Javier Martinez
28 April 2014
WRIT 340
Dr. Ramsey
Illumin Article
Biography
Javier Martinez is a native Angelino, born and raised in the center of Koreatown. He is a
first generation college student pursuing a bachelor’s degree in Mechanical Engineering. Javier
is in his second year and has become an active leader within the USC community. He is
passionate about retaining and increasing diversity within fields of engineering and has been
recently elected the Internal Vice President for the Society of Hispanic Professional Engineers
(SHPE).
Engineering Food Preservation
by
Javier Martinez
Submitted to Dr. Ramsey of the University of Southern California
on April 28th, 2014, in partial fulfillment of the
requirements for WRIT 340
Abstract
An analysis of the effects dehydrating food techniques have had on the increase in quality
of human life. Included, is a description of dehydration techniques and the concurrent changes
that industrialized regions saw during their development. Reasons for the advancement of
dehydrated food technologies are discussed. In parallel, the direct and lasting impact of these
technologies is explored and the potential for further research and application of dehydration
technologies are placed under consideration.
Keywords: food preservation, dehydration, space, drying, NASA
Multimedia Suggestions: Animation of a fruit being dried to demonstrate the weight and
volume reduction effects of dehydration. A video of a meal being rehydrated aboard the
International Space Station to depict practically of dehydrated food.
Introduction
Many people remain oblivious to the simplicity engineers have introduced into their daily
lives. At its essence, engineering describes the action of converting knowledge into useful
applications. Engineers seek to develop new applications for technology in addition to making
current applications more feasible for daily use. The impact of such ingenuity can be seen in
products that have increased the quality of human life all across history. If we consider the
conception and development of food preservation methods, we begin to see examples of the
profound effects engineering applications can have on daily life.
Drying Food
Among the worries of the first humans, was the need to preserve food for consumption at
a later time. With little to no technology, these humans resorted to using the most natural
resources at their disposal. By applying their common knowledge, regardless of their lack of
scientific understanding, early cultures developed the ability to preserve food by drying it.
Drying works by removing moisture from food in order to deprive enzymes and biological
organisms the material they need to complete their respective processes [1], thus preventing
spoiling. The earliest use of food drying may be traced back as early as 12,000 B.C., when heat
from the sun was used to dry food by evaporating water [2] (see Figure 1).
Figure 1.- Example of dried tomatoes
Source: (http://nogmoseedbank.wordpress.com/2010/08/01/
how-to-dry-fruits-and-vegetables-without-sulfites/)
Evidence left by early cultures suggests that heat drying was not only applied to meat and
fish, but also fruits, vegetables, and spices [2]. The benefits of drying food were not limited to
increased durability. By evaporating water from food products, the total volume and weight of
the product was reduced. These effects allowed early cultures to transport more food due to
decreased weight, optimize storage space, and maintain dry food for extended periods of time
because of their significantly slower expiration. In fact, the effects of drying food became so
desirable that later societies engineered complex ways to reproduce the ability to dry food.
During the Middle Ages, Romans desired the ability to dry food but lacked the strong sunlight
needed to complete the process. This spurred the Romans to create specialized rooms, known as
“still houses,” to dry food by circulating heat from fireplaces [2]. The ability to dry food had
significant impacts on the daily life of Roman people. The increased complexity of their
civilization allowed them to utilize dry food to a much larger extent than previous cultures. As
the technological capabilities and interconnectedness of societies progressed, the impact of
technologies that led to food preservation became more notable and complex as well.
Dehydrated food
During the 20th century, the rate of technological growth and interconnectedness between
countries reached unprecedented limits. Armed conflicts resulted from some of these interactions
and the need to reengineer the logistics involving food supply during war became evident.
During conflicts, the U.S Army sought to replace heavy, wet, canned food rations with meals
that were lighter and more durable. Dehydrated food was engineered by using mechanical means
to extract water from food. While dried food contains about 18-22% of original moisture,
dehydrated food contains merely 4-5% [3]. However, the distinguishing difference between the
two methods lies in how moisture is separated from the food. Dehydrating food withdraws
moisture without damaging cell walls, thereby maintaining the majority of a food’s nutritional
value and allowing it to be rehydrated at a later time. Drying on the other hand, happens over
extended periods in which cell walls are permanently cracked [4].
