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This study aimed to selectively determine the main products of the pyrolysis of pre-treated lignocellulosic biomass, namely, two structural isomers of 1,6-anhydro-β- D -glucose (AG) – its pyranose (levoglucosan, LG) and furanose (AGF) forms. The influence of AGF on the iodometric titration of LG was evaluated. The presence of AGF had a clear impact on the titration results, but with sample oxidation at pH 9 it was possible to obtain accurate (relative error 1–5%) titration results for total AG, summing up both isomers. More importantly, several liquid chromatography methods were compared for LG and AGF quantification to develop a simultaneous selective determination of the AG isomers. Three columns showed promising results for the selective quantification of LG and AGF – ligand exchange columns with Ag+ or Pb2+ as counterion coupled to HPLC-RID, and a HILIC column coupled to UHPLC-ELSD under gradient conditions. All three methods showed acceptable precision, linearity, and recovery of AGF and LG. UHPLC-ELSD with an amide column could only be used to quantify the summed amount of AG isomers without chromatographic separation. AGF and LG had similar response factors in RID and ELSD methods. Moreover, it was shown that UHPLC-QTOF-MS could be used for qualitative investigations of the sugar derivatives found in biomass pyrolysis products. Samples of fast pyrolysis products were analysed with varying content of AGF (7–55%) and LG (25–64%). The samples were obtained from pre-treated birch wood, and anhydrosugar fractions were separated from the pyrolysis liquids. • The importance of discriminating between the structural isomers of 1,6-anhydro-β- D -glucose has been shown. • Pyrolysis product samples rich with 1,6-anhydro-β- D -glucofuranose have been obtained and analysed. • Several analytical methods for determining the isomers of 1,6-anhydro-β- D -glucose have been compared. [ABSTRACT FROM AUTHOR]

Lipophilic sea buckthorn pomace extract isolated by supercritical CO2 (LSBPE) was structurized with different amounts of carnauba wax or beeswax as oleogelators. Oleogels were also made with added water at an LSBPE:water ratio of 70:30. LSBPE was characterized by a favorable ratio of omega‐6 to omega‐3 fatty acids (1:3) and reasonable amounts of omega‐7 fatty acids (4.45% of total), tocopherols (63.0 mg/100 g) and carotenoids (700.1 mg/100 g). The oleogels were characterized by their structural and rheological properties, and physical and chemical stability during storage. Carnauba wax produced a gel‐like structure with a highly condensed network of aggregated crystals, while beeswax oleogels displayed elongated crystals which formed interconnected networks. Carnauba wax gels were harder than beeswax gels with better oil‐binding capacity and higher crystallization and melting temperatures. Both oleogels showed good physical and oxidative stability during storage due to the immobilization of oil in the three‐dimensional structures, and the presence of strong lipophilic antioxidants in LSBPE, respectively. As the proportion of waxes increased from 5 to 17.5%, the hardness, oil‐binding capacity, crystallization, and melting temperatures increased in both gels due to the more developed crystalline associations. Addition of water had no significant effect on the physical and chemical stability of oleogels during storage. Water was distributed as small droplets in the crystalline network of oleogelators. However, hardness and oil‐binding capacity decreased as water was added. Rich in polyunsaturated fatty acids and bioactive compounds, LSBPE oleogels offer the opportunity to deliver bioactives while simultaneously acting as fat substitutes. [ABSTRACT FROM AUTHOR]

Silver birch (Betula pendula Roth) leaves, known for their long-standing uses in traditional medicine, are bioactive compound-rich by-products of the birch logging industry, abundantly available throughout the northern hemisphere. Considering the current demands for the sustainable valorization of various plant materials and their processing by-products, this study aimed to optimize pressurized ethanol extraction (PLE-EtOH) parameters in order to produce hyperoside and other valuable polar antioxidant-rich extracts from silver birch leaves. A central composite design along with response surface methodology (CCD-RSM) was used to optimize the temperature and time of PLE-EtOH for yield, total phenolic (TPC) and flavonoid (TFC) content, Trolox equivalent antioxidant capacity (TEAC) measured in oxygen radical absorbance capacity (ORAC), cupric ion reducing antioxidant capacity (CUPRAC), and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays, and hyperoside content measured by ultraperformance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI/MS2) analysis. The optimal PLE-EtOH conditions were 86 °C and 39 min, which produced an extract with 32.2% yield, high TPC (97.3 mg gallic acid equivalents/g), TFC (37.3 mg quercetin equivalents/g) and proanthocyanidin (301.2 mg catechin hydrate equivalents/g) content, also strong in vitro antioxidant capacity in ORAC, CUPRAC and ABTS assays (999.3, 297.0 and 392.3 mg Trolox equivalents/g, respectively). Hyperoside (54.1 mg/g), betuloside (18.3 mg/g) and chlorogenic acid (11.5 mg/g) were the prime phenolic compounds in the PLE-EtOH extract. Additionally, a high sun protection factor (37.4 at 1 mg/mL) was determined by in vitro method for this extract. Such products from B. pendula leaves have potential cosmetical, nutraceutical, and pharmaceutical applications. [Display omitted] • Pressurized ethanol extraction time and temperature were optimized for birch leaves. • Pressurized ethanol extraction at 86 °C and 39 min recovered 32% of polar substances. • Birch leaves extract was rich in hyperoside (54 mg/g) and betuloside (18 mg/g). • Birch leaves extract had strong antioxidant and sun protection potential in vitro. [ABSTRACT FROM AUTHOR]

