Organic Acids Research Articles

B-168 Development and Validation of a Quantitative Ultra-Performance Liquid Chromatography Quadrupole Time-of-Flight (UPLC-QToF) Method for Urine Organic Acid Analysis

Abstract Background Urine organic acid (UOA) analysis is essential for the diagnosis of inborn errors of metabolism (IEMs). Traditionally, UOA analysis is performed with gas chromatography-mass spectrometry (GC-MS) and requires time-consuming sample preparation steps including liquid-liquid extraction and derivatization. The rapid development of Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) in the past few years provides the opportunity to perform UOA analysis with a dilute-and-shoot methodology. We describe the development and validation of a quantitative Ultra-Performance Liquid Chromatography Quadrupole Time-of-Flight (UPLC-QToF) method for UOA analysis. Methods Urine specimens were diluted to normalize creatinine concentrations to 1 mmol/L. 20 µL of urine specimen (diluted), calibrator, or quality control (QC) material was mixed with 400 µL of mobile phase A (0.05% formic acid in water) and a mixture of isotope-labeled internal standards. After centrifugation, 10 µL of the supernatant was analyzed using a Xevo G3 QTOF mass spectrometer (Waters) with a ACQUITYTM Premier HSS T3 1.8 µm VanGuardTM FIT 2.1 x 150 mm column (Waters). Data collection was performed with negative electrospray ionization (ESI) mode using the MSE method to produce fragment ions when applicable. Repeatability, reproducibility, and carryover were assessed using the QC materials. The analytical measuring range (AMR) was assessed using synthetic urine spiked with increasing concentrations of each organic acid. Accuracy was assessed by method comparison with the UOA test performed at Mayo Clinic Laboratory and by spike-recovery study using a pooled urine specimen. Matrix effect was also evaluated with matrix dilution study. Results An optimized LC method was used to enable high-resolution separation of selected UOAs (N = 29) and isomers. Total analytical time was 20 min per injection. Both linear and quadratic regressions were used to build the calibration curves. AMR and correlation coefficients of a few representative UOAs were: orotic acid (3.4 to 214.2 mmol/mol creatinine, R^2 = 0.99, linear regression); 2-methylcitric acid (4 to 189 mmol/mol creatinine, R^2 = 0.99, linear regression); 3-methylcrotonylglycine (0.3 to 18.0 mmol/mol creatinine, R^2 = 0.99, linear regression). Repeatability and reproducibility were mostly <=10% CV and no carryover was observed. Spike-recovery study demonstrated recoveries between 80% and 120%, and method comparison study demonstrated no discrepancies with results from Mayo Clinic Laboratory. Conclusions We have developed and validated a novel UPLC-QTOF method for UOA analysis to support the diagnosis of IEMs with acceptable analytical and clinical performances. Compared with the traditional GC-MS method, the UPLC-QTOF method requires a very small specimen volume and does not require laborious and time-consuming sample preparation steps. Continued optimization of the method will be pursued to measure more UOAs to support the diagnosis of more IEMs.

Effects of different rootstocks on fruit quality and non-volatile flavor-related compounds of sweet cherry ‘summit’

In practical sweet cherry production, grafting onto rootstocks is a common practice to enhance environmental adaptability. Rootstocks play a crucial role in influencing scion growth and fruit quality by regulating the absorption and utilization of mineral elements. In this study, the influence of five rootstocks with or without root fertilization during the fruit color conversion period on the fruit quality of sweet cherry ‘Summit’ was observed. The physicochemical characteristics, external color characteristics, and total anthocyanin content of ‘Summit’ were significantly affected by both rootstock and fertilization, with an interaction between the two factors. The content of certain sugar components, organic acid components and phenolic acid components in ‘Summit’ were significantly affected by rootstocks and fertilization. ‘Summit’ grafted on Gisela 5 and H22 exhibited higher sugar content, while ‘Summit’ grafted on H11 and H17 exhibited higher organic and phenolic acid content.

