Influence of Drying and Storage Conditions on Nonstructural Carbohydrate Analysis of Herbage Tissue—a Review

No one method of drying can be relied upon for all plant species, plant parts, or form (e.g., fresh v. ensiled herbage). Least changes in nonstructural carbohydrates appear to occur when fresh tissue is immersed in boiling alcohol. Freeze‐drying provides results more similar to fresh tissue than heat‐drying. Heat‐drying at high temperatures (above 80°C) can cause thermo‐cbemical degradation, while slow drying at low temperatures (below 50°C) allows time for DM losses by respiration and enzymatic conversions. The most acceptable heat‐drying results have been obtained by drying for a short time at a high temperature (i.e. 100°C) and thereafter at a moderate temperature (i.e. 70°C). Changes in nonstructural carbohydrate concentrations occur during the storage of either freeze‐ or heat‐dried tissues. Thus, analyses should be conducted as soon as possible after tissue sampling. The least changes occur during storage in alcohol, following killing of the tissue in boiling alcohol.