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

Natural Sources of Food Colorants as Potential Substitutes for Artificial Additives

In recent years, the demand of healthier food products and products made with natural ingredients has increased overwhelmingly, led by the awareness of human beings of the influence of food on their health, as well as by the evidence of side effects generated by different ingredients such as some additives. This is the case for several artificial colorants, especially azo colorants, which have been related to the development of allergic reactions, attention deficit and hyperactivity disorder. All the above has focused the attention of researchers on obtaining colorants from natural sources that do not present a risk for consumption and, on the contrary, show biological activity. The most representative compounds that present colorant capacity found in nature are anthocyanins, anthraquinones, betalains, carotenoids and chlorophylls. Therefore, the present review summarizes research published in the last 15 years (2008-2023) in different databases (PubMed, Scopus, Web of Science and ScienceDirect) encompassing various natural sources of these colorant compounds, referring to their obtention, identification, some of the efforts made for improvements in their stability and their incorporation in different food matrices. In this way, this review evidences the promising path of development of natural colorants for the replacement of their artificial counterparts.

Fermentation of Murta (Ugni molinae) Juice: Effect on Antioxidant Activity and Control of Enzymes Associated with Glucose Assimilation

Berries are rich in bioactive compounds, including antioxidants and especially polyphenols, known inhibitors of starch metabolism enzymes. Lactic acid fermentation of fruits has received considerable attention due to its ability to enhance bioactivity. This study investigated the effect of fermentation with L. mesenteroides of juice from the Chilean berry murta on antioxidant activity, release of polyphenols, and inhibitory activity against α-amylase and α-glucosidase enzymes. Three types of juices (natural fruit, freeze-dried, and commercial) were fermented. Total polyphenol content (Folin-Ciocalteu), antioxidant activity (DPPH and ORAC), and the ability to inhibit α-amylase and α-glucosidase enzymes were determined. Fermented murta juices exhibited increased antioxidant activity, as evidenced by higher levels of polyphenols released during fermentation. Inhibition of α-glucosidase was observed in the three fermented juices, although no inhibition of α-amylase was observed; the juice from freeze-dried murta stood out. These findings highlight the potential health benefits of fermented murta juice, particularly its antioxidant properties and the ability to modulate sugar assimilation by inhibiting α-glucosidase.

Exploring the Potential of Wild Andean Blueberries for Powdered Juice Production through Spray Drying

The Andean blueberry (Vaccinium meridionale Sw) is an underutilized wild fruit native to South America. It is known for its antioxidant properties and potential health benefits. In this study, Andean blueberry juice powders were produced via spray drying, using maltodextrin (MD), gum Arabic (GA) or a combination of both (MD:GA) as wall materials. The spray-dried juices were analyzed for the recovery percentage of total polyphenols and monomeric anthocyanins, as well as for their physicochemical and technological properties. Results showed that the type of carrier agent used caused statistically significant differences in the bioactive content and the antioxidant activity of the powders (p < 0.05). It was found that the MD samples has the highest monomeric anthocyanins content (0.88 ± 0.02 mg cyanidin 3-glucoside equivalents/g) and the highest anthocyanins recovery (96.3 ± 1.7%), while the MD:GA powders showed the highest values of total polyphenol content (5.70 ± 0.09 mg gallic acid equivalents/g), DPPH scavenging capacity (2.49 ± 0.02 mg gallic acid equivalents/g) and phenolics recovery (87.2 ± 1.1%). Furthermore, all the spray-dried powders exhibited low moisture content (<5.5%) and water activity (<0.40), as well as high solubility in water (>94%) and good flowability. Future prospects include evaluating the stability of the Andean blueberry juice powders during storage and exploring the formulation of new foods and beverages that incorporate these spray-dried powders.

