Search Results (2,121)

Cold supply chains require coordinated inventory and storage decisions to preserve product quality while managing high energy consumption. This paper develops a joint economic lot-sizing model for a two-echelon cold supply chain that explicitly integrates time–temperature-dependent quality degradation with energy consumption in refrigerated warehouses. Unlike traditional approaches, energy is modeled as an endogenous function of warehouse filling level and warehouse temperature, allowing the interaction between inventory volume, energy efficiency, and quality preservation to be captured. The model is formulated under three coordination policies—Lot-for-Lot, traditional agreement, and consignment stock—and solved under joint decision making. Numerical results for chilled and frozen products show that neglecting energy and quality costs can lead to sub-optimal policies with total cost penalties exceeding 300% compared to the proposed integrated optimization. Results further indicate that a consignment stock agreement can reduce total system costs by up to 9% relative to traditional policies, while the optimal lot size is highly sensitive to energy prices, product value, and warehouse temperature. These findings highlight the critical role of jointly optimizing inventory, energy, and quality decisions in cold supply chains and provide actionable insights for designing more sustainable and energy-efficient production inventory systems. Full article

Background: Thermostability remains a key bottleneck for equitable access to mRNA-LNPs vaccines, mainly due to cold-chain requirements. Objectives and methods: Here, we optimized freeze-drying formulations by screening excipients (sugars, sugar alcohols, and proteins) and buffers to preserve mRNA-LNPs as solid formulations under ambient and refrigerated conditions. Physicochemical properties (size, polydispersity index [PDI], and encapsulation efficiency [EE]) and functional integrity, assessed by fluorescence-based in vitro transfection assays, were evaluated during long-term storage of up to six months. Results: Preliminary screening identified 20% sucrose and trehalose with Tris or histidine buffers as optimal for preserving physicochemical properties during freeze-drying, including high encapsulation efficiency (>90%), particle size (~200 nm), and low polydispersity (PDI < 0.2). Mannitol, gelatin, and PBS-based buffers showed adverse effects. At 4 °C, formulations F1–F3 maintained physicochemical stability and functional transfection activity for up to four months. In contrast, 20 °C storage caused progressive destabilization, with increased size, PDI, and encapsulation loss (>60% by six months). Among all formulations, 20% sucrose with 5 mM Tris (F1) showed the most robust preservation of physicochemical integrity and in vitro transfection efficiency under refrigerated and ambient conditions. Conclusions: Sugars outperformed sugar alcohols and gelatin as cryoprotectants. All formulations were stable, including functionally active at 4 °C for up to four months, while a sucrose/Tris formulation retained acceptable stability at 20 °C. Overall, the results demonstrate the feasibility of storing mRNA drug products as solid formulations at non-freezing temperatures. Full article

This study investigated shelf-life prediction of a cold-stored mixed mango–passion fruit smoothie (60:40) using kinetic modeling to compare the effects of dimethyl dicarbonate (DMDC, 250 ppm), pasteurization (90 °C for 100 s), and packaging type (glass vs. polyethylene terephthalate (PET)) during six weeks at 4 °C. Physicochemical parameters, functional properties (total phenolic content, total flavonoid content, and antioxidant activity by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power assay (FRAP), and microbial stability were monitored weekly. Zero- and first-order kinetic models were applied to describe quality changes, with the first-order model showing superior fit (average R² = 0.936). pH remained relatively stable (p > 0.05), while total soluble solids (TSS) gradually declined in all treatments from approximately 16–17 °Brix to 13–14 °Brix by week 6. PET packaging resulted in a significantly higher total color difference (ΔE) than glass by the end of storage (p ≤ 0.05), particularly in DMDC-treated samples. Pasteurization reduced initial polyphenol oxidase (PPO) activity by 44–56% compared with untreated and DMDC-treated samples (p ≤ 0.05), whereas PET generally exhibited higher residual PPO activity than glass. DMDC treatment better preserved antioxidant capacity, phenolics, and flavonoids, with significantly higher DPPH and FRAP values than controls at week 6 (p ≤ 0.05). Microbiologically, DMDC effectively suppressed total viable counts (<5 log CFU/mL) and yeast and mold (<3 log CFU/mL), outperforming pasteurization. Shelf-life was estimated at 27–29 days for pasteurization and 41–42 days for DMDC (250 ppm), particularly when combined with glass packaging. Overall, the DMDC–glass combination demonstrated strong potential as a non-thermal preservation approach for fruit beverages. Full article

