How long does food last
This presentation is the property of its rightful owner.
Sponsored Links
1 / 26

How LONG Does Food Last? PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on
  • Presentation posted in: General

How LONG Does Food Last?. Michelle Lloyd Department of Nutrition, Dietetics and Food Science Brigham Young University 15 June 2009. General Principles. Sensory. Nutritional. Toxicological. What defines shelf-life?. Is it edible? appearance flavor texture. Is it nutritious?.

Download Presentation

How LONG Does Food Last?

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


How long does food last

How LONG Does Food Last?

Michelle Lloyd

Department of Nutrition, Dietetics and Food Science

Brigham Young University

15 June 2009


General principles

General Principles


What defines shelf life

Sensory

Nutritional

Toxicological

What defines shelf-life?

  • Is it edible?

  • appearance

  • flavor

  • texture

Is it nutritious?

Is it safe?


Vitamin loss

Vitamin Loss

SOURCE: Institute of Food Technologists


Vitamin stability

Vitamin Stability

Caution: These conclusions are oversimplifications and may not accurately represent stability under all circumstances.

Source: Fennema’s Food Chemistry, 4th Edition, p 442; Adapted from Harris, RS (1971). General discussion on the stability of nutrients, in Nutritional Evaluation of Food Processing


What affects shelf life of food

What affects shelf-life of food?

  • Composition

    • Water

    • Fat

    • Protein

    • Carbohydrate

    • Other components

  • Storage Conditions


To preserve your food storage keep it away from

Humidity

Air

Light

Temperature

To preserve your food storage, keep it away from…

SOURCE: Oscar A. Pike, “Storing Fats and Oils,” Ensign, June 1999, 71


Effect of humidity

Stored ~26 yrs

Fresh

Effect of Humidity

Nutrient Loss

  • Thiamin-71%

  • Riboflavin-21%

  • Vitamin A -70%

  • Lysine-80%

~3% moisture>5% moisture

From BYU Master’s Research of Michelle Lloyd, 2003


How long does food last

Effect of Air (Oxygen)

Oxygen absorber packets can extend shelf-life

Oxygen reacts with food

  • Vitamin loss

  • Off-colors

  • Off-flavors

  • Allows bugs to survive


Effect of light

Effect of Light

  • Speeds up reactions

    • Vitamin loss

    • Off-colors

    • Off-flavors


Effect of light on hexanal in whole milk powder

Effect of Light on Hexanal in Whole Milk Powder


Effects of temperature

Effects of Temperature

Figure 173 – Dehydrated nitrogen-packed tomato samples after 30 months storage at 40°F, 70°F, and 100°F.

From BYU Master’s Thesis of Amy Norseth, 1986


Effects of temperature1

Effects of Temperature

Hot storage

Ideal storage

Bread made from ~20 year old wheat


Wet canned foods

Wet-Canned Foods

Source: “Progress in the Tin Plate Industry,” Food Technology, Vol. 5, #10, 1951 and Food Company Information


Corroded cans

Corroded Cans


Byu research on long term storage

BYU Research on Long-term Storage


Collecting samples

Collecting Samples

LDS Church News, 29 Dec 2001, 10


Collecting samples1

Collecting Samples


Foods tested at byu from residential locations

Foods Tested at BYU (from residential locations)

  • Nonfat Dry Milk

  • Oatmeal

  • Instant Potatoes

  • Rice

  • Dried Apples

  • All-Purpose Flour

  • Baking Powder

  • Powdered Eggs

  • Macaroni

  • Pinto Beans

  • Wheat

  • Cornmeal

  • Margarine Powder

  • Split Peas

  • Dehydrated Carrots


How long does food last

Dehydrated apple slices

stored up to 30 yrs

Dehydrated potatoes stored up to 30 yrs

Is it Edible?

From BYU Food Storage Research, 2003


How long does food last

Mark whether or not you would drink each sample in an emergency situation

Is it Edible?

SOURCE: Lloyd MA, Zou J, Ogden LV, Pike OA. 2004. Sensory and Nutritional Quality of Nonfat Dry Milk in Long-term Residential Storage. J Food Sci 69(8):S326-31.


Is it nutritious

Is it Nutritious?

  • In general, the vitamins we have measured in properly stored foods are fairly stable over time.

  • Thiamin

  • Riboflavin

  • Vitamin C

  • Vitamin E

SOURCE: Lloyd MA, Zou J, Ogden LV, Pike OA. 2004. Sensory and Nutritional Quality of Nonfat Dry Milk in Long-term Residential Storage. J Food Sci 69(8):S326-31.


Is it nutritious1

Is it Nutritious?

Vitamin C stores well in dry form

From BYU Food Storage Research, 2004


Is it safe

Is it Safe?

  • Ames test for mutagenicity

  • Tested rice stored long term

Conclusions

“The results of this study suggest that rice held in accelerated and

long-term storage does not increase in mutagenic compounds.”

Pahulu HF et al. 2007. Change in mutagenicity in white rice after accelerated and long-term storage . J Food Sci. 72 (2): C126-C131


Life sustaining shelf life

"Life Sustaining" Shelf-Life

http://providentliving.org/content/display/0,11666,7798-1-4224-1,00.html


Shelf life summary

Shelf-life summary

Weeks:

Fresh produce

1-2 years:

Cooking Oil, Flour

Several years: Wet Canned Foods, Yeast

15-30 years: Powdered Milk, Oats, Instant Potatoes, Dried Apples, Macaroni Pasta, Pinto Beans

30+ years: Wheat, White Rice

No known limit: Granulated Sugar, Salt, Baking Soda, Baking Powder


  • Login