We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byKeegan Manders
Modified over 2 years ago
Procedure for Isoelectric Point of Milk: Making Curds & Whey Hands-on module for identifying the isoelectric point of milk and understanding pH. Food Safety Scientist Curriculum © 2014 Board of Regents, South Dakota State University iGrow.org This project was supported by the USDA NIFA grant number 2011-38411-30625
iGrow.org pH: Food & Microogranisms Pathogenic Bacteria grow well at a pH of 4.6-7.5 Meat & Milk have a pH of 5.5-6.8 making them an excellent growth media for foodborne pathogens Fruits: 3.9-4.5 Vegetables: 3.8-6.0 Pathogens grow slowly with a pH BELOW 4.6 & can be minimized even more with a pH of 4.2 Increasing acidity has been used for centuries to preserve foods and is still used today. © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Lab Safety Protocol Lab coat is advised Keep long hair tied back away from face Wear closed toe shoes © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Properties of Milk Milk is a Colloid Colloid: A mixture of liquid and tiny particles that do not settle (unlike orange juice). Examples of Colloids: Glue, Cream, & Paint When Milk is heated, the proteins denature and with the addition of the acid the milk will begin to separate (coagulate) into solid particles (curds) and the remaining liquid is known as whey. Cheese is made from the curds (milk protein & casein) of milk either left unripened or through curing, another food preservation method Examples of unripened cheese: cottage, ricotta, cream cheese Examples of cured cheese: Cheddar, parmesan, jack, mozzarella, provolone © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Properties of Milk Continued Milk has a pH between 6.5-6.7 The pH is controlled by a buffer system of three components: Phosphate, Citrate, & Carbonate When vinegar is added to lower the pH of the milk it inactivates the buffer system pH can decrease – reach isoelectric point Formation of curds © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Isoelectric Point in Milk Isoelectric Point: When a molecule carries neither a positive or negative charge In milk, the isoelectric point indicates when the protein, casein, no longer has a positive or negative charge The isoelectric point for casein is pH value of 4.6. Once 4.6 is reached, the casein protein will separate from the liquid and clump together. © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Procedure: Making Curds & Whey Supplies & Equipment per test: (Calibrated) pH Meter 450 mL (2 cups) Milk 10 mL (2 tsp.) White Distilled Vinegar 500 mL Beakers (or larger) Bunsen Burner Thermometer Colander or Cheese Cloth © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Isoelectric Point: Making Curds & Whey Make sure the pH meter is calibrated to ensure precision & accuracy when taking readings Measure 450 mL of milk into a 500+ mL beaker-Take 2 pH readings of the milk and record the average Take 2-pH readings of the vinegar and record the average © 2014 Board of Regents, South Dakota State University iGrow.org 1 2 3
iGrow.org Isoelectric Point: Making Curds & Whey Place the beaker on a Bunsen Burner and heat milk until it reaches 180°F Continuously check the temperature with a thermometer and stir the milk to prevent burning © 2014 Board of Regents, South Dakota State University iGrow.org
iGrow.org Isoelectric Point: Making Curds & Whey Once 180°F is reached, remove the milk carefully from the Bunsen burner Slowly pour 10 mL of white distilled vinegar into the milk. Stir occasionally. Once cooled, take a pH reading after adding the acid and record. © 2014 Board of Regents, South Dakota State University iGrow.org * Notice the change of consistency in the milk
iGrow.org Isoelectric Point: Making Curds & Whey Once the milk has cooled down, pour the beaker into a colander or filter though cheese cloth Filtering the milk separates the curds from the whey © 2014 Board of Regents, South Dakota State University iGrow.org * Why does the liquid (whey) now have a more opaque appearance?
Procedure for Acidifying Salsa Food Safety Scientist Curriculum © 2014 Board of Regents, South Dakota State University iGrow.org This project was supported.
Procedure for Testing the pH of Various Foods Hands-on module Food Safety Scientist Curriculum © 2014 Board of Regents, South Dakota State University iGrow.org.
Making Cheese. 1. Warm the milk slightly 2. Add a started of lactic-acid producing bacteria 3. Milk becomes slightly-acid, rennin is added. This causes.
Whole milk contains vitamins (vitamins A, D, and K), minerals (calcium, potassium, sodium, phosphorus,), proteins (which include all the essential.
Measuring and Manipulating the pH Level of Egg Yolks Lab Protocol: pH Testing Food Safety Scientist Curriculum © 2014 Board of Regents, South Dakota State.
DAIRY CHAPTER 18 Food for Today. Nutrients in Milk Milk has been called an almost perfect food Especially high in: protein, vitamin A, riboflavin,
simple protein hydrolyze to yield only amino acids e.g.: albumins, globulins. conjugated protein is a protein that functions in interaction with other.
