Topic: Fermentation in food preparation processes

Target group

High school / technical school student

Core curriculum

New core curriculum:

High school and technical high school. Chemistry – basic level:

XXI. Chemistry around us. Pupil:

7) describes the fermentation processes that occur during kneading and baking bread, wine production, obtaining sour milk, yogurt, cheese; writes equations for the reaction of alcoholic, vinegar and lactic fermentation.

High school and technical high school. Chemistry – extended level:

XXI. Chemistry around us. Pupil:

7) describes the fermentation processes that occur during kneading and baking bread, wine production, obtaining sour milk, yogurt, cheese; writes equations for the reaction of alcoholic, vinegar and lactic fermentation.

Old core curriculum:

High school and technical high school. Chemistry – basic level:

XXI. Chemistry around us. Student:

6) describes the fermentation processes occurring while kneading dough and baking bread, making wine, obtaining sour milk, yogurts, cheeses; writes the equation for the reaction of alcoholic, acetic and lactic fermentation.

General aim of education

The student discusses selected fermentation processes that are used for food processing

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to explain the concept of fermentation;

• to exchange known types of fermentation;

• to exchange the conditions that must be met for the fermentation process to take place;

• to indicate food products that have been produced through fermentation processes;

• to indicate examples from everyday life in which fermentation processes occur;

• to justify that a given fermentation process is desirable and explain when it is not desired;

• to write down equations of the alcoholic and acetic fermentation reaction equation.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

• exposing

  • exposition.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Introduction

1. The teacher hands out Methodology Guide or green, yellow and red sheets of paper to the students to be used during the work based on a traffic light technique. He presents the aims of the lesson in the student's language on a multimedia presentation and discusses the criteria of success (aims of the lesson and success criteria can be send to students via e‑mail or posted on Facebook, so that students will be able to manage their portfolio).

2. The teacher together with the students determines the topic – based on the previously presented lesson aims – and then writes it on the interactive whiteboard/blackboard. Students write the topic in the notebook.

3. Health and safety – before starting the experiments, students familiarise themselves with the safety data sheets of the substances that will be used during the lesson. The teacher points out the need to be careful when working with them.

Realization

1. The teacher, introducing students to the subject of classes, asks them to think about what they have in common curd milk, yogurt, kefir, beer, wine, bread and bun. It should be answered that these are products for which fermentation processes are used, currently referred to as biotechnology processes.

2. The teacher introduces the JIGSAW method. Divide the class into three groups (or six groups - each two will receive the same topic for development) with the same number of students. They are so‑called expert groups. Each participant should become an expert who will significantly contribute to the success of the entire group. Each student performs as a learner and preacher.

3. The teacher distributes sheets of paper and markers to the groups, assigning them with a different problem to be developed (with a temporary purpose of about 10 minutes):
   Group I - alcoholic fermentation
   Group II - lactic fermentation
   III group - acetic fermentation.

4. The groups will read the material for their subject using the abstract, textbook and internet. They prepare them, taking into account reaction reagents, the course of the fermentation process, recording the fermentation in the form of the equation of reactions with the use of summary formulas, fermentation conditions, the use of fermentation processes for food processing. All students working in teams discuss, explain each other unintelligible issues.

5. On the agreed sign, students create new teams, so that in each new group there are experts from all other teams (if there are 6 groups, then students exchange within 3 groups).

6. Experts report on what they have learned in their original groups: the first group expert gives the others the knowledge he has gained a moment ago. Then the expert group II, group III expert (and subsequent) take the floor. Teaching students communicate information to the rest until the scope is exhausted. Each group gets acquainted in this way with all the material planned for implementation on a given lesson (time: about 10 minutes).

7. Experts return to their original groups, confront the acquired knowledge, supplement, check to see if everyone has learned the whole material (time about 7 minutes).

8. The teacher checks, completes and optionally explains unintelligible issues.

9. The instructor informs students that he will conduct experiment „Identification of gas evolved during yeast activity”. Before this happens, they are to formulate a research question and hypotheses and write them down in the form in an abstract. After the experiment, they set together observations, then conclusions, and write them down as well.

10. At the end of the lesson, the teacher asks students to do an interactive exercise - individual work.

Summary

1. The teacher asks the students to finish the following sentences:

   • Today I learned ...

   • I understood that …

   • It surprised me …

   • I found out ...

   The teacher can use the interactive whiteboard in the abstract or instruct students to work with it

Homework

1. Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

2. Make at home a note from the lesson using the sketchnoting method.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Fermentation in food preparation processes

FermentationIndeks dolny is used for centuries to process food. It consists in the practical use of transformati Indeks dolny koniec_{is used for centuries to process food. It consists in the practical use of transformati}ons occurring under the influence of enzymes produced by yeasts and bacteria. It is one of the basic biotechnological processes.

Alcoholic fermentation occurs under the influence of enzymes produced by yeast that break down sugar (e.g. from fruit juice) into ethanol (ethyl alcohol) and carbon dioxide.
The alcoholic fermentation proceeds according to the equation:

Alcoholic fermentation is used, among others in the production process of beer, wine and high‑grade alcoholic beverages.

Lactic acid creates a flavour of dishes such as kefir, curd, cucumbers in brine, sauerkraut or white borscht. Lactic acid is formed in the process of anaerobic lactic fermentation of sugars caused by the action of special bacteria (Bacillus acidi lactici). The protein present in milk congeals under the influence of acid (colloquially it is called „curdling”). After heating of curdled milk, you can separate the cheese and get so‑called whey, which consists of lactic acid and small amounts of lactose, protein and fats.

The milk fermentation process has two stages:

1. The first stage is the hydrolysis of the disaccharide (lactose) contained in the milk into simple sugars (the reaction takes place with the participation of appropriate enzymes).

2. In the second stage, with the participation of lactic bacteria from glucose, lactic acid is formed.

Beverages consisting of fermented milk have many advantages. These are characterized by higher absorption of nutrients, these contain less lactose in comparison with milk (important for people with lactose intolerance) and have valuable taste values.

Sometimes beverages with a low alcohol content, such as wine and beer, left for a long time in open vessels, sour. This process involves converting ethyl alcohol to acetic acid and is called acetic fermentation. Acetic fermentation occurs under the influence of oxygen from the air, involving microorganisms (bacteria or fungi). This process can be presented in the form of the following equation:

In nature, fermentation is a way of breathing in an anaerobic environment. By conducting the fermentation, organisms, such as some bacteria and yeasts, obtain the energy necessary for life. The energy obtained in this way enables the course of various biochemical processes, called metabolic changes, serving the growth and development of these organisms and their life activities, such as movement, reaction to stimuli or reproduction.

Fermentation processes may occur under limited oxygen access – anaerobic fermentations, e.g. alcoholic fermentation, lactic acid fermentation, but also with oxygen – aerobic fermentation, e.g. acetic fermentation.

• Fermentation processes occur with the participation of microorganisms (bacteria and yeasts). These are used in food production.

• Alcoholic fermentation (with the participation of yeast) is the basis for the production of wine, beer and other types of alcohol. This process is also used when baking yeast dough (the carbon dioxide formed as a result of fermentation scarifies the dough).

• Lactic acid fermentation makes it possible to produce such milk products as kefir and yogurt.

• Alcoholic and lactic acid fermentation are processes occurring under anaerobic conditions.

• In the acetic fermentation process, under aerobic conditions, with the participation of acetic acid bacteria, ethyl alcohol is transformed into acetic acid (ethanoic).