Prolonged Storage Research Articles

Biogenic synthesis of silver nanoparticles using essential oil of aerial part of cyclospermum leptophyllum and their application in colorimetric determination of metallic ions

The focus of this research was to synthesize biogenic silver nanoparticles (AgNPs) using the essential oil of the aerial part of Cyclospermum leptophyllum (CLEO) and investigate their colorimetric determination of metallic ions. In the synthesis of CLEO mediated AgNPs (CLEO-AgNPs), the one-factor-at-a-time method was used to optimize the reaction parameters. Ultraviolet-visible (UV-Vis) peak of CLEO-AgNPs was determined at 426 nm. Fourier transform-infrared (FTIR) spectra analysis identified the functional groups participating in the bio-reducing, capping, and stabilizing processes in the CLEO-AgNPs synthesis. Scanning electron microscope (SEM) image demonstrated the predominately spherical shape and the average size of 70.86+1.80 nm of CLEO-AgNPs. Energy dispersive X-ray spectroscopy (EDX) peak profile depicted the presence of Ag elements in CLEO-AgNPs. The X-ray diffraction (XRD) peaks observed at 38.5°, 44°, 65°, and 77° which represent Ag(111), Ag(200), Ag(220), and Ag(311) lattice faces, respectively. The average zeta nanosize, zeta potential, and polydispersity index of CLEO-AgNPs were determined as 69.70 nm, -43.5 mV, and 0.256, respectively. The stability test exhibited the prolonged storage stability of CLEO-AgNPs for over six months at room temperature. CLEO-AgNPs demonstrated the potential colorimetric detection of K+, Mg2+, Al3+, Cr6+, Mn2+, Fe3+, Ni2+, Cu2+, Zn2+, Hg2+, Pb2+, and Cd2+ ions in the real samples.
 KEY WORDS: Cyclospermum leptophyllum, Essential oil, Biogenic silver nanoparticles, Bio-reductants, Colorimetric detection 
 Bull. Chem. Soc. Ethiop. 2024, 38(1), 213-228. DOI: https://dx.doi.org/10.4314/bcse.v38i1.16

A scaling procedure for designing thermochemical energy storage system

Thermochemical energy storage (TCES) technology offers a promising avenue for achieving prolonged thermal energy storage through reversible gas-solid reactions. In the present work, a scaling analysis approach is presented to derive the relevant length and time scales for heat charging and discharging processes occurring inside a porous reactor bed of a TCES system. The processes involved are vapour flow through the porous bed, coupled heat and mass transfer, and heat and mass absorption/release in conjunction with reaction kinetics, for the case of water vapour and potassium carbonate as the gas-solid pair. This analysis employs an order-of-magnitude approach on mass, momentum, and energy conservation equations. The scaling analysis of continuity and momentum equations derives the scale for critical vapour penetration depth. It signifies the length scale beyond which pressure drop becomes significant, leading to a significant reduction in the reaction rate. Similarly, a critical thermal diffusion length scale is derived from the scaling analysis of the energy equation. This scale signifies the length beyond which the reaction rate drops significantly due to limited thermal diffusion. The derived scales characterize the performance of the energy storage bed and help in determining bed dimensions for an effective flow of heat and water vapour through the bed.

Ordered structural changes of retrograded instant rice noodles during the long-term storage

Temperature-induced textural, cooking properties and structural variations of retrograded instant rice noodles (IRN) during the long-term storage were systematically investigated. IRN samples stored at 4 °C exhibited a relative high cooking loss (2.45 %), and their hardness values gradually increased with prolonged storage. Moreover, the higher storage temperature (35 °C) accelerated the deterioration of IRN texture. Fresh IRN displayed a typical B-type XRD pattern with 9.65 % relative crystallinity (RC). During the initial 2 weeks of storage, the formation of a long-range ordered structure led to an increase in RC, which was closely related to the duration and temperature of storage (ranging from 4 °C to 25 °C to 35 °C). Over the 12-week storage period, there was likely a disorganization of the supra-molecular structure, as evidenced by the considerably decreased RC and reduced water mobility. Furthermore, Pearson's correlation analysis highlighted that the tight integration between starch molecules and water molecules endowed IRN samples with enhanced smoothness and tenderness in flavor profiles. Hence, the study is expected to provide a comprehensive understanding of the mechanisms underlying molecular order changes in retrograded starch gel products during the long-term storage.