Little Miss Muffet Little Miss Muffet, Sat on her tuffet, Eating her curds and whey. Along came a spider, Who sat down beside her, And frightened Miss.
Isolation of casein from milk
Cooking with Milk and Dairy Products
All About Milk FOOD SCIENCE MS. MCGRATH. Quick Facts About Milk Pasteurization to kill harmful bacteria, milk is heated through a process called pasteurization.
CHEESE OTHER MILK PRODUCTS. DEFINED Curds – coagulated proteins (casein) of milk FDA – product made from curd Whey – liquid remaining; some may be trapped.
THE BIOCHEMISTRY OF MILK
Transition Metal Pigment Lab
BIOTECHNOLOGY IN MANUFACTURING CHEESE. What is Biotechnology? Biotechnological process is one that uses microorganisms in various branches of industry,
Introduction to Biotechnology
+ Dairy Products Family Foods Mrs. Heckman. + Nutrients Major source of calcium High quality protein Riboflavin, phosphorus, Vitamin A Most milk is fortified.
Mixtures And Solutions
Cows. Cattle Breeds There are more than 800 breads of cattle worldwide most are used for beef. About 35 breads of cattle are used for milk.
Steps of Cheesemaking heese.com/wisconsin/ho w_cheese_is_made.aspx heese.com/wisconsin/ho w_cheese_is_made.aspx.
Precipitation of Proteins at isoelectric Point A.Protein solubility: The solubility of proteins in aqueous buffers depends on the distribution of hydrophilic.
DAIRY PRODUCTS. Dairy Products Essential as beverages as well as key ingredients in many dishes Cheese is an important food served by itself or as.
Dairy Products. Dairy Products include milk, yogurt, cheese, ice cream, and pudding. Cream, butter, sour cream are also dairy products but they also have.
Lab Protocol: Gram Staining Yogurt Sample or Milk (raw or pasteurized)
Protein Structure Over 50% of the body’s dry mass is protein; proteins are the most important organic molecule in the body. The building blocks of proteins.
Casein Glue Lab. Purpose and Background 1.Prepare your notebook for recording observations at each step of the procedure. 2.Predict the characteristics.
Strand 5 Knows that materials made by chemically combining two or more substances may have properties that differ from the original materials. GLEs Knows.
All About Dairy. Milk: the “Almost Perfect Food!” Excellent sources of: Excellent sources of: Vitamin D Vitamin D Good sources of: Good sources of: Protein.
EGG AND CHEESE UNIT. EGGS: 1. Eggs are rich in which main nutrient? protein.
COOKING WITH MILK. COOKING WITH MILK FILM or SCUM formation on the top. -May form when milk is HEATED at a HIGH temperature. -As temperature is increased.
The Biochemistry of Milk
* concentrated form of milk *milk is treated so that it curdles (thickens and separates) and changes into CURD- the solid part-made into cheese Whey-
Unit C3-8 Food Science. Problem Area 3 Agricultural Processing Systems.
Unit 14: Milk, Yogurt, and Cheese Family and Consumer Sciences I.
Procedure for QuickTox™ Kit for Aflatoxin Bulk Grain
What makes a serving? One serving of dairy= –1 cup of milk –1 cup of yogurt –1 to 1 ½ oz. of cheese.
Cooking with Milk and Dairy Products Breaking these rules can result in a skin forming on the surface of the milk, scorching, and/or curdling.
States of Matter Slime. Eureka! States of Matter: Liquids.
How it’s made and the classifications of cheese
Chapter 7. A heterogeneous mixture is a nonuniform blend of 2 or more substances Examples of heterogeneous mixtures: fruit salad salsa granite.
Chapter 11 Protein Proteins are mainly composed of the elements carbon, hydrogen, oxygen, and nitrogen Proteins are made up of subunits called organic.
Cheese (strong cheese)(strong cheese) A durable form of milk! times milk concentrate Likely first prepared from soured milk and as milk was stored.
Milk, Yogurt, and Cheese The serving size from the milk and dairy food group is 2-3 CUPS. There are some people that should have more servings from this.
Contain have END SHOW. Soil is Important! Soil is the link between the rocky crust of the Earth and all life on the Earth’s surface. It is a subsystem.
Milk Nutritive Value An excellent source of calcium and phosphorus High in protein Low in iron Vitamin A and D added Source of riboflavin Properties.
Enzymes Lab – the Cheese Factory Chapter 5 Please sign field trip form.
Made from milk Yogurt is made with milk and good bacteria “Good” bacteria is also known as __________ There a many ways to make cheese All of.
© 2017 SlidePlayer.com Inc. All rights reserved.