Physiochemical changes in wheat of different hardnesses during storage

We compared physiochemical changes in wheat cultivars of different hardnesses during long-term storage. Respiration, ATP content, germination ability, expansin gene expression, and the activities of dehydrogenase, catalase, and peroxidase were studied in soft wheat ('Zhengmai 004'), medium hard wheat ('Aikang 58'), and hard wheat ('Zhengmai 9023'). Wheat cultivars were stored under natural conditions for one year or harvested fresh and then stored for eight weeks either naturally or with artificial aging. Enzymatic activities decreased about 10% during one year of natural storage. Physiochemical properties of fresh and naturally aged wheats did not change significantly in eight weeks of further storage at 12% moisture content (MC) and 30 °C, which suggests that wheat stores well. However, physiochemical quality deteriorated rapidly in artificially aged wheat stored at 12% MC and 30 °C. Changes were relatively small in the soft wheat cultivar, with low basal metabolism and slow reduction of physiological enzymes indicating that soft wheat may have better storage tolerance than harder cultivars. This study provides important data for determining storage tolerances of different wheat cultivars.