Less watering increases the taste and antioxidants of some blueberries

16/03/2016

Researchers from the areas of Ecological Production and Natural Resources (IFAPA center in Las Torres-Tomejil, Seville) and Technology, Postharvest and Agrifood Industry (IFAPA Alameda del Obispo center, Córdoba) have shown in certain varieties of blueberries that reducing the water of Irrigation does not affect the quality of the product but, in some cases, improves it. Specifically, the water deficit studied influences the increase in the firmness of the fruit and the total content of sugars and beneficial compounds for health, such as antioxidants.

The saving in water consumption also implies the reduction of the environmental impact by reducing the amount of fertilizers that, according to experts, can contaminate the aquifers of the growing area.

To carry out the study, the researchers analyzed three types of blueberry varieties that are grown in Huelva. Regarding the need for water from the crop, this was reduced by 20 percent with a double objective: to check the effects of saving water on the fruit and to reduce the amount of water and fertilizers to minimize leaks to the aquifers.

In the first place, the scientists determined that the water deficit does not negatively affect the quality of the different types of blueberries, but that in some of them there is an improvement.

"With the decrease in water, we are subjecting the plant to a stress situation. Therefore, achieving a production with a quality equal to that obtained in normal water conditions is already a success. If, in addition, we improve some parameters in certain varieties, better ", comments the researcher dedicated to quality analysis, José Manuel Moreno Rojas, of IFAPA.

Benefits for health and taste

Another of the conclusions of the study, which is collected in a study published in the journal Food Chemistry, is that the decrease in irrigation input increases the content of polyphenols, chemical compounds present in vegetables that have a high antioxidant capacity.

“A situation of hydric stress, such as the decrease in water, causes a defense reaction in the plant that generates a greater quantity of antioxidants. These counteract the effects of free radicals, chemicals produced by the body, related to cellular aging or the appearance of some diseases such as cancer. Many studies show that a diet rich in polyphenols reduces the incidence of these processes and, in general, improves the quality of life ", the researcher points out.

Similarly, water scarcity influences the increase of total soluble solids or sugars of the varieties analyzed. "This factor, balanced or balanced with the acidity, improves the taste of the product. Sometimes we complain that strawberries or blueberries are tasteless. The sugars avoid it. Therefore, the consumer will find a higher sensory quality fruit "says the expert.

Along with the increase in soluble solids, the lower contribution of irrigation also affected the level of acidity of some types of blueberries. "The decrease in water implies a change in acidity. This fact, not by itself but combined with the concentration of sugars, has to be taken into account to observe the sensory effects it causes on the final product ", explains the researcher collaborator of this project, directed by José Luis Muriel Fernández and financed by the Ministry of Employment, Business and Commerce of the Junta de Andalucía.

Experts also highlight the increased firmness of the product, that is, its external hardness. "A fruit with greater consistency implies a longer postharvest life. This can be extended around 10 or 15 days, under optimal consumption conditions. This implies a greater competitiveness of the product for export and therefore, a better economic performance for the company that produces them ", indicates Moreno Rojas.

Environmental awareness

“The problem with crops in Huelva is fertigation, that is, you water and fertilize at the same time”says Moreno Rojas

The consequences on the environment of the lower contribution of water are determined by the characteristics of the land where these fruits are grown. According to scientists, practically all of the Spanish blueberry production is produced in the province of Huelva, in plantations near the Doñana Natural Park, and in sandy soils that do not retain water but rather quickly pass to deeper layers.

"The problem of crops in Huelva is fertigation, that is, you irrigate and fertilize at the same time. In this type of soil, substances not absorbed by the plant are filtered and go to aquifers. That is why it is so important to optimize irrigation: you not only reduce water, but also fertilizers. You make the crop more environmentally conscious ", qualifies the expert.

The study of the quality of the food, including the relationship between antioxidants and health, centers the research carried out by the Moreno Rojas group. Thus, experts have studied the influence of the method of cultivation, ecological and conventional, on the quality and quantity of antioxidants in fruits such as plum. On the other hand, in the field of health, they try to verify the impact of these compounds on the proliferation of cancer cells.

Source: Discover Foundation