Gómez Gómez Lourdes, Morote Lucía, Frusciante Sarah, Rambla José Luis, Diretto Gianfranco, Niza Enrique, López-Jimenez Alberto José, Mondejar María, Rubio-Moraga Ángela, Argandoña Javier, Presa Silvia, Martín-Belmonte Alejandro, Luján Rafael, Granell Antonio, Ahrazem Oussama
Instituto Botánico, Universidad de Castilla-La Mancha, Albacete, Spain.
Departamento de Ciencia y Tecnología Agroforestal y Genética, Facultad de Farmacia, Universidad de Castilla-La Mancha, Albacete, Spain.
Front Nutr. 2022 Nov 30;9:1045979. doi: 10.3389/fnut.2022.1045979. eCollection 2022.
Carotenoids are C40 isoprenoids with well-established roles in photosynthesis, pollination, photoprotection, and hormone biosynthesis. The enzymatic or ROS-induced cleavage of carotenoids generates a group of compounds named apocarotenoids, with an increasing interest by virtue of their metabolic, physiological, and ecological activities. Both classes are used industrially in a variety of fields as colorants, supplements, and bio-actives. Crocins and picrocrocin, two saffron apocarotenoids, are examples of high-value pigments utilized in the food, feed, and pharmaceutical industries. In this study, a unique construct was achieved, namely O6, which contains , , and genes responsible for the biosynthesis of saffron apocarotenoids driven by a patatin promoter for the generation of potato tubers producing crocins and picrocrocin. Different tuber potatoes accumulated crocins and picrocrocin ranging from 19.41-360 to 105-800 μg/g DW, respectively, with crocetin, crocin 1 [(crocetin-(β-D-glucosyl)-ester)] and crocin 2 [(crocetin)-(β-D-glucosyl)-(β-D-glucosyl)-ester)] being the main compounds detected. The pattern of carotenoids and apocarotenoids were distinct between wild type and transgenic tubers and were related to changes in the expression of the pathway genes, especially from , , and . In addition, the engineered tubers showed higher antioxidant capacity, up to almost 4-fold more than the wild type, which is a promising sign for the potential health advantages of these lines. In order to better investigate these aspects, different cooking methods were applied, and each process displayed a significant impact on the retention of apocarotenoids. More in detail, the bioaccessibility of these metabolites was found to be higher in boiled potatoes (97.23%) compared to raw, baked, and fried ones (80.97, 78.96, and 76.18%, respectively). Overall, this work shows that potatoes can be engineered to accumulate saffron apocarotenoids that, when consumed, can potentially offer better health benefits. Moreover, the high bioaccessibility of these compounds revealed that potato is an excellent way to deliver crocins and picrocrocin, while also helping to improve its nutritional value.
类胡萝卜素是C40类异戊二烯化合物，在光合作用、授粉、光保护和激素生物合成中发挥着既定作用。类胡萝卜素的酶促或ROS诱导裂解产生了一组名为脱落类胡萝卜素的化合物，由于其代谢、生理和生态活性，人们对其兴趣与日俱增。这两类化合物在工业上都被用作着色剂、补充剂和生物活性物质，应用于各个领域。藏红花中的两种脱落类胡萝卜素——藏红花素和苦藏花素，是食品、饲料和制药行业中使用的高价值色素的例子。在本研究中，构建了一种独特的构建体，即O6，它包含由马铃薯patatin启动子驱动的负责藏红花脱落类胡萝卜素生物合成的 、 和 基因，用于培育产生藏红花素和苦藏花素的马铃薯块茎。不同的块茎马铃薯积累的藏红花素和苦藏花素分别为19.41 - 360 μg/g干重和105 - 800 μg/g干重，主要检测到的化合物为藏红花酸、藏红花素1 [（藏红花酸 - （β - D - 葡萄糖基） - 酯）]和藏红花素2 [（藏红花酸） - （β - D - 葡萄糖基） - （β - D - 葡萄糖基） - 酯]。野生型和转基因块茎中的类胡萝卜素和脱落类胡萝卜素模式不同，且与途径基因的表达变化有关，特别是来自 、 和 的基因。此外，经过基因工程改造的块茎显示出更高的抗氧化能力，比野生型高出近4倍，这对于这些品系潜在的健康益处来说是一个有希望的迹象。为了更好地研究这些方面，采用了不同的烹饪方法，每个过程对脱落类胡萝卜素的保留都有显著影响。更详细地说，发现这些代谢物在煮土豆中的生物可及性更高（97.23%），相比生土豆、烤土豆和炸土豆（分别为80.97%、78.96%和76.18%）。总体而言，这项工作表明可以通过基因工程使马铃薯积累藏红花脱落类胡萝卜素，食用后可能带来更好的健康益处。此外，这些化合物的高生物可及性表明，马铃薯是递送藏红花素和苦藏花素的绝佳方式，同时也有助于提高其营养价值。