Lemon (Citrus limon L.) is a widely cultivated citrus fruit valued for its nutritional and medicinal properties; however, it is highly perishable and prone to postharvest losses. This study aimed to evaluate the efficacy of natural edible coatings, chitosan (CS) and aloe vera gel (AV gel), applied individually and in combination, in preserving the postharvest quality of lemon fruits during 60 days of cold storage at 4 °C and 85% relative humidity. Nine treatments were tested, including a control, two concentrations of CS (2% and 3%), two concentrations of AV (10% and 15%), and four combinations of CS and AV gel. Various quality parameters were monitored at 0-, 10-, 20-, 30-, 40-, 50-, and 60-day intervals, including weight loss, fruit decay, juice content, firmness, total soluble solids (TSS), titratable acidity (TA), total sugars (TS), reducing sugars (RS), non-reducing sugars (NRS), total phenolic content (TPC), total antioxidant capacity (TAC), and antioxidant enzyme activities (catalase, peroxidase and superoxide dismutase) were monitored at 10-day intervals. The results demonstrated that the combined coating of 2% CS and 10% AV was the most effective in minimizing weight loss (34.25%) and decay incidence (9.22%) at day 60, while maintaining biochemical quality, including higher vitamin C content, phenolic content, and antioxidant activity. This research highlights the potential of CS and AV gel-based coatings as eco-friendly alternatives to synthetic preservatives for extending shelf life. Full article

Injection-molding purges are heterogeneous, bulky residues whose uncertain composition and irregular geometry hinder direct reinsertion, making cold shredding costly and maintenance-intensive. This work develops a low-infrastructure solar-assisted pre-processing route using a PMMA Fresnel lens to induce controlled sub-onset softening and enable clean shear cutting without destructive thermal histories. The sub-onset softening is here defined into a viscoelastically active range (at or above T_g for the amorphous phase) while remaining below the melting onset (T_m, onset) and below the onset of thermal degradation (T_d, onset). The station was engineered via QFD and risk-oriented design tools, while a weighted Pugh matrix selected shear cutting over saw-based alternatives. A screening factorial DOE showed that lens height, angle, and their interaction significantly govern focal-spot diameter and receiver temperature, yielding linear relations for conservative set-point selection. Receiver benchmarking further indicated that copper reaches substantially higher temperatures than graphite under identical exposure conditions, supporting copper as the simplest, rapid-heating receiver. Under DOE-calibrated operation, tear-free shear cutting was achieved across representative purge families (PP–ABS, PC–ABS–PP, PA66, PA66-filler, and POM) without forced convection. From a recycling and waste-management perspective, the approach converts bulky purge scrap into mill-compatible feedstock with reduced mechanical resistance, lowering tool wear and fines generation, accelerating downsizing, and limiting stockpiling that elevates combustible-inventory fire risk. Overall, the proposed DOE-calibrated, operator-friendly framework improves recycling feasibility by enabling safer handling, more stable preprocessing throughput, and reduced reliance on disposal or long-term storage for heterogeneous industrial purges. Full article

