|Question 9Verbal

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Text
The food industry has long used thermal technologies to preserve food in large batches. Recent advancements in ohmic heating were made through research in Brazil on the preservation of acerola pulp. Ohmic heating is generally considered to be an improvement over more conventional thermal preservation methods: whereas conventional methods transfer energy from the surface of a food to its interior, ohmic heating passes electric current through food products to generate heat within the food itself, thus reducing industrial cooking times.
Based on the text, what is one disadvantage of some conventional thermal preservation methods?
Their cooking times are longer than those of other methods.
A
They are especially vulnerable to technological breakdowns.
B
They are only effective in heating foods that are lightweight and small in size.
C
They require more energy than do other methods.
D