Reclaim and Valorization of Sea Buckthorn (Hippophae rhamnoides) By-Product: Antioxidant Activity and Chemical Characterization

Abstract

The by-product resulting from the production of the sea-buckthorn (Hippophae rhamnoides) juice may be a functional food ingredient, being a valuable source of bioactive compounds, such as polyphenols, flavonoids, minerals, and fatty acids. For checking this hypothesis, two extracts were obtained by two different methods using 50% ethyl alcohol solvent, namely through maceration–recirculation (E-SBM) and through ultrasound extraction (E-SBUS), followed by concentration. Next, sea-buckthorn waste (SB sample), extracts (E-SBM and E-SBUS samples) and the residues obtained from the extractions (R-SBM and R-SBUS samples) were characterized for the total polyphenols, flavonoid content, antioxidant capacity, mineral contents, and fatty acids profile. The results show that polyphenols and flavonoids were extracted better by the ultrasound process than the other methods. Additionally, the antioxidant activity of the E-SBUS sample was 91% higher (expressed in Trolox equivalents) and approximately 45% higher (expressed in Fe2+ equivalents) than that of the E-SBM sample. Regarding the extraction of minerals, it was found that both concentrated extracts had almost 25% of the RDI value of K and Mg, and also that the content of Zn, Mn, and Fe is significant. Additionally, it was found that the residues (R-SBM and R-SBUS) contain important quantities of Zn, Cu, Mn, Ca, and Fe. The general conclusion is that using the ultrasound extraction method, followed by a process of concentrating the extract, a superior recovery of sea-buckthorn by-product resulting from the juice extraction can be achieved.

Effects of Different Drying Methods on Drying Characteristics and Quality of Glycyrrhiza uralensis (Licorice)

“…In HAD and IR-HAD, the direct contact between licorice and oxygen and their longer drying times led to greater browning, thus, enhancing the occurrence of enzymatic browning. This was consistent with the results from Luntraru et al [ 38 ]. The samples of licorice dried using MVD also had a high degree of browning because the drying speed of MVD was fast and the high power easily caused the licorice to cook, resulting in color degradation, which is consistent with the results from Li Xiaofeng et al [ 39 ], who used MVD to dry Phyllanthus emblica .…”

Optimizing the Solvent Selection of the Ultrasound-Assisted Extraction of Sea Buckthorn (Hippophae rhamnoides L.) Pomace: Phenolic Profiles and Antioxidant Activity

“…SBP was ground into a powder using a FW80 high-speed grinder (Tianjin Taisite Instrument Co., Ltd., Tianjin, China) and then sifted through a 60-mesh sieve. The concentrations of solvents used for SBP extraction were determined as 25%, 50%, and 75%, based on commonly used concentrations for organic solvent extraction in various reports [35,38,41,42]. Solutions of varying concentrations of methanol, ethanol, glycerol, ethyl acetate, and petroleum ether were prepared separately.…”

“…Additionally, the methanol and ethanol groups also displayed higher TFCs, showing a trend similar to TPCs. The use of 50% ethanol in the ultrasound-assisted extraction of SBP was reported to result in a TFC of 11.22 ± 1.89 mg RTE/g [38]. It is possible to achieve a higher TFC by using higher concentrations of ethanol.…”

“…Ethanol, another commonly used solvent, was applied for the sequential extraction of defatted SBP, and it was found that ethanol extraction gave higher yields but the extracts had lower antioxidant activity than the water extracts [37]. A study using 50% ethanol for SBP extraction revealed an enhanced extraction of phenols and flavonoids through ultrasonication [38]. Guo et al used ethyl acetate to extract and evaluate bound phenolics in four different species of sea buckthorn [39].…”

In Search of Authenticity Biomarkers in Food Supplements Containing Sea Buckthorn: A Metabolomics Approach

“…Other vegetative parts (e.g., stems, bark, roots), even if still underutilized, showed therapeutical potential [89][90][91], e.g., the root and stem have antioxidant and antimicrobial activity [92,93], while the bark has antimetastatic activity [94]. The by-products resulting from berry waste [95] and biomass (leaves and branches) [96] can be further valorized in the food industry, nutraceuticals, and cosmetics [97][98][99].…”