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The diagram shows one method of yogurt production - Edexcel - GCSE Biology - Question 4 - 2014 - Paper 1
Question 4
The diagram shows one method of yogurt production. (a) (i) Explain why the milk is kept at a temperature of 40 °C during fermentation.
Worked Solution & Example Answer:The diagram shows one method of yogurt production - Edexcel - GCSE Biology - Question 4 - 2014 - Paper 1
Step 1
Explain why the milk is kept at a temperature of 40 °C during fermentation.
Answer
The milk is kept at a temperature of 40 °C during fermentation to optimize the activity of the starter culture bacteria, such as Lactobacillus bulgaricus and Streptococcus thermophilus.
These bacteria thrive at warm temperatures, and maintaining the milk at 40 °C encourages them to ferment lactose into lactic acid. This not only thickens the milk, transforming it into yogurt, but also helps develop the characteristic flavor and texture.
Additionally, this temperature prevents the growth of undesirable microorganisms that could spoil the product, ensuring a safe and successful fermentation process.