Nutritional Merits of Home Grown Vs. Store

Nutritional Merits
of Home Grown Vs.
Store Bought Produce
This paper addresses the nutritional merits of eating fresh, home grown
produce from an AeroGarden as opposed to commercially available produce from a
grocery store. A look into the scientific facts about the nutrition of produce on store shelves,
creates an uncomfortable revelation about the food we’re serving our families.
Four big factors that impact the nutritional value of the produce you eat:
l
l
The ripeness of the produce
The length of time since harvest
l
l
The varieties chosen
The harvesting methods
The Problem
Independent Distributor
Nothing compares to the juicy flavor of a tomato picked fresh off the vine and eaten right in the garden. Today’s
global food system ensures that we can find ripe tomatoes any day of the year in any store across the country but
the flavor of those tomatoes is often a far cry from that deep red, vine ripened fruit in your garden.
Moreover the fresh produce we find in our grocery stores today actually contains fewer nutrients than the same
types of produce did just 30 years ago. In 1951, an adult woman could meet her daily requirements of vitamin
A by eating two peaches. By 2002, she would need to eat 53 peaches to obtain the same amount of vitamin A
(Ramberg and McAnnelley, 2002). Commercial agriculture of the 21st century seems focused on enhancing shelf
life of produce, often at the expense of taste and nutrition. This means that maximizing your nutrient dollar in our
current grocery store climate is a daunting task and can result in produce lacking in both flavor and quality.
Ripeness Impacts Nutritional Value
How can our advanced technological world create fruits and vegetables that contain fewer nutrients than they
did in the past? Several things are to blame. First in order to accommodate the 1500-2500 mile trip that the
average produce item travels to reach your grocery cart, the fruit must be harvested well before it is ripe (Pirog et
al., 2001). This premature harvest interrupts the natural ripening process and limits the fruit’s ability to develop
its full nutrient potential.
Studies have shown that tomatoes harvested green have 31% less vitamin C than those allowed to ripen on the
vine (Lee and Kader, 2000). Vine ripened red peppers too, have about 30% more vitamin C than green peppers
(Howard et al., 1994). It is not just vitamin C content that is reduced, in fact vine ripened tomatoes contain more
of the important antioxidants beta carotene and lycopene than those harvested prematurely (Arias et al., 2000).
Continued on Next Page
The Impact of Storage and Travel Times on Nutritional Value
A third important factor in the loss of
nutrients in our food is the storage
and travel times that produce must
endure while being shipped such great
distances.
All fruits and vegetables steadily lose
vitamins while in storage, even at
optimal temperatures. Lettuce loses
46% of some key nutrients within seven
days of cold storage. Spinach loses
22% of lutein and 18% of beta carotene
content after just eight days of cold
storage (Ramberg and McAnnelley,
2002). Culinary herbs, when used fresh, contain significant amounts of antioxidants. These antioxidants decrease
rapidly after harvest making it difficult to reap the full health benefits of fresh culinary herbs with products from
commercial grocery stores (Bottino, 2010).
Plant Variety and Nutritional Value
One of the biggest determinate of nutritional value is plant variety. Even among salad greens, the nutritional
value of many nutrients can more than double from one variety to the next. However, most commercially
available fresh foods today are chosen for their ability to ship well, store well, and continue to “look fresh” while
waiting for a sale to consumers. Often, these choices are made instead of choosing foods with the best flavor or
nutrition.
Tomatoes are the easiest example. Today’s store-bought tomatoes are varieties picked for their ease of shipping
and for their ability to turn red even when unripe. They are uniformly round, hard and, many would say,
flavorless – perfect for shipping and storing on-shelf – but not great for eating!
Harvesting and Nutrition
The harvesting methods used in the field and subsequent handling of the fruits and vegetables also affect the
ultimate nutrient contents achieved. Mechanical harvesting methods used in most commercial farms today,
have a higher probability of bruising or injuring the produce. This type of damage can accelerate nutrient loss or
even affect the ability of the fruit to fully ripen (Lee and Kader, 2000). The vitamin C content in bruised portions
of tomato fruits was found to be 15% less than that of non-damaged tomato tissue (Moretti et al., 1998). Lettuce
leaves sliced by sharp knives had 25-63% lower vitamin C levels than lettuce torn manually (Barry-Ryan and
O’Beirne, 1999).
