Application of Crude Pomace Powder of Chokeberry, Bilberry, and Elderberry as a Coloring Foodstuff

Abstract

Berry pomace, rich in polyphenols, especially anthocyanins, accumulates during the production of red juices. Pomace from chokeberry (Aronia melanocarpa Michx.), bilberry (Vaccinium myrtillus L.), and elderberry (Sambucus nigra L.) represent good sources of coloring foodstuffs. Pomace powders (PP) were prepared by milling the seedless fractions of the three dried berry pomaces (50 °C, 8 h). Techno-functional properties of the powders such as particle size distribution, bulk density, sedimentation velocity, and swelling capacity were determined to evaluate the powders for possible food applications. Total anthocyanin content was quantified by UHPLC-DAD before and during a storage experiment to monitor the degradation of anthocyanins in the PP and in a yogurt model application. The high content of phenolic compounds and the still intact cell structure ensured high stability of anthocyanins over 28 days of storage. In the model application, color saturation was stable over the whole storage time of 14 days. Regarding the techno-functional properties, only a few differences between the three PP were observed. The particle size of elderberry PP was larger, resulting in lowest bulk density (0.45 g/mL), high cold-water solubility (16.42%), and a swelling capacity of 10.16 mL/g dw. Sedimentation velocity of the three PP was fast (0.02 mL/min) due to cluster formation of the particles caused by electrostatic and hydrophobic properties. Compared to other high-intensity coloring foodstuffs, the use of PP, showing acceptable color stability with potential health-promoting effects, represents a wide applicability in different food applications and especially in products with a longer shelf-life.

Potential Use of Elderberry (Sambucus nigra L.) as Natural Colorant and Antioxidant in the Food Industry. A Review

“…Moreover, this stability was higher in the yoghurts formulated with elderberry powder than those made with reference substances (black carrot and purple sweet potato pigments). A possible explanation for this behavior could be that in elderberry powder, the anthocyanins are bound to the intact cell structures and are progressively released during storage (14 days) [39]. This fact also explains the results of total phenolic compounds content, which increased slightly in elderberry yoghurts during storage and was due to the progressive release of these compounds from powder to yoghurt.…”

“…Therefore, this section will introduce and discuss the main effects of the use of elderberry in the formulation of different foods and also as a new natural additive for use in the food industry. According to published manuscripts, both the baking [6,50,51] and dairy [19,23,39,43] food industries use elderberries as natural additives to improve the color and shelf-life of their products. Likewise, although the application of elderberry products in the meat industry is scarce, the characteristic intense-red color of meats and meat products and their high perishability mean that elderberries can potentially be used in these products [14] due to the colorant and antioxidant properties that are discussed throughout this manuscript.…”

“…The final study in which elderberry was used to reformulate yoghurt was conducted by Nemetz et al [39]. Unlike the other studies, these authors used pomace powder collected after obtaining elderberry juice.…”

“…This is because of their low stability under some conditions, such as light exposure, oxygen exposure, thermal treatments, pH changes, etc. [39]. However, these are common situations during food processing, forcing researchers to find new techniques to stabilize anthocyanins.…”

“…In this regard, various recent studies investigated the optimal conditions for obtaining high anthocyanins extracts from elderberries [14,34] and also explored their stabilization using encapsulation processes [18,34,40]. In another study, the authors also proposed the production of pomace powder from elderberry and its application as a coloring foodstuff [39]. Therefore, and taking into account the previously mentioned enormous benefits that elderberries possess, this manuscript reviews the possible uses of these berries to obtain natural antioxidants and coloring compounds or extracts and their potential use in the food industry.…”