Food Production - Biotechnology - Yoghurt Production - GCSE Biology (9-1)

Summary

This script delves into the role of microorganisms in food production, specifically biotechnology. It highlights two key examples: yeast in bread making and bacteria in yogurt production. The process of making yogurt involves sterilization, pasteurization of milk, and fermentation using lactobacillus bacteria. These bacteria convert lactose to lactic acid, creating the yogurt's sour taste and solid texture. The final product can be flavored and cooled to yield a tangy, live bacteria-rich yogurt.

Takeaways

• 🔬 Microorganisms are tiny life forms that can be seen only with a microscope and can have both harmful and beneficial roles.
• 🍞 In food production, microorganisms are used in biotechnology, such as yeast in bread making and bacteria in yogurt production.
• 🥛 The yogurt-making process involves adding a specific bacteria, lactobacillus, to milk to ferment the lactose sugar into lactic acid, giving yogurt its sour taste.
• 🔥 Sterilization of equipment is crucial in yogurt production to prevent unwanted bacteria growth and ensure the safety of the final product.
• 🌡️ Pasteurization of milk is done at 72 degrees Celsius for 15 seconds to kill any existing bacteria, ensuring only the desired lactobacillus is present.
• 🌡️ After adding lactobacillus, the milk is incubated at a temperature between 37 and 44 degrees Celsius for 3 to 6 hours to allow fermentation.
• 🍯 Lactic acid produced during fermentation lowers the pH, causing the milk to solidify and form yogurt.
• 🍓 Once the yogurt is cooled, it becomes a thick product with live bacteria and a tangy taste, which can be enhanced with fruits or flavors.
• 🧊 Cooling the yogurt after fermentation is essential to stop the bacterial activity and achieve the desired consistency and flavor.
• 🧑‍🔬 The entire process of yogurt production is a careful balance of microbiology and temperature control to create a safe and tasty product.

Q & A

What are microorganisms and why are they important in food production?

Microorganisms are tiny life forms that can only be seen with a microscope. They are important in food production because they can be harnessed for beneficial uses, such as in biotechnology.

How do microorganisms cause disease in humans?

Some microorganisms can cause serious diseases in humans by infecting the body and disrupting normal bodily functions.

What is biotechnology in the context of food production?

Biotechnology in food production refers to the use of microorganisms to create or modify food products, such as using yeast to make bread or bacteria to produce yogurt.

What is the role of yeast in bread making?

Yeast plays a crucial role in bread making by fermenting sugars in the dough, producing carbon dioxide gas which causes the dough to rise and gives bread its texture.

Which bacteria is used in yogurt production and what is its function?

Lactobacillus is the bacteria used in yogurt production. It ferments lactose in milk, producing lactic acid which gives yogurt its sour taste and causes the milk to solidify.

What is the process of sterilization in yogurt production and why is it necessary?

Sterilization in yogurt production involves cleaning equipment with bleach or steam to kill any unwanted bacteria. This is necessary to prevent contamination and ensure that only the desired bacteria, like Lactobacillus, are present.

What is pasteurization and how does it relate to yogurt production?

Pasteurization is the process of heating milk to 72 degrees Celsius for 15 seconds and then cooling it rapidly. It is used in yogurt production to kill any existing bacteria in the milk, ensuring that only the added Lactobacillus bacteria will grow.

What happens during the incubation stage of yogurt production?

During the incubation stage, pasteurized milk is mixed with Lactobacillus bacteria and kept at a temperature between 37 and 44 degrees Celsius for 3 to 6 hours. This allows fermentation to occur, converting lactose to lactic acid and causing the milk to solidify.

Why does the pH of milk drop during yogurt production?

The pH of milk drops during yogurt production due to the production of lactic acid by Lactobacillus bacteria as they ferment lactose. This acidification contributes to the sour taste and texture of yogurt.

How does cooling affect the final yogurt product?

Cooling the yogurt after fermentation slows down or stops the bacterial activity, solidifying the yogurt and giving it a thick consistency. It also helps to preserve the yogurt by inhibiting bacterial growth.

Can yogurt be flavored after production and what are some common additions?

Yes, yogurt can be flavored after production. Common additions include fruits, sweeteners, and various flavorings to enhance taste and provide variety to the yogurt product.