New Freeze-Dried Andean Blueberry Juice Powders for Potential Application as Functional Food Ingredients: Effect of Maltodextrin on Bioactive and Morphological Features

Abstract

Andean blueberry (Vaccinium meridionale Swartz) fruits are an underutilized source of anthocyanins and other valuable bioactive phytochemicals. The purpose of this work was to obtain Andean blueberry juice powders via freeze-drying processing and evaluate the effect of maltodextrin as a drying aid on their physicochemical, technological, microstructural, and bioactive characteristics. Andean blueberry juices were mixed with variable proportions of maltodextrin (20–50%); freeze-dried; and characterized in terms of their tristimulus color, Fourier transform infrared spectra (FTIR), moisture content, water activity, morphology, water solubility, flow properties, total polyphenols and anthocyanins content, and DPPH•-scavenging capacity. The powders obtained presented suitable characteristics in terms of their water activity (<0.5), solubility (>90%), and bioactive compound recovery (>70% for total phenolics, and >60% for total monomeric anthocyanins), with antioxidant activities up to 4 mg equivalent of gallic acid/g of dry matter. Although an increased content of maltodextrin resulted in lower concentrations of phytochemicals, as expected, it also favored an increased % recovery (over 90% of total phenolics at the highest maltodextrin proportion) and improved their flow properties. Freeze-dried juice powders are a potential alternative for the stabilization and value addition of this fruit as a new source of functionality for processed foods.

Evaluation of mixtures of maltodextrin and gum Arabic for the encapsulation of Andean blueberry (Vaccinium meridionale) juice by freeze–drying

“…Due to the correspondence of the spectra of the encapsulating agents in this mid‐infrared region, the resulting spectra of the juice powders obtained with different GA/MD ratios were also quite similar. These results indicate that there were no evident chemical interactions between the wall compounds and the characteristic compounds of the juice, in agreement with previous studies (Estupiñan‐Amaya et al ., 2020).…”

“…The juice extraction and filtration procedures were carried out less than 1 h before the mixture with the encapsulating agents. The resulting juice had the following characteristics: 13.27 ± 0.05 °Brix; pH: 2.91 ± 0.07; total polyphenol content: 2032.5 ± 41.7 mg GAE L −1 (mg equivalents of gallic acid per litre); total anthocyanin content: 371.5 ± 20.1 mg C3G L −1 (mg equivalents of cyanidin‐3‐O‐glucoside); and DPPH• scavenging activity: 19.1 ± 0.3 mg GAE g −1 (Estupiñan‐Amaya et al ., 2020).…”

“…This can be overcome by the use of adjuvants materials, which act as wall materials, enhancing the encapsulation of the juice dry matter. Maltodextrin (MD) is one of the most commonly used carrier agents for the encapsulation of fruit extracts, and it has been extensively described as suitable for obtaining fruit juice powders through freeze–rying (Estupiñan‐Amaya et al ., 2020; Sharif et al ., 2020; Rosales & Fabi, 2022).…”

“…It has been suggested by several in vitro studies that these juices exhibit pro‐apoptotic and antiproliferative effects in transformed leukaemic and colorectal cancer cell lines (Arango‐Varela et al ., 2021, 2022). Given their sensory appealing features, their high concentration of phenolic compounds, in particular of anthocyanins, and their bioactivity (Garzón et al ., 2010; Maldonado‐Celis et al ., 2014; Bravo et al ., 2016; Agudelo et al ., 2018; Gallego‐Peláez et al ., 2021), their transformation into more stable products with different functionalities as ingredients have arisen interest (Alzate‐Arbeláez et al ., 2019; Estupiñan‐Amaya et al ., 2020; Garzón et al ., 2021). Despite the underlying potential in the development of new functional foods and ingredients, there are several challenges associated with the preservation of these perishable juices, and few studies have been performed on the topic (Estupiñan‐Amaya et al ., 2020).…”

“…In a previous work, we evaluated for the first time the feasibility of obtaining freeze–dried Andean blueberry juices powders with and without the addition of MD as coadjutant (Estupiñan‐Amaya et al ., 2020). MD allowed obtaining free‐flowing powders with suitable technological properties and high content of bioactive compounds (total polyphenols and monomeric anthocyanins).…”