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Harvesting and Storing Fresh Vegetables

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Variety in preparation and recipes makes eating vegetables more interesting and healthy ... Ground Beef. 1 pound. How Freezing Affects Food ... – PowerPoint PPT presentation

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Title: Harvesting and Storing Fresh Vegetables


1
(No Transcript)
2
Harvesting and Storing Fresh Produce
  • Jean F. Austin
  • Family and Consumer Science Educator
  • Maryland Cooperative Extension

It is the policy of Maryland Cooperative
Extension that no person shall be subjected to
discrimination on the grounds or race, color,
sex, religion, disability, age or national origin.
3
Todays Program
  • A little food science What causes deterioration
    in fresh produce?
  • A little food history How and why we preserve
    food.
  • A little nutrition The importance of vegetables
    to diet and health.
  • Not too much gardening advice!

4
Harvesting Garden Produce Sources
  • Your home garden (or your neighbors!)
  • Local farmers market and farm stands
  • Pick Your Our (PYO) farmers markets
  • CSA Community Supported Agriculture

5
Harvesting Garden Produce WHEN?
  • Days to maturity as a general guideline
  • Temperature, daylight hours, rainfall, variety
    and soil conditions all affect maturity
  • Harvest in the cool morning hours
  • Dont harvest after a heavy rainfall

6
Harvesting Garden Produce HOW TO
  • Hold the plants with one hand and remove fruit
    with the other hand. Try to avoid bruising
  • Have the right tools and containers kitchen
    scissors, pruners or a sharp knife and baskets or
    other containers that permit ventilation
  • Know your plants some plants need to be
    harvested to continue bearing. What are the
    maturity or ripeness indicators color
    changes, height of top growth, stem and flower
    separation can all be indicators

7
Harvesting Garden Produce Guidelines
  • Know how you plan to use the vegetable eat it,
    store it, preserve it
  • Harvest only what you can use a meals worth or
    the batch you plan to preserve
  • Cool the vegetable to the appropriate temperature
    as quickly as possible after harvesting
  • Store unwashed until just before using

8
Color Flavor Smell Texture Appearance Nutritional
Value
Harvesting Garden Produce Freshness
9
Harvesting Garden Produce Nutrition
10
Harvesting Garden Produce Nutrition
  • Select locally grown, in-season vegetables if
    possible
  • Eat your vegetables as quickly as possible after
    harvesting
  • Cook your vegetables lightly. Steam, microwave,
    stir fry, roast are good techniques to preserve
    taste and nutritional value

11
Harvesting Garden Produce Nutrition
  • Season your vegetables with low calorie sauces or
    fresh herbs
  • Variety in preparation and recipes makes eating
    vegetables more interesting and healthy
  • Vegetables provide vitamins, minerals, fiber and
    phytochemicals (beta carotene, lycopene) and very
    few calories

12
Harvesting Garden Produce Health
  • Of all dietary factors associated with cancer
    fruit and vegetable consumption has the strongest
    correlation as a protective factor
  • National Institute of Health
  • A 40 reduction in cancer rate could be possible
    in the US if we
  • - Exercise regularly
  • - Maintain a healthy weight
  • - Eat more fruits and vegetables
  • American Institute for Cancer Research

13
Harvesting Garden Produce Health
  • Epidemological research supports increased
    vegetable consumption as beneficial
  • - Decreasing risk of heart attack and stroke
  • - Lowering blood pressure
  • - Avoiding diverticulitus
  • - Protecting against cataracts and macular
    degeneration
  • Willett Eat, Drink and Be Healthy

14
Harvesting Garden Produce Storage
How long does fresh produce remain fresh?
  • 3-4 days refrigerator storage is a good rule of
    thumb for home storage
  • Timely harvest proper storage Increased fresh
    quality

15
Harvesting Garden Produce Storage
What causes spoilage?
  • Physical Damage Bruising leads to water loss,
    provides a place for microbial growth
  • Growth of microorganisms molds, yeast and
    bacteria
  • Enzyme Activity (Enzymes are small proteins in
    foods that start or help with reactions, such as
    those that cause browning, off-flavors,
    mushiness, etc.)

