
• Based on calorie content alone,
cereals and oilseeds contribute
to 61% of total 1.5 quadrillion
kilocalories of food lost or
wasted (FAO, 2011).
• In developing countries, food
losses occur predominantly
after harvest
• By region, cereal postharvest
handling and storage losses are
estimated at 10% in
industrialized Asia, 8% in
SubSaharan Africa, 7% in
Southeast Asia and 4% in Latin
America (FAO, 2011)
3. • For cereal grains, feed and
fiber, quality degradation is
quantified in terms of dry
matter loss (DML). Why?
• Harvested crops are ‘living’
organisms and continue to
perform metabolic functions
even after harvest.
• the amount of DML over a
storage period of time can be
estimated and used in
evaluating safe storage
practices and conditions for
different foods
Introduction
4. Respiration
• DML is the loss of available carbohydrates via
aerobic respiration:
C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + 2835 𝑘𝐽/𝑚𝑜l
• Cell and enzyme respiration in cereals seed work
as living plant
• carbohydrates (cellulose and hemicellulose),
lignin, fats and proteins are respired
5.
6.
7. • carbohydrates tend
to be combusted, or
respired, at faster
rates
• The cereals has
respiration rate
faster than soybean
or peanut, because
these carbohydrate
dominancy.
• 3 factors affecting
respiration: oxygen,
moisture content,
and temperature
Respiration
8. O2
• Oxygen as input of respiration process
• Increasing oxygen concentration can increase
respiration, vice versa
• Limited oxygen can inhibit respiration
9. Moisture Content
• Increasing moisture can
increase respiration rate
• Moisture/water can trigger
hydrolase enzyme 🡺
breakdown food reserves
in endosperm
• O2 consumption rates of
0.5, 5 and 18 mg O2/(kg·h)
for 15.0, 16.6 and 18.0%
moisture corn
• Then, respiration release
H2O as product. It
stimulate next respiration
