Pereira Nelson, Ramos Ana Cristina, Alves Marco, Alves Vítor D, Roseiro Cristina, Vida Manuela, Moldão Margarida, Abreu Marta
Unidade de Tecnologia e Inovação, INIAV-Instituto Nacional de Investigação Agrária e Veterinária, 2780-157 Oeiras, Portugal.
LEAF-Linking Landscape, Environment, Agriculture and Food Research Center, Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisboa, Portugal.
Molecules. 2024 Dec 6;29(23):5771. doi: 10.3390/molecules29235771.
Sweet potato ( (L.) Lam.) is a nutrient-dense crop rich in fibre, minerals, and antioxidant compounds, including carotenoids and phenolic compounds, such as anthocyanins. Dehydrating sweet potato (SP) for flour production enhances its value and produces shelf-stable, health-promoting food products. This study investigated the effects of hot-air drying (HAD: 75 °C/20 h) and freeze-drying (FD: -41-30 °C/70 h) on the bioactive composition of flours from three SP varieties: (white-fleshed), (orange-fleshed), and (purple-fleshed). Key assessments included the total phenolic content (TPC), the total carotenoid content (TCC), and the total anthocyanin content (TAC) and the antioxidant activity (DPPH and FRAP). The results revealed distinct raw materials' bioactive profiles: was rich in TCC (49.3 mg of β-carotene/100 g db), showed elevated TAC (27.3 mg of cyanidin-3-glucoside/100 g db), and exhibited minimal content of bioactive compounds. Both drying methods yielded significant losses of bioactive compounds, with the TPC decreasing by over 60%, while TAC and TCC losses did not exceed 32%, revealing higher stability. Multivariate analysis indicated that the variety significantly influenced the bioactive profiles more than the drying method. The interaction between carotenoids and anthocyanins and the SP fibrous composition likely contributed to their stability during drying, indicating that FD showed no advantages over HAD. The appealing colours and high antioxidant content of and flours suggest their potential as ingredients for enhancing foods' bioactivity and sensory acceptance.
甘薯（Ipomoea batatas (L.) Lam.）是一种营养丰富的作物，富含纤维、矿物质和抗氧化化合物，包括类胡萝卜素和酚类化合物，如花色苷。将甘薯脱水用于面粉生产可提高其价值，并生产出货架稳定、有益健康的食品。本研究调查了热风干燥（HAD：75°C/20小时）和冷冻干燥（FD：-41 - 30°C/70小时）对三个甘薯品种（白肉、橙肉和紫肉）面粉生物活性成分的影响。主要评估指标包括总酚含量（TPC）、总类胡萝卜素含量（TCC）、总花色苷含量（TAC）和抗氧化活性（DPPH和FRAP）。结果显示了不同原料的生物活性特征：白肉品种富含TCC（49.3毫克β-胡萝卜素/100克干重），紫肉品种TAC升高（27.3毫克矢车菊素-3-葡萄糖苷/100克干重），而橙肉品种生物活性化合物含量最低。两种干燥方法均导致生物活性化合物显著损失，TPC下降超过60%，而TAC和TCC损失不超过32%，显示出较高的稳定性。多变量分析表明，品种对生物活性特征的影响比干燥方法更大。类胡萝卜素和花色苷之间的相互作用以及甘薯的纤维组成可能有助于它们在干燥过程中的稳定性，这表明冷冻干燥相对于热风干燥没有优势。白肉和紫肉面粉吸引人的颜色和高抗氧化剂含量表明它们有潜力作为增强食品生物活性和感官接受度的成分。
