Blackcurrants (Ribes nigrum): A Review on Chemistry, Processing, and Health Benefits.

Blackcurrants (BC; Ribes nigrum) are relatively new to the U.S. market; however, they are well known and popular in Europe and Asia. The use of BC has been trending worldwide, particularly in the United States. We believe that demand for BC will grow as consumers become aware of the several potential health benefits these berries offer. The objectives of this review were to provide an up-to-date summary of information on BC based on articles published within the last decade; furthermore, to provide the food industry insights into possibilities for the utilization of BC. The chemistry, processing methods, and health benefits have been highlighted in addition to how the environment and variety impact the chemical constituents of BC. A search for journal publications on BC was conducted, which included keywords such as chemical characterization, health benefits, processing, technologies, anthocyanins (ANC), and proanthocyanidins. This review provides up-to-date information available on the subject. In conclusion, BC and their products have industrial uses from which extractions can be made to produce natural pigments to be used as food additives. BC contain flavonoids, specifically ANC, which provide the fruits with their purple color. BC are a rich source of phytochemicals with potent antioxidant, antimicrobial, and anti-inflammatory properties. Also, BC have the potential to improve overall human health particularly with diseases associated with inflammation and regulation of blood glucose.

Protection of color and chemical degradation of anthocyanin from purple corn (Zea mays L.) by zinc ions and alginate through chemical interaction in a beverage model.

Anthocyanin-rich purple corn pericarp water extract (PCW) has the potential to be used as a natural pigment in beverages. However, it has a limited shelf-life in aqueous solutions. The aim was to evaluate the effect of zinc ion (Zn2+) and alginate on color and chemical stability of anthocyanins from colored corn (PCW) in a beverage model for 12weeks. PCW was incorporated to Kool-Aid® Invisible™ along with ZnCl2 and/or alginate. Individual ANC were quantified through HPLC, and color stability was evaluated through the CIE-L*a*b* color system. Complexation between PCW and Zn/alginate was evaluated with fluorescence spectroscopy. The combination of Zn and alginate was the most effective treatment improving the half-life of total ANC concentration (10.4weeks), cyanidin-3-O-glucoside (7.5weeks) and chroma (18.4weeks), compared to only PCW (6.6, 4.5 and 12.7weeks, respectively). Zn and alginate had bimolecular quenching constants (Zn kq: 3.4×1011 M-1S-1 and AA kq: 1.0×1012 M-1S-1) suggesting that fluorescence quenching was binding rather than collisional. Results suggested that Zn/alginate interacted with ANC from purple corn slowing its chemical degradation.

Natural Pigments: Stabilization Methods of Anthocyanins for Food Applications.

The production of natural food pigments continues to grow worldwide. The global market is expected to grow at a compound annual growth rate of 6.22%, by revenue, over the period 2015 to 2019. Pigments such as anthocyanins, carotenoids, betalains, and chlorophylls have been used to color foods. However, there are challenges related to color losses during food processing, storage, and commercialization due to a low stability of natural pigments compared to synthetic colorants. This review summarizes the most recent studies and patents aimed at enhancing anthocyanin stability in food systems. The stabilizing methods include additions of copigment compounds, such as polymers, phenolic compounds, and metals. In addition, the exclusion of O2 during processing and storage, hard-panned candy coating methods for blue, green, and brown colors, and various encapsulation techniques were considered. Combining strategies and evaluating new materials capable of stabilizing anthocyanins will enhance their potential for use as value-added natural food pigments.