Dehydrated food retains many of its original nutritional characteristics, unlike canned
food which loses nutrients in the surrounding water and dried food which results in ruptured cell
walls [2]. The added benefits of dehydrated food became imperative during the years of WWII.
Similar to early humans and their dried food, deployed soldiers could store and carry dehydrated
food in larger quantities for longer distances. Domestically, resources were very limited due to a
combined war effort. Metal that was used to manufacture canned goods was restricted, fresh
produce was scarce, and rationing was enacted. Because of these conditions, having the ability to
dehydrate vegetables, grains, meat, fruit, and even dairy had a profound impact on daily life.
Dehydrated food allowed people to have a substitute that was usually undistinguishable from the
fresh alternative [1] and it presented added economic value. Simpler packaging, labor, and
transportation costs, which resulted from the decreased size and weight of dehydrated food, led
to it being cheaper and more available.
The promulgation of dehydrated food continued throughout the years and presently, the
use of dehydrated food reaches across the entire breadth of the food industry. Soup companies
rely heavily on the use of dehydrated vegetables, condiments, and meat in their products.
Industries that supply dog food, baby food, and microwaveable meals also depend on the import
of dried materials. The food service industry may account for up to a total of a third of use all
dehydrated vegetables [5] in meal preparation because of its similarity to fresh produce and its
extended shelf life. Dehydrated food has become an integral part of the food industry and
ubiquitous in the lives of people living in industrialized societies. Dehydrated materials are
integrated into all kinds of food including sauces, processed meat, rice mixes, and drinks [3].
Some people may choose to exclusively purchase dehydrated food, however, it is more than
likely that its use will impact them regardless of their choice.
Freeze-Dried Food
Concurrent with the integration of dehydrated food into the food industry, was a new
method of extracting moisture from food. The process is known as freeze-drying and involves
freezing food before removing its water. Once frozen, the food is exposed to a vacuum having
low temperature and pressure, which allows ice to quickly become a gas without returning to the
liquid phase [6] (see Figure 2). Like its predecessors, freeze-drying significantly reduces the size
and weight of food but has the added benefit of being able to maintain more of the intrinsic
properties of the object being dried. Beginning in the 1950’s, the National Aeronautics and Space
Administration (NASA) helped pioneer the use of freeze-drying technology for use in space, by
funding research into how to freeze-dry and package food.
Figure.2
Source: (http://www.packitgourmet.com/trail-foodfacts/fieldguide/articles/driedexplained.html?xid_83175=2d29b50ee31782b4f95e50c3b19f0dd6)
During the first manned missions to space, astronauts carried dreadful freeze-dried
powders to rehydrate and ate semi-liquids from tubes [7]. By the 1970’s, research into freezedrying technology had been developed such that astronauts could enjoy a full complement of
meals (see Figure 3). This research led to innovative devices that easily rehydrate and heat entire
pre-cooked meals aboard spacecraft. More importantly, pioneering freeze-dried food led to
applying the technology outside the space industry into medical, military, and commercial use.
Figure.3 – Range of food options for astronauts
Source: (http://www.nasa.gov/centers/johnson/slsd/about/divisions/hefd/
laboratories/Snack_food_SFSL.html)
The process of freeze-drying is more complex than that of drying or dehydrating food but
the added benefits associated with freeze-drying completely distinguish it. Unlike the two latter
methods, freeze-drying allows products besides food to be preserved. Pharmaceutical companies
are able to use the technique to freeze products of biological origin such as blood, enzymes, and
vaccines; allowing for the experimentation, storage, and transport of these time sensitive
materials [8]. Engineering the methods and equipment to freeze-dry materials has led to profound
applications in the area of pharmaceuticals in addition to the industry from which the technology
originated from.
Once NASA had progressed in their study of freeze-drying technology, the military
sought to introduce full entrée rations that could be easily packaged and rehydrated [9]. The new
rations of freeze-dried meals became known as Meals-Ready-to-Eat (MRE’s) (see Figure 4).
MRE’s were specifically tailored for use in situations in which soldiers were isolated and lacked
a proper food supply line [10]. However, the use of food packets similar to MRE’s has not been
limited to the military. They have seen use in both commercial and emergency applications.
