Comparison On Moisture Content Of Three Typical Feeds Measured By Different Methods

Determinated the moisture in feeds has played an important role in feeds products control. The moisture value in feeds serves both as a quality and an economic indicator. It is also closely connected with the calculation and determination of other technical indicators. In recent years, China’s global trade relations with other countries become increasingly close. At home and abroad, there are multiple ways of testing the moisture content in feeds. So the comparison on moisture content in feeds by different methods becomes more important. This research used soybean fish meal and fat powder three typical feeds to measure and analysis the moisture content by different methods at home and abroad. Whether different methods may lead to different results was determined. This will provide a reference in feeds judgments and also can be a prove in import and export trade disputes. The main researches are listed as follows.Firstly, used GB/T 5497-1985, ASAE and GAC2100 rapid determination method to measure the moisture content in soybeans. The results were compared by SPSS Statistics using paired sample test, ANOVA and multiple comparisons. Significant differences between the three methods were found. The recoveries of three methods were determined and compared as well. ASAE method can get the highest recovery. And the result was the closest to the true moisture value in soybeans. In consideration of the equipment safety, utilization and efficiency, the priority use of GB/T 5497-1985 was recommended. If the workload is heavy, the use of GAC2100 rapid determination method is recommended.Secondly, used GB/T 6435-2006, AOAC 930.15 and AOAC 934.01 to measure the moisture content in fish meal. The results were compared by SPSS Statistics. Protein contents in dry base were measured. And that protein components cause no differences in fish meal moisture results were determined. Volatile basic nitrogen contents were measured and different temperatures can affect the volatile small molecule nitrogenous substances in fish meal were found. The loss of volatile basic nitrogen should be considered in the calculation of fish meal moisture content to recompense the moisture results based on the dry weight method. Reference is provided in detecting the moisture content in fish meal.Thirdly, used AOCS Ca 2c-25, AOAC 984.20 and GB/T 5528-2008 three methods to measure the moisture content in fat powder. Whether different methods may lead to different results were determined. Eight parallel results were measured by using three methods. No significant difference between the AOCS Ca 2c – 25 method and GB/T 5528-2008 method were found. The stability and reproducibility of AOAC 984.20 Karl Fischer method was relatively low. The stability of the method was improved by detecting the titer and changing the sample injection method. Compared with the results of the former two methods the new results were basically identical. So in routing test different methods can be chose in different experimental environments. This will provided a reference in fat powder judgments and also can be a prove in import and export trade disputes.