New study lays foundation to obtain apple cubes enriched with probiotics

Spanish and Brazilian researchers have studied the use of drying techniques along with ultrasounds in order to enrich apple snacks with Lactobacillus casei

Researchers of the Universitat Politècnica de València and the Universidade Federal do Ceará (Brazil) have completed a study that lays the foundation to obtain apple cubes enriched with probiotics, namely Lactobacillus casei. The work has been published in the most recent edition of the Journal of Functional Foods.

According to the researchers in their article, the enrichment of foodstuffs with probiotic strains can provide important health benefits. "They contribute towards, for example, reducing the risk of cardiovascular diseases and type 2 diabetes, they have anti-inflammatory potential and protect against colitis, among other benefits", states Juan Andrés Cárcel, researcher of the Analysis and Simulation of Agri-food Processes Group at the Universitat Politècnica de València.

In order to obtain these new products, the Spanish and Brazilian researchers applied three temperatures to dry the fruit during their study - 60 degrees being the highest, followed by an intermediate one of 40 and lastly 10 - combined, or not, with ultrasounds.

"The process is relatively simple: the fruit is impregnated in a dilution of probiotics and the product is then subjected to the aforementioned drying techniques. Initial results show they could be a viable, low-cost alternative to obtain new foodstuffs, snacks, etc, enriched with probiotics", stresses Cárcel.

Mathematic model

In the study, researchers of the Universitat Politècnica de València and the Universidade Federal do Ceará developed a mathematic model which made it possible to predict the drying kinetics and the inactivation of Lactobacillus casei in the analysed samples.

Of the different tests performed, the application of ultrasounds, both for the drying at 60 and 10 degrees, made it possible to obtain a final product which contained a high enough concentration of Lactobacillus to surpass the established threshold to be considered probiotic food.

"The drying speeds rose as the temperature of the process increased and with the application of ultrasounds. In regards to the concentration of probiotics in the apple cubes, in some of the tested conditions, it was similar to the concentration of microorganisms present in commercial probiotic dairy products. The results obtained after drying at 10 and 60 degrees with ultrasounds were specifically interesting. This opened up the possibility of producing dry probiotic apple snacks", adds Antonio Mulet, also a researcher for the Analysis and Agro-food Processes Simulation Group at the Universitat de València.

Until now, probiotics were found mainly in dairy or liquid products. As the researchers highlight, this study offers positive preliminary results and constitutes a first step in order to obtain fruits enriched with these strains.