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Appréciation
Concernant la présentation orale.
Ton oral est un peu trop court (4:44 mins au lieu de 5 mins!),
Il y a quelques erreurs, par exemple "…tried to answer a problem that is following" =} "the following problem-question", ou "First of" =} First of all, "that is problematic" =} "that is my problem-question, ou "The seconds experience" =} "the second experiment
Il y a certains mots qui restent au singulier comme "both cheeses", donc types of cheese
"…how my class group and I try" =} "tried" …car ce sont des actions au passé, donc il faut utiliser le prétérit.
Attention à la prononciation de certains mots comme "pasteurized", "goat's", "research", "salting", "types", "compared", " "pathogenes", "petri", "SRM", "analysis", "Baird-Parker", "quantify", "eradicated", "appreciated", "demonstrate"
Il faut bien prononcer les "s" à la 3ème personne du singulier et après chaque mot au pluriel, exemple "This text explains", "some questions",
C'est bien présenté et ton texte est assez bien écrit.
Hello, this text explains how my class group and I tried to answer a problem that is the following:
Is pasteurized milk cheese better for humans than raw milk cheese?
To do this, we asked a cheese maker (artisant-fromager in french) to ask him some questions.
To start with we were interested in the simple production of a cheese. Our cheese maker uses raw goat's milk. With his answers and our research we now know every step of the cheese making process globaly (curdling, moulding, draining and salting).
To come to this problem we asked ourselves what is the difference between a cheese made from pasteurized milk and a cheese made from raw milk. So what is the difference between them?
First of all milk, that's the problematic, there are two main types of milk, pasteurized milk and raw milk. Raw milk is used as it is with everything in it compared to pasteurized milk. Pasteurized milk undergoes a pasteurization that is to say it is heated to remove all these pathogens and therefore no longer has the same characteristics as raw milk, it is mainly used in large distributions.
To find out the difference between these two cheeses we have carried out experiments, I will explain two of them to you:
The first experiment is on lactobacillus. We have take an enumeration of Lactobacillus by pour plate technique. We know that both cheeses are in comport so we decided to quantify them.
For that we made a seeding in the mass. We made 2 mother's suspensions of each cheese (with raw milk and pasteurized milk bought in supermarkets) then we made a dilution up to 10-8. We placed 1 mL of each dilution in an empty petri dish and then poured the SRM agar in order to inoculate the mass. We made 2 boxes per dilution. The incubation time of the plates is done in an anaerobic jar for 24 hours at 37°C.*
SRM agars are selective agars for lactobacillus.
The seconds experience is on S. aureus.
Staphylococcus aureus is a protein harmful to humans. So in view of the problem we also carried out a quantitative analysis of S. aureus in the two different cheeses.
For this purpose we made 2 mother's suspensions like in the protocol of the previous experiment and then diluted them to 10-2. Then we inoculated the mass with 1mL in each empty petri dish and poured the Baird-Parker agar. Incubation was done at 37°C for 24 hours.
This agar is specific for Staphylococcus aureus and therefore will allow us to quantify this protein in both cheeses.
For the results, we are wrong on the second experiment we think we made a mistake of manipulations because the results are inconsistent. There should be less S. aureus in the pasteurized milk because it underwent a pasteurization that should have eradicated these proteins in the raw milk cheese.
The first experiment is a success we can see that the level of lactobacillus is higher in raw milk cheese than in pasteurized milk which is good for the body.
To conclude a cheese can be appreciated by everyone. Some people prefer raw milk cheese for its "rustic" taste because it is often made by cheese makers while others prefer pasteurized milk cheese for its price or simply for the person's choice, everyone is free to choose the cheese they prefer.
But thanks to our experiments we have been able to demonstrate that raw milk cheese contains more nutrients than pasteurized milk cheese because pasteurized milk cheese has only the nutrients added during the manufacturing process.