Donor Heart Preservation: Current Knowledge and the New Era of Machine Perfusion

Heart transplantation remains the conventional treatment in end-stage heart failure, with static cold storage (SCS) being the standard technique used for donor preservation. Nevertheless, prolonged cold ischemic storage is associated with the increased risk of early graft dysfunction attributed to residual ischemia, reperfusion, and rewarming damage. In addition, the demand for the use of marginal grafts requires the development of new methods for organ preservation and repair. In this review, we focus on current knowledge and novel methods of donor preservation in heart transplantation. Hypothermic or normothermic machine perfusion may be a promising novel method of donor preservation based on the administration of cardioprotective agents. Machine perfusion seems to be comparable to cold cardioplegia regarding donor preservation and allows potential repair treatments to be employed and the assessment of graft function before implantation. It is also a promising platform for using marginal organs and increasing donor pool. New pharmacological cardiac repair treatments, as well as cardioprotective interventions have emerged and could allow for the optimization of this modality, making it more practical and cost-effective for the real world of transplantation. Recently, the use of triiodothyronine during normothermic perfusion has shown a favorable profile on cardiac function and microvascular dysfunction, likely by suppressing pro-apoptotic signaling and increasing the expression of cardioprotective molecules.

Accounting of physical qualities of root crops during sugar beet reception and storage

This article studied the quality of sugar beet roots during storage. The determining factor in the efficiency of beet sugar production is the output of sugar at a plant. Root crops are characterized by a sharp change in technological quality depending on the areas of beet seeding, agrometeorological conditions of a year, cultivation technology and storage conditions. They are easily damaged during harvesting and transportation, they are relatively poorly stored. The physical properties of root crops depend mainly on the settings of the beet harvesters, weather conditions during the harvesting period; chemical properties depend on the varietal characteristics and agricultural cultivation techniques. When growing under the same conditions, varietal characteristics play a decisive role in the yield and technological quality of root crops. Therefore it is important to use two or three hybrids when growing on the farm, which belong to different groups according to the initial technological qualities and the level of sugar loss during storage. The hybrids must provide a high sugar yield during the sugar factory operation. Therefore, it is necessary to have hybrid-specific data on sugar yield during the entire harvesting period, the date of achieving maximum sugar content, resistance to gray rot and the intensity of sugar loss during the storage. Root crops with higher sugar content lose more sugar during prolonged storage, and its yield is reduced to a greater extent. Root crops of such hybrids should not be stored, but immediately sent for processing. Studies show that in piles where raw materials with 9–10 % of mechanically damaged root crops are stored, rotting processes are activated 4.5 times, and with 17– 18 % – 10 times faster compared to undamaged ones. To reduce the damage to root crops by gray rot during storage, biocidal preparations should be used. During storage in the field in open piles for 12 days, sugar losses in root crops reach 1.7 % in September in absolute weight. Sugar losses in such conditions reach 1.3 % in September and 0.9 % in October. The increased amount of green mass reduces the technological quality of root crops. For each per cent of green mass without storage, sugar yield is reduced by 0.2 %, molasses yield and sugar losses increase due to additional non-sugars in the juice. During storage such root crops germinate quickly, which reduces sugar yield. Key words: sugar beet, root crop, root crops quality, premature seeding, gray rot, piles.

Association Between Storage Time of Transfused Red Blood Cells and Infection After Clean-contaminated Surgery: A Retrospective Cohort Study.