An attempt to reduce, replace, or even eliminate the synthetic resins from wood-based panels alongside broadening the array of raw lignocellulosics is still essential and attractive. Many pretreatments of lignocellulosics have been studied, among which steam explosion (SE) resulted in superior physical-mechanical properties of the obtained binder-less boards. However, the SE pretreatment leads to a relatively strong odor, which is even emitted from the obtained binder-less boards independent of the raw lignocellulosic, raising concern about the use of the boards. Emissions of volatile organic compounds (VOCs) were investigated in the framework of the study from binder-less boards obtained from different SE raw lignocellulosics and SE-untreated suberinic acids-bonded particleboard. VOCs were collected by headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography–mass spectrometry (GC–MS) for 28 days with an interval of 2 weeks. The results showed that the number of detected VOCs and their chromatographic peak area varied significantly depending on the raw lignocellulosic, board density, and post-treatment (overlayering), decreasing over time. The lowest area of detected VOCs was demonstrated by the suberinic acids-bonded particleboard, while the highest area was detected from the high-density binder-less board obtained from SE hemp shives with the main compound of furfural (up to 70%) in all board types. [ABSTRACT FROM AUTHOR]

Lactic acid is an important platform chemical used in the food, agriculture, cosmetic, pharmaceutical, and chemical industries. It serves as a building block for the production of polylactic acid (PLA), a biodegradable polymer, which can replace traditional petroleum-based plastics and help to reduce environmental pollution. Cost-effective production of optically pure l- and d-lactic acids is necessary to achieve a quality and thermostable PLA product. This paper evaluates research advances in the bioproduction of l- and d-lactic acids using microbial fermentation. Special emphasis is given to the development of metabolically engineered microbial strains and processes tailored to alternative and flexible feedstock concepts such as: lignocellulose, glycerol, C1-gases, and agricultural-food industry byproducts. Alternative fermentation concepts that can improve lactic acid production are discussed. The potential use of inducible gene expression systems for the development of biosensors to facilitate the screening and engineering of lactic acid-producing microorganisms is discussed. [ABSTRACT FROM AUTHOR]

• 5% co-solvent ethanol increased supercritical CO 2 extract yield from cranberry pomace. • Precipitation of extract in the 1st separator at 0 ÷ −−30 °C and 7 MPa gave 2 products. • The fractions (lighter) in the 2nd separator were remarkably stronger antioxidants. • Higher content of polyunsaturated triacylglycerols was determined in lighter fraction. • Higher contents of tocopherols, phytosterols and volatiles were in the 2nd separator. The study investigated the possibilities of fractionation of cranberry pomace after its extraction with supercritical CO 2 (scCO 2) without and with 5% ethanol (EtOH) at previously optimized 42.4 MPa pressure and 53 °C temperature. The extract was separated into heavier (HF, 1st separator, S 1) and lighter (LF, 2nd separator, S 2) fractions by decreasing temperature in the S 1 from 0 to −−30 °C at the constant 7 MPa pressure. In case of scCO 2 61–74% of extracts precipitated in S 1 ; when EtOH was added the content of LF at 0 and −10 °C was higher, while at −20 and −30 °C the content of HF was 2.9–3.5-fold higher. LF was remarkably stronger antioxidant than HF. The differences in triacylglycerol (TAG) and fatty acid composition were not remarkable; higher percentages of higher saturation TAGs were in HFs. Higher amount of squalene was in scCO 2 /EtOH extracts; its concentration in HF was up to 12-fold (at −30 °C) higher. The amounts of carotenoids were also higher in the HF. The concentrations of phytosterols, tocopherols and volatile compounds were remarkably higher in the LFs, particularly in case of scCO 2 /EtOH. The results demonstrated that different classes of lipophilic compounds present in pomace may be pre-concentrated at freezing temperatures. [ABSTRACT FROM AUTHOR]

