Moisture and Ash Determination in Flour (TGA801)

Importance of the Topic

Accurate measurement of moisture and ash in flour products is critical for maintaining quality safety and consistency in food production Moisture affects texture taste microbial stability and yield calculations while ash content serves as an indicator of mineral content and potential contaminants such as bran in refined flours

Objectives and Study Overview

The primary goal of this application note is to demonstrate a reliable thermogravimetric protocol for simultaneous determination of moisture and ash in different flour matrices using the LECO TGA801 macro thermogravimetric analyzer The study adapts AOAC Official Methods 925.10 and 923.03 to the TGA801 instrument specifications and evaluates performance with corn wheat and barley flours

Methodology

A representative sample of approximately one gram of flour is weighed into a large ceramic crucible Sample weight is maintained between 0.8 and 1.2 grams The thermogravimetric procedure comprises two sequential steps
1 Drying step ramp from ambient to 130 °C at 10 °C per minute followed by a 30 minute hold until mass constancy within 0.0005 grams
2 Ashing step ramp from 130 °C to 550 °C at 20 °C per minute followed by a 30 minute hold in air atmosphere Flow rate is maintained at ten liters per minute Total analysis time is approximately four hours for each batch of up to nineteen samples

Used Instrumentation

• LECO TGA801 macro thermogravimetric analyzer with dual furnace capability allowing parallel measurement of multiple samples
• Ceramic crucibles with mass range nineteen to thirty grams and lid assembly
• Double ended scoop for consistent sample transfer

Main Results and Discussion

Typical results for ten replicates of each flour type show high precision and reproducibility

• Corn flour average moisture seven point 39 percent standard deviation zero point 02 percent ash zero point 44 percent SD zero point 03 percent dry ash zero point 47 percent SD zero point 03 percent
• Wheat flour average moisture seven point 52 percent SD zero point 02 percent ash one point 49 percent SD zero point 07 percent dry ash one point 62 percent SD zero point 07 percent
• Barley flour average moisture seven point 92 percent SD zero point 03 percent ash one point 86 percent SD zero point 04 percent dry ash two point 02 percent SD zero point 04 percent

Results indicate consistent moisture determination and clear differentiation of ash content among flour types reflecting differences in mineral composition and processing levels

Benefits and Practical Applications

This thermogravimetric method provides laboratories with an automated high throughput solution for flour quality control Alignment with AOAC official protocols ensures compliance in food safety and labeling assessments The ability to run up to nineteen samples concurrently reduces turnaround time and improves laboratory productivity

Future Trends and Applications

Advances in thermogravimetric instrumentation may include real time data analytics for process control integration with near infrared spectroscopy for complementary compositional analysis and miniaturized furnace designs for rapid on line monitoring Further development of method libraries can expand application to other food matrices and complex ingredient blends

Conclusion

The LECO TGA801 based protocol delivers accurate reproducible moisture and ash determinations in flour samples Method performance meets stringent AOAC criteria and offers significant efficiency gains for routine quality assurance in food laboratories

References

• AOAC Official Method 925.10 Solids and Moisture in Flour
• AOAC Official Method 923.03 Ash of Flour