Cheese Production—The Evolution of Cheese Making

Cheese Production—The Evolution of Cheese Making Lab 1C Biotechnology Lab Manuel

Objectives • Each student performs an individual trial of producing cheese using one of four curdling agents • Students gather, process, and analyze data from multiple replications of cheese made with various agents • Students evaluate the cause and effect of variables in an experiment and attempt to limit variations between trials • Students report experimental findings in a standard conclusion format.

Watch Tutorials of Skills 1. Reading Pipets 2. Using Pipets 3. Micro Pipeting 4. P-10 P-20 Micropipeting 5. P-100 P-200 Micropipeting 6. P-1000 Micropipeting

Timeline • Today: Review Key Concepts and set-up lab • Tuesday: Procedures Quiz, Steps 1-6 • Thursday: Steps 7-9, data analysis, start conclusion write-up

The World of Cheese • Who likes it? • How big of a business? • How is it made? • How do you get so many kinds of cheese? • How have Biotechnology improvements in the cheese making process impacted the industry?

Biotechnology Impact on Cheese • Look at page 7 and 8 of lab manual • The increasing use of technology includes enzymes: rennin and chymosin

Enzyme Info. • No matter the origin, the enzymes are doing the curdling; either bacterial enzymes, fungus enzymes, or enzymes extracted from bacteria, fungi, plant or animal cells. • The enzymes are specialized proteins, are like other proteins, their production is coded for on DNA molecules. Some cells produce milk-curdling enzymes, and others do not, depending upon their DNA code. • Enzyme activity depends on several things: concentration, temperature, pH, agitation

Hypothesis If we test each of these curdling agents, buttermilk (a bacterial culture starter), rennin, chymosin, and no additional curdling agent (milk is a negative control), which agent do you think will produce the most cheese in the shortest period of time? And why do you think so?

Procedures/Flow Chart • Make sure you write your procedures with the tips we discussed last week • Make a flow chart…see example

Lab Set-up: Today Set-up stations with everything ACCEPT: • whole milk, buttermilk, rennin and chymosin • 1ml pipet and pump (we will use the P-1000 instead)

Lab Work: Tuesday (Day 1) Steps 1-6 Key Points • Measure 30mL of whole milk and take to bench • Bring tubes to front to get .25 mL buttermilk, rennin and chymosin • Looking for curds • If no curds—take home

Lab Work: Thursday (Day 2) Steps 7-9 Key Points • Step 7—let filter for at least 30 min. • Use a lab scoop to get curds out of tube • Folding filter paper demo—don’t tear • Whey-o-meter set-up demo • Calculating curd volume • When finish with your table 1.2, 1 person per group should input it on the front computer

Data Analysis • This chart will be filled in by each group, then posted to the website, so you can finish the rest of the write-up and graphs

Conclusion/REE, PE, PA • REE=Results, Evidence, Explanation • PE=Possible Errors • PA=Possible Application • See page 10 Conclusion for further explanation

Witnessing • Make sure you get your lab signed by a classmate • See page 6-7 for details

Thinking Like a Biotechnician Helpful Hints to get you thinking • temperature, timing, shaking, measurements, etc. • Sufficient would require results to all (or almost all) be similar • Transfer of curds, filter paper absorbtion

Bar Graphs You will need to draw (or use excel) bar graphs for the class averages (4) and then compare your results to those averages (4). You will have 8 bar graphs in total. Make sure to draw your bar graph right next to the averages. See example

Graph Details • A three part title that includes the subject tested, the independent variable and the dependent variable • Proper data-table set-up, independent on the left (x) and dependent on the right (y) • Label and units • Individual entries and averages

Cheese Production—The Evolution of Cheese Making