Effects of calcium phosphate and phosphorus-dissolving bacteria on microbial structure and function during Torreya Grandis branch waste composting

Background Burkholderiais a phosphorus solubilizing microorganism discovered in recent years, which can dissolve insoluble phosphorus compounds into soluble phosphorus. To investigate the effects of Burkholderia and calcium phosphate on the composting of Torreya grandis branches and leaves, as well as to explain the nutritional and metabolic markers related to the composting process.MethodsIn this study, we employed amplicon sequencing and untargeted metabolomics analysis to examine the interplay among phosphorus (P) components, microbial communities, and metabolites during T. grandis branch and leaf waste composting that underwent treatment with calcium phosphate and phosphate-solubilizing bacteria (Burkholderia). There were four composting treatments, 10% calcium phosphate (CaP) or 5 ml/kg (1 × 108/ml Burkholderia) microbial inoculum (WJP) or both (CaP + WJP), and the control group (CK).ResultsThe results indicated that Burkholderia inoculation and calcium phosphate treatment affected the phosphorus composition, pH, EC, and nitrogen content. Furthermore, these treatments significantly affected the diversity and structure of bacterial and fungal communities, altering microbial and metabolite interactions. The differential metabolites associated with lipids and organic acids and derivatives treated with calcium phosphate treatment are twice as high as those treated with Burkholderia in both 21d and 42d. The results suggest that calcium phosphate treatment alters the formation of some biological macromolecules.ConclusionBoth Burkholderia inoculation and calcium phosphate treatment affected the phosphorus composition, nitrogen content and metabolites of T. grandis branch and leaf waste compost.These results extend our comprehension of the coupling of matter transformation and community succession in composting with the addition of calcium phosphate and phosphate-solubilizing bacteria.

Identification of Key Genes Controlling Sugar and Organic Acid Accumulation in Wampee Fruit (Clausena lansium) via Genome Assembly and Genome-wide Association Analysis.

Wampee (Clausena lansium) is an economically significant subtropical fruit tree widely cultivated in Southern China. To provide high-quality genomic resources for C. lansium, we report a chromosome-level genome sequence for the "JinFeng" cultivar. The 297.1 Mb C. lansium genome contained nine chromosomes with a scaffold N50 of 29.2 Mb and encoded 23,468 protein-coding genes. Selective sweep analysis between sweet and sour C. lansium varieties and genome-wide association analysis identified 14 candidate genes putatively involved in sugar and acid accumulation. ClERF061, encoding an ethylene response factor, and ClSWEET7, encoding a Sugars Will Eventually be Exported Transporters (SWEET) family protein, were proposed as key regulators of the sweet and sour tastes of the wampee fruit. ClERF061 and ClSWEET7 overexpression in tomatoes increased the total sugar and acid content in fruits. ClSWEET7 promoter activation by ClERF061 was confirmed via Nicotiana benthamiana transient expression. Our study provides valuable genomic resources for C. lansium genetics and breeding.

Distinguishing Artifactual Fatty Acid Dimers from Fatty Acid Esters of Hydroxy Fatty Acids in Untargeted LC-MS Pipelines.

Untargeted metabolomics is a powerful profiling tool for the discovery of possible biomarkers of disease onset and progression. Analytical pipelines applying liquid chromatography (LC) and mass spectrometry (MS)-based methods are widely used to survey a broad range of metabolites within various metabolic pathways, including organic acids, amino acids, nucleosides, and lipids. Accurate and complete identification of putative metabolites is an ongoing challenge in untargeted metabolomics studies. Highly sensitive instrumentation can result in the detection of adduct and fragment ions that form reproducibly and contain identifiable ions that are difficult to distinguish from metabolic pathway intermediates, which may result in false-positive identification. At concentrations as low as 10μM, free fatty acids have been found to form homo- and heterodimers in untargeted metabolomics pipelines that resemble the lipid class fatty acid esters of hydroxy fatty acids (FAHFAs), resulting in misidentification. This chapter details a protocol for LC-MS-based untargeted metabolomics using hydrophilic interaction chromatography (HILIC) that specifically aids in distinguishing artifactual fatty acid dimers from endogenous FAHFAs.

