Tartaric Acid Research Articles

Constructing Photocatalytic Covalent Organic Frameworks with Aliphatic Linkers.

Photocatalytic covalent organic frameworks (COFs) are typically constructed with rigid aromatic linkers for crystallinity and extended π-conjugation. However, the essential hydrophobicity of the aromatic backbone can limit their performances in water-based photocatalytic reactions. Here, we for the first time report the synthesis of hydrophilic COFs with aliphatic linkers [tartaric acid dihydrazide (TAH) and butanedioic acid dihydrazide] that can function as efficient photocatalysts for H2O2 and H2 evolution. In these hydrophilic aliphatic linkers, the specific multiple hydrogen bonding networks not only enhance crystallization but also ensure an ideal compatibility of crystallinity, hydrophilicity, and light harvesting. The resulting aliphatic linker COFs adopt an unusual ABC stacking, giving rise to approximately 0.6 nm nanopores with an improved interaction with water guests. Remarkably, both aliphatic linker-based COFs show strong visible light absorption, along with a narrow optical band gap of ∼1.9 eV. The H2O2 evolution rate for TAH-COF reaches up to 6003 μmol h-1 g-1, in the absence of sacrificial agents, surpassing the performance of all previously reported COF-based photocatalysts. Theoretical calculations reveal that the TAH linker can enhance the indirect two-electron oxygen reduction reaction for H2O2 production by improving the O2 adsorption and stabilizing the *OOH intermediate. This study opens a new avenue for constructing semiconducting COFs using nonaromatic linkers.

Response to Various Water Regimes of the Physiological Aspects, Nutritional Water Productivity, and Phytochemical Composition of Bush Tea (Athrixia phylicoides DC.) Grown under a Protected Environment

The influence of water regimes on plants is crucial for integrating bush tea (Athrixia phylicoides DC.) into strategies in Sub-Saharan Africa to tackle food and nutritional insecurity by considering physiological aspects, nutritional yield, nutritional water productivity, and metabolite composition. The objective of the study was to determine the physiological aspects, including leaf gas exchange and chlorophyll fluorescence, nutritional yield, nutritional water productivity, and metabolite composition of bush tea under varying water regimes. The tunnel experiment was laid out in a randomized complete block design (RCBD) with treatments consisting of three water regimes: 100% of crop water requirement (ETa), 30% of ETa, and a control (no irrigation), all replicated three times. The morphological aspects were recorded on a weekly basis. However, yield, nutrient content, nutritional water productivity (NWP), and phytochemical composition were determined at harvest. The phytochemical analysis by liquid chromatography mass spectrometry (LC-MS), coupled with visualization of the detected chemical spaces through molecular networking, indicated Athrixia phylicoides DC. to be rich in various bioactive compound derivatives, including methyl chlorogenate, flavonoids, tartaric acid, caffeoylquinic acid, and glutinane. The results showed that 30% ETa enhanced plant growth, nutrient content, and nutritional water productivity compared to other water treatments. Nevertheless, 100% ETa yielded more (95.62 kg ha−1) than 30% ETa (60.61 kg ha−1) and control (12.12 kg ha−1). The accumulation of chlorogenic acids was higher under 30% ETa compared to 100% ETa and control. Therefore, this study is the first to determine the accumulation of various bioactive compounds in bush tea leaf extracts under varying water regimes. This confirms that in areas with low water availability, bush tea is well adapted for production without limiting nutrients.

Determination of Inorganic Arsenic Species in Drinking Water by Cloud Point Extraction Coupled with Ultraviolet-Visible Spectrophotometry

A novel method has been developed for accurately quantifying arsenic species, including As(III), As(V), and total inorganic arsenic, in drinking water. The technique combines ultraviolet-visible spectrophotometry with cloud point extraction (UV/CPE), ensuring high sensitivity and selectivity. The methodology relies on complex formation between As(III) and Pyronin B in the presence of tartaric acid. The resulting complex is efficiently extracted into the surfactant-rich phase consisting of 5.0% (v/v) Triton X-114. Under optimized conditions, a linear calibration relationship from 3 to 500 µg/L is obtained. The method offers low detection and quantification limits of 1.04 and 3.48 µg/L, respectively, with a corresponding relative standard deviation below 5% for 11 replicates. Furthermore, spiked samples demonstrated excellent recovery values from 95.1% to 102.3%. The accuracy was verified by the analysis of the standard reference material SRM 1643e (trace elements in water), revealing no significant differences at the 95% confidence level. The approach was successfully utilized for the quantification of As(III), As(V), and total inorganic arsenic in commercial and domestic drinking water.

