An investigation by FAUBA generates new knowledge about the nutraceutical properties of these products and the cultivation strategies so that it reaches the consumer in optimal conditions. They propose to diversify the diet with different organs of the same plant species whose properties surpass the traditional product.
The best results were obtained with white light: "We achieved shoots with a thicker hypocotyl, as well as larger and well expanded cotyledons, of an intense green color, and good levels of bioactive compounds both at harvest and post-harvest."
(SLT-FAUBA) The Chinese consumed them 3000 years before Christ and now they have become popular again on the supermarket shelves. The sprouts of different vegetables stand out for their high nutritional value and for possessing certain attributes for people's health, but they do not always reach the consumer in optimal conditions. For this reason, at the Faculty of Agronomy of the UBA (FAUBA) they focus on the study of broccoli sprouts, whose benefits would be much higher than those that can be provided by seeds or mature vegetables (the inflorescences that are traditionally used in the kitchen).
“The species belonging to the Brassicaceae family have been and are currently being studied for their benefits to human health: they are excellent sources of fiber, vitamins and minerals. In addition, the secondary compounds (mainly glucosinolates) from these plants help reduce the risk of degenerative diseases ”, explained Diana Frezza, a professor in the Horticulture department at FAUBA, who directs research on the management and components of broccoli sprouts. , together with a team of thesis students and professors from different institutions.
"In broccoli sprouts, the concentration of bioactive compounds (which improve the beneficial properties for health derived from the consumption of this vegetable) is up to 10 times higher compared to the adult plant due to its young tissues", he pointed out, adding: "Given this, the alternative arises of diversifying the diet, seeking not only variability of vegetables, but also different consumption organs of the same species whose properties surpass the traditional product, such as broccoli inflorescences".
Apparently, the consumption of broccoli has been growing in a different way in other countries: “I had the opportunity to be in England, and in supermarkets they offer some trays containing two servings of unharvested broccoli sprouts. They are simply offered with the substrate (the medium in which the plant develops) so that the consumer can cut what they want and when they want ”, he recalled.
Investigations with local results
Frezza referred to the shortage of scientific literature produced in Argentina on harvest indicators and nutritional composition of sprouts in general, which motivated the need to generate local knowledge, also taking into account that the products sold in shops do not always present good quality. According to the professor: “The sprouts have a high respiratory rate, which is why their useful life during postharvest is short. It is also a fragile product, which is quickly destroyed when it is handled, and many times it reaches the shelves in conditions that do not respond to the desired quality ”.
The research team of the Horticulture department at FAUBA has been working on these studies for three years. The project, financed by the University of Buenos Aires (UBACyT) and supported by a group of thesis students, sought to determine sprout harvest indices and to determine qualitatively and quantitatively bioactive compounds (flavonoids, carotenoids, ascorbic acid, d-hydroascorbic acid, antioxidant capacity , etc.), chlorophyll at harvest and its postharvest stability, whose content depends on aspects such as species, cultivar, age of the plant and harvested organ, temperature, effect of light and type of soil, as well as agronomic practices and cultivation.
For this, the growth conditions of the shoots were evaluated with different qualities of light (red, white, blue and in the dark) in periods of one week (the time it takes for a shoot to reach the harvest state). In another trial, the effect of supplementing with selenium and sulfur was tested to promote a higher concentration of glucosinolates. In postharvest, different temperatures were evaluated under modified atmospheric conditions and the application of 1-MCP, a product that acts on the production of ethylene.
According to Frezza, the best results so far were obtained with exposure to white light: “We achieved shoots with thicker hypocotyl cells, as well as larger and well-expanded cotyledons, with an intense green color, and good levels of bioactive compounds both at harvest as in postharvest ”.
One of the fundamental aspects when advancing with the tests referred to the seeds used. Since most of the materials available on the market are treated with fungicides, untreated (organic) seeds were imported from the USA through a commercial seed company.
In addition to Frezza, the work team was made up of thesis students Nicolás Nápoli, Soledad Cervoni, Joaquín Pérez, Belén Barón and Gabriel Koch. Carlos Mazza, researcher at the Institute of Physiological and Ecological Research Linked to Agriculture, IFEVA (FAUBA-CONICET), Edgardo Mónaco, professor of the Horticulture chair at FAUBA, and Diego Matta, from the INTA Institute of Floriculture also collaborated. For his part, Gustavo Martínez made possible the determination of glucosinolates. The work was carried out by Eugenia Lobato, from the School of Exact Sciences of the National University of La Plata and INFIVE, who received training at the University of Davis, USA, in the determination of these compounds. Their results contributed to the FAUBA studies. Verónica Feuring and Alina Crelier, from the FAUBA Biochemistry laboratory, fine-tuned the measurement techniques for bioactive compounds, gave support to the thesis workers for the extractions and made the measurements on different equipment.
The FAUBA trials were transferred from the field to the Sensorial Analysis Laboratory, directed by Alejandra Picallo, to evaluate the freshly harvested products with consumer panels, in relation to their appearance and flavor, and the different lights to which they had been exposed during its growth.
The tests were conducted recently and the researchers are still working on analyzing the results.