Using Bone Char as a Renewable Resource of Phosphate Fertilizers in Sustainable Agriculture and its Effects on Phosphorus Transformations and Remediation of Contaminated Soils as well as the Growth of Plants

AbstractRecycling slaughterhouse waste such as bone and converting it into bone char is a promising environmentally friendly, low-cost strategy in a circular economy and an important source of phosphorus. Therefore, this review focused on the impacts of bone char on the availability, dynamics, and transformations of phosphorus in soils as well as plant growth and utilizing bone char in remediating contaminated soils by heavy metals. Bone char is material produced through bone pyrolysis under limited oxygen at 300–1050 °C. Bone char applications to the soils significantly increased phosphorus availability and plant growth. Agricultural practices such as co-applying organic acids or sulfur or nitrogen fertilizers with bone char in some soils played an important role in enhanced phosphorus availability. Also, co-applying bone char with phosphate-solubilizing microorganisms enhanced plant growth and phosphorus availability in the soils. Applying bone char to the soils changed the dynamics and redistribution of phosphorous fractions, enhanced fertility, promoted crop growth and productivity, reduced heavy metals uptake by plants in contaminated soil, and decreased heavy metals bioavailability. Bone char has shown positive performance in remediating soils contaminated by heavy metals. Bone char proved its efficiency in sustainable agriculture and practical applications as an alternative source of phosphate fertilizers, it is safe, cheap and helps in remediating contaminated soils by heavy metals. Using bone char as a slow-release fertilizer is potentially beneficial because it reduces the hazard of excessive fertilizing and nutrient leaching which have negative impacts on the ecosystem.

Evaluation of commercial and taste qualities of plum fruits in the foothills of Kabardino-Balkaria

Breeding varieties with high commercial and consumer qualities of fruits is one of the priority areas in the selection and variety study of domestic plum. Accordingly, the evaluation of some commercial and consumer qualities of fruits in plum varieties in the specific conditions of the mountains and foothills of the region is of great practical and scientific interest. Taking into account market requirements and the growth of consumer demand for fruit products, it is necessary to constantly update the range of plums. In this regard, varieties and hybrid forms of European plum for the subsequent selection of variety samples with high commercial characteristics have been studied (fruit weight, their uniformity and shape, cover color, aroma, pulp juiciness, taste, etc.). As a result of the studies, variety samples with the best commercial and taste properties of fruits have been selected. The following varieties have been distinguished by a high sugar content: Čačakska rannyaya - 18.8%, Grosso de Felicio - 16.5%, Big Heart - 14.7%, Milena - 13.8%, Velikiy Gertsog - 12.7%. The following varieties have been noted for the content of organic acids: Big Heart - 1.31%, Velikiy Gertsog - 1.1%, Milena - 0.92%, Čačakska rannyaya - 0.9%, Grossa de Felicio - 0.89%. Vitamin C is found in the highest amounts in the fruits of the following varieties: Big Heart – 7.85%, Grossa de Felicio – 6.34%, Angelina – 6.2%, Kyrgyzskaya Prevoskhodnaya – 5.34%. The size of the fruit is one of the characteristic varietal properties, despite the fact that it is largely determined by the cultivation conditions, the agricultural technology used, the age of the plant, its crop load, the variety-rootstock combination, as well as a number of other circumstances. The highest fruit weights are shown by the following varieties: Big Heart - 39.1 g, Kyrgyzskaya Prevoskhodnaya - 46.3 g, Zheltaya Afaska - 53.3 g, Zheltaya Large - 56.0 g, Kabardinskaya Rannyaya - 59.0 g, Fortuna - 65.1 g, Black Star - 78.7 g, Byron Gold - 84.2 g, Grossa de Felicio - 85.3 g, Angelina - 87.0 g, Ti Chi San - 97.1 g, Burbank Giant - 120.0 g.

Enhancing nutritional composition and aroma characteristics of kiwifruit wines through indigenous non-Saccharomyces yeast extracellular extract treatment

To unlock the potential of strains for further enhancing the aromatic complexity of kiwifruit wines while avoiding undesirable flavors, indigenous non-Saccharomyces yeast extracellular extract treatment for fermentation was established. The extracellular extract from Zygosaccharomyces rouxii, Pichia kudriavzevii, and Meyerozyma guilliermondii were prepared and supplemented individually or in pairs to the kiwifruit wine fermentation system. Subsequently, the changes in physicochemical properties, antioxidants, and volatile characteristics of kiwifruit wines produced by different protocols were comprehensively evaluated, and the major aroma descriptors affecting sensory acceptability were analyzed by sensory evaluation and partial least squares regression. The results showed that extracellular extract treatment significantly improved the organic acids and monomeric phenols content, antioxidant capacity, and volatiles of kiwifruit wines. Compared to Sc, the increase in esters and alcohols, along with the decrease in aldehydes and acids in Pk-Zr and Mg-Zr, enhanced the aromatic complexity while reduce grassy and fungal flavors, resulting in higher sensory acceptability.

