Comparative Study on Phenolic Compounds and Antioxidant Activities of Hop (Humulus lupulus L.) Strobile Extracts

In this study, we investigated the phenolic compounds in hop strobile extracts and evaluated their antioxidant property using DPPH and ABTS assay. The total phenolic compound (TPC) and total flavonoid compound (TFC) estimated in two different solvent extracts considerably varied depending on the extraction solvent. The most abundant phenolic compound in hop strobile was humulones (α-acid) with levels ranging from 50.44 to 193.25 µg/g. El Dorado accession revealed higher antioxidant activity in ethanol extracts (DPPH: IC50 124.3 µg/mL; ABTS: IC50 95.4 µg/mL) when compared with that of the other accessions. Correlations between DPPH (IC50) scavenging TFC in ethanol extract (TFC_E, −0.941), and TPC_E (−0.901), and between ABTS (IC50) scavenging TFC_E (−0.853), and TPC_E (−0.826), were statistically significant at p < 0.01 level, whereas no significant correlation was observed between antioxidant activities, TPC and TFC in water extract. This study is the first to report that variations in the level of phenolic contents and antioxidant activity of various hop cultivars depended on the type of extraction solvent used and the cultivation regions. These results could provide valuable information on developing hop products.

Dispersive liquid–liquid microextraction of 11-nor-Δ9-tetrahydrocannabinol-carboxylic acid applied to urine testing

Aim: THC-COOH is the major metabolite of Δ9-tetrahydrocannabinol commonly tested in urine to determine cannabis intake. In this study, a method based on dispersive liquid–liquid microextraction was developed for testing THC-COOH in urine. Materials & methods: Hydrolyzed urine specimens were extracted via dispersive liquid–liquid microextraction with acetonitrile (disperser solvent) and chloroform (extraction solvent). Derivatization was performed with N,O-Bis(trimethylsilyl)trifluoroacetamide with 1% trichloro(chloromethyl)silane. Analysis was performed by GC–MS/MS. Results: The method showed acceptable linearity (5–500 ng/ml), imprecision (<10.5%) and bias (<4.9%). Limits of detection and quantitation were 1 and 5 ng/ml, respectively. Twenty-four authentic samples were analyzed, with 22 samples being positive for THC-COOH. Conclusion: The proposed method is more environmentally friendly and provided good sensitivity, selectivity and reproducibility.

Innovative Extraction Technologies for Development of Functional Ingredients Based on Polyphenols from Olive Leaves

Olive tree (Olea europea L.) leaves represent around 10% of the total weight of olives arriving at any given mill, which are generally discarded, causing economic and environmental issues. However, these are rich sources of natural bioactive compounds (i.e., polyphenols), which have health-promoting potential. Thus, the valorization of olive leaves by recovering and reusing their components should be a must for food sustainability and circular economy. This review provides an insight into the principal polyphenols present in olive leaves, together with agronomic variables influencing their content. It also summarizes the recent advances in the application of novel extraction technologies that have shown promising extraction efficacy, reducing the volume of extraction solvent and saving time and cost. Moreover, potential industrial uses and international patents filed in the pharmaceutic, food, and cosmetic sectors are discussed.

Color and antibacterial activity of annatto extracts at various pH of distilled water solvent and extraction temperature

Annato (Bixa orrelana L.) has been renowned as a tropical plant rich in carotenoid pigments such as nonpolar bixin and polar norbixin. This study was aimed to obtain natural colorant and antimicrobials from annatto extracts. The extraction was carried out by maceration for 10 mins using distilled water as the extraction solvent at various pH and extraction temperatures. The variations of solvent pH used in this research were 4, 7, and 9, while that of extraction temperatures were 70, 80, and 90oC. The potential of annatto extract as an antimicrobial agent was tested by analyzing the extract's ability to inhibit pathogens and its phytochemical compounds. Escherichia coli and Staphylococcus aureus were used as the pathogenic bacteria by using the agar diffusion method. The color of annatto extracts was measured using Munsel Chard to determine the level of hue (color), value (brightness), and chroma (intensity), as well as maximum absorbance. The results showed that all extracts have the potential to inhibit E. coli and S aureus (weak-moderate). The observed annatto extracts had different color intensities as indicated by the hue, value, and chroma and a maximum absorbance at a wavelength of 400 nm.

Efficient Extraction of the RuBisCO Enzyme from Spinach Leaves Using Aqueous Solutions of Biocompatible Ionic Liquids

Ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) is the most abundant protein on the planet, being present in plants, algae and various species of bacteria, with application in the pharmaceutical, chemical, cosmetic and food industries. However, current extraction methods of RuBisCO do not allow high yields of extraction. Therefore, the development of an efficient and selective RuBisCOs’ extraction method is required. In this work, aqueous solutions of biocompatible ionic liquids (ILs), i.e., ILs derived from choline and analogues of glycine-betaine, were applied in the RuBisCO’s extraction from spinach leaves. Three commercial imidazolium-based ILs were also investigated for comparison purposes. To optimize RuBisCO’s extraction conditions, response surface methodology was applied. Under optimum extraction conditions, extraction yields of 10.92 and 10.57 mg of RuBisCO/g of biomass were obtained with the ILs cholinium acetate ([Ch][Ac]) and cholinium chloride ([Ch]Cl), respectively. Circular dichroism (CD) spectroscopy results show that the secondary structure of RuBisCO is better preserved in the IL solutions when compared to the commonly used extraction solvent. The obtained results indicate that cholinium-based ILs are a promising and viable alternative for the extraction of RuBisCO from vegetable biomass.