16
Harvesting Garden Produce Storage
  • Goal is to avoid undesirable change in plant
    tissue
  • - Stop or slow down metabolic activity of the
    enzymes
  • - Stop or slow down microorganism activity

17
Harvesting Garden Produce Storage
  • Determine best temperature and humidity level for
    storage. Different vegetables need different
    conditions (MN Fact Sheet)
  • Cool and dry 50-60 F 60 humidity
  • Cold and dry 32-40 F 65 humidity
  • Cold and moist 32-40 F 95 humidity

18
Harvesting Garden Produce Storage
  • Determine best temperature and humidity level for
    storage (Idaho Bulletin)
  • Cold and moist
  • Cool and moist
  • Cool and dry
  • Warm and moist
  • Warm and dry

19
Harvesting Garden Produce Storage
  • Microorganisms, especially bacteria, are slowed
    by reduced moisture and very low or very high
    temperature. Bacteria thrive between 40-140 F
    60 humidity
  • Most bacteria grow best in a low acid
    environment. (pH4.6 or gt)
  • Temperature, moisture and the acid content of
    foods influence storage potential.

20
Harvesting Garden Produce Preservation
21
Preservation Methods Canning Freezing Preservin
g Pickling Drying Smoking
22
Harvesting Garden Produce Preservation
  • Food preservation methods are a part of ethnic
    identity and social development
  • Preservation extends availability of foods,
    increases available variety and decreases food
    costs
  • Drying is the earliest method
  • Methods today include freezing, pasteurization,
    irradiation and ultra high temperature packaging

23
Harvesting Garden Produce Preservation
  • Preservation methods manipulate the factors
    considered for good storage.
  • Acid content of food is important in most
    preservation methods.
  • Heat, cold, sugar, salt, smoke, vinegar and
    spices are used in preservation

24
Harvesting Garden Produce Home Canning Basics
  • Boiling Water Bath
  • Pressure Canner Processing
  • Acidity
  • Hot pack or raw pack
  • Proper Jars and Jar Preparation
  • Recipe Selection
  • Headspace
  • Sealing the Jar
  • Storing Canned Foods

25
Harvesting Garden Produce Labels
  • Name of product
  • Added ingredients
  • Form of food - halves, whole, ground, etc.
  • Packaging date
  • Number of servings or amount

9/15/02 Ground Beef 1 pound
26
How Freezing Affects Food
  • To prevent color and flavor changes, as well as
    loss of some nutrients, enzymes should be
    controlled.
  • Enzymes in Vegetables
  • Are destroyed by heat, called blanching, before
    packaging and freezing.
  • Enzymes in Fruits
  • Usually controlled by ascorbic acid (also called
    vitamin C) or some other additives.
  • Fruits are usually not blanched, but can be.
  • People like them raw and uncooked.

27
How Freezing Affects Food --Rancidity
  • Another natural change that causes off-flavors,
    particularly in fatty foods.
  • Not a common problem in fruits veggies.
  • Will continue to happen at freezer temperatures,
    but slower than at warmer temps.
  • Best control is to keep as much air out of the
    package as possible.

28
Freezer Storage What happens when the freezer is
above 0oF ? Shelf life (storage time) for best
quality is shorter.
  • For same final quality
  • Length of Storage
  • 1 year
  • 6 months
  • 3 months
  • 6 weeks
  • 3 weeks
  • 10 days
  • 5 days
  • Temperature
  • 0o F.
  • 5o F.
  • 10o F.
  • 15o F.
  • 20o F.
  • 25o F.
  • 30o F.

29
How Freezing Affects Food
  • Fluctuating Freezer Temperatures
  • Ice in food thaws a little and then re-freezes.
  • Ice crystals get bigger each time.
  • Mushiness because large ice crystal growth
    damages cells more and more.
  • Moisture pulled from product.
  • Other quality losses speeded up due to higher
    temperatures.
  • Moisture Loss
  • Freezer burn tough and dry, but safe.

30
Harvesting Garden Produce Preservation
  • A 1999 nationwide survey by CSREES researched
    home canning activity
  • 27 of households did some home canning
  • Tomatoes were the most frequently canned food.
  • Survey showed that many households did not follow
    best practices, putting people at risk of food
    borne illnesses.

31
Additional Resources
  • www.uga.edu/nchfp/index/html CSREES supported
    website with complete information.
  • USDA Agriculture Information Bulletin No.539
    Complete Guide to Home Canning September 1994
  • Preserving Summers Bounty A Quick and Easy
    Guide to Freezing, Canning, Preserving and Drying
    What You Grow Rodale Press, 1998

32
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