Microbes and Food 4

Name / Date
Science / Class

Microbes and Food

Instructions

1.  Work with your assigned group. Each person picks an assigned task (see grading guide).

2.  Choose a food made with microbes, or a food preservation technique that discourages microbes. Sign up on the class list so that we do not have any duplicates. Choices follow:

Foods Made with Microbes
Yogurt, cheese, sour cream, buttermilk / Vinegar, soy sauce / Sauerkraut and dill pickles
Yeast bread / Salami / Cocoa (chocolate)
Food Preservation Techniques that Discourage Microbes
Refrigeration/ Freezing / Drying / Salting
Sugaring (e.g. jellies) / Pickling / Irradiation
Dehydration / Vacuum-packing / Pasteurizing
Smoking, curing / Canning / Adding preservatives

3.  Research online how your food is made or preserved.

·  Find one or more credible information sources.

·  Find a video to show the class (about 3 minutes long)

·  Find 1-2 images

4.  Write a good paragraph about your food. Explain how it is made or preserved. Make sure that you explain the connection between your food and microbes. An example follows.

5.  Type up your final copy, using MLA format. Use www.easybib.com to format your sources. Include the two images, and think of an engaging title.

6.  Bring in samples of your food products to show and share.

Grading Guide

Information
WRITER / Report (a full paragraph) Explain how your food product is made or preserved. Make sure you explain the connection between your food and microbes.
SUPPORT / Video (about 3 minutes). Find an educational video about your food product. Look for a video that supports or extends what you say in your paragraph.
Graphic. Include at least one image with a caption. A before and after approach works well.
Food. Bring in samples of your food product to share with the class.
PRODUCER / Format. Incorporate the report, the video link, the graphic, and the sources into a single document. Use a word processor. Use MLA format with full citations (use www.easybib.com). Send your finished document electronically and on time to Mrs. Lutz. Coordinate efforts from the rest of the team. Make any edits recommended by the teacher.
DIRECTOR / Presentation. Present your food product to the class. Offer a full explanation about how this food product is made with microbes, or how it is preserved in a way to discourage microbes. Try for some entertainment value (a song, a dance, questions for the audience?). Everyone in your group must participate in the presentation.

Student name(s)

Mrs. Lutz

Science Class

Data

From Grapes to Raisins

Figure 1. Grapes come in different types and colors.
http://www.floridahillnursery.com/images/categories/three-grapes.jpg / Figure 2. Grapes dry into raisins that are shelf-stable for about a year.
http://healthbenefitsoff.com/wp-content/uploads/2013/04/health-Benefits-Of-Raisins-kishmish.jpg

As long as 4,000 years ago, people discovered that sunlight can be used to dry grapes into raisins. Nowadays, we use seedless grapes to make raisins. Raisins taste similar to grapes, but they are sweeter because the drying process used to make them concentrates the sugar. Approximately four pounds of fresh grapes are used to make one pound of raisins. The drying process, which takes up to eight weeks, reduces moisture content from 75% to under 15%. The drying process also darkens the color of the grapes/raisins and causes them to wrinkle. Raisins can be dried on the vine, or picked and dried in trays. The finished product, which is then sold in boxes, last for about a year without refrigeration. Raisins resist spoilage by microbes for three reasons. First, their concentrated sugar causes bacteria to lose water, which interferes with their ability to live and reproduce. Second, the low moisture content of raisins keeps microbes from thriving. Third, raisins are acidic, which also discourages microbes. In other words, raisins are good for us to eat, but do not provide an inviting living environment for microbes.

Sources

"How Products Are Made."How Raisins Is Made. N.p., n.d. Web. 10 May 2015. http://www.madehow.com/Volume-4/Raisins.html

"How It’s Made Raisins Discovery Channel."YouTube. YouTube, n.d. Web. 10 May 2015. https://www.youtube.com/watch?v=7e8DepWX4_4

"How Does Sugar Act as a Preservative?"Science Focus. N.p., n.d. Web. 10 Dec. 2016. http://www.sciencefocus.com/qa/how-does-sugar-act-preservative