RESUMEN
Brassicaceae edible plants are rich in bioactive compounds and promote health benefits. However, there is less interest in expanding knowledge about the Brassica cultivars to date. In particular, underutilized species and local cultivars could constitute a source of agrodiversity in adapting to the territory with likely higher contents of nutraceutical compounds. In this context, Bróquil (Brassica oleracea var. italica) is a traditional Brassicaceae crop grown in the Spanish region of Aragón. Currently, it is cultivated mainly in family orchards for autoconsumption and, in minority, in small farms for local markets. This study evaluates a collection of 13 bróquil landraces from the Spanish Vegetable Genebank of the Agrifood Research and Technology Center of Zaragoza (BGHZ-CITA), describing their mineral contents, bioactive compounds, and antioxidant activities, including a broccoli commercial variety "Parthenon" as the control. The study reports data on the health-promoting nutrients and antioxidants of bróquil for the first time. Under our experimental conditions, we found that bróquil has a great variability for these compounds that showed on average similar or higher levels than the broccoli control. The different bróquil landraces also revealed variability in both intraccessions and interaccessions due to the lack of a formal breeding selection. Despite this variability, we highlight accession HB5 that corresponds to Headed Bróquil BGHZ6685. In particular, we can stand out its antioxidant activity of 87.07 ± 0.81%I, total phenolic content of 13.21 ± 0.53 mg GAE g-1 dw, total flavonoid content of 14.50 ± 1.29 mg QE g-1 dw, total glucosinolate content of 43.70 ± 1.09 mg SnE g-1 dw, and vitamin C content of 7.21 ± 0.13 mg AA g-1 dw. Regarding bróquil mineral composition, K was the highest macroelement (22.66-33.62 mg g-1 dw), followed by Ca, P, and S whose values were relatively lower compared to K. Mg and Na showed the lowest values. Among the microelements evaluated (Mn, Zn, and Fe), iron was the most abundant detected, higher in all bróquil accessions than in broccoli, except for one accession. Therefore, the results reported for bróquil landraces show promising nutritional quality. This could lead to an increase in agrobiodiversity and contribute to a more diversified and healthy diet.
RESUMEN
Borage (Borago officinalis L.) is a traditional vegetable grown and consumed in some Spanish regions. The objective of this study was to determine the variability and evolution of fatty acid composition in a borage germplasm collection formed by wild types, breeding lines, commercial varieties, and landraces. Fatty acids were analysed in petioles, the commonly edible part of the leaves, and the leaf blades, the by-product of the borage industry, in two growth stages: at the optimal harvest period (120 days after sowing) and at the end of the harvest period (150 days after sowing). The results showed that for each of the eight fatty acids identified, there were significant differences among the twelve borage genotypes depending on the developmental plant stage at sampling date and the part of the leaf analysed, the interaction effect also being statistically significant. The main polyunsaturated fatty acids identified were: linoleic acid (18:2 n6, LA), α-linolenic acid (18:3 n3, ALA), γ-linolenic acid (18:3 n6, GLA), and stearidonic acid (SDA, 18:4, n-3), account for approximately 70% of polyunsaturated fatty acids. Blue-flowered genotypes differ from white-flowered genotypes by their high content of ALA and SDA, which can be exploited in borage breeding programs. Petioles from young plants present higher n6 fatty acids, while older plants produce a great amount of n3 fatty acids. Besides, the higher content of ALA in the leaf blades gives them a good dietary potential. All these fatty acids, with multiple health benefits, support the nutraceutical interest of borage leaves (both petioles and leaf blades) for human consumption, animal feeding, medicine, and pharmacy.
RESUMEN
Vitamins, especially vitamin C, are important micronutrients found in fruits and vegetables. Vitamin C is also a major contributor to their antioxidant capacity. Lettuce is one of the most popular vegetables among consumers worldwide. An accurate protocol to measure vitamin C content in lettuce and other related species is crucial. We describe here a method using the ultra-high-performance liquid chromatography-ultraviolet (UPLC-UV) technique, in which sample preparation, vitamin extraction and chromatography conditions were optimized. Samples were collected to represent the entire plant, frozen at -80 °C and lyophilized to prevent undesirable oxidation and make their manipulation easier. The extraction of vitamin C was carried out in acidic media, which also contributed to its stability. As vitamin C can be present in two different interconvertible forms, ascorbic acid (AA) and dehydroascorbic acid (DHAA), both compounds should be measured for accurate quantification. The DHAA was quantified indirectly after its reduction to AA because AA shows a higher absorptivity than DHAA in the UV range of the spectrum. From the same extract, two measurements were carried out, one before and one after that reduction reaction. In the first case, we were quantifying the AA content, and in the second one, we quantified the sum of AA and DHAA (TAA: total ascorbic acid) in the form of AA. Then, DHAA quantity was indirectly obtained by subtracting AA coming from the first measurement from TAA. They were determined by UPLC-UV, using a commercial AA standard to build a calibration curve and optimizing the chromatographic procedure, to obtain AA peaks that were completely resolved in a short time. This protocol could be easily extrapolated to any other plant material with slight or no changes. Its accuracy revealed statistically significant differences otherwise unperceived. Other strengths and limitations are discussed more in depth in the manuscript.