Satsuma mandarin is a non-climacteric fruit with limited storage potential, as dehydration and physiological stress can accelerate postharvest quality loss. This study evaluated the combined effects of hot-water dips (HWD; 48 °C or 52 °C for 3 min) and cold storage temperatures (1 °C or 3 °C for 8 weeks, followed by 7 days at 18–20 °C) on ‘Owari’ (Citrus unshiu Marc.) fruit quality and peel oxidative status. HWD reduced weight loss compared with untreated fruit at both temperatures, and total weight loss at 1 °C was 17.85% (HWD 48) and 18.27% (HWD 52), compared with 22.26% in the control. Storage at 1 °C reduced fruit weight loss compared with 3 °C, while fruit stored at 3 °C retained higher juiciness. Peel hydrogen peroxide level was lower at 1 °C, with the lowest value in HWD 48 fruit (5.56 nmol g⁻¹ FW). Lipid peroxidation increased after storage across treatments but was lowest in HWD 48 at 1 °C (thiobarbituric acid reactive substances 11.82 nmol g⁻¹ FW). HWD 48 at 1 °C also maintained the highest α-tocopherol level (411.18 µg g⁻¹ FW) and showed the highest catalase activity. Overall, HWD 48, combined with storage at 1 °C, provided the most favourable peel oxidative stability. However, the risk of chilling injury at low temperatures must be assessed using a defined scoring protocol before commercial recommendation. Full article

Rural households in cold regions still rely heavily on coal for cooking and domestic hot water, while single renewable energy sources suffer from intermittency and limited system-level assessment. This study proposes a solar–biogas complementary energy supply system integrating evacuated-tube solar collectors, an above-ground anaerobic digester, thermal storage, and biogas utilization for rural residential applications in Minqin, Northwest China. A dynamic system-wide model was developed by coupling TRNSYS with nonlinear representations of anaerobic fermentation and biogas boilers, enabling hour-by-hour simulation of energy production, conversion, storage, and consumption. Field measurements were used for validation, and the root mean square deviation between simulated and measured temperatures and gas production remained below 10%. During the heating season, the solar subsystem supplied 10% of the digester heating demand and 90% of the domestic hot-water load, while the biogas subsystem contributed 9.29% and 90.71%, respectively. The system delivered 4728.96 MJ of heat against a seasonal demand of 4636.22 MJ, fully meeting user requirements. A comprehensive 3E (energy–environment–economic) assessment shows that, compared with traditional rural energy supply modes, the proposed system reduces CO₂ and NOx emissions by 65.85% and 98.13%, respectively, and demonstrates favorable economics with a benefit–cost ratio of 2.41 and a discounted payback period of 3.27 years. The proposed modeling and evaluation framework provides a replicable solution for clean energy substitution and circular waste utilization in rural areas. Full article

A considerable proportion of perishable goods, including fruits and vegetables, deteriorate prior to reaching customers. Inadequate refrigeration infrastructure, particularly in developing nations with arid climates and markets distant from agricultural sources, accounts for most of these losses. A food cold chain has three primary phases: pre-cooling, cold storage, and refrigerated transportation. All phases of the cold chain rely fundamentally on refrigeration to preserve perishable products at designated temperatures, relative humidity, and CO₂ concentrations, thus prolonging their shelf life. Solar-driven or aided refrigeration systems use solar energy to power cooling systems and preserve the food in the cold chain. These systems are especially beneficial in off-grid or developing areas for preserving perishable goods such as fruits, vegetables, and other food items, mitigating postharvest losses that can exceed 30–50% in areas with inconsistent energy supplies. Despite progress in efficiency and scalability, numerous research gaps remain across technological, economic, social, policy, and regional dimensions, including technical aspects, optimization, and integration. There is a need to enhance energy-efficient designs, particularly by managing solar intermittency to address non-uniform cooling, which leads to inconsistent ripening and spoilage, and by integrating sustainable refrigerants to mitigate environmental impact. Further development is necessary for micro-scale, transportable, or decentralized systems designed for small farms, while economic and financing obstacles include high upfront costs and limited financial accessibility. Substantial deficiencies exist in creating affordable models and funding channels for small-scale agriculturalists. Addressing these deficiencies could expedite adoption, thereby reducing global food loss and waste (accounting for 8–10% of GHG emissions) while improving food security. Future research must emphasize multidisciplinary methodologies that amalgamate engineering, economics, and social sciences to provide comprehensive solutions. Full article