To investigate the association between the storage time of transfused red blood cells (RBCs) and risks of infections after clean-contaminated surgery. Storage lesions of RBCs can aggravate transfusion-related immunomodulation. Very few randomized controlled trials have investigated the impacts of storage time on postoperative outcomes in noncardiac patients. We included adult patients who had undergone clean-contaminated surgery from 2014 to 2018 and received allogeneic RBC transfusion. In transfusion episode-level analysis, the exposure was the storage time of each transfusion episode. In patient-level analysis, the exposures were the mean, weighted mean, maximum storage time, and Scalar Age of Blood Index of RBCs transfused into each patient. The primary outcome was infections that developed after transfusions within postoperative day 30. The 4046 patients were included who received 11604 transfusion episodes. Of these, 1025 (25.3%) patients developed postoperative infections. An increased storage time of transfused RBCs was not associated with increased odds of postoperative infections in either transfusion episode-level analysis [odds ratio (OR), 1.03 per 5 days, 95% CI, 0.95-1.11] or patient-level analysis (mean: OR, 1.02, 95% CI, 0.95-1.10; weighted mean: OR, 1.02, 95% CI, 0.95-1.10; maximum: OR, 1.06, 95% CI, 0.98-1.14; Scalar Age of Blood Index: OR, 0.99, 95% CI, 0.96-1.03), after adjusting 17 confounders. Prolonged storage time of transfused RBCs was not associated with increased risks of infections after clean-contaminated surgery.

Effect of atmospheric cold plasma treatment modes on the quality of red shrimp (Solenocera crassicornis) during cold chain storage

An increasingly popular non-thermal approach for food preservation is atmospheric cold plasma (ACP), which can efficiently inactivate various microorganisms. This study explored the impact of different ACP treatment modes on the preservation of red shrimp in cold chain storage. A novel treatment mode, ACP cyclical, was introduced as an alternative to ACP one-time treatment. The results indicated that the ACP cyclical treatment extended the ozone and shrimp exposure time to 35 min compared to one-time treatment, resulting in a notable enhancement in preservation effectiveness. While ACP treatment significantly reduced the total viable count (TVC) of red shrimp at day 0, it does not affect total volatile basic-nitrogen (TVB-N), pH value, or color. At day 8, the ACP cyclical group showed a 17.38% reduction in TVB-N, 36.90% decrease in TVC, and 32.39% decline in sulfur-producing bacteria compared to the ACP one-time treatment group. Electronic nose analysis indicated improved odor stability in both ACP treatment modes. Moreover, correlation and partial least squares discriminant analysis revealed that ACP cyclical treatment delayed shrimp’ color deterioration and TVB-N increase during prolonged storage. This study highlighted the potential of ACP cyclical treatment for enhancing red shrimp preservation in cold chain storage.

Comparative Proteomics Reveals Prolonged Corneal Preservation Impaired Ocular Surface Immunity Accompanied by Fibrosis in Human Stroma.

Cornea transplantation is one of the most commonly performed allotransplantations worldwide. Prolonged storage of donor corneas leads to decreased endothelial cell viability, severe stromal edema, and opacification, significantly compromising the success rate of corneal transplantation. Corneal stroma, which constitutes the majority of the cornea, plays a crucial role in maintaining its shape and transparency. In this study, we conducted proteomic analysis of corneal stroma preserved in Optisol-GS medium at 4 °C for 7 or 14 days to investigate molecular changes during storage. Among 1923 identified proteins, 1634 were quantifiable and 387 were significantly regulated with longer preservation. Compared to stroma preserved for 7 days, proteins involved in ocular surface immunomodulation were largely downregulated while proteins associated with extracellular matrix reorganization and fibrosis were upregulated in those preserved for 14 days. The increase in extracellular matrix structural proteins together with upregulation of growth factor signaling implies the occurrence of stromal fibrosis, which may compromise tissue clarity and cause vision impairments. This study is the first to provide insights into how storage duration affects corneal stroma from a proteomic perspective. Our findings may contribute to future research efforts aimed at developing long-term preservation techniques and improving the quality of preserved corneas, thus maximizing their clinical application.

