Physicochemical, Antioxidant, Microstructural Properties and Bioaccessibility of Dark Chocolate with Plant Extracts

Abstract

In this study, dark chocolates (DCh) containing zinc lactate (ZnL) were enriched with extracts from elderberries (EFrE), elderflowers (EFlE), and chokeberries (ChFrE) to improve their functional properties. Both dried plant extracts and chocolates were analyzed for antioxidant capacity (AC) using four different analytical methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), cupric ion-reducing antioxidant capacity (CUPRAC), and ferric-reducing antioxidant power (FRAP), while total phenolic content (TPC) was determined by Folin–Ciocalteu (F–C) assay. An increase in antioxidant properties of fortified chocolates was found, and the bioaccessibility of their antioxidants was evaluated. The highest AC and TPC were found in ChFrE and chocolate with chokeberries (DCh + ChFrE) before and after simulated in vitro digestion. Bioaccessibility studies indicated that during the simulated digestion the AC of all chocolates reduced significantly, whereas insignificant differences in TPC results were observed between chemical and physiological extracts. Moreover, the influence of plant extracts on physicochemical parameters such as moisture content (MC), fat content (FC), and viscosity of chocolates was estimated. Furthermore, scanning electron microscopy with dispersive energy spectroscopy (SEM-EDS) was used to analyze surface properties and differences in the chemical composition of chocolates without and with additives.

Effect of Enriching Gingerbread Cookies with Elder (Sambucus nigra L.) Products on Their Phenolic Composition, Antioxidant and Anti-Glycation Properties, and Sensory Acceptance

“…These results confirm that EF was a richer source of free and bound phenolics than EB. In our previous study, a water extract from elderflowers also revealed approximately 2.5 times higher TPC (81.9 mg gallic (GA) acid/g) than a water extract from elderberries (TPC = 32.5 mg GA/g) [ 40 ]. Additionally, flowers of different elderberry species or interspecific hybrids (TPC = 7410–40137 μg GA/g) contained significantly higher levels of phenolic compounds compared to berries (TPC = 2687.6–6831.1 μg GA/g) [ 41 ].…”

“…On the contrary, a water extract from elderberries had significantly lower radical scavenging properties of DPPH • (1911.6 μM TE/g) and ABTS •+ (2337.1 μM TE/g) than elderflower extract (DPPH = 4756.0 μM TE/g and ABTS = 6258.7 μM TE/g) [ 40 ]. Moreover, the ABTS values (3.20–39.59 μM TE/g) of various elderberry species and hybrids were considerably lower compared to the ABTS results (44.87–118.26 μM TE/g) of elderberry flowers [ 41 ].…”

Dark chocolate: An overview of its biological activity, processing, and fortification approaches

“… The dried plant extract was used for fortification. Poliński et al (2021) Dates and palms To increase the amount of natural sugar extracted from dates and palms and also to reduce the total sucrose content of dark chocolate. The palm and dates were added in the form of syrup.…”

“…The highest TPC and antioxidant capacity were observed in dark chocolate enriched with chokeberries (DCh + ChFrE). Viscosity, total fat content and some physiochemical properties (moisture content) were also checked ( Poliński et al, 2021 ).…”

“… SEM and Viscometer. Poliński et al (2021) Dates and palm syrup The overall sugar content was reduced after fortification with some modification of physiochemical properties. Palm and dates syrup fortified chocolate produced higher moisture content 4.18% and 3.96% respectively.…”