Chilean University identified drying method to conserve antioxidant capacities of blueberries
Our country registers 14.800 hectares of blueberry surface (Vaccinium corymbosum L.), being the largest in South America and the second worldwide, with approximately and a production close to 95.000 tons in the 2012 year.
These data position it as the second largest producer and exporter of fresh blueberries worldwide with about 70.000 tons per year.
For no one is a mystery the number of benefits that bring this fruit to health for its high concentrations of phytochemical compounds such as anthocyanins and polyphenols with antioxidant properties, which are relevant to the health of people.
In this context, the study developed by Victoria López Casanova, as part of her thesis of the Master in Food Science of the Universidad Austral de Chile, entitled "Bioaccessibility of the bioactive compounds (anthocyanins / polyphenols) of cranberry (Vaccinium corymbosum L.) fresh and dehydrated. "
The thesis was sponsored by Dr. Ociel Muñoz, 
director of the Institute of Food Science and Technology (ICYTAL) of the Faculty of Agricultural Sciences of the Austral University of Chile as part of the project led by the academic DID-UACh 2015-11 "Effect of osmotic dehydration and ohmic heating on bioaccessibility of Anthocyanins (bioactive phytochemicals), in Blueberries [Vaccinium myrtillus], and Maqui [Aristotelia chilensis].
The objective of the work was to determine the stability of the antioxidant compounds (anthocyanins / polyphenols) of the cranberry and its antioxidant capacity, in blueberries subjected to different processes of dehydration (technological conservation process), and compare them with fresh fruit explained the professional.
"That means that we try to ensure that blueberries do not lose their antioxidant capacity when processed technologically, and that, when consumed by people, bioactive compounds remain stable during the gastrointestinal process and are available for absorption," says Dr. Muñoz.
LABORATORY WORK
The research was carried out in the laboratories of the Food Science and Technology Institute (ICYTAL) of the UACh. The blueberries analyzed belonged to the town of San José de la Mariquina in the Region of Los Ríos.
To achieve the proposed objectives, blueberries were applied to dehydration processes such as convective drying, osmotic dehydration and lyophilization.
Victoria López explains that the convective drying consists in subjecting the berry, under a current of hot air, to a certain temperature to allow the humidity to migrate towards the surface.
He details that the osmotic dehydration is a process carried out in countercurrent, consists of submerging the blueberry in an osmotically active solution, where the moisture of the cranberry will migrate towards the solution and therefore the solids content will increase.
Finally, he points out that lyophilization is a drying process, which is carried out at freezing temperatures and at low pressures, where the water of the food passes from solid to vapor without passing through a liquid state, allowing to maintain the structure of the food and its organoleptic qualities. and biological.
It was determined that the convective drying process turns out to be an efficient method to conserve cranberry, keeping its antioxidant compounds, which are beneficial for health, reported Victoria.
NOVEDOSO IN VITRO MODEL AND CONTRIBUTIONS
To determine the effect of the drying processes on the polyphenolic compounds, an in vitro model was used that simulates the human gastrointestinal process, from the time the food is ingested, until the nutrients are released at the intestinal level.
The in vitro model consists of quantitatively studying the bioactive compounds, in the different stages of the digestive process (chewing, stomach, intestine) outside the living organism, on a laboratory scale.
The results suggested that convective drying allows to obtain good quality blueberries, rich in antioxidant compounds, which turn out to be more bioaccessible, during the gastrointestinal process in vitro.
In this sense the "main contribution of this study was to determine, a conservation method that can be applied on this berry, since, being a seasonal fruit, it has a short shelf life," says the Engineer.
"This finding can be used by the industries, as an option, for their commercialization, since transport costs would decrease and in turn, consumers would have another alternative for their consumption and take advantage of the great variety of benefits they provide", underlines .
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