Chemical composition, granular morphology and pasting properties of native starch extracted from tubers of Plectranthus edulis were analyzed. Starch was extracted from tubers of 6 accessions collected from 4 different areas in Ethiopia. Particle size analysis (PSA) and cryo-scanning electron microscope (cryo-SEM) imaging were used to examine the granular morphology and visualize the starch paste, respectively. Pasting properties, water absorption, and gelation capacity were compared. A wide range was found for the amylose (14.2% to 23.9%), calcium (216 to 599), potassium (131 to 878), and phosphorus (1337 to 2090) contents (parts per million per dry matter). PSA showed a bimodal distribution containing small spherical (14.6 μm) and large ellipse-shaped (190.4 μm) granules. Major differences were found for the pasting with peak viscosities differing from 3184 to 7312 mPa⋅s. Starch from accessions Chencha and Inuka showed a difference in packing density as clearly seen through cryo-SEM image at 75% of the peak viscosity (PV), and the granular integrity was mainly responsible for the significant difference in their PV and breakdown. Principal component analysis revealed 2 distinct groups: native starch extracted from accessions at the Wolayta zone (Inuka, Lofua, and Chenqoua) and other accessions (Jarmet, Arjo white, and Chencha). The study revealed the potential of P. edulis starch for its application in food industries. However, the inherent variation due to environmental conditions on physicochemical properties of the starch needs further investigation. PRACTICAL APPLICATION Plectranthus edulis is cultivated in considerable amounts throughout Ethiopia, which makes it a valuable starch source. Due to its low tendency to retrograde, it could be applied in food industry as an equivalent for the current starch sources. Moreover, the low amylose content makes it preferable for an application in refrigerated foods as this unique quality trait prevents syneresis in end products during storage. Based on the significantly higher pasting temperature of the studied P. edulis starch extracts, it can form an alternative for potato starch, which is less suitable for its use in pasteurized foods.

中文翻译：

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Plectranthus edulis (Oromo dinich) 块茎中天然淀粉的组成、颗粒结构和糊化特性

分析了香菇块茎中提取的天然淀粉的化学成分、颗粒形态和糊化特性。淀粉是从埃塞俄比亚 4 个不同地区收集的 6 个种质的块茎中提取的。粒度分析 (PSA) 和冷冻扫描电子显微镜 (cryo-SEM) 成像分别用于检查颗粒形态和可视化淀粉糊。比较了糊化性能、吸水率和凝胶能力。发现直链淀粉（14.2% 至 23.9%）、钙（216 至 599）、钾（131 至 878）和磷（1337 至 2090）含量（每干物质的百万分之几）的范围很广。PSA呈双峰分布，包含小球形（14.6 μm）和大椭圆形（190.4 μm）颗粒。对于峰值粘度从 3184 到 7312 mPa·s 不同的粘贴，发现了主要差异。Chencha 和 Inuka 的淀粉在峰值粘度 (PV) 的 75% 处通过冷冻 SEM 图像清楚地显示出堆积密度的差异，颗粒完整性是其 PV 和分解的显着差异的主要原因。主成分分析揭示了 2 个不同的组：从 Wolayta 区（Inuka、Lofua 和 Chenqoua）的种质和其他种质（Jarmet、Arjo white 和 Chencha）中提取的天然淀粉。该研究揭示了 P. edulis 淀粉在食品工业中的应用潜力。然而，环境条件对淀粉理化性质的内在变化需要进一步研究。实际应用 Plectranthus edulis 在埃塞俄比亚各地大量种植，这使其成为有价值的淀粉来源。由于其低逆行趋势，它可以作为当前淀粉来源的等效物应用于食品工业。此外，低直链淀粉含量使其更适合用于冷藏食品，因为这种独特的质量特性可防止最终产品在储存过程中发生脱水收缩。基于所研究的 P. edulis 淀粉提取物显着较高的糊化温度，它可以形成马铃薯淀粉的替代品，其不太适合用于巴氏杀菌食品。低直链淀粉含量使其更适合用于冷藏食品，因为这种独特的质量特性可防止最终产品在储存过程中发生脱水收缩。基于所研究的 P. edulis 淀粉提取物显着较高的糊化温度，它可以形成马铃薯淀粉的替代品，其不太适合用于巴氏杀菌食品。低直链淀粉含量使其更适合用于冷藏食品，因为这种独特的质量特性可防止最终产品在储存过程中发生脱水收缩。基于所研究的 P. edulis 淀粉提取物显着较高的糊化温度，它可以形成马铃薯淀粉的替代品，其不太适合用于巴氏杀菌食品。