Sustainable production of organic acids from chitin biomass catalyzed by Keggin-type heteropolyacid under hydrothermal condition

The “shell biorefinery,” which valorizes the shell waste chitin into fine chemicals, has developed rapidly in recent years. Herein, we present a novel base-free heteropolyacid-catalyzed oxidation method for the transformation of chitin biomass into organic acid. After a series of optimization experiments, a 5.93 % yield of formic acid and 25.09 % yield of acetic acid were achieved in the presence of 0.5 equivalent of Mo-V-P heteropolyacids (H4PMo11VO40·2H2O) and air at 180 °C under hydrothermal conditions for 4 h. Meanwhile, we have demonstrated that the Keggin-type heteropolyacid catalysts are capable of efficiently converting microcrystalline chitin into organic acids. The synthesized heteropolyacids are well characterized with FT-IR, XRD, ICP-AES, and TGA. The possible reaction pathway was speculated accordingly. This method offers several advantages, including readily available raw materials, simple operation, and relatively higher yield.

Urine organic acid metabolomic profiling by gas chromatography mass spectrometry: Assessment of solvent extract evaporation parameters on the recovery of key diagnostic metabolites

BackgroundAnalysis of urinary organic acids (UOAs) by gas chromatography mass-spectrometry (GC–MS) is widely used in metabolomic studies. It is a complex test with many limitations and pitfalls yet there is limited evidence in the literature to support best practice. This study investigated the impact of drying down time and temperature on the recovery of 16 key analytes from solvent extracts. MethodsPooled urine specimens were enriched with organic acids. Urine aliquots (n = 3) were acidified and extracted into diethyl ether and ethyl acetate. Extracts were dried under nitrogen at ambient temperature (25 °C); 40 °C; 60 °C then left for 0; +5; +15 min. Dried extracts were derivatised with N,O,-bis-(trimethylsilyl)trifluoroacetamide prior to analysis by GC–MS. Urine specimens from individuals with biotinidase deficiency, maple syrup urine disease (MSUD) and ketotic hypoglycemia were analysed to demonstrate the potential clinical impact. ResultsRecovery of shorter chain hydroxycarboxylic acids decreased significantly when extracts were dried above 25 °C (mean recovery 89 % at 60 °C, p < 0.01) or left under nitrogen post-drying (mean recovery at ambient + 15 min, 40 °C + 15mins and 60 °C + 15mins was 56 %, 12 % and 2 %, respectively, p < 0.01). Whilst dicarboxylic acids/medium chain fatty acids were unaffected by temperature (mean recovery 100 %), prolonged drying reduced recovery (mean recovery 85 % at 60 °C + 15mins, p < 0.01). ConclusionsEvaporation of solvent extracts with heat and/or prolonged drying under nitrogen results in significant losses of the shorter chain hydroxycarboxylic acids. The evaporation protocol must be carefully controlled to ensure accurate and reproducible results, preventing misdiagnoses and/or misinterpretation of results.

Effects of acetic acid fermentation on the phytochemicals content, taste and aroma of pineapple vinegar

Acetic acid fermentation of pineapple vinegar was processed by self-priming fermenter, and this study aimed to show the relationship between flavor and metabolic substances in industrial production. E-nose and E-tongue respectively characterized the changes in aroma and taste. Meanwhile, the organic acids, free amino acids, volatile components were monitored in real time by HPLC and HS-SPME-GC-MS. The results show that the most significant flavor changes took place in the initial stage (0–4 days). The floral aromas initially provided by ethanol diminished, was replaced by the emergence of rich fatty and fruity aromas attributed to acetic acid and Ethyl-2-methylbutanoate, respectively. The bitter of pineapple vinegar was reduced, acidity and astringency were significantly increased, which may be due to changes in amino acids and organic acids. In addition, the DPPH radical and FRAP scavenging activity remain stable, while HFRC radical scavenging activity increased significantly in pineapple vinegar, reached 55.78%. Our study findings provided valuable information on the functional characteristics and quality of pineapple vinegar.