Biotechnological production of phenolic acids is attracting increased interest due to their superior antioxidant activity, as well as other antimicrobial, dietary, and health benefits. As secondary metabolites, primarily found in plants and fungi, they are effective free radical scavengers due to the phenolic group available in their structure. Therefore, phenolic acids are widely utilised by pharmaceutical, food, cosmetic, and chemical industries. A demand for phenolic acids is mostly satisfied by utilising chemically synthesised compounds, with only a low quantity obtained from natural sources. As an alternative to chemical synthesis, environmentally friendly bio-based technologies are necessary for development in large-scale production. One of the most promising sustainable technologies is the utilisation of microbial cell factories for biosynthesis of phenolic acids. In this paper, we perform a systematic comparison of the best known natural sources of phenolic acids. The advances and prospects in the development of microbial cell factories for biosynthesis of these bioactive compounds are discussed in more detail. A special consideration is given to the modern production methods and analytics of phenolic acids. [ABSTRACT FROM AUTHOR]

Some species of acetic acid bacteria (AAB) play relevant roles in the metabolism and physiology of Drosophila spp. and in some cases convey benefits to their hosts. The pest Drosophila suzukii harbors a set of AAB similar to those of other Drosophila species. Here, we investigate the potential to exploit the ability of AAB to produce volatile substances that attract female D. suzukii. Using a two-way olfactometer bioassay, we investigate the preference of D. suzukii for strains of AAB, and using solid-phase microextraction gas chromatography-mass spectrometry we specifically characterize their volatile profiles to identify attractive and non-attractive components produced by strains from the genera Acetobacter, Gluconobacter, and Komagataeibacter. Flies had a preference for one strain of Komagataeibacter and two strains of Gluconobacter. Analyses of the volatile profiles from the preferred Gluconobacter isolates found that acetic acid is distinctively emitted even after 2 days of bacterial growth, confirming the relevance of this volatile in the profile of this isolate for attracting flies. Analyses of the volatile profile from the preferred Komagataeibacter isolate showed that a different volatile in its profile could be responsible for attracting D. suzukii. Moreover, variation in the concentration of butyric acid derivatives found in some strains may influence the preference of D. suzukii. Our results indicate that Gluconobacter and Komagataeibacter strains isolated from D. suzukii have the potential to provide substances that could be exploited to develop sustainable mass-trapping-based control approaches. [ABSTRACT FROM AUTHOR]

• Lingonberry pomace biorefining process was optimized by multistep extractions. • Supercritical carbon dioxide extraction recovered 11.8% of lipophilic substances. • Pressurized liquid extraction effectively recovered higher polarity compounds. • Pomace oil consisted mainly of α-linolenic and linoleic fatty acids. • Polar pomace extracts contained valuable phenolic antioxidants, anthocyanins. Due to the lack of innovative valorization strategies, berry pomaces are a poorly utilized as a cheap source of valuable nutrients and phytochemicals. An effective biorefining scheme was developed to recover functional components from lingonberry pomace by consecutive supercritical CO 2 (SFE-CO 2), pressurized liquid (PLE) and enzyme assisted (EAE) extractions. SFE-CO 2 at optimized parameters yielded 11.8 g/100 g of lipophilic fraction, containing 43.3 and 37.4% of α-linolenic and linoleic fatty acids, respectively. The combined PLE with ethanol and water additionally recovered 61.8 g/100 g of polar constituents and reduced the antioxidant capacity of starting material by up to 94%. The major portion of the antioxidants (89–94% in different assays), anthocyanins (231 mg/100 g pomace) and proanthocyanidins (15.9 g/100 g pomace) was present in PLE-EtOH extract. Cyanidin-3-galactoside was the major anthocyanin (146.9 mg/100 g). High-pressure fractionation was more efficient for obtaining bioactive pomace constituents as compared with conventional and enzyme-assisted extractions. [ABSTRACT FROM AUTHOR]

• Blackberry pomace biorefining process was optimized by multistep extractions. • Supercritical carbon dioxide extraction yielded 9.9% of lipophilic substances. • Pressurized liquid extraction effectively recovered higher polarity compounds. • Lipophilic pomace extracts contained polyunsaturated fatty acids. • Polar pomace extracts contained valuable phenolic antioxidants. In this study supercritical carbon dioxide (SFE-CO 2) and pressurized liquid (PLE) extractions were optimized for the recovery of valuable fractions from blackberry pomace. Consecutively applied SFE-CO 2 and PLE at optimized parameters yielded 9.9, 26.3 and 5.1 g/100 g of CO 2 , ethanol (EtOH) and water-soluble extracts, respectively. Oil of lipophilic fraction was composed mainly of healthy polyunsaturated fatty acids (linoleic 64.1%, α-linolenic 12.9%), while polar solvents effectively recovered antioxidants (up to 29.1 mg gallic acid and 168.7 mg Trolox equivalents from g pomace). PLE-EtOH extract contained 12.2 mg/g of cyanidin-3-glucoside, while other anthocyanins were detected in significantly lower quantities (0.5–0.7 mg/g). SFE-CO 2 and PLE reduced the antioxidant capacity of starting plant material by 86–93%. In terms of extraction time, solvent consumption, total yields, and phytochemical characteristics, high-pressure fractionation was more efficient for obtaining valuable pomace constituents as compared to conventional and enzyme-assisted extractions. [ABSTRACT FROM AUTHOR]