Eco-friendly alkali lignin-assisted water-based graphene oxide ink and its application as a resistive temperature sensor

Inkjet-printable ink formulated with graphene oxide (GO) offers several advantages, including aqueous dispersion, low cost, and environmentally friendly production. However, water-based GO ink encounters challenges such as high surface tension, low wetting properties, and reduced ink stability over prolonged storage time. Alkali lignin, a natural surfactant, is promising in improving GO ink’s stability, wettability, and printing characteristics. The concentration of surfactant additives is a key factor in fine-tuning GO ink’s stability and printing properties. The current study aims to explore the detailed effects of alkali lignin concentration and optimize the overall properties of graphene oxide (GO) ink for drop-on-demand thermal inkjet printing. A meander-shaped temperature sensor electrode was printed using the optimized GO ink to demonstrate its practical applicability for commercial purposes. The sensing properties are evaluated using a simple experimental setup across a range of temperatures. The findings demonstrate a significant increase in zeta potential by 25% and maximum absorption by 84.3%, indicating enhanced stability during prolonged storage with an optimized alkali lignin concentration compared to the pure GO dispersions. The temperature sensor exhibits a remarkable thermal coefficient of resistance of 1.21 within the temperature range of 25 °C–52 °C, indicative of excellent sensitivity, response, and recovery time. These results highlight the potential of alkali lignin as a natural surfactant for improving the performance and applicability of inkjet-printable GO inks in various technological applications.

Leadfree SnAgCu Solder Materials Characterization at High Strain Rates at Low Test Temperatures and Drop and Shock Simulation Using Input-G Method

Abstract Electronics will experience high and low working temperatures during operations, handling, and storage in severe environments applications such as download drilling, aircraft, and transportation. Temperatures in the vehicle underhood applications can range from −65 °C to +200 °C. Lead-free solder materials continue to evolve under varying thermal workloads. Material characteristics may deteriorate if operating conditions are harsh or heavy. Nonetheless, lead-free solders are susceptible to high strains, which can lead to electronic device failure. A better understanding of solder alloys is needed to ensure reliable operation in harsh environments. New doped solder alloys have recently been created by adding Ni, Co, Au, P, Ga, Cu, and Sb to SnAgCu (SAC) solder alloys to improve mechanical, thermal, and other qualities. SAC-Q has recently been made using Sn–Ag–Cu and the addition of Bi (SAC+Bi). It was discovered that adding dopants to SAC alloys may enhance mechanical characteristics and reduce aging damage. There is no published data on SAC solder alloys after prolonged storage at high strain rates and low functioning temperatures. The materials characterization of SAC (SAC105 and SAC-Q) solder after extended storage at low working temperatures (−65 °C–0 °C) and high strain rates (10–75 per sec) is investigated in this article. To characterize the material constitutive behavior, the Anand viscoplastic model was utilized to derive nine Anand parameters from recorded Tensile data. The generated nine Anand parameters were used to validate the Anand model's reliability. A strong correlation was established between experimental data and Anand's predicted data. The Anand parameters were used in a finite element framework to simulate drop events for a ball-grid array package on printed circuit board assembly to calculate hysteresis loop and plastic work density. The plastic work per shock event measures the damage progression of the solder interconnects. Thermal aging effects have been studied in terms of the hysteresis loop and the evolution of PWD.

Effect of crocin supplementation in the extender on the quality of chilled canine semen

The aim of the study was to evaluate the effects of crocin on canine sperm quality parameters during prolonged storage at 4 °C. Ejaculates from 10 dogs were diluted in a TRIS- egg yolk extender supplemented with 0 (control group), 0.5, 1, and 2 mM crocin and stored at 4 °C. Sperm membrane functional integrity, motility, and kinetics were assessed after 3 h, 24 h, 4 days and 7 days of storage. Based on the results, the more efficient concentration of crocin (0.5 mM) was chosen to evaluate sperm intracellular ROS levels, lipid peroxidation, and DNA fragmentation vs. the control. Semen with the addition of 0.5 mM crocin with respect to the control exhibited: i) increased (P < 0.05) sperm membrane functionality at 4 and 7 days of storage; ii) higher (P < 0.05) average path (VAP), straight-line velocities (VSL), and beat cross frequency (BCF) at 4 d of storage at 4 °C; iii) decreased (P < 0.05) intracellular ROS levels after 3 and 24 h storage. No differences in lipid peroxidation and DNA fragmentation were recorded between the control and C0.5 groups at any time point. Lipid peroxidation did not increase over time, while DNA fragmentation increased (P < 0.05) in both groups after 4 days of storage. The results demonstrated that the enrichment of extender with crocin improves to a certain extent canine semen quality, particularly after 4 days of storage at 4 °C.

