196. A food product having water activity of 0.6 is exposed to conditions of 30°C and 70% R.H. This product will
tend to ___________
1. Gain moisture
2. Lose moisture
3. Neither gain, nor lose moisture
4. Initially lose, then gain moisture

Introduction:

Water activity (aw) is a key parameter in determining the behavior of moisture in food products. It indicates the amount of water available for microbial growth, chemical reactions, and physical changes. When a food product is exposed to environmental conditions with different relative humidity (RH), moisture transfer occurs to maintain equilibrium. This article explains how a food product with a water activity of 0.6 behaves when exposed to conditions of 30°C and 70% RH.

Given Information:

• Water activity (aw) of the food product: 0.6

• Environmental conditions: 30°C and 70% RH

Understanding Water Activity and Moisture Transfer:

• Water activity (aw) ranges from 0 to 1, with 1 being pure water. It influences the moisture content of the food and its ability to interact with the environment.

• Relative humidity (RH) refers to the percentage of water vapor in the air compared to the maximum amount of moisture the air can hold at a given temperature. At 70% RH, the air has more moisture compared to air with lower humidity levels.

Key Considerations:

• If the water activity of the food product is higher than the ambient RH, the product will lose moisture to the environment.

• If the water activity of the food product is lower than the ambient RH, the product will gain moisture from the environment.

• If the water activity of the product equals the ambient RH, no moisture transfer occurs.

Analysis:

• Food product’s water activity: 0.6

• Environmental RH: 70% (0.70)

Since 0.6 < 0.70, the food product has a lower water activity than the surrounding environment. Therefore, the product will tend to gain moisture from the air to reach equilibrium.

Conclusion:

Given that the food product has a lower water activity (0.6) compared to the relative humidity of the surrounding air (70%), the food will gain moisture from the environment.

Answer:
1. Gain moisture