Advances in the application of ion chromatography-mass spectrometry in the fields of life and health

Ion chromatography is a technique commonly used to separate strongly polar and ionizable substances; it can be used to separate, identify, and quantify ionizable compounds in complex samples when coupled with mass spectrometry, and is currently being used in the application of food analysis, drug analysis, metabolomics and clinical poisoning analysis. Herein, we review the development of ion chromatography-mass spectrometry (IC-MS), its progress over the past 20 years, and future trends in the abovementioned areas. The IC-MS research progress and applications for the determination of inorganic anions, organic acids, polar pesticides, biogenic amines, and sugars in the food field are discussed. Drug analysis applications are discussed mainly in relation to the analysis of drug impurities, identifying drug degradation products, and determination of plasma concentration, while the separation and analysis of strongly polar metabolites, such as organic acids, sugar phosphates, and nucleotides in biological matrices are discussed in relation to metabolomics. Advances in the analysis of strongly polar or ionizable toxic compounds, such as alkyl methylphosphonic acid, methylphosphonic acid, glyphosate, 3-nitropropionic acid, and indandione rodenticides, are mainly discussed in clinical poisoning analysis field. This paper is expected to become a useful reference for the further expansion and application of IC-MS in the life and health fields.

Fast identification of Baijius based on organic acid response colorimetric sensor array

Herein, a simple colorimetric sensor array sensitive to organic acids was designed by gold (Au) and silver (Ag) nanoparticles modified with four different compounds for the identification of 16 famous Baijius containing different organic acids. In detail, the sensing mechanism of the colorimetric sensor array was based on the charge transfer between the nanoparticle surface protectant and H+, which reduced the electrostatic force between the nanoparticles, leading to the aggregation and color change of the nanoparticles. The unique color change of the colorimetric array before and after the reaction was used as a unique fingerprint profile for each specific analyte, which can be identified by the naked eye. The generated digital database was analyzed using pattern recognition methods, including principal component analysis (PCA), hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). All Baijius can be easily identified by fingerprint mapping or PCA scoring maps. 32 blind samples were tested by LDA and 30 samples were correctly classified. The HCA results showed that all samples were correctly classified and even very similar 1 % dilutions of the Baijiu can be easily distinguished, demonstrating the potential of the constructed colorimetric sensor array technology for quality control applications of Baijius and other beverages.

Scalable membrane-assisted ion exchange (MEM-IE) strategy for organic acid purification in biorefinery process

The transition towards a carbon-neutral society necessitates radical approaches in the bio-refinery pipeline, particularly in the production of organic acids. The current downstream process from a dilute fermentation broth is limited by the extensive use of acids and bases, along with heavy reliance on energy-intensive distillation. In this work, we propose an entirely membrane-based process to purify organic acids (e.g., gluconic acid) from a crude solution of catalytic dehydrogenation of glucose. To facilitate downstream purification, we introduce an innovative membrane-assisted ion exchange (MEM-IE) strategy, which is a scalable process that can protonate ionic compounds entirely in the solution phase. Instead of a solid ion exchange resin, a bulky yet soluble acidification agent is used to protonate the target compound, which can be easily separated via a size exclusion membrane. We selected non-toxic poly (4-styrene sulfonic acid) (H-PSS, 75 kDa) as the acidification agent to selectively protonate gluconate ions and to enable facile fractionation. The proposed MEM-IE strategy can overcome the scale-up limitation of traditional solid ion exchange resins and can be applied to many types of ionic compounds. The versatility of the proposed process was also demonstrated on formate and lactate compounds. A techno-economic evaluation using the Verberne cost model showed that the proposed process achieves an 80 % reduction in energy consumption compared to the fermentation-based process, and the return on investment (ROI) of a 330 ton-per-day plant was less than a year. The proposed membrane-based process for the purification of organic acids, particularly the MEM-IE strategy, offers a sustainable and energy-efficient downstream separation platform.

