Serrano Carmo, Lamas Beatriz, Oliveira M Conceição, Duarte Maria Paula
Instituto Nacional de Investigação Agrária e Veterinária (INIAV, I.P.), Av. da República, 2780-157 Oeiras, Portugal.
Associated Laboratory TERRA, LEAF-Linking Landscape, Environment, Agriculture and Food-Research Center, Instituto Superior de Agronomia, University of Lisbon, Tapada da Ajuda, 1349-017 Lisboa, Portugal.
Foods. 2024 Aug 2;13(15):2450. doi: 10.3390/foods13152450.
This study aims to develop purple-coloured polymeric coatings using natural anthocyanin and desoxyanthocianidins (3-DXA) colourants for application to chocolate almonds. The objective is to achieve a stable and uniform colour formulation throughout processing and storage, enhancing the appearance and durability of the almonds to appeal to health-conscious consumers and align with market demands. Plant materials like sweet potato pulp, sweet potato peel, radish peel, black carrot, and sorghum were employed to obtain the desired purple hue. Anthocyanidins and 3-DXA were extracted from the matrices using solvent extraction and ultrasound-assisted methods at different pH values. High-performance liquid chromatography with diode array detection (HPLC-DAD) and high-resolution tandem mass spectrometry (HRMS/MS) were used to identify the compounds in the extracts. The highest antioxidant capacities, as measured by the DPPH and FRAP methods, were observed in purple sweet potato and dye factory extracts, respectively; meanwhile, sorghum extract inhibited both α-amylase and α-glucosidase, indicating its potential for managing postprandial hyperglycemia and type 2 diabetes. The degradation kinetics of coloured coatings in sugar syrup formulations with anthocyanins and 3-DXA revealed that locust bean gum offered the best colour stabilization for plant extracts, with sorghum extracts showing the highest and black carrot extracts the lowest colour variation when coated with Arabic gum. Sweet potato pulp extracts exhibited less colour variation in sugar pastes, both with and without blue spirulina dye, compared to factory dye, highlighting their potential as a more stable and suitable alternative for colouring purple almonds, particularly over a five-month storage period. This study supports sustainable practices in the confectionery industry while aligning with consumer preferences for healthier and environmentally friendly products.
本研究旨在利用天然花青素和脱氧花青素（3-DXA）着色剂开发紫色聚合物涂层，用于巧克力杏仁。目的是在整个加工和储存过程中实现稳定且均匀的颜色配方，提升杏仁的外观和耐久性，以吸引注重健康的消费者并符合市场需求。采用红薯果肉、红薯皮、萝卜皮、黑胡萝卜和高粱等植物材料来获得所需的紫色调。使用溶剂萃取和超声辅助方法在不同pH值下从基质中提取花青素和3-DXA。采用二极管阵列检测高效液相色谱法（HPLC-DAD）和高分辨串联质谱法（HRMS/MS）鉴定提取物中的化合物。通过DPPH和FRAP方法测定，紫色红薯提取物和染料厂提取物分别具有最高的抗氧化能力；同时，高粱提取物对α-淀粉酶和α-葡萄糖苷酶均有抑制作用，表明其在控制餐后高血糖和2型糖尿病方面具有潜力。含花青素和3-DXA的糖浆配方中彩色涂层的降解动力学表明，刺槐豆胶对植物提取物具有最佳的颜色稳定性，用阿拉伯胶包衣时，高粱提取物的颜色变化最大，黑胡萝卜提取物的颜色变化最小。与工厂染料相比，无论有无蓝色螺旋藻染料，红薯果肉提取物在糖膏中的颜色变化都较小，这突出了它们作为给紫色杏仁着色更稳定、更合适替代品的潜力，尤其是在五个月的储存期内。本研究支持了糖果行业的可持续做法，同时符合消费者对更健康、环保产品的偏好。
