Hibiscus rosa-sinensis as Flavoring Agent for Alcoholic Beverages

Abstract

The present work is an evaluation of the chemical composition of the aroma and the sensorial characters of a beer flavored with Hibiscus rosa-sinensis flowers. Moreover, the total polyphenol, flavonoid and anthocyanin contents and the antioxidant activity of the plant materials and beers were assessed. A comparison with a liqueur flavored with the same hibiscus flowers was also performed. Non-terpene derivatives constituted the main class of components of the aroma of both samples, representing 96.4% of the whole volatilome in the control beer and 99.0% in the hibiscus one. Among this class, esters were the most abundant compounds, being significantly higher in the treated sample (77.6%) than in the control (68.4%), followed by the alcohols (20.9% in control beer and 18.8% in hibiscus beer). From a sensorial point of view, the control beer was characterized by malty and hoppy notes, attributable to the noticeable content in myrcene and α-humulene in its headspace, while in the hibiscus beer, floral and fruity notes, typical of esters and alcohols, prevailed. The polyphenol content was significantly higher in the treated beer (143.96 mg/g) than in the control, as well as the total flavonoids and the total anthocyanins, and, consequently, the antioxidant activity (DPPH-assay).

Essential Oil from Hibiscus Flowers through Advanced Microwave-Assisted Hydrodistillation and Conventional Hydrodistillation

“…e table shows the results of a direct comparison between the percentage of chemical compounds in crude Monoterpenes and sesquiterpenes are said to be "oxygenated" or "oxygenated" when an oxygen molecule is incorporated into their molecular structure. Our findings corroborate previous findings [42][43][44][45][46]. e crude extract percentages, however, were not the same between the two extraction strategies.…”

Resilience of Stevia rebaudiana (Bertoni) Bertoni in the Underwater Biospheres of Nemo’s Garden®: Adaptation to New Cultivation Systems

“…However, the analyzed plants appeared well adapted to develop in all the analyzed growth conditions. The same result was also obtained from the biochemical analysis, which highlighted the lower content of polyphenols in the Nemo’s plants than in the control plants and, as a consequence, their lower antioxidant activity, since it is well known that polyphenols work as scavengers of free radicals and as natural metal chelators [ 27 ]. This discrepancy between the plants cultivated in the biosphere environment and in the terrestrial conditions was attributable to the different environments of cultivation responsible for the different size and behavior of the plants.…”

Halophyte Artemisia caerulescens L.: Metabolites from In Vitro Shoots and Wild Plants

“…The antioxidant activity, detected with two different assays (FRAP or DPPH), was therefore the highest in the flowers of A. caerulescens, followed by the leaves. The activity could be linked to the polyphenols, including the anthocyanins, since they work as scavengers of free radicals and as natural metal chelators [30], and to the carotenoids, which have achieved increasing interest in the last decades for their antioxidant properties [31]. On the other hand, the contribution of other antioxidant molecules can be included and further investigated.…”