Final answer:
A hygrometer measures humidity, which is crucial for controlling environmental conditions that affect food safety and quality by preventing microbial growth. It does not measure mold spores, bacteria count, nor does it identify irradiated food. option b is correct.
Step-by-step explanation:
A hygrometer is a device that measures humidity, which can be vital for a variety of applications, including monitoring food storage conditions to prevent spoilage and ensuring indoor air quality. Microorganisms, including bacteria and fungi, depend on available water to grow. In food preservation, understanding and controlling the water activity (aw) is crucial because bacteria require high aw to thrive, while fungi can tolerate drier conditions.
To prevent food spoilage, methods such as drying, freeze-drying, or adding substances to increase osmotic pressure like in brines and jams are used. These methods decrease the water content and aw, thereby inhibiting microbial growth.
Adjusting the humidity levels is part of ensuring the right storage condition. Therefore, a hygrometer doesn't directly measure mold spores, bacteria count, or determine if food has been subjected to irradiation, but provides important information about the environmental conditions that could affect food safety and quality.