Encapsulation of beetroot extract (Beta vulgaris L.) obtained by internal and external ionic gelation: A comparative study

Authors: ALEXANDRE, JOANA - State University Of Ceará; BARROSO, TIAGO - State University Of Campinas; DA SILVA, LUANA - State University Of Ceará; CASTELO, RACHEL - State University Of Ceará; FREIRE, GABRIELLE - State University Of Ceará; NASCIMENTO, AMADNA - State University Of Ceará; Cheng, Huai; Biswas, Atanu; BRUNO, LAURA - Embrapa Tropical Agroindustry; ROSELAYNE, FURTADOF - Embrapa Tropical Agroindustry

Submitted to: Food Science and Technology (Campinas)
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/14/2023
Publication Date: 4/2/2024
Citation: Alexandre, J.D.B., Barroso, T.L.C.T., Da Silva, L.C., Castelo, R.M., Freire, G.A., Nascimento, A.B.D, Cheng, H.N., Biswas, A., Bruno, L.M., Furtado, R.F. 2024. Encapsulation of beetroot extract (Beta vulgaris L.) obtained by internal and external ionic gelation: A comparative study. Food Science and Technology (Campinas). 44. Article e00225. https://doi.org/10.5327/fst.00225.
DOI: https://doi.org/10.5327/fst.00225

Interpretive Summary: Many food additives, like pigments, spices, vitamins, and Many food additives, like pigments, spices, vitamins, and nutraceuticals, are prone to oxidation or have undesirable taste, and their use in food is then restricted. For these food additives, encapsulation is a method to encase these substances and minimize adverse issues. A common approach is ionic gelation through the use of alginate, and it can done via external gelation or internal gelation. In this work, the betalain pigments present in beets were encapsulated with both internal and external gelation methods, and their behavior in terms of encapsulation and release was compared. The two gelation methods have their advantages and disadvantages, and the choice of either method depends on the food matrix and the nature of the food application. This work may be useful to other food scientists interested in using sugarbeet betalain as food additive. The results may also serve as a guide for future scientists working with encapsulation of food additives.

Technical Abstract: Natural pigments, such as betalains present in beets, are sensitive to environmental conditions, thereby affecting their reactivity and shelf-life. This sensitivity makes it difficult for the food industry to increase the use of these pigments in food formulations. Microencapsulation is an attractive alternative for the delivery of these compounds, as it protects the active agents through polymeric microcapsules. The aim of this study was to compare two ionic gelation methodologies, external (EG) and internal gelation (IG), in the microencapsulation of beet aqueous extract. The particles were obtained by mixing sodium alginate with the aqueous extract of beetroot and crosslinking with calcium chloride solution using the extrusion method. Encapsulation characteristics and physical, morphological, and colorimetric features were evaluated. The particles showed 10.72% and 89.90% encapsulation efficiency for EG and IG, respectively. The loading capacity was 18.90% for the EG and 25.60% for the IG. For rehydration, those microparticles obtained by IG had a greater capacity to absorb water. Texture analysis indicated that the EG particles showed greater hardness. The release kinetics indicated that the EG particles followed the Korsmeyer-Peppas model, while the IG particles followed the Higuchi model. Thus, the appropriate encapsulation technique should be selected depending on the food matrix to be used and the specific objective of delivering the active encapsulated molecules.