Use of Organic Acids as Additives for Plasma Electrolytic Oxidation (PEO) of Titanium

The present study investigates the influence of organic acids, added to the electrolytic solution, on the structure, morphology, and corrosion behaviour of plasma electrolytic oxidation (PEO) coatings produced on titanium grade 2. Particular attention is paid to the role of functional groups in the modification of the oxide’s properties. For this reason, all three selected acids, namely glutaric, glutamic, and tartaric acid, display two carboxylic groups, thus they interact with the substrate material mainly through –COO− adsorption. However, glutamic acid also has an amine group, while tartaric acid has two hydroxyl groups. The presence of such additional functional groups is found to impact the formation of the PEO coatings. According to scanning electron microscopy (SEM) analyses, the number of defects and their dimension increase with an increasing number of active groups present in the organic molecules. Then, when glutaric acid with only two carboxyl groups, is employed as an additive, smaller pores are produced. The dimension of defects increases when glutamic and tartaric acid are used. X-ray diffraction (XRD) testing demonstrates that rutile and anatase are present in all the coatings and that when using tartaric acid, a relatively high level of amorphism is reached. The electrochemical and corrosion behaviours are evaluated by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) performed in a heated sulphuric acid solution. It is found that all types of coatings provide protection against corrosion, with oxides produced using glutamic acid showing the lowest corrosion current density (0.58 mA·m−2) and low corrosion rate (1.02 μm·y−1).

Comparative study on the effects of grain blending on functional compound content and in vitro biological activity

In this study, changes in bioactive compound contents and the in vitro biological activity of mixed grains, including oats, sorghum, finger millet, adzuki bean, and proso millet, with eight different blending ratios were investigated. The total phenolic compounds and flavonoid contents ranged from 14.43–16.53 mg gallic acid equivalent/g extract and 1.22–5.37 mg catechin equivalent/g extract, respectively, depending on the blending ratio. The DI-8 blend (30% oats, 30% sorghum, 15% finger millet, 15% adzuki bean, and 10% proso millet) exhibited relatively higher antioxidant and anti-diabetic effects than other blending samples. The levels of twelve amino acids and eight organic acids in the grain mixes were measured. Among the twenty metabolites, malonic acid, asparagine, oxalic acid, tartaric acid, and proline were identified as key metabolites across the blending samples. Moreover, the levels of lactic acid, oxalic acid, and malonic acid, which are positively correlated with α-glucosidase inhibition activity, were considerably higher in the DI-blending samples. The results of this study suggest that the DI-8 blend could be used as a functional ingredient as it has several bioactive compounds and biological activities, including anti-diabetic activity.

ФЛУОРИМЕТРИЧЕСКАЯ ОЦЕНКА ВЛИЯНИЯ РИБОКСИНА, МЕДНОГО ХЛОРОФИЛЛИНА, ТРОЛОКСА И РАСТВОРИМОЙ ФОРМЫ ИНДРАЛИНА НА РОСТОВЫЕ СВОЙСТВА КЛЕТОК А549 В КУЛЬТУРЕ

