Environmental Engineering Reference
In-Depth Information
Flow of materials
Agricultural
products
Distribution
centers
Retailers
Customers
Ingredients
Processing
Packaging
Flow of information
Supply of
raw
materials
Warehousing and
distribution
Manufacturing
Consumption
Figure 3.1
Simplified supply chain for food products. Black arrows in between steps represent
transportation. Materials flow in opposition to information.
In a food supply chain, the main raw materials are produced in the fields, farms, or harvested
from oceans, lakes, and rivers. Some raw materials are processed immediately after harvest
(e.g., fish from oceans and fish farms), whereas others are preprocessed (e.g., some vegetables
are packaged and temperature preconditioned) and then transported for further processing or
distribution. More stable materials (e.g., rice and potatoes) are stored for longer periods of
time before they are finally processed for consumption.
In terms of processing, raw materials may undergo several manufacturing stages at different
locations along the chain. For instance, wheat is harvested and then transported to mills where
it is transformed into flour. Flour is then retailed directly to consumers or sold to the bread and
baking industry that further process it.
Ingredients are the second component of the supply of raw materials and may be domestically
produced or supplied from all around the world. Spices are normally produced in tropical coun-
tries, whereas chemical additives are domestically produced or imported from countries such as
China that have become major players in the production and distribution of food ingredients.
Packaging is an essential third element of the supply of materials for the successful distribution
of food products.
Food processing techniques are very diverse and product specific, and therefore difficult to
generalize. However, for the purpose of studying the environmental impact of food production
systems, Foster et al. (2006) have classified food production according to the degree of pro-
cessing in three categories: low-, medium-, and high-processed foods. Low-processed foods
are mostly fruits and vegetables, which are commercialized as fresh and require minimal
processing, including sorting, washing, and packaging. Medium-processed foods are canned
and frozen products, bread type products, and so on. High-processed foods are those such as
ready-to-eat meals, which encompass several suppliers of raw materials, ingredients, and sev-
eral processes or processors.
After processing, food is packaged in primary containers that are grouped in secondary
containers. These secondary containers are often arranged and held in tertiary containers to
facilitate handling and distribution. Most food processing plants have warehouses to store
products either at room temperature, in cold rooms, or in freezers as needed.
Processed-packed food is then transported from warehouses to distribution centers that are
strategically located in different areas of the country or in other countries. Distribution centers
are specialized buildings equipped with receiving docks, storage areas equipped with