Bonding stability of universal adhesives to feldspathic ceramic with or without prior silane application.

This study aimed to assess the bonding stability of three universal adhesives to a CAD-CAM feldspathic ceramic with or without prior silane application. The universal adhesives tested were Ambar Universal (FGM), Single Bond Universal (3M), and Ybond Universal (Yller). Scotchbond Multipurpose Plus (3M) was used as a control. The silane used was RelyX Ceramic Primer (3M). Microtensile bond strength (μTBS) to Vitablocs Mark II was measured after 24 h or 6 months of water aging (n = 20). Failure modes were observed through scanning electron microscopy, and pH and degree of C = C conversion (DC) of the adhesives were measured (n = 3). Data were analyzed using One-, Two-, and Three-Way ANOVA. The pH values differed significantly among the adhesives (P<0.001), while the DC was similar (P = 0.141). The universal adhesives showed significant differences in μTBS, with higher immediate results when using silane and lower results after aging. Notably, a significant decrease in μTBS was observed after 6 months when silane was applied. In contrast, the control adhesive exhibited consistent results between the 24-hour and 6-month storage periods. The universal adhesives showed a decrease in μTBS ranging from 25.5% to 40.1% after prolonged storage. Adhesive failures were predominant in all groups. The presence or absence of silane in the adhesive composition did not affect the bonding performance. The application of a separate silane coupling agent improved the immediate bond strength of universal adhesives to CAD-CAM feldspathic ceramic. However, this bond strength significantly decreased after 6 months of water aging. The bond strength remained stable for universal adhesives when applied without silane after 6 months of aging. This article is protected by copyright. All rights reserved.

Anti-migratory Properties of Cryoprotective Isoliquiritigenin-zein Phosphatidylcholine Nanoparticles Prevent Triple-negative Breast Cancer through PI3K-mTOR and MMP2/9 Pathways.

Triple-negative breast cancer (TNBC), an aggressive type of breast cancer, remains difficult to treat. Isoliquiritigenin (ISL) is a bioactive compound that is insoluble in water and exhibits significant anti-TNBC activity. We previously prepared oral aqueous ISL@ZLH NPs; however, they were less stable in a freezing environment. Hence, the present study aimed to improve the stability of ISL@ZLH NPs using cryoprotectants that can withstand long storage times and are effective in TNBC treatment by creating an efficient oral drug delivery system. Freeze-dried ISL@ZLH NP powder was prepared by solvent evaporation, followed by the addition of trehalose and sucrose. The freeze-dried ISL@ZLH NP pow was optimized and characterized. The anti-TNBC efficacy and pharmacokinetics of the ISL@ZLH NP-pow were examined in plasma and organs, compared with those of aqueous ISL@ZLH NPs. The ideal particle size of the ISL@ZLH NP pow was 118 nm, which was not filtered out by the glomerulus and allowed the drug to be delivered to the lesions more effectively. Cellular uptake and biodistribution of the ISL@ZLH NP-pow in vivo and in vitro showed prolonged storage in the organs. In addition, cryopreserved ISL@ZLH NP-treated tumors showed significant anti-proliferative and anti-migratory effects through the downregulation of the PI3K-Akt-mToR and MMP2/9 signaling pathways. These results suggest that oral ingestion of cryopreserved ISL@ZLH NP has the potential for longterm storage and can be employed as a clinical therapeutic approach to treat TNBC.

Distinct Effects of Moxifloxacin and Bedaquiline on Growing and 'Non-Culturable' Mycobacterium abscessus.