Currently, cell cultures are most often used as an experimental model system in biological research. However, to correctly plan studies using this model system, many aspects must be taken into account. Thus, to be able to correctly assess the effect of radioprotective drugs on cells, it is first necessary to study the effect of these substances on the properties of cells in culture. And the main property for work using plate readers is the ability of cells to adhere to the bottom of the plate and the rate of cell proliferation. This work is devoted to the study of human riboxin (inosine), copper chlorophyllin, trolox and indralin, the growth properties of cells in a culture based on the A549 cell line - human lung adenocarcinoma. Riboxin, chlorophyllin and trolox are promising compounds that make it possible to study their radioprotective properties. Indralin is a reference classic radioprotector. This process used a water-soluble form containing tartaric acid to allow indralin to dissolve in water. The experiment consisted of incubating A549 cells for 24 hours in a solution of riboxin (inosine), copper chlorophyllin, Trolox or tartaric acid at a concentration of 2 mM or in a mixture of 2 mM tartaric acid and 1.9 mM indralin, followed by assessment of the cell content in the samples compared to cells incubated without the addition of these substances, based on the fluorescence of the Hoechst-33342 dye. An additional experiment with chlorophyllin consisted in incubating cells with chlorophyllin already attached to the bottom of the tablet in the concentration range of 50–500 μM for 2.5 hours, followed by an assessment of the content of the remaining cells in the tablet. All studied substances statistically significantly reduced the cell content in the samples compared to the control. The greatest decrease in cell content was observed in the sample with chlorophyllin, and the least – with riboxin. As a result of additional experience in incubating already attached cells in chlorophyllin solution with concentrations of 50–500 μM, it was shown that this substance dose-dependently inhibits the adhesive properties of cells of the A549 line. At the same time, chlorophyllin already at a concentration of 50 μM statistically significantly reduced the cell content in the sample after washing the wells of the tablet compared with the control sample. The decrease in cell content in the sample containing a mixture of indralin and tartaric acid was statistically significantly more pronounced than that caused by incubation in a solution of tartaric acid alone. That is, the recognized radioprotector indralin demonstrated a pronounced inhibition of the growth properties of the A549 cell line. Based on the information obtained, we can conclude that when planning future studies of the substances studied in this work on a cell culture model, it is necessary to take into account the fact that they inhibit the growth of the cell culture.

Mechanism of tartaric acid promoting CuO/H2O2 Fenton-like degradation of sarafloxacin

Tartaric acid (TA) as an organic assistant was investigated to degrade sarafloxacin (SARA) in an advanced oxidation process (AOP) with CuO catalyst. The promotional effect of TA is to activate H2O2 decomposition to •OH and HO2•/O2•- by accelerating the Cu(II)/Cu(I) redox cycle on the CuO surface while inhibiting 1O2 generation. TA could increase the conversion percentage of H2O2 to •OH from 18.47 % to 46.23 % and decrease the conversion percentage of H2O2 to O2 from 71.98 % to 45.64 % on CuO in 60 min. In addition, TA was further demonstrated to coordinate with the surface Cu(II) by forming Cu(II)-TA, which leads to an acidic environment and exposing more Cu active sites on the surface and releasing Cu2+ into aqueous solution, thus boosts the AOP. Adding TA into the reaction system not only improves the heterogeneous Fenton-like process (HFLP) but also promotes homogeneous Fenton-like process. In the SARA/TA/CuO/H2O2 system, •OH, HO2•/O2•- and 1O2 are the primary oxide species for SARA degradation. Plausible mechanisms for the degradation of TA and SARA were proposed as well.

Visible light-driven molecular oxygen activation by lead-zinc smelting slag and tartaric acid for efficient organic pollutant degradation and Cr(VI) reduction

The remediation of heavy metal and organic-contaminated wastewater remains a significant concern in environmental science, necessitating the development of cost-effective and efficient treatment systems. This study focuses on the setup of a highly effective molecular oxygen (O2) activation system using lead–zinc smelting slag (LZSS) and tartaric acid (TA) under visible light. The LZSS-TA complex exhibited rapid photochemical reactions and demonstrated a remarkable capacity for O2 activation, resulting in the in situ generation of hydrogen peroxide (H2O2) and 99 % degradation of para-chloroaniline (p-CA). The formation of H2O2 occurred through a two-step single electron transfer pathway, whereby C-centered radicals (CHOHCHOHCOO−) generated within the system initiated the reduction of O2 to form O2−, as a crucial intermediate. The produced O2− is then reduced by Fe(II) to generate H2O2 via proton-coupled electron transfer (PCET) processes. Light-induced ligand-to-metal charge transfer (LMCT) process is the key to the production of C-centered radicals and Fe(II), which determines the production efficiency of H2O2 and OH. Additionally, this system enabled simultaneous oxidation of p-CA by 98 % and reduction of Cr(VI) by 100 % within 60 min. More importantly, O2 activation by TA-assisted LZSS under natural sunlight/solar irradiation could efficiently degrade p-CA in both ultrapure water (94 %) and reservoir water (92.5 %) within 210 min. This study significantly contributes to the understanding of light-driven O2 activation and lays the foundation for the design of cost-effective and efficient pollution remediation systems.

