不同发育时期甘薯类胡萝卜素组分及其含量变化

Changes in Carotenoid Composition and Content of Sweet Potatoes at Different Developmental Stages

摘要:

为探究甘薯块根发育过程中类胡萝卜素的积累规律，通过色度仪及超高效液相色谱法检测不同肉色甘薯块根在移栽后45、75、105、135及165 d的薯肉色特征值和类胡萝卜素组分及含量。结果表明随着薯肉色加深，橘红肉甘薯（ORFSP）中类胡萝卜素总含量远高于其他品种，高达299.07 μg.g-1。在发育过程中，类胡萝卜素总量在前期不断积累，但大部分品种在165 d出现明显下降。8个甘薯品种中共检测到11种类胡萝卜素单体，其中，β-胡萝卜素、紫黄质、新黄质、环氧玉米黄质以及叶黄素在甘薯发育过程中含量较高且较稳定。黄肉甘薯（YFSP）中紫黄质、环氧玉米黄质具有较高的占比，橘黄肉甘薯（OFSP）主要积累叶黄素和β-胡萝卜素，ORFSP中β-胡萝卜素含量占类胡萝卜素总量的81.20%~94.38%，是甘薯中最主要的类胡萝卜素。甘薯中类胡萝卜素与亮度（L*）、色度角（H*）呈负相关，与红度（a*）、色彩饱和度（C*）呈正相关，新黄质与黄度（b*）呈极显著正相关。综合可得，OFSP和ORFSP类胡萝卜素组分更丰富，ORFSP类胡萝卜素含量更高，YFSP中含氧官能团的类胡萝卜素单体在类胡萝卜素中占比较高；甘薯类胡萝卜素在发育末期出现明显下降。研究结果可为甘薯营养品质研究和品种筛选提供理论基础。

Abstract:

To analyze the accumulation of carotenoids during the development of sweet potato tubers, color characteristic values as well as carotenoid composition and content in sweet potato tubers with different flesh colors on the 45th, 75th, 105th, 135th, and 165th days after transplanting were measured using a chroma meter and ultra-high performance liquid chromatography. The results showed that the total content of carotenoids (299.07 μg•g-1) in orange-red-flesh sweet potatoes (ORFSPs) was much higher than those in other varieties. During the developmental process, the total amount of carotenoids accumulated continuously in the early stage, but most varieties showed a significant decrease on the 165th day. A total of 11 types of carotenoid monomers were detected in eight sweet potato varieties. Among them, β-carotene, violaxanthin, neoxanthin, antheraxanthin, and lutein exhibited high content and remained stable throughout the development of sweet potatoes. Yellow-flesh sweet potatoes (YFSPs) exhibited high levels of violaxanthin and antheraxanthin, whereas orange-flesh sweet potatoes (OFSPs) mainly accumulated lutein and β-carotene. The content of β-carotene in ORFSP accounted for 81.20%~94.38% of total carotenoid content, making β-carotene the most important carotenoid in sweet potatoes. Carotenoids in sweet potatoes were negatively correlated with brightness (L*) and chroma angle (H*), but positively correlated with redness (a*) and color saturation (C*). Neoxanthin was significantly positively correlated with yellowness (b*). In summary, OFSPs and ORFSPs possess more carotenoids, ORFSPs have higher carotenoid concentrations, and carotenoid monomers containing oxygen functional groups in YFSP account for a relatively high proportion in the carotenoid composition. The results provide a theoretical basis for the study of nutritional quality and variety breeding of sweet potatoes.