Mycobacterium abscessus has recently emerged as the cause of an increasing number of human infections worldwide. Unfortunately, it is highly resistant to existing drugs, and new specific agents to combat M. abscessus have not yet been found. The discovery of antibiotics that are effective not only against replicating but also against dormant and often recalcitrant cells is a daunting challenge. In this study, we developed a model of non-replicating M. abscessus, which represents a valuable screening tool for antibacterial agents. Thus, we demonstrated that, under a deficiency of potassium ions in the growth media and prolonged incubation, M. abscessus entered a 'non-culturable' state with a significant loss of colony-forming ability, but it retained viability, as confirmed using the most-probable-number (MPN) assay. The 'non-culturable' mycobacteria possessed decelerated cellular metabolism and noticeable differences in cell morphology from actively growing mycobacteria. 'Non-culturable' cells were used in a comprehensive screening of the efficacy of antibiotics, along with actively growing cells. Both CFU and MPN tests confirmed the prominent bactericidal effect of moxifloxacin on actively growing and 'non-culturable' M. abscessus, as proven by less than 0.01% of cells surviving after antibiotic treatment and prolonged storage. Bedaquiline exhibited a comparable bactericidal effect only on metabolically inactive non-culturable cells aged for 44 days. There were reductions ranging from 1000 to 10,000-fold in CFU and MPN, but it was not so efficient with respect to active cells, resulting in a bacteriostatic effect. The demonstrated specificity of bedaquiline in relation to inert non-replicating M. abscessus offers a new and unexpected result. Based on the findings of this research, moxifloxacin and bedaquiline can be regarded as potential treatments for infections caused by M. abscessus. In addition, a key outcome is the proposal to include the combination of viability assays for comprehensive testing of drug candidates. Relying on CFU-based assays alone resulted in overestimates of antibacterial efficacy, as demonstrated in our experiments.

Loss of Autophagy Activity during Storage of Hematopoietic Stem Cell Grafts Is Associated with Reduced Potency

Maximizing the potency of hematopoietic stem cell (HSC) grafts including cord blood (CB) units (CBU) is essential to minimize risk of engraftment delays and failures. Low cell dose in CB transplantation is partially responsible for the slower engraftment but processing delays could also be at play since CBU can be stored at room temperature (RT) up to 48 hours before cryopreservation. We hypothesized that such prolong storage reduces graft potencies due to a loss in hematopoietic stem cell and progenitors (HSPC) content. CBU were used as HSC graft. Units were split in 2 halves; one processed shortly after collection (&amp;lt;15 hrs, fresh) or after storage at RT (~43 hrs, stored). The impact of storage on graft quality was assessed using standard assays and bioinformatic analysis used to identify molecular pathways impacted by storage. Monitoring assays revealed that all CBU samples passed the minimal FACT-criteria threshold for post-thaw CD34+ cell viability and potency. However, the net number of ISHAGE CD34+ cell counts were reduced in stored samples (-20%, p&amp;lt;0.01). The colony forming-unit (CFU) assay used to measure the impact of storage on potency also revealed a 20% reduction in CFU in stored samples (&amp;lt;0.05, n=7). Losses in potency was confirmed with a second assay, the IL-3-phospho-STAT5 (pSTAT5) assay, which revealed a 10-fold loss in STAT5 signalling in stored vs. fresh CD34+ cells (p&amp;lt;0.0001, n=3). We hypothesized that factors released by CB could be responsible for the reduction of HSPC. In support of this, plasma isolated from stored CBU induced greater apoptosis of CD34+ cells than fresh plasma (+30% AnnexinV+ cells, p&amp;lt;0.01, n=3). This translated into losses of potency detectable after 30 minutes (CFU assay, p&amp;lt;0.001) and with further reduction over time peaking around 2 hours. Next, we sought to identify the molecular programs that govern this detrimental effect within CD34+ cells. Towards this we performed RNAseq analysis of CD34+ cells exposed to fresh or stored plasma for 20 minutes and 4 hours. A time course comparative analysis of differentially expressed genes (DEG, Log 2Fold &amp;gt;1.5, and q&amp;lt;0.05) between cells exposed to fresh vs stored plasma identified a total of 810 DEG genes. Gene ontology enrichment analysis identified autophagy, cell cycle, histone and DNA methylation and mRNA regulation as the major molecular programs that might be up regulated by the paracrine factors from fresh plasma but repressed by those from stored plasma. Autophagy flux assay confirmed that CD34+ cells isolated from stored UCB samples had reduced autophagy activity, and that stored plasma induced a 50% reduction in autophagy flux (p&amp;lt;0.001, n=3). Furthermore, RT-qPCR analysis confirmed that prolonged storage of CBU samples at RT increased the cellular senescence marker p21(CDKN1B), down regulated cell cycle genes ( CDK4 and CDK7) and autophagy genes ( ATG4, ATG12 and BECN1). We hypothesized that re-activation or prevention of autophagy loss could prevent losses of HSPC within CBUs stored at RT. To test this, CBUs were divided and individually supplemented with either autophagy activators (rapamycin or trehalose), autophagy inhibitor (3-methyladenine, 3-MA) or DMSO control and stored up to 43 hours. As expected, the early autophagy inhibitor 3-MA failed to restore HSPC numbers and potency. However, addition of trehalose prior to storage restored 99% of both net number and potency of HSPCs in HSC grafts as measured by the ISHAGE CD34+ counts, CFU and pSTAT5 assays to baseline level (n=3). Interestingly, the near complete restoration mediated by trehalose coincided with restauration of autophagy activity, repression of senescence gene CDKN1B and activation of cell cycle genes. In contrast, rapamycin only partially restored HSPC numbers and potency which coincided with the activation of autophagy genes but not others mentioned above. In conclusion, the loss of potency and viability seen in CBU grafts originates in part by paracrine-mediated mechanisms that lead to loss of autophagy, down regulation of cell cycle regulators and induction of senescence in HSPCs. Interestingly, addition of trehalose as a natural supplement precludes these molecular changes and restores CBU potency during storage. Taken together, these results stress the importance of rapid processing of HSC grafts and identify an attractive new solution to maintain high HSC graft potency post-collection during storage at ambient temperature.