Probiotic Bifidobacterium animalis ssp. lactis Probio-M8 improves the fermentation and probiotic properties of fermented milk

Probiotics are increasingly used as starter cultures to produce fermented dairy products; however, few studies have investigated the role of probiotics in milk fermentation metabolism. The current study aimed to investigate whether adding Bifidobacterium animalis ssp. lactis Probio-M8 (Probio-M8) as a starter culture strain could improve milk fermentation by comparing the physicochemical characteristics and metabolomes of fermented milks produced by a commercial starter culture with and without Probio-M8. Our results showed that adding Probio-M8 shortened the milk fermentation time and improved the fermented milk texture and stability. Metabolomics analyses revealed that adding Probio-M8 affected mostly organic acid, AA, and fatty acid metabolism in milk fermentation. Targeted quantitative analyses revealed significant increases in various metabolites related to the sensory quality, nutritive value, and health benefits of the probiotic fermented milk, including 5 organic acids (acetic acid, lactic acid, citric acid, succinic acid, and tartaric acid), 5 EAA (valine, arginine, leucine, isoleucine, and lysine), glutamic acid, and 2 essential fatty acids (α-linolenic acid and docosahexaenoic acid). Thus, applying probiotics in milk fermentation is desirable. This study has generated useful information for developing novel functional dairy products.

Xanthan gum/Guar gum-based 3D-printed scaffolds for wound healing: production, characterization, and biocompatibility screening

Biodegradable and eco-sustainable medical devices represent an urgent need to face up to the increasing pollution associated to plastic device wastes. The present study aimed to develop semisolid extruded 3D (SSE-3D)-printed medical devices using mixtures of Xanthan gum (XG) and Guar gum (GG) as a green alternative to non-biodegradable synthetic polymers. The final purpose is to prepare biocompatible, biodegradable, and sterilizable implantable scaffolds with pro-regenerative and wound-healing properties. Inks prepared with 12 % w/v XG/GG (50:50) and blended with citric (CA), succinic (SA), or tartaric acid (TA) possessed suitable rheological profiles and allowed the 3D printing of porous scaffolds with high precision and structural control. Steam-heat sterilization triggered the cross-linking through ester bond formation (confirmed by ATR-FTIR and CP/MAS 13C-NMR). The scaffold crosslinked with SA had reproducible porosity (SEM and pycnometer), maintained the initial shape after 7 days swelling in PBS pH 7.4 and subjected to compression cycles (texturometer analysis), showed good cytocompatibility and hemocompatibility, and promoted angiogenesis in ovo in a chorioallantoic membrane model, evidencing tissue integration without toxicity. Furthermore, these scaffolds attenuated collagenase activity by trapping divalent ions (Ca2+ and Zn2+). Hence, by coupling angiogenic and anticollagenase activity, XG/GG scaffolds are promising candidates for wound healing and pro-regenerative applications.

Investigation of Leaching Conditions and Leaching Kinetics of Oxidized Copper Ore Malachite at Atmospheric Pressure Using Tartaric Acid Solution

Investigation of Leaching Conditions and Leaching Kinetics of Oxidized Copper Ore Malachite at Atmospheric Pressure Using Tartaric Acid Solution

Assessment of the Content of Glycoalkaloids in Potato Snacks Made from Colored Potatoes, Resulting from the Action of Organic Acids and Thermal Processing.

