Optimizing milling quality of combine-harvested paddy: the impact of pre-drying temperature and intermediate storage duration

نوع مقاله : مقاله پژوهشی

نویسنده

عضو هیات علمی موسسه تحقیقات برنج کشور

چکیده

Combine harvesting has become widespread in northern Iran, improving efficiency but creating bottlenecks in drying capacity. This often leads to delayed drying and intermediate storage of high-moisture paddy, risking quality deterioration. This study investigated the effects of pre-drying temperature and storage duration on the milling quality of Hashemi rice, a major Iranian variety. Freshly harvested paddy (~20% moisture, w.b.) was pre-dried in a recirculating dryer at 40, 50, or 60 °C to 15% moisture, then stored for 15, 30, or 45 days before undergoing final drying in a conventional batch dryer to 8.5% moisture. A factorial experiment based on a randomized complete block design (RCBD) with five replications was conducted. Results showed that both pre-drying temperature and storage duration significantly affected head rice yield (HRY) and grain fissure percentage (p < 0.01). Increasing the pre-drying temperature from 40 °C to 60 °C reduced HRY by approximately 2% and increased fissures by 3%. Similarly, extending storage from 15 to 45 days reduced HRY by 2.6% and increased fissures by 4.7%. Milling recovery was not significantly affected. These findings highlight that high-temperature pre-drying and prolonged intermediate storage negatively impact grain integrity. To optimize milling quality, it is recommended to use moderate pre-drying temperatures (≤40 °C) and minimize the time between pre- and final drying stages.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Optimizing milling quality of combine-harvested paddy: the impact of pre-drying temperature and intermediate storage duration

نویسنده [English]

  • ALIREZA Allameh
Scientific Staff, Rice Research Institute of Iran
چکیده [English]

Combine harvesting has become widespread in northern Iran, improving efficiency but creating bottlenecks in drying capacity. This often leads to delayed drying and intermediate storage of high-moisture paddy, risking quality deterioration. This study investigated the effects of pre-drying temperature and storage duration on the milling quality of Hashemi rice, a major Iranian variety. Freshly harvested paddy (~20% moisture, w.b.) was pre-dried in a recirculating dryer at 40, 50, or 60 °C to 15% moisture, then stored for 15, 30, or 45 days before undergoing final drying in a conventional batch dryer to 8.5% moisture. A factorial experiment based on a randomized complete block design (RCBD) with five replications was conducted. Results showed that both pre-drying temperature and storage duration significantly affected head rice yield (HRY) and grain fissure percentage (p < 0.01). Increasing the pre-drying temperature from 40 °C to 60 °C reduced HRY by approximately 2% and increased fissures by 3%. Similarly, extending storage from 15 to 45 days reduced HRY by 2.6% and increased fissures by 4.7%. Milling recovery was not significantly affected. These findings highlight that high-temperature pre-drying and prolonged intermediate storage negatively impact grain integrity. To optimize milling quality, it is recommended to use moderate pre-drying temperatures (≤40 °C) and minimize the time between pre- and final drying stages.

کلیدواژه‌ها [English]

  • Paddy drying
  • head rice yield
  • grain fissure
  • intermediate storage
  • drying temperature
  • post-harvest quality

مقالات آماده انتشار، پذیرفته شده
انتشار آنلاین از تاریخ 11 بهمن 1404
  • تاریخ دریافت: 25 آذر 1404
  • تاریخ بازنگری: 30 دی 1404
  • تاریخ پذیرش: 11 بهمن 1404
  • تاریخ اولین انتشار: 11 بهمن 1404
  • تاریخ انتشار: 11 بهمن 1404