Oven Drying of Small Herbage Samples1
- D. D. Wolf and
- T. L. Ellmore2
The method of preservation of forage tissue may influence the quality and quantity of the product. Oven drying with hot air is widely used; however, enzyme activity and respiration are stimulated during the moisture reduction process. Criterion for selecting efficient drying conditions, such as sample density, kind of container (cloth or paper), and size of container were investigated using alfalfa (Medicago sativa L.) herbage. The dry matter, total nonstructural carbohydrate (TNC), starch, reducing sugar, and nonreducing sugar percentages were related to drying rate.
Drying rate was linear until 80% dry weight was reached. Conditions requiring no more than 15 hours to reach 80% dry wt (density of 12 g dry wt per liter for paper sacks) were needed to hold loss within limits of experimental error for estimation of dry weight percentage. The TNC in all oven-dried samples was less than in freeze-dried tissue; however, data from cloth bags showed less loss and carbohydrate interconversion than paper sacks. Conditions requiring no more than 8 hours to reach 80% dry wt (density of 7 g per liter for paper sack) were required for sufficiently rapid drying to limit loss and interconversions of nonstructural carbohydrates within limits of experimental error. About twice this density was acceptable if cloth bags were used since the drying tune was reduced by about one-half with cloth as compared to paper containers that had equal densities. Acceptable bulk densities will differ with efficiency of the drying equipment, but time needed for drying to 80% dry wt should not exceed these limits.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .