Major Nikola, Išić Nina, Kovačević Tvrtko Karlo, Anđelini Magdalena, Ban Dean, Prelac Melissa, Palčić Igor, Goreta Ban Smiljana
Department of Agriculture and Nutrition, Institute of Agriculture and Tourism, K. Hugues 8, 52440 Poreč, Croatia.
Centre of Excellence for Biodiversity and Molecular Plant Breeding, Svetošimunska 1, 10000 Zagreb, Croatia.
Antioxidants (Basel). 2023 Aug 10;12(8):1596. doi: 10.3390/antiox12081596.
The Mediterranean area is especially rich in old, both sweet and pungent, varieties of onion. The synthesis of phytochemicals takes place concurrently with the overall development and maturation of vegetables; however, it is unclear whether there is a correlation between onion bulb size and antioxidant compound content, antioxidant capacity, and nutritional parameters and what the origin of these variations is. The aim of this work was to investigate the biochemical and nutritional aspects of the sweet onion landrace "Premanturska kapula", as well as to investigate the influence of onion bulb size on onion phytochemical and nutritional profile. The sweet onion landrace "Premanturska kapula" has a high soluble sugar content, a high antioxidant capacity, and a high phenolic compound content. Quercetin-3,4'-diglucoside and quercetin-4'-glucoside were the major flavonols, while protocatehuic acid was the major phenolic acid detected. The choice of onion bulb size can impact the profile of the sugars present, with large bulb sizes favoring higher sucrose and fructooligosaccharides content compared to small bulb sizes which were more abundant in glucose. The total sugars or bulb dry matter were not affected by bulb size. Phenolic compounds were more abundant in smaller bulb sizes, thus indicating a link between bulb development and phenolic compound allocation within the plant. This link possibly derived from agronomic practices such as bare-root transplants, or even open pollination which causes a broader genetic variability. From a consumer perspective, it can be a choice between the small and medium bulb sizes on one hand, which are more abundant in polyphenolics and simple sugars, or on the other hand, the larger bulbs which are more abundant in fructooligosaccharides known to carry excellent health benefits.
地中海地区尤其盛产各种古老的洋葱品种，有甜洋葱，也有辛辣洋葱。植物化学物质的合成与蔬菜的整体发育和成熟同时进行；然而，目前尚不清楚洋葱鳞茎大小与抗氧化化合物含量、抗氧化能力及营养参数之间是否存在关联，以及这些差异的根源是什么。这项研究的目的是调查甜洋葱地方品种“Premanturska kapula”的生化和营养方面，同时研究洋葱鳞茎大小对洋葱植物化学成分和营养状况的影响。甜洋葱地方品种“Premanturska kapula”具有高可溶性糖含量、高抗氧化能力和高酚类化合物含量。槲皮素-3,4'-二葡萄糖苷和槲皮素-4'-葡萄糖苷是主要的黄酮醇，而原儿茶酸是检测到的主要酚酸。洋葱鳞茎大小的选择会影响所存在的糖的分布情况，与葡萄糖含量较高的小鳞茎相比，大鳞茎的蔗糖和低聚果糖含量更高。总糖或鳞茎干物质不受鳞茎大小的影响。酚类化合物在较小的鳞茎中含量更高，这表明鳞茎发育与植物体内酚类化合物的分配之间存在联系。这种联系可能源于诸如裸根移栽等农艺措施，甚至是导致更广泛遗传变异性的开放授粉。从消费者的角度来看，一方面可以选择中小鳞茎，它们富含多酚和单糖；另一方面可以选择大鳞茎，它们富含已知对健康有益的低聚果糖。