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The perceived convenience of global food sourcing and mass shipping of
produce to achieve lower prices has been a detriment to our diets and our
planet. Not only has the nutrient availability of fruits and vegetables decreased, but there is an
environmental cost of transporting produce such great distances. Eleven percent of the energy
used in the US food system is spent on transportation (Pirog et al., 2001). This 11% adds up to over
166 million BTU’s of fuel used just on transporting food from farm to table in 2009 (US EIA 2010).
What is the solution to this problem?
Ideally, obtain your produce from local growers or
even better, grow your own. Nothing compares
with the ability to pick a tomato and snip some
fresh basil to go with it right in your own home.
Of course not everyone owns a farm, or even
has access to an outdoor space capable of
supporting a garden. Seasonal restrictions also
limit your ability to grow produce at home, even
for experienced gardeners. Indoor small scale
hydroponics such as the AeroGarden may
provide the best answer for year round fresh
produce at home.
With home grown produce, you control the time
of harvest and obtain perfect, ripe fruits and
vegetables every time. There is no harvesting
or handling damage when growing at home, all
produce is handled gently by only you before it is
prepared and consumed. The ability to pick and
eat within minutes means that your home grown
produce supplies you with the most nutritionally
rich fruits and vegetables available, maximizing
your nutrient dollar and providing your family
with the healthiest produce possible.
Growing fruits and vegetables at home allows you
to combat commercial agriculture’s assault on
the nutrient value of your food while keeping it
affordable and fun for you and your family.
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Commercial Produce
Home Grown Produce
Seed varieties selected for transportability and
shelf life, not nutrient content or flavor
Nutrient rich, flavorful seed varieties
Growing conditions (temperature, light,
fertilizer applications) not always consistent or
optimal for maximizing nutritional content
Consistent, optimal levels of light, fertilizer and
temperature to create nutritionally rich produce
Harvested using mechanical methods, often
causing injury and nutrient loss
Hand-picked & handled just by you
Often prematurely harvested to prolong shelf
life, the produce is unable to reach nutritional
peak
Harvested at the peak of ripeness, maximizing
nutrient content
Can travel 1500 miles or more from farm to
table, losing nutrients each day along the way
Eaten on day of harvest, no travel necessary
References
Arias, T., Lee, C., Specca, D. and Janes, H. (2000). Quality comparison of hydroponic tomatoes (Lycopersicon
esculentum) ripened on and off vine. Journal of Food Science, 65, 545-548.
Barry-Ryan, C. and O’Beirne, D. (1999). Ascorbic acid retention in shredded iceberg lettuce as affected by
minimal processing. Journal of Food Science, 64, 498-500.
Bottino, A (2010). Yield and Quality of Green Leafy Vegetables in Postharvest. Universita Degli Studi Di Napoli
Federico II.
Howard, L., Smith, R., Wagner, A., Villalon, B. and Burns, E (1994). Provitamin A and ascorbic acid content of
fresh pepper cultivars (Capsicum annuum) and processed jalapenos. Journal of Food Science, 59, 362-365.
Lee, S. and Kader, A. (2000). Preharvest and postharvest factors influencing vitamin C content of
horticultural crops. Postharvest Biology and Technology, 20, 207-220.
Moretti,C., Sargent, S., Huber, D., Calbo, A. and Puschmann, R. (1998). Chemical composition and physical
properties of pericarp, locule, and placental tissues of tomatoes with internal bruising. Journal of American
Society of Horticultural Science, 123, 656-660.
Pirog, R., Van Pelt, T., Enshayan, K. and Cook, E. (2001). Food, Fuel and Freeways: An Iowa Perspective on How
Far Food Travels, Fuel Usage and Greenhouse Gas Emissions. Retrieved May 5, 2011 from Leopold Center for
Sustainable Agriculture www.leopold.iastate.edu
Ramberg, J. and McAnnelley, B. (2002). From the Farm to the Kitchen Table: A Review of the Nutrient Losses
in Foods. Glycoscience and Nutrition, 3 (5), 1-12.
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www.eia.doe.gov.
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