Food Science College, Tibet Agriculture & Animal Husbandry University, R&D Center of Agricultural Products with Tibetan Plateau Characteristics, The Provincial and Ministerial Co-founded Collaborative Innovation Center for R&D in Tibet Characteristic Agricultural and Animal Husbandry Resources, Nyingchi 860000, Tibet, China.
Tibet Autonomous Region Grain Administration Grain and Oil Center Laboratory, Lhasa 850000, Tibet, China.
Ultrason Sonochem. 2023 May;95:106394. doi: 10.1016/j.ultsonch.2023.106394. Epub 2023 Mar 31.
Highland barley is a grain crop grown in Tibet, China. This study investigated the structure of highland barley starch using ultrasound (40 kHz, 40 min, 165.5 W) and germination treatments (30℃ with 80% relative humidity). The macroscopic morphology and the barley's fine and molecular structure were evaluated. After sequential ultrasound pretreatment and germination, a significant difference in moisture content and surface roughness was noted between highland barley and the other groups. All test groups showed an increased particle size distribution range with increasing germination time. FTIR results also indicated that after sequential ultrasound pretreatment and germination, the absorption intensity of the intramolecular hydroxyl (-OH) group of starch increased, and hydrogen bonding was stronger compared to the untreated germinated sample. In addition, XRD analysis revealed that starch crystallinity increased following sequential ultrasound treatment and germination, but a-type of crystallinity remained after sonication. Further, the Mw of sequential ultrasound pretreatment and germination at any time is higher than that of sequential germination and ultrasound. As a result of sequential ultrasound pretreatment and germination, changes in the content of chain length of barley starch were consistent with germination alone. At the same time, the average degree of polymerisation (DP) fluctuated slightly. Lastly, the starch was modified during the sonication process, either prior to or following sonication. Pretreatment with ultrasound illustrated a more profound effect on barley starch than sequential germination and ultrasound treatment. In conclusion, these results indicate that sequential ultrasound pretreatment and germination improve the fine structure of highland barley starch.
青稞是中国西藏地区种植的一种谷物作物。本研究采用超声（40 kHz，40 min，165.5 W）和发芽处理（30℃，相对湿度 80%）对青稞淀粉的结构进行了研究。评估了青稞的宏观形貌和微观及分子结构。经过连续的超声预处理和发芽处理后，青稞与其他组之间的水分含量和表面粗糙度存在显著差异。所有测试组的颗粒尺寸分布范围均随发芽时间的增加而增加。FTIR 结果还表明，经过连续的超声预处理和发芽处理后，淀粉分子内羟基（-OH）基团的吸收强度增加，与未处理的发芽样品相比，氢键更强。此外，XRD 分析表明，淀粉结晶度在连续超声处理和发芽后增加，但在超声处理后仍保持 a 型结晶度。进一步，在任何时间进行连续超声预处理和发芽的 Mw 均高于连续发芽和超声。经过连续的超声预处理和发芽，青稞淀粉链长含量的变化与单独发芽一致。同时，聚合度（DP）的平均值略有波动。最后，淀粉在超声过程中发生了变化，无论是在超声之前还是之后。超声预处理对青稞淀粉的影响比连续发芽和超声处理更为显著。综上所述，这些结果表明，连续的超声预处理和发芽可以改善青稞淀粉的微观结构。