Packets of freeze-dried food are sold commercially and used by backpackers and other
recreational outdoorsmen who rely on a lightweight, long-lasting food when venturing out into
the wilderness [11]. Additionally, freeze-dried food can be stored for use in emergency situations
almost indefinitely [12] and in fact has been distributed by rescue forces after natural disasters.
Figure.4 – Meal Ready to Eat, Boneless Pork Chop
Source: (http://www.liftlovelife.com/how-to-make-the-best-of-mres-and
-glutendairysugar-free-choc-chip-cookie-dough/)
Continued Impact
The development of methods to dehydrate food did not begin with the intent to
revolutionize everyday life. However, by continuously altering existing methods and integrating
advancements in technology, food dehydration has led to greater ease in multiple aspects of day
to day living. Furthermore, as a result of experimenting with the applications of dehydrating
food, the possibility of expanding dehydration and freeze-drying technologies past their intended
use has been made available. These technologies were developed with specific intentions in mind
but after being adapted, they show promise of being able to meet a wide range of different
objectives. Freeze-drying has been implemented in pharmaceuticals to increase the half-life of
sensitive biological materials. With advancements that increase efficiency and reduce cost,
freeze-drying may lead to a new standard in medicine. As humans look to explore the stars and
establish their presence in space, the experimentation done with freeze-dried food by NASA will
serve as the basis for developing a solution to maintaining food storages in deep space. By
considering even seemingly simple inventions like the development of drying and dehydrating
food, we can see how pursuing new applications through engineering can lead to profound
effects in our daily lives.
Works Cited
[1] "Dehydration", Encyclopaedia Britannica. Encyclopaedia Britannica Online Academic
Edition. Encyclopædia Britannica Inc., [online],
http://www.britannica.com/EBchecked/topic/156046/dehydration. (Accessed: 28 February
2014).
[2] Brian A. Nummer, Ph.D, Historical Origins of Food Preservation, National Center for Home
Food Preservation, [online] 2002,
http://nchfp.uga.edu/publications/nchfp/factsheets/food_pres_hist.html. (Accessed: 28 February
2014).
[3] J. H. By. Dehydrated foods. New York Times (1923-Current File) pp. 1. 1943. Available:
http://search.proquest.com/docview/106614903?accountid=14749.
[4] AN AERIAL OBSERVER.,A.LOUISE ANDREALOUIS W.FEHR.19.ISABELLA
PENMAN MacKAY.DR.S.DADAKIS.S.L.O.GEORGE B.MOFFAT.CHARLES MOORE.
DEHYDRATED FOODS. New York Times (1857-1922) pp. 10. 1919. Available:
http://search.proquest.com/docview/100255446?accountid=14749.
[5] R. Kortbech-Olesen. Dehydrated vegetables: A market to watch in the future. International
Trade Forum (1), pp. 26. 1994. Available:
http://search.proquest.com/docview/231395315?accountid=14749.
[6] Space Foods, Mountain House, [online] http://www.mountainhouse.com/M/spc_fds.html.
(Accessed: 28 February 2014).
[7] Food for Space Flight., National Aeronautics and Space Administration, [online] 2004,
http://www.nasa.gov/audience/forstudents/postsecondary/features/F_Food_for_Space_Flight.htm
l (Accessed: 28 February 2014).
[8] General Principles of Freeze Drying, AmericanLyophilizer Inc., [online] 2004,
http://freezedrying.com/freeze-dryers/general-principles-of-freeze-drying/#0. (Accessed: 28
February 2014).
[9] Morris, Thomas Norman, The Dehydration of Food. New York, D. Van Nostrand company
inc 1948. http://babel.hathitrust.org/cgi/pt?id=mdp.39015021223600.
[10] V. R. Sagar and P. Suresh Kumar. Recent advances in drying and dehydration of fruits and
vegetables: A review. Journal of Food Science and Technology 47(1), pp. 15-26. 2010.
Available: http://search.proquest.com/docview/871572277?accountid=14749. DOI:
http://dx.doi.org/10.1007/s13197-010-0010-8.
[11] Space Foods, Mountain House, [online] http://www.mountainhouse.com/M/spc_fds.html.
(Accessed: 28 February 2014).
[12] Emergency Food Supplies, Center for Disease Control and Prevention, [online]
http://emergency.cdc.gov/preparedness/kit/food//. (Accessed: 28 February 2014).