Development of a functional ingredient from the fruit of Ardisia compressa kunth: optimization of the extraction and encapsulation process by coacervation

ROCÍO CORFIELD; CAROLINA SCHEBOR; AGUILAR-ZÁRATE, P.; WONG-PAZ, J.E.; MUÑIZ-MÁRQUEZ, D.B.

Congreso; E-CONGRESS OF FOOD BIOTECHNOLOGY AND ENGINEERING; 2020

Introduction. Ardisia compressa Kunth, also known as Capulin, is a shrub that grows in the tropical and subtropical regions of Mexico. Its fruits are small, deep purple with a bittersweet flavor. These fruits have been reported to contain anthocyanins and other polyphenolic compounds such as quercetin glycosides and some phenolic acid derivatives. In this sense, capulin is presented as an important source of bioactive compounds for the development of alternative ingredients with potential health benefits. The main problem is the deterioration of its bioactive compounds. For this reason, the aim of this work was to develop a functional ingredient from an optimized Capulin extract, encapsulated by coacervation with whey proteins and pectins and subsequently dehydrated by spray drying.Methodology. Capulin (dehydrated and pulverized fruit) from Puebla, Mexico was used. Three extraction treatments were performed: 1) maceration with Mili-Q water for 24 h (MS), 2) application of ultrasound for10 min. and subsequent maceration for 24 h (USm) and 3) extraction using an automatic Soxhlet (8 continuous cycles with absolute ethanol). To select the best treatment, the content of compounds with antioxidant capacity (AC) was evaluated by DPPH2 assay, expressing the results in mg of gallic acid (GAE)/g of Capulin. Once the extract was selected, it was encapsulated through the coacervation method. An experimental design was carried out using the Taguchi methodology2. Three factors with three levels were evaluated (array L9): pH (3,6,9); citric pectin content (0.50, 0.75; 1.00 %W/V) and whey protein content (4.00,6.00,8.00 %W/V). The encapsulation efficiency (%EE) was evaluated as a function of the total polyphenol content using the Folin Ciocalteu3 methodology. The best formulation according to the experimental design was validated. Finally, the selected formulation was spray-dried using a Buchi B-290 device and the AC was quantified by ABTS3 methodology, expressing the results in mg GAE/g powder. All experiments were performed in triplicate and compared by ANOVA analysis using GraphPad Prism 6.0.Results. The extracts developed using the MS and USm treatments did not show significant differences, obtaining a AC= 0.8676 ± 0.0481 and AC= 0.8297 ± 0.0277 mg GAE/g of Capulin, respectively. Regarding the treatment by Soxhlet, the extraction was superior and therefore it was the selected treatment, resulting in AC= 2.6743 ± 0.3160 mg GAE/g Capulin. This is possibly because Capulin contains a high concentration of anthocyanin compounds, whose extraction was favored with ethanol and repeated cycles. Regarding encapsulation, 27 experiments were carried out following the Taguchi matrix, the best formulation being: 0.50 %W/V pectin, 8.00 %W/V, whey protein and pH 9. The expected %EE was 52%, while in the validation 58% was obtained. Finally, the selected coacervate was dehydrated and obtained AC= 14.9 mg GAE/g of powder, a value higher than those reported for other berry powders.Conclusions. Three extraction treatments could be evaluated, demonstrating that the automatic Soxlet system is an effective, fast and superior system for the extraction of bioactive compounds, compared to other methods such as Ms or USm. Additionally, a coacervation formulation with relatively high encapsulation efficiency was achieved. Finally, the dehydration of the coacervates rendered a powder ingredient, which due to its composition promises to have great potential to be used in the formulation of potentially functional food products.