From millets to medicine: ADMET insights into diabetes management with P. sumatrense compounds

Diabetes mellitus, a prevalent metabolic disorder characterised by impaired blood glucose regulation, has escalated into a global health crisis, exacerbated by high-glycaemic diets and unhealthy eating habits. While therapeutic agents such as acarbose mitigate diabetes by inhibiting alpha-amylase and alpha-glucosidase, their use is marred by adverse side effects, underscoring the need for safer, plant-based alternatives. This study explores the antidiabetic potential of Little Millet, an underutilised cereal grain with a low glycaemic index, rich in bioactive compounds. Unlike common staples such as wheat and rice, Little Millet contains unique compounds, including octodrine, 18,19-secoyohimban-19-oic acid, and phenylephrine, which were investigated for their novel application in diabetes management. Gas chromatography-mass spectrometry (GCMS) analysis identified 120 bioactive compounds, selected for their abundance and potential bioactivity. These compounds span fatty acids, phenols, flavonoids, organic acids, sugar alcohols, and amino acids, all of which were rigorously docked to alpha-amylase and human maltase-glucoamylase receptors. Notably, key ligands such as chlorogenic acid and 18,19-secoyohimban-19-oic acid exhibited superior binding affinities compared to acarbose, with promising drug-likeness and ADMET profiles, suggesting higher absorption and fewer side effects. A 100-ns dynamics simulation further validated the stability of these compounds, positioning them as viable candidates for diabetes treatment. These findings advance drug design and highlight the potential of incorporating Little Millet into diets for diabetes prevention. Further validation through In-vitro, In-vivo, and clinical studies is essential to fully realise their therapeutic potential. This research also opens avenues for exploring Little Millet in managing related conditions and enhancing its health benefits through breeding programmes.

Extending More than One Week the Shelf Life of Fresh-Cut Lettuce Using Vinegar Enriched in Bioactive Compounds Encapsulated in α-Cyclodextrins.

Fresh-cut salads are highly appreciated by consumers due to their healthy and convenient nature. Fresh-cut (FC) lettuce is one of the best-selling FC products due to its freshness and low preparation time for salads. However, FC lettuce is very perishable and, in addition, has been recently associated with severe foodborne illness alerts. Alternative natural sanitizing treatments to conventional sodium hypochlorite are needed. The antimicrobial activity of vinegar has been well-known since ancient times. In addition, bioactive compounds from plant byproducts are widely recognized for their antioxidant properties. This work aimed to evaluate the use of a novel and encapsulated vinegar powder enriched with bioactive compounds from fruit byproducts with high antimicrobial and antioxidant properties to preserve the physicochemical (titratable acidity, total soluble solids, weight loss, and color), microbial (psychrophiles, enterobacteria, lactic-acid bacteria, molds, and yeasts), and sensory quality of FC lettuce at 4 °C for up to 10 days. Small to no differences were observed in terms of physicochemical quality (≈0.1% titratable acidity; 2.3-3.3% total soluble solids; <1% weight loss) in comparison to control samples through storage. Vinegar treatments reduced by 2-4 log CFU g-1 the microbial loads after 10 days. In addition, a synergistic sensory antibrowning effect (greener and less yellowish appearance, showing -a* and -b*) between organic acids and the released polyphenols from the encapsulated plant byproduct extracts was observed. Hence, the enriched encapsulated vinegar represents an effective green alternative to conventional sanitizers to maintain the quality of FC lettuce through storage time.

Yeast mycobiome of fruit and vegetable biowastes revealed by culture-dependent and metabarcoding approaches: Screening for the production of succinic acid and single cell oils

Fruit and vegetable by-products and agro-residues from food processing industries and households negatively impact the environment, economy, and society. Yeasts are metabolically efficient at converting food wastes into value-added products such as biopeptides, single-cell oils, single-cell proteins, and organic acids. This work explores the valorization of twelve fruit and vegetable-derived wastes as inexpensive substrates for obtaining high-value products and metabolically efficient yeasts. Culture-dependent and metabarcoding methods provided a comprehensive overview of the yeast mycobiome, revealing 33 common species. From a biobank of 252 isolates obtained from the twelve biowastes, the 31 most promising isolates were evaluated using a synthetic medium that mimicked fruit and vegetable waste. The results showed that the metabolism was mainly directed towards the Krebs cycle, with lower production of single-cell oil compared to organic acids. Kazachstania humilis stood out from the general metabolic heterogeneity, producing 0.9 g/L of succinic acid and 1.4 g/L of acetic acid. Our results demonstrate that these natural isolates can produce high-value compounds at levels comparable to those obtained under optimal conditions for yeast growth.