Glycoalkaloids (TGAs, total glycoalkaloids), toxic secondary metabolites, are found in potatoes (110-335 mg·kg-1 DW), mainly in the peel. Colorful, unpeeled potatoes are an innovative raw material for the production of snacks which are poorly tested in terms of their glycoalkaloid content. Third-generation snacks and French fries made from red-fleshed Mulberry Beauty (MB) and purple-fleshed Double Fun (DF) potatoes were produced with the use of 1% solutions of ascorbic, citric, lactic, malic, and tartaric acids to stabilize the structure of anthocyanins in the raw material and maintain their color in obtained products. The influence of the type of acid and thermal processes, like frying, microwaving, and baking, on the content of glycoalkaloids in ready-made products was examined. Only 0.45-1.26 mg·100 g-1 of TGA was found in pellet snacks and 1.32-1.71 mg·100 g-1 in French fries. Soaking blanched potatoes in organic acid solution reduced the α-chaconine content by 91-97% in snacks and by 57-93% in French fries in relation to the raw material to the greatest extent after the use of malic acid and the DF variety. The effect of lactic and citric acid was also beneficial, especially in the production of baked French fries from MB potatoes.

An Updated Review on Analytical Method Validation of Tartaric Acid from Sodium Bicarbonate, Sodium Citrate, Citric Acid and Tartaric Acid Granules by RP-HPLC

The purpose of this work was to develop and validate an appropriate analytical technique using RP-HPLC in conjunction with organic acids and (C4H6O6) tartaric acid. For the quantitative measurement of tartaric acid, sodium bicarbonate, sodium citrate, and tartaric acid granules, a straightforward, sensitive, and reliable technique was created. For the quantitative analysis, reverse-phase and 210nm UV/visible detectors were discovered and used. For this decision, an easy isocratic procedure was questioned. With the aid of (H3PO4) orthophosphoric acid, the optimal mobile phase was (KH2PO4) 0.01M potassium dihydrogen phosphate, which had a pH of around 2.6. The pH balance is maintained with orthophosphoric acid. The chromatographic conditions for the best separation of tartaric acid, RP-column C18 Shimadzu GIST Shim pack (4.6mm x 250mm, 5um) with a flow rate of 1ml, wavelength of 210nm, and injection volume of 20 l. The oven is set to a temperature of around 30 °C, and the RP-HPLC method takes about 15 minutes to complete.

Structural Insights of a cis-Epoxysuccinate Hydrolase Facilitate the Development of Robust Biocatalysts for the Production of l-(+)-Tartrate.

l-(+)-Tartaric acid plays important roles in various industries, including pharmaceuticals, foods, and chemicals. cis-Epoxysuccinate hydrolases (CESHs) are crucial for converting cis-epoxysuccinate to l-(+)-tartrate in the industrial production process. There is, however, a lack of detailed structural and mechanistic information on CESHs, limiting the discovery and engineering of these industrially relevant enzymes. In this study, we report the crystal structures of RoCESH and KoCESH-l-(+)-tartrate complex. These structures reveal the key amino acids of the active pocket and the catalytic triad residues and elucidate a dynamic catalytic process involving conformational changes of the active site. Leveraging the structural insights, we identified a robust BmCESH (550 ± 20 U·mg-1) with sustained catalytic activity even at a 3 M substrate concentration. After six batches of transformation, immobilized cells with overexpressed BmCESH maintained 69% of their initial activity, affording an overall productivity of 200 g/L/h. These results provide valuable insights into the development of high-efficiency CESHs and the optimization of biotransformation processes for industrial uses.

