What percent of moisture should be present in the food grains at the time of storage?

Explanation

### Step-by-Step Solution:

1. **Understanding the Importance of Moisture in Food Grains:**
- Food grains often have high moisture content when harvested. This moisture can lead to spoilage due to bacterial and fungal growth if not managed properly.

2. **Methods of Reducing Moisture:**
- To prevent spoilage, it is essential to reduce the moisture content of food grains. This can be done using various methods such as:
- Sun drying
- Shade drying
- Mechanical dryers

3. **Determining the Safe Moisture Level:**
- After drying, the moisture content in food grains should be monitored. The safe moisture level for storage is crucial to prevent spoilage.

4. **Identifying the Permissible Moisture Percentage:**
- The ideal moisture content for storing food grains should be below 15%. This level helps in minimizing the risk of bacterial and fungal infections.

5. **Conclusion:**
- Therefore, the percentage of moisture that should be present in food grains at the time of storage is below 15%.