Application of Coating Chitosan Derivatives (N,O–Carboxymethyl Chitosan/Chitosan Oligomer Saccharide) in Combination with Polyvinyl Alcohol Solutions to Preserve Fresh Ngoc Linh Ginseng Quality

The postharvest preservation of Ngoc Linh ginseng (NL ginseng) is essential to retain its quality and sensory values for prolonged storage. In this study, the efficacy of NL ginseng preservation by coating chitosan derivatives in combination with polyvinyl alcohol (PVA) solutions was investigated under refrigeration conditions (~3 °C; ~40% RH) for 56 days. The effect of the chitosan–based solutions, including N,O–carboxymethyl chitosan (NOCC), chitosan oligomer saccharide (COS), or chitosan (CS), and the blend solutions (NOCC–PVA or COS–PVA) on the coated NL ginsengs was observed during storage. The pH values, viscosity, and film-forming capability of the coating solutions were determined, while the visual appearance, morphology, and mechanical properties of the films formed on glass substrates as a ginseng model for coating were also observed. The appearance, skin lightness, weight loss, sensory evaluation, total saponin content (TSC), total polyphenol content (TPC), and total antioxidant capacity (TAC) of the coated NL ginsengs were evaluated. The findings showed that the observed values of the coated NL ginsengs were better than those of the non-coated samples, with the exception of the COS–coated samples, which had completely negative results. Furthermore, the NOCC–PVA solution exhibited a better preservation effect compared with the COS–PVA one based on the observed indices, except for TPC and TAC, which were not impacted by the coating. Notably, the optimal preservation time was determined to be 35 days. This study presents promising preservation technology using the coating solution of NOCC–PVA, harnessing the synergistic effect of pH 7.4 and the form–firming capacity, to maintain the shelf life, medicinal content, and sensory attributes of NL ginseng.

