Solution properties and taste behavior of lactose monohydrate in aqueous ascorbic acid solutions at different temperatures: Volumetric and rheological approach

The influence of pH on auto-oxidative browning of flavan-3-ols and gallic acid as a promising browning inhibitor

The effect of pH and of flavan-3-ols' structural features on undesired auto-oxidative browning of ready-to-drink green tea is still largely unknown. Thus, we investigated auto-oxidative browning of epicatechin (EC), epicatechin gallate (ECg), epigallocatechin (EGC), epigallocatechin gallate (EGCg) in pH-regulated aqueous model systems. In the typical pH range of green tea infusions (pH 5-7), the brown color intensity of flavan-3-ols after auto-oxidation was found to be EC > ECg > EGCg > EGC. Characterization of brown auto-oxidation products by RP-UHPLC-ESI-HRMSn revealed that most of these can only be formed through multi-step reactions. Therefore, oxidation potentials of the starting flavan-3-ols are unsuitable for predicting browning. Browning inhibition in real green tea can be achieved by maintaining a pH below 4 with either conventional additives (i.e. ascorbic or citric acid) or with gallic acid, a compound naturally abundant in tea. In conclusion, gallic acid is a promising candidate for clean-label auto-oxidative browning inhibition.

Harnessing NMR technology for enhancing field crop improvement: applications, challenges, and future perspectives

INTRODUCTION

Nuclear Magnetic Resonance (NMR) spectroscopy has emerged as a transformative technology in agricultural research, offering powerful analytical capabilities for field crop improvement. With global challenges such as food security and climate change intensifying, there is an urgent need for innovative methodologies to enhance our understanding of plant health, metabolic pathways, and crop-environment interactions. NMR's ability to provide nondestructive, real-time analysis of plant metabolites and soil chemistry positions it as a critical tool for addressing these pressing concerns.

OBJECTIVE

This review aims to elucidate the potential of NMR spectroscopy in advancing field crop improvement by highlighting its applications, challenges, and future perspectives in agricultural methodologies. The focus is on the evolution and application of NMR in agricultural research, particularly in metabolomics, phenotyping, and quality assessment.

METHOD

A comprehensive literature review was conducted to analyze recent advancements in NMR applications in agriculture. Particular emphasis was given to high-resolution magic angle spinning (HR-MAS) and time-domain NMR techniques, which have been instrumental in elucidating plant metabolites and soil chemistry. Studies showcasing the integration of NMR with complementary technologies for enhanced metabolic profiling and genetic marker identification were reviewed.

RESULTS

Findings indicate that NMR spectroscopy is an indispensable tool in agriculture due to its ability to identify biomarkers indicative of crop resilience, monitor soil composition, and contribute to food safety and quality assessments. The integration of NMR with other technologies has accelerated metabolic profiling, aiding in the breeding of high-yielding and stress-resistant crop varieties. However, challenges such as sensitivity limitations and the need for standardization remain.

CONCLUSION

NMR spectroscopy holds immense potential for revolutionizing agricultural research and crop improvement. Overcoming existing challenges, such as sensitivity and standardization, is crucial for its broader application in practical agricultural settings. Collaborative efforts among researchers, agronomists, and policymakers will be essential for leveraging NMR technology to address global food security challenges and promote sustainable agricultural practices.

Exploring the effects of saccharides on the solvation behaviour of L-Citrulline in aqueous medium: Volumetric, transition state theory, transfer parameters and spectroscopic approach

This study examines the volumetric, viscometric and UV-vis characteristics of L-Citrulline in water and aqueous saccharides at atmospheric pressure across the whole concentration range and the absorber operating temperature range of 293.15 K -313.15 K. Density, partial molar volume, apparent molar isobaric expansion, Hepler's constant and hydration number were among the examined volumetric parameters, and viscosity coefficients, viscosity deviation and free energy for viscous flow activation were among the examined viscometric parameters. Stronger interactions between L-Citrulline and L-Arabinose were indicated by the increase in the transfer characteristics in the following order: L-Arabinose > D-xylose. A comparison of the taste behaviours of L-Citrulline in water and in an aqueous solution of saccharides has also been attempted. L-Citrulline interacts with all solvents in a significant way, as evidenced by the UV-visible spectra suggested by the shift in UV-visible absorption maxima that correspond with a rise in L-Citrulline content in the solvent systems chosen.

Volumetric and taste behavior of D(+)-glucose and D(-)-fructose in aqueous solutions of ethanolammoium acetate

The hydration and taste behaviour of glucose and fructose in aqueous ethanolammonium acetate solutions were investigated by measuring volumetric properties. Density and speed of sound were measured at four different temperatures. Apparent and partial molar volumes, apparent specific compressibility, apparent specific volume, transfer volumes, and hydration numbers were determined from the measured density and speed of sound data. Positive transfer properties of saccharides from water to aqueous ethanolammonium acetate solutions suggested the dominance of hydrophilic-ionic interactions. However, such interactions weakened with incremental concentrations of ethanolammonium acetate. The transfer properties increased in the order: glucose > fructose, indicating stronger interactions between glucose and ethanolammonium acetate. The apparent specific volume and apparent specific isentropic compressibility values for monosaccharides in water and in aqueous ethanolammonium acetate were found to fall within the sweet taste modality.