Deciphering of the morpho-physiological traits of two native grasses from Argentina with contrasting drought resistance strategies

Context Semiarid environments, such as the Patagonian shrublands, are characterised by having shrubby patches surrounded by grasses with different ecophysiological strategies to tolerate long dry periods. Aims We hypothesised that coexisting grasses of the Patagonian rangeland, already classified as drought-escaping or drought-tolerant, have different traits according to the season and the annual rainfall events. Methods Two dominant native grasses were selected: Pappostipa speciosa (evergreen) and Poa ligularis (deciduous). Samples were collected in the four seasons for the term of 1 year. Rainfall events and soil water content of each season were determined. Spring was the wettest season and autumn the driest. Physiological (relative water content, pigments, hormones), biochemical (polyphenols, antioxidant activity) and morphological traits were measured in the four seasons. Key results P. speciosa was characterised by keeping evergreen leaves with high production of polyphenols as secondary metabolites with high antioxidant capacity during the dry autumn and winter seasons. P. ligularis was characterised by high contents of gibberellin (GA1), auxin (IAA), total phenols, total flavonoids and tartaric acid esters, and high antioxidant capacity in roots during the autumn dry season. In addition, P. ligularis leaves had higher content of carotenoids and polyphenols than P. speciosa during the summer dry season. Conclusions The major adaptive strategy to tolerate dry periods is the high activity of the secondary metabolism, mainly in leaves in P. speciosa (a drought-tolerant grass) and in roots in P. ligularis (a drought-escaping grass). Implications Rainfall variations during a year can affect the phenological growth stages and the metabolism of two native grasses from Argentina characterised by different drought resistance mechanisms.

Effect of Organic Acid-Aided Extraction on Characteristics and Functional Properties of Pectin from Cannabis sativa L.

The extraction of cannabinoids from the inflorescence and leaves of Cannabis sativa L. is gaining interest from researchers, in addition to addressing the under-utilization of the by-products in the stems and roots of the trees. The present study investigated the recovery of pectin from the left-over parts of hemp tress using an eco-friendly method with the aid of organic acids. Different cannabis cultivars-Chalotte's Angels (CHA) and Hang-Krarog (HKR)-were used as plant materials. The stems of both cannabis cultivars contained more pectin than the roots, and tartaric acid-aided extraction provided higher yields than from citric acid. Extracting the acid solution affected some characteristics, thereby differentiating the functional properties of the derived pectin. Extraction using tartaric acid provided pectin with a higher galacturonic acid content, whereas pectin with a higher methylation degree could be prepared using citric acid. The pectin samples extracted from the stems of CHA (P-CHA) and HKR (P-HKR) had low methoxyl pectin. P-CHA had better free radical scavenging capability, whereas P-HKR showed more potent reducibility. Considering the functional properties, P-CHA showed greater emulsion formability and foaming activity, whereas P-HKR possessed a better thickening effect. The present work suggests the feasible utilization of P-CHA and P-HKR as food additives with bioactivity.

A drug–excipient interaction impurity of bromhexine hydrochloride injection: Structure and formation mechanism elucidation

A long-term stability study using high performance liquid chromatography (HPLC) revealed an unidentified impurity in the bromhexine hydrochloride injection, which was employed as a mucolytic agent. Investigations into stress degradation and elemental impurities revealed one of the elemental impurities Fe3+ in this injection as the primary generator of these impurities. This impurity, named N-carboxymethyl bromhexine, was a product formed during drug–excipient interaction between bromhexine and tartaric acid with Fe3+. The structure of the impurity was identified through ultra-high-performance liquid chromatography with diode array detector (UHPLC-DAD), liquid chromatograph mass spectrometer (LC-MS). Further, the formation mechanism of the impurity was discussed. Overall, this study elucidates the cause, origin, and mechanism of an unknown impurity in bromhexine hydrochloride injection, providing a basis for quality control for bromhexine hydrochloride injections and drug products containing both amine and tartaric acid.

Tartaric acid ameliorates experimental non-alcoholic fatty liver disease by activating the AMP-activated protein kinase signaling pathway

