THE PROPERTY CHANGE OF HULLED BUCKWHEAT PRODUCED FROM IMPURE GRAIN DURING LONG-TERM STORAGE
Lately the quality of buckwheat grain received for processing has declined due to equipment deterioration and degraded quality of agronomic practices. A sample of buckwheat grain with impurities was stored for 5 months; then the grain was processed into hulled buckwheat and left for storage for 20 months. During the storage the fat acidity value, acidity and fat content in the grain was measured. It was found the change in the fat acidity value, acidity and fat content may be described by S-shaped curve. This curve is divided into three portions. The first stage (the induction period) lasts up to 7 months. The second stage (process development) lasts from the 7th to 15th month. The third stage (process damping) lasts from the 15th to 20th month. The fat acidity values of the test and control samples of hulled buckwheat at the end of storage were close - 10 mg KOH per 1 g of fat. This may be explained by enzymatic hydrolysis and the establishment of acid-alkaline balance in grain germs regardless of the buckwheat sample background. After steam treatment the buckwheat grain with impurity weight percentage up to 19.8%, without post-harvest processing and stored for 5 months in the producer’s facility is suitable for processing into hulled buckwheat which then may be stored up to 20 months.