Biology subjects

Vij, S.

Publications and source records attributed to Vij, S..

3 recordsLinked to original sources

bioRxiv2025

Designing Functional Dairy Food Products: Peptide-Fortification Approaches to Improve Safety, Quality, and Consumer Acceptance

This study focused on the development of functional dairy products fortified with bioactive peptides derived from Lactobacillus rhamnosus C25-fermented sheep milk and their evaluation during storage. Microencapsulated peptides were incorporated into flavoured milk and srikhand, and their antimicrobial, antioxidant, and sensory properties were monitored over refrigerated storage. Flavoured milk supplemented with free peptides exhibited strong antimicrobial activity, while encapsulated peptides provided a controlled and sustained release, maintaining functionality over six days. In srikhand, both plain and mango-flavoured formulations demonstrated enhanced biofunctional properties, with encapsulated peptides showing gradual peptide release, higher antioxidant activity, and better preservation of sensory quality over 15 days. Sheep milk used for fermentation showed good microbial quality, supporting safe peptide production. Fermentation yielded peptide fractions (<3, <5, and <10 kDa), which were analyzed using RP-HPLC and LC-MS/MS, identifying over 3,100 peptides. In silico screening predicted 34 peptides with antimicrobial potential, including cationic and amphipathic -helical peptides primarily derived from {beta}-casein and {kappa}-casein. Functional assays demonstrated potent antimicrobial activity against Gram-positive and Gram-negative pathogens, particularly in the 5-10 kDa fractions. Antioxidant activity was highest in the 5 kDa retentate, indicating that medium-sized peptides contributed most to radical scavenging. Microencapsulation using sodium alginate improved peptide stability and controlled release, mitigating bitterness and preserving product acceptability. Overall, the study highlights the potential of L. rhamnosus C25-fermented sheep milk peptides as natural bioactive ingredients for functional dairy products with enhanced shelf life, antimicrobial efficacy, and antioxidant capacity. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=135 SRC="FIGDIR/small/673363v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1c368bdorg.highwire.dtl.DTLVardef@118db8org.highwire.dtl.DTLVardef@6f4addorg.highwire.dtl.DTLVardef@9c2ddc_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2023

Dynamics of endogenous and water cortisol release in Asian Seabass Lates calcarifer after acute stress in a farm scale recirculating aquaculture system

Stress in farmed fish is associated with poor feeding, slow growth, disease, and mortality. Therefore, it is essential to closely monitor the stress levels in fish to optimize farming practices which could then enhance productivity and welfare in aquaculture operations. Cortisol, a stress hormone that can be found in the blood, is a reliable biomarker for evaluating fish stress. As blood sampling is highly invasive, alternative cortisol sampling methods such as fin, mucus, and the surrounding water which contains released cortisol, have been proposed as less invasive or non-invasive sampling methods. However, a comprehensive understanding of their temporal dynamics and associations with plasma cortisol levels is still lacking. In this study, we subjected Lates calcarifer, Asian sea bass within a farm-scale (3,000 L tank, 9,000 L system) high-flow rate (8,000 L/hour) Recirculating Aquaculture System (RAS) to an acute handling stress challenge specifically involving chasing and air exposure, and quantified cortisol dynamics both within different biological samples including blood, fin, and mucus and in tank water from multiple sampling points. We showed that handling stress induced an expected increase in plasma and mucosal cortisol, peaking at 1 hour and 24-48 hours, respectively, and that plasma and mucus cortisol were moderately correlated, especially during the stress period. Fin cortisol did not show consistent dynamics. Water cortisol similarly rose, but peaked within 40 minutes from the start of the stressor, in a pattern that was dependent on the site of sampling within the RAS system, likely due to RAS circulation dynamics. Our study is the first to examine the impact of stress on cortisol accumulation and release in Asian Sea bass in a farm-scale RAS, thus complementing existing research on the efficacy of fin, mucus, and water cortisol as stress indicators that could help optimize aquaculture productivity and welfare.

physiology↗

bioRxiv2017

Inter-subject phase synchronization and the dynamics of human cognition

Massive whole-brain blood-oxygen-level dependent (BOLD) signal modulation (up to 95% of brain voxels) in response to task stimuli has recently been reported in functional MRI investigations. These findings have two implications. First, they highlight inability of a conventional 'top-down' general linear model approach to capture all forms of task-driven brain activity. Second, as opposed to a static 'active' or 'non-active' localization theory of the neural implementation of cognitive processes, functional neuroimaging should develop and pursue dynamical theories of cognition involving the dynamic interactions of all brain networks, in line with psychological constructionist theories of cognition. In this study, we describe a novel exploratory, bottom-up approach that directly estimates task-driven brain activity regardless of whether it follows an a priori reference function. Leveraging the property that task-driven brain activity is associated with reductions in BOLD signal variability, we combine the tools of instantaneous phase synchronization and independent component analysis to characterize whole-brain task-driven activity in terms of group-wise similarity in temporal signal dynamics of brain networks. We applied this novel framework to task fMRI data from a motor, theory of mind and working memory task provided through the Human Connectome Project. We discovered a large number of brain networks that dynamically synchronized to various features of the task scan, some overlapping with areas identified as 'active' in the top-down GLM approach. Using the results provided through this novel approach, we provide a more comprehensive description of cognitive processes whereby task-related brain activity is not restricted to dichotomous 'active' or 'non-active' inferences, but is characterized by the temporal dynamics of brain networks across time.

neuroscience↗