Tartaric acid (TA) has been shown beneficial effects on blood pressure and lipid levels. However, its effect on non-alcoholic fatty liver disease (NAFLD) remains unknown. This study aimed to investigate the role of TA in experimental NAFLD. Mice were fed a Western diet for 8 weeks, followed by administration of TA or a vehicle for an additional 12 weeks while continuing on the Western diet. Blood biochemistry including transaminases and glucose tolerance test and liver tissue RNA sequencing (RNA-seq), lipid content, and histology were investigated. The HepG2 cell line was used to explore the mechanism by which TA regulates lipid metabolism. We found that TA significantly improved weight gain, insulin resistance, hepatic steatosis, inflammation and fibrosis in Western diet-fed mice. By comparing gene expression differences, we found that TA affects pathways related to lipid metabolism, inflammatory response, and fibrosis. Furthermore, TA effectively reduced oleic acid-induced lipid accumulation in HepG2 cells and downregulated the genes associated with fatty acid synthesis, which were enriched in the AMP-activated protein kinase (AMPK) signaling pathway. TA also enhanced the phosphorylation of AMPK which could be reverted by the AMPK inhibitor Compound C in HepG2 cells. Our study suggests that TA improves experimental NAFLD by activating the AMPK signaling pathway. These findings indicate that TA may serve as a potential therapy for the human NAFLD.

Morpho-biochemical Characterization of Tamarind (Tamarindus indica L.)

Background: The research was conducted at the ICAR-CRIDA Hayatnagar Research Farm in Hyderabad, India. The plant material consists of tamarind trees planted in 1998 with 5m spacing to improve the morphological and reproductive characteristics of elite genotypes as well as quality and biochemical characters among the twenty tamarind accessions maintained at the research farm. The experiment was started in 1998 and observations were taken over the fruiting season of 2021-2022 with twenty tamarind accessions; the experiments were established in a randomized block design. The trees were identified for their consistent health and development. Methods: Biometric observations mainly average number of flowers per inflorescence, average number of inflorescence per branch, average number of branches per tree, average fruit weight (g), average yield per plant (kg), fruit, pulp, seed weights as well as shell, fiber, fruit, number of normal seeds per pod as well as damaged number of seeds per pod, Carbohydrates g/ 100 g, Polyphenols g/100 g, Anthocyanin mg/100 g, % Antioxidant activity and % Tartaric acid were recorded and analyzed statistically. Result: Significant differences among the tamarind accessions evaluated, NZB(S), Hasanur #5, Salem 132, NTI-14 and SMG-3 recorded the highest values in all the growth, pod and yield characters. NZB(S) recorded the highest number of flowers per inflorescence (14.62) while Hasanur # 5 recorded the highest number of inflorescence per branch (13.87). In yield attributes, NZB(S) recorded the highest average yield per plant (kg) (15.72) followed by Hasanur #5 (15.09), Salem 132 (14.81) and NTI-14 (14.65). The results revealed that NZB(S) showed the highest mean performance in terms of growth, yield and quality characters. The best performing accessions are being multiplied through vegetative propagation methods for planting on large scale in different locations.

Influence of organic acids on the viscosity and rheological behavior of guar gum solution

The present study aims to determine the influence of four edible organic acids (ascorbic, citric, malic, and tartaric) at two concentrations (0.5, and 1 %) on the viscosity and rheological behavior of guar gum dispersion (0.2 %, w/v). The finding of this study revealed that the apparent viscosity of guar gum dispersions reduced when the shear rate increased. Additionally, the apparent viscosity of the guar gum dispersions reduced as the organic acids concentration increased from 0 to 1 %. The highest decrease in viscosity was related to 1 % ascorbic acid and the lowest was related to 0.5 % malic acid. The rheological behavior of dispersions were successfully modeled using Power law, Bingham, Herschel-Bulkley, and Casson models, and the Power law model was the best one for describing the behavior of guar gum dispersions containing organic acids. The Power law model showed good performance with the maximum r-value (mean = 0.9988) and least sum of squared error (SSE) values (mean = 0.0021) and root mean square error (RMSE) values (mean = 0.0119) for all samples. The consistency coefficient (k-value) values of the samples (Power law and Herschel-Bulkley models) reduced as the acid percent was increased. The sample containing 1 % tartaric acid had the lowest k-value and the sample containing 0.5 % ascorbic acid had the highest k-value. The flow behavior index (n-value) (Power law and Herschel-Bulkley models) of the samples increased when the acid percent was increased. In summary, the use of guar gum in food products containing high concentrations of tartaric and ascorbic acids is not recommended.