Impact of hydrocolloid and foaming agent on the physicochemical, microstructural and bioactive characteristics of foam-mat freeze-dried tapai (fermented black glutinous rice) powder

The aim of this study was to obtain fermented black glutinous rice (FBGR) powder using the foam-mat freeze-drying method and to evaluate the physicochemical, microstructural, and bioactive characteristics of FBGR powder. To obtain FBGR foams, maltodextrin (MD; 0%-40% w/w) and whey protein isolate (WPI; 7.5% w/w) were used. The results showed that MD concentration had a significant effect (p ≤ .05) on powder recovery and bulk density which increased from 68.9% to 80.5% and 0.46% to 0.63 g/ml, respectively. The lowest moisture content (2.17%) and water activity (0.48) were found in powders produced with 20% MD. The solubility of FBGR powders ranged from 74% to 75% and increasing MD concentration gave higher lightness (L*) and yellowness (b*) readings in color properties of powders. Although the addition of the carrier agent caused reductions in total phenolic content and anthocyanins, the retention of these bioactive compounds rose with increasing MD content from 67% to 76% and 78% to 84%, respectively. FBGR produced with 40% MD had the most superior physical and technological properties, and foam-mat freeze-drying is a promising technology for retaining the bioactive compounds in FBGR.

Encapsulation of Bilberry Extract with Maltodextrin and Gum Arabic by Freeze-Drying: Formulation, Characterisation, and Storage Stability

Anthocyanins are polyphenolic plant pigments associated with antioxidant and health-promoting properties. However, their application in the food industry is limited due to their poor stability. The purpose of this study was to encapsulate anthocyanin-rich bilberry (Vaccinium myrtillus L.) extract by freeze-drying and to investigate the effects of different wall materials and extract contents on the physicochemical and bioactive properties of the obtained encapsulates. Ethanolic bilberry extract was encapsulated with the use of maltodextrin (16.5–19.5 DE) (MD), gum Arabic (GA), and their combination in a 1:1 w/w ratio (MIX). Bilberry solids to wall material ratios were examined at 20:80, 30:70, and 40:60. All encapsulates showed an attractive red colour and low water activity values (aw ≤ 0.3) that indicated a low risk of microbial spoilage. In general, the biggest losses of total phenolic compounds and anthocyanins during three-week storage in the dark and at room temperature (20 ± 2 °C) were detected in the case of encapsulates with a higher content of bilberry extract (MIX30 and MIX40, and GA30 and GA40, respectively). The use of maltodextrin provided the best protection to bilberry anthocyanins during forced storage. Overall, the obtained encapsulates show suitable potential for the development of food products with added nutritional benefits.

Micro-Encapsulation and Characterization of Anthocyanin-Rich Raspberry Juice Powder for Potential Applications in the Food Industry

Raspberry juice obtained from fresh raspberry fruits was encapsulated separately using gum Arabic (GA), maltodextrin (MT), and waxy starch (WS) (1:10, w/v) and freeze-dried to develop raspberry juice powders (RBJP). The powders were characterised based on their physicochemical and phytochemical composition and their rheological and antioxidative properties, which significantly varied among the carriers. GA- and MT-encapsulated RBJP exhibited a better colour, higher yield, oil holding capacity, total anthocyanin content, and antioxidant properties. WS-encapsulated powder showed a better water holding capacity and total phenolic content; however, the powder was characterised by low solubility, total soluble solids, and redness. Hygroscopicity and titratable acidity did not significantly (p > 0.05) vary among the powders. Cyanidin diglucoside, the main anthocyanin compound identified in the RBJP, was significantly higher in MT (2549.89 µg/g) compared to GA (1935.45 µg/g) and WS (1458.81 µg/g). The RBJP produced using MT and GA showed irregular-shaped and non-spherical particles, which were less agglomerated and relatively larger, while the WS powder exhibited more uniform, spherical particles, which agglomerated together. An X-ray diffraction analysis showed that GA and MT powders had an amorphous structure with minimum crystallinity, while RBJP from WS was crystalline. It can be concluded that GA and MT produced RBJP with quality attributes relevant to the food industry.