The study – published in Food and Bioproducts Processing – evaluates new methods for the production of pomegranate seed oil for the food industry. The technique was developed based on the extraction of the polyphenol-rich seed oil and its subsequent encapsulation by spray drying.
“Pomegranate is one of the oldest known edible fruit that contains the highest concentration of total polyphenols in comparison with other fruits studied,” note the authors, who note that the fresh fruit is popularly consumed whole or as part of other food and beverage products.
The team, led by Dr Athanasia Goula from the Aristotle University of Thessaloniki, Greece, note that during the industrial processing of pomegranate, large volumes of industrial wastes – including seeds, peels, leaves – are produced, all of which have a wide range of nutritional values that could be utilised as functional ingredients for the food industry.
Goula and her colleagues note that pomegranate seed oil has been suggested to have several beneficial properties, including, antioxidant and eicosanoid enzyme inhibition properties, skin photoaging inhibition effects, and the ability to modify immune function and lipid metabolism.
“Due to the above-mentioned pharmaceutical and nutraceutical properties of pomegranate seed oil and also due to the large annual production of pomegranate seeds as a by-product of the juice and concentrate industries, the seeds could have more beneficial applications in food industries,” suggest the researchers.
“One way to utilize the seeds is to extract the oil and use it in various food products.”
Encapsulation study
“The objective of this work was to develop a new method for pomegranate seed application in food industries based on its extraction and subsequent encapsulation by spray drying,” explains Goula and her co-workers.
In the study the team developed a new technique based on oil encapsulation using skimmed milk as an encapsulating agent.
The ratio of core to wall material, feed solids concentration, inlet air temperature, and drying air flow rate were the factors investigated with respect to encapsulation efficiency using a central composite design.
The resulting microcapsules were evaluated in terms of moisture content, particle size, bulk density, and hygroscopicity.
“The optimum operating conditions were found to be: ratio of core to wall material, 1/9; feed solids concentration, 30% (w/w); inlet air temperature, 187 °C; drying air flow rate, 22.80 m3/h. Under these conditions, the maximum encapsulation efficiency was about 95.6%,” wrote the authors.
Source: Food and Bioproducts Processing
Published online ahead of print, doi: 10.1016/j.fbp.2012.06.001
“A method for pomegranate seed application in food industries: Seed oil encapsulation”
Authors:A.M. Goula, K.G. Adamopoulos