Production, Nutritional Quality and Microbial Safety of Selected Nigerian Dried Meat Products: A Review

Production and consumption of dried meat products are increasing considerably across all nations because they are nutritious, low in fat, easily accessible, and convenient for customers to eat. Over the years, its roles have become vital in human diet as they are consumed to combat protein malnutrition and boost food security of undernourished people in underdeveloped and developing nations. Initially, dried meat products are made to satisfy consumer expectations for sensory and nutritional attributes as well as to reduce meat wastage and increase the meat shelf life during prolonged transportation and storage. Recently, the discovery of contamination that is above the minimal threshold advised for meat safety has made the safety of dried meat products the focus of microbiological evaluation. It is well recognized that eating meat products with poisoning microorganisms could put customers at risk for health problems. As a result, it is critical to refocus the research to determine the viability of dried meat products for eating after production by evaluating the production processes, nutritional quality, and microbial safety. Therefore, this review aimed to highlight the production procedures, nutritional quality and microbial safety of dried meat products and their suitability for consumption after production.

Akkermansia muciniphila Encapsulated in Calcium-Alginate Hydrogelated Matrix: Viability and Stability over Aerobic Storage and Simulated Gastrointestinal Conditions.

Akkermansia muciniphila is considered a next-generation probiotic to be incorporated in new food and pharmaceutical formulations. Effective delivery systems are required to ensure high probiotic viability and stability during product manufacture, shelf-life, and post-consumption, namely, throughout digestion. Hydrogelated matrices have demonstrated promising potential in this dominion. Hence, this work aimed to evaluate the effect of a calcium-alginate hydrogelated matrix on A. muciniphila viability during 28-days refrigerated aerobic storage and when exposed to simulated gastrointestinal conditions, in comparison with that of free cells. Akkermansia muciniphila was successfully encapsulated in the calcium-alginate matrix via extrusion (60% encapsulation yield). Furthermore, encapsulated A. muciniphila exhibited high stability (a loss in viability lower than 0.2 log-cycle) after 28-days of refrigerated aerobic storage, maintaining its viability around 108 CFU/g. Prominently, as the storage time increased, encapsulated A. muciniphila revealed higher viability and stability regarding in vitro gastrointestinal conditions than free cells. This suggests that this encapsulation method may attenuate the detrimental effects of prolonged aerobic storage with a subsequent gastrointestinal passage. In conclusion, encapsulation via extrusion using a calcium-alginate hydrogelated matrix seems to be a promising and adequate strategy for safeguarding A. muciniphila from adverse conditions encountered during refrigerated aerobic storage and when exposed to the gastrointestinal passage.

Accelerated loss of diastase in mānuka honey: Investigation of mānuka specific compounds.

Diastase is used internationally as a quality monitor for excessive heat treatment and prolonged storage of honey; honey must contain an activity of at least 8 diastase numbers (DN) for it to be considered export quality. Freshly harvested mānuka honey can have diastase activity close to the export threshold of 8 DN without excess heating, increasing susceptibility for export failure. This research investigated the effect of compounds unique to or high in concentration in mānuka honey on diastase activity. Investigation of the effect of methylglyoxal, dihydroxyacetone, 2-methoxybenzoic acid, 3-phenyllatic acid, 4-hydroxyphenyllactic acid and 2'-methoxyacetophenone on diastase activity was carried out. Mānuka honey was stored at 20 and 27°C and clover honey spiked with compounds of interest were stored at 20, 27 and 34°C and monitored overtime. Methylglyoxal and 3-phenyllactic acid were found to accelerate the loss of diastase above the loss normally observed with time and elevated temperature.

A STUDY ON THE DEVELOPMENT AND EVALUATION OF TAMARIND CANDY BY BLENDING WITH DIFFERENT SPICES

The study was done to look into the physicochemical properties of tamarind candy developed from blending different spices. The proximate analysis and the analysis of the antioxidants reveal that the candy contains reasonable amounts, which is beneficial for health. The sample was produced and stored at ambient temperature (43 0C) for 20 days. The colour of the sample was visually observed, and it was found that there was no difference in colour during accelerated storage conditions. The reading for the water activity of fresh candy was 0.344, and the result indicates that water activity was decreased as per the prolonged storage of the sample. The overall acceptability of tamarind candy after 20 days of accelerated storage was good. As per the study, the accelerated ageing test calculation indicates that a product shelf life of more than three months at ambient temperature is acceptable.