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In relation to freezing vegetables, explain how loss of vitamin B₁ and vitamin C may occur. - Leaving Cert Home Economics - Question 5 - 2011
Question 5
In relation to freezing vegetables, explain how loss of vitamin B₁ and vitamin C may occur.
Worked Solution & Example Answer:In relation to freezing vegetables, explain how loss of vitamin B₁ and vitamin C may occur. - Leaving Cert Home Economics - Question 5 - 2011
Step 1
Blanching results in loss of vitamins
Answer
Blanching is a common pre-treatment process for vegetables before freezing. It involves briefly boiling the vegetables and then rapidly cooling them. This process can lead to the loss of water-soluble vitamins, particularly vitamin B₁ and vitamin C, as these vitamins dissolve in water and are sensitive to heat.
High temperatures during blanching can degrade these vitamins, leading to nutrient loss.
Step 2
Effects of slow freezing
Answer
If vegetables are frozen slowly, the formation of larger ice crystals occurs. These larger crystals can rupture cell walls, damaging the structure of the vegetable. As a result, when the frozen vegetables are thawed, more vitamins, including B₁ and C, can leach out into the thawed juice, leading to further nutrient loss.
Step 3
Loss during thawing
Answer
A certain loss of vitamin B₁ and vitamin C can also occur during the thawing process. If the thawed vegetables are not cooked immediately, or if they are thawed at improper temperatures, there may be further degradation of these vitamins due to exposure to air and light, which can oxidize vitamin C.