Improvement of the Solubilization and Extraction of Curcumin in an Edible Ternary Solvent Mixture

A water-free, ternary solvent mixture consisting of a natural deep eutectic solvent (NADES), ethanol, and triacetin was investigated concerning its ability to dissolve and extract curcumin from Curcuma longa L. To this purpose, 11 NADES based on choline chloride, acetylcholine, and proline were screened using UV–vis measurements. A ternary phase diagram with a particularly promising NADES, based on choline chloride and levulinic acid was recorded and the solubility domains of the monophasic region were examined and correlated with the system’s structuring via light scattering experiments. At the optimum composition, close to the critical point, the solubility of curcumin could be enhanced by a factor of >1.5 with respect to acetone. In extraction experiments, conducted at the points of highest solubility and evaluated via HPLC, a total yield of ~84% curcuminoids per rhizome could be reached. Through multiple extraction cycles, reusing the extraction solvent, an enrichment of curcuminoids could be achieved while altering the solution. When counteracting the solvent change, even higher concentrated extracts can be obtained.

Energy-efficient bioethanol recovery process using deep eutectic solvent as entrainer

Bioethanol is commonly recovered from fermentation broth via distillation because it is the most economical and reliable process for large-scale industrial operations. Because extraction is a highly energy-efficient process applicable to low-composition bio-product separation, high-performance solvents are necessary for efficient bioethanol recovery. 2-Methyl pentanol, a branched long-chain alcohol, which was used as the extraction solvent, and a deep eutectic solvent, choline chloride and ethylene glycol (1:2), was employed as an entrainer for product refinement. Thermodynamic models of vapor–liquid equilibrium (VLE) and liquid–liquid equilibrium (LLE) systems were derived using molecular simulations and experimental results to develop the bioethanol extraction and refinement processes. The heat duty of the designed process was reduced by a quarter compared to that of previous recovery processes. Graphic abstract

Characterization of Key Odorants in Scallion Pancake and Investigation on Their Changes during Storage

To characterize key odorants in scallion pancake (SP), volatiles were extracted by solvent extraction-solvent assisted flavor evaporation. A total of 51 odor-active compounds were identified by gas chromatography-olfactometry (GC-O) and chromatography–mass spectrometry (GC-MS). (Z/E)-3,6-Diethyl-1,2,4,5-tetrathiane was detected for the first time in scallion food. Application of aroma extract dilution analysis to extracts showed maltol, methyl propyl disulfide, dipropyl disulfide and 2-pentylfuran had the highest flavor dilution (FD) factor of 4096. Twenty-three odorants with FD factors ≥ 8 were quantitated, and their odor active values (OAVs) were calculated. Ten compounds with OAVs ≥ 1 were determined as the key odorants; a recombinate model prepared from the key odorants, including (E,E)-2,4-decadienal, dimethyl trisulfide, methyl propyl disulfide, hexanal, dipropyl trisulfide, maltol, acetoin, 2-methylnaphthalene, 2-pentylfuran and 2(5H)-furanone, successfully simulated the overall aroma profile of SP. The changes in odorants during storage were investigated further. With increasing concentrations and OAVs during storage, hexanal became an off-flavor compound.

Intsia bijuga Heartwood Extract and Its Phytosome as Tyrosinase Inhibitor, Antioxidant, and Sun Protector

Intsia bijuga (Colebr.) wood (Indonesian: Merbau) is commercial wood with high economic value and is most commonly found in Indonesia. Intsia wood extractives have biological activities related to their potential as natural active ingredients for antiaging cosmetics This study aimed to select the best extraction solvent and phytosome formulation of I. bijuga heartwood extract as an active ingredient for topical antiaging cosmetics. There were five and three variations on extraction solvent and phytosome formulation, respectively. Three main antiaging activity parameters, namely antioxidant, antityrosinase, and sun protection factor (SPF) values, were considered in selecting the best extract and phytosome formula. The results showed that 50% ethanol possessed good antioxidant and antityrosinase activity, but was lower in SPF value, which was significantly different than in other extracts. The phytochemical profile revealed robidanol and robinetin as the main constituent in five I. bijuga extracts. Phytosome F3 possessed high antioxidant, antityrosinase, and SPF values compared to other 50% ethanol phytosome extracts. It could be concluded that I. bijuga ethanol extracts and its phytosome are potent enough to be developed as an antiaging active ingredient in topical use cosmetics.