Biochemical characteristics of some varieties of peach and nectarine grown in Sochi

Biochemical characteristics and features of the most promising varieties of stone fruit crops (peach, nectarine) submitted for research have been shown. Biochemical analyzes of peach and nectarine fruits grown in the humid subtropics of Russia were carried out in 2019-2020 at the Subtropical Scientific Center of the Russian Academy of Sciences in the Laboratory of Plant physiology and Biochemistry. The following varieties were used for biochemical analyzes: Rannyaya zarya, Larisa (control one), Osenniy rymyanets, Anton Chekhov, Big Top, Nectarine Sklor. The content of biologically valuable substances in stone fruits, which determine not only their taste characteristics, but also their nutritional and therapeutic and prophylactic effects, is a criterion for high commercial quality of products. That is why we are faced with the task of assessing the chemical composition of peaches and nectarines, which directly depends on weather and climate conditions, varietal characteristics, place of growth, etc. It is known that the pulp of peaches and nectarines contains a large amount of sugars, organic acids (mainly malic), vitamins, enzymes, macro- and microelements. In assessing the taste qualities of peaches and nectarines, the content of sugars, acids and vitamin C (or ascorbic acid), which acts as an antioxidant, is of great importance. Biochemical analysis of peach and nectarine fruits revealed the maximum sugar content - 10.16% in the Larisa variety (control one) of mid-late ripening period, the minimum in the Rannyaya Zarya variety of early ripening period, which is significantly lower by 1.3 times compared to the control one. High vitamin C content in the Larisa variety fruits was noted - up to 16.56 mg%, which is significantly higher than other studied varieties by 2.60-5.19 mg%. Promising varieties Larisa and Anton Chekhov were distinguished by a balanced taste of fruits and resistance to abiotic factors of the environment of the Black Sea coast of Russia.

Polyphenol compounds contributing to the improved bioactivities of fermented Rubus chingii Hu

This research aims to evaluate the phenolic composition, antioxidant and enzyme inhibition activities of fermented Rubus chingii Hu wine, and explore the correlation between them. TPC (Total Phenolic content) and TFC (Total Flavonoid content) increased rapidly from 0 h to 72 h, followed by a slight decrease in TPC and a significant decrease in TFC. Fermentation could significantly increase the antioxidant activity and α-amylase/α-glucosidase enzyme inhibitory activity of Rubus chingii Hu. A total of 39 polyphenols and organic acids in fermented Rubus chingii Hu were identified by UPLC-ESI-Q-TOF-MS/MS and 11 of them were quantitatively analyzed. After fermentation, the contents of all the detected polyphenol compounds, except for quercetin and ellagic acid, significantly increased (p < 0.05). Correlation analysis showed that protocatechuic acid and catechin played an important role in the antioxidant activity of fermented Rubus chingii Hu, while protocatechuic acid and hypericin played an important role in the α-amylase inhibition activity. This study indicated that Rubus chingii Hu could be applided as a potential meterial for the wine production, and has the potential to be a functional food for promoting health.

Streamlined fractionation for recovery of high-yield xylo-oligosaccharides, pure lignin and ethanol from poplar using short-chain organic acid/pentanol biphasic system

Biphasic pretreatment offers a sustainable method by integrating the fractionation of hemicellulose, lignin, and cellulose into a single process, thereby enhancing biomass resource utilization while reducing environmental impact. However, this process faces the challenge of diverse hemicellulose products with low added value. This study employed organic acid-catalyzed water/pentanol biphasic pretreatment to selectively convert hemicellulose into xylooligosaccharides (XOS), while simultaneously separating lignin and cellulose. Both the organic acids and pentanol used are biodegradable and compatible. The lactic acid (LA)/pentanol biphasic system was particularly effective for XOS production and lignin removal, attributed to the high acidity of LA and its relatively low partition coefficients in the water/pentanol system, crucial factors influencing hemicellulose and lignin separation efficiency. The XOS yields reached 46.9 %, while the lignin removal rate was 74.6 %. Additionally, LA/pentanol pretreatment significantly enhanced cellulose digestibility, demonstrated by an ethanol production of 54.1 g/L during simultaneous saccharification fermentation at 15 % solids loading. The recovered lignin from the organic phase retained the structural characteristics of native lignin. It also had a low molecular weight and abundant phenolic hydroxyl groups, indicating its suitability for further valorization. Pentanol maintained its performance after four cycles of reuse, demonstrating the stability and reusability of the solvent system. This study highlighted the potential of the LA/pentanol biphasic system for simultaneous hemicellulose conversion and lignin isolation, offering a simplified and sustainable one-step valorization route for biomass.