SCHOOL COMPANY UNION STUDENTS GET IN TOUCH WITH LOCAL FOOD PRODUCTION COMPANIES

Transcription

1 rganic hemistry SL MPAY UI STUDETS GET I TU WIT LAL FD PRDUTI MPAIES EBK MADE BY STUDETS FR STUDETS by Julia Adam and annah Jost

2 Table of contents 1. Yoghurt production 1.1 Ingredients 1.2 Preparation 1.3 hemical background 2. aprino production 2.1 Ingredients 2.2 Preparation 3. Mozzarella production 3.1 Ingredients 3.2 Preparation 3.3 hemical background

3 Ingredients for the yoghurt production 2 liters of fresh semi-skimmed milk 0,3 tsp. of starters

4 Production of yoghurt 1. Preperation: eat milk in a stainless steel pan over medium heat until it reaches 82. Pour heated milk into clean canning jars and cool, either by sitting on the counter or in a cool water bath until the temperature drops to 46. Add culture-2 tablespoons (of yoghurt from a previous batch, store bought yoghurt) per quarter of milk. Lightly stir just enough to incorporate into the milk. Place the jars into the oven with the light on for hours. The light should provide a consistent heat of about 43. Put jars into the refrigerator until the yoghurt is cold and set. nce the yoghurt is set you can pour off the liquid whey from the top or strain the yoghurt using cheesecloth for a thicker consistency. At the end, you can enrich the flavour by adding some kinds of fruits or jam. 2. Results of yoghurt production in Poland

5 3. hemical processes of the yoghurt production Lactic acid fermentation 2 Lactose (milk sugar) LATASE 2 2 D- Galactose 2ADP+ 2P i 2ATP D-Glucoze 2AD + 2AD Pyruvate L-(+)-Lactate Lactate dehydrogenase

6 Acid Milk lotting Acidic milk clotting (acidic p) P casein submicelle - e.g protonation of amino acid residues on the micelle surface or 2 2 P change of micelle surface: -formation of zwitterions -shift of isoelectric point -> weakening if hydration shell precipitation and finally coagulation of casein micelles

7 Enzymatic milk clotting Enzymatic milk clotting (nautral p) Pyro- Glu (1) First step: casein degradation by hydrolysis with lab ferment 2 Phe (105) ( kappa) - casein 2 3 Met (106) lab-ferment (chymosin + pepsin) 2 S Pyro- Glu (1) para - - cesein Met (1) 2 S 3 3 Val (64) - Phe (105) caseino macropeptide (MP) change of micelle surface: hydrophilic, negatively charged hydrophobic, neutral Second step: destabilisation and finally coagulation of casein micelles

8 Ingredients for the aprino production 5 liters of fresh semi-skimmed milk 0,3 ml of rennet 0,1 g of starters salt (1 g per 100 g of cheese)

9 Production of aprino 1. Preparation: The first step is to heat the milk up to 26 while stirring it. In the meantime we need to turn on the thermostat at 23/24. Then add the rennet and the starters and stir for 2-3 minutes. Let it rest for 24 hours during which an enzymatic coagulation is operated by the rennet and the starters which make the environment acid. over the pot with tinfoil. ut the curd with a knife following a regular order: this is important to facilitate its separation from the whey, when you pour it in a form with a cloth. ow the process is near to the end: close the cloth, tie it up and put it in the fridge for another 24 hours. The remaining whey will drip in the basin below. n the next day there s the final step: adding salt (1 gram per every 100 g of cheese) and mix it again! We came up with almost 1,3 kg of cheese so we added 13 grams of salt

10 Ingredients for the Mozzarella production 300 ml of water 1,5 tsp. of lemon powder 2,5 ml of rennet 3,7 liters of whole milk 1 tsp. of salt

11 Production of Mozzarella 1. Preparation: First you prepare the lemon powder and rennet 240 ml of water + lemon powder (7 g) 60 ml of water + rennet (2,5 ml) ext you heat the milk up to and add lemon powder Then you remove the pot from the stove and add rennet stir 30 seconds wait 5 minutes By now the milk should be curdled (if it is not curdled wait) ext you cut the curd into square blocks like a grid pattern ow you cook the curds at a temperature of and stir gently Then you stop heating and stir for 5 minutes Use a strainer to seperate the curds from the whey Boil the curds at a temperature of for 5 minutes Take the curds out and stretch and form them. 2. ur produced mozzarella:

12 3. hemical processes of the Mozzerella production caseino macropeptid submicells with kappa-casein Acidic milk clotting submicells (acid p) Acidic milk clotting calciumphosphat (acid p) Acid milk - clotting: P - casein - submicelle 3 Pprotonation - of casein 3 amino acid residues 3 - submicelle 3 on the micelle surface rotonation of 3 + P protonation of mino acid residues 3 + amino acid residues n the micelle surface on the micelle surface 2 citric 2 acid citric acid P P + change Effectsof ofmicelle rennet on surface: the milk protein + -formation of zwitterions -shift of isoelectric point ydrophilic amino -> weakening of hydration shell acid chain and itric acid change of micelle surface: water (the whey) change of micelle -formation surface: of zwitterions -formation of zwitterions -shift of isoelectric point precipitation and finally -> weakening of hydration shell -shift of isoelectric point coagulation of casein micelles -> weakening of hydration shell precipitation and finally coagulation of casein micelles precipitation and finally coagulation of casein micelles Acidic milk clotting (acid p) P casein submicelle

13 Enzymatic milk clotting with rennet Pyro- Glu (1) First step: casein degregation by hydrolysis with rennet Phe (105) S Met(106) 2 Lab-fermant (chymosin+pepsin) 3 3 Val (169) Pyro- Glu (1) para- -casein Phe (105) Met (1) 2 S 3 3 Val (64) caseino macropeptide (MP) hange of micelle surface ydrophilic, negatively charged hydrophobic, neutral Second step: destabilisation and finally coagulation of casein micells

14 Lab (hymosin) The lab enzyme splits the kappa-casein of the submicelles and casein fails. Because of this process cheese is easier to digest than cow milk.

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