Yeast vitality during storage is essential for maintaining consistent fermentation performance. This study compares the physiological responses of top- and bottom-cropped Saccharomyces cerevisiae stored at 4 °C for 20 days and evaluates Optical Nanomotion Detection (ONMD) as a rapid, label-free vitality assessment tool. Classical assays (FUN-1, methylene blue, propidium iodide, glucose acidification power, glycogen content, and ethanol tolerance) were used to monitor metabolic activity, membrane integrity, and stress resilience. Bottom-cropped yeast retained metabolic activity, membrane stability, and energy reserves longer than top-cropped cells. ONMD revealed distinct single-cell nanomotion signatures and detected mechanically active subpopulations even when traditional vitality indicators declined. Analysis of nanomotion slopes showed an increasingly negative trend in the decline over storage time in top-cropped cells, indicating reduced temporal stability of nanomechanical activity during the 180 min recordings. Ethanol-challenge experiments confirmed the vitality dependence and stress-sensitivity of the ONMD signal. Together, these findings demonstrate that ONMD resolves cold-storage-induced changes in yeast nanomechanical vitality and provides complementary information beyond conventional vitality and viability assays. ONMD offers a fast, reagent-free method for monitoring brewing yeast physiology and represents a promising basis for future development toward brewery quality-control applications. Full article

To address the critical issue of low cold storage rate of phase-change materials in commercial phase-change modules, this study designed and constructed four heat-conducting-fin-enhanced cold storage blocks featuring different heat-conducting fin configurations: semi-equilateral triangles, semi-squares, semi-regular pentagons, and semi-circles. It systematically investigates the influence of the fin shape and thickness parameters of heat-conducting fins on the cooling charging process of cold storage blocks and clarifies the correlation between heat transfer enhancement and the cooling storage and release performance of refrigerators. The results show that laying copper high-thermal-conductivity fins on the surface of cold storage blocks can significantly accelerate the phase change cold storage rate. Among these structures, the semi-square fin configuration exhibits the optimal enhancement effect: compared with the baseline model without fins, its solidification time is shortened by 35 min. The results indicate that with the increase in fin thickness, the cooling charging time decreases continuously, and there exists a nonlinear positive correlation between cooling charging efficiency and fin thickness. Specifically, the cooling charging time reaches the minimum value when the fin thickness increases to 2.5 mm, while the rate of reduction in cooling charging time slows down significantly after the thickness exceeds 1.5 mm. In addition, the phase-change cold storage block can notably prolong the cooling release duration of the refrigerator. However, although the introduction of heat-conducting fins can improve the cooling charging rate, it will shorten the continuous cooling release time, thus presenting a trade-off between cooling charging efficiency and cooling release duration. The conclusions of this study provide theoretical support and practical guidance for the structural design and performance optimization of efficient commercial phase-change thermal storage and release systems. Full article

Postharvest fruit losses significantly impact producers and distributors. Although synthetic preservatives mitigate these losses, consumer safety concerns and regulatory restrictions drive interest in alternative approaches. Propolis, rich in polyphenols, exhibits antioxidant and antimicrobial activities, making it a promising natural strategy to preserve fruit quality. This study aimed to evaluate the effects of the pre- and postharvest applications of Portuguese propolis extracts on the preservation of postharvest quality of ‘Rocha’ pear, an exclusively Portuguese variety of major economic importance. Treatments were applied by spraying the fruits one month before and at harvest. After five months of cold storage, the main quality parameters, phenolic content, antioxidant capacity, physiological disorders, and microbial contamination were assessed. The results showed that the application of propolis extract, either 30 days before or immediately after harvest, reduces the total microbiological load on the fruit’s epidermis (~1-log to 2-log reduction, after treatment). Moreover, the treatment enhanced the preservation of key quality attributes, including a reduction in water loss of up to 44%, a 13–33% decrease in firmness loss relative to the control, and a lower incidence of physiological disorders during postharvest storage. Furthermore, the application of propolis can enhance the production of fruits with higher levels of bioactive compounds, while also adding value to a bee product that is often underappreciated by most beekeepers. Full article

Ensuring product integrity across Malaysia’s East Malaysian states (Sabah and Sarawak) requires a cold chain that is resilient to tropical heat, long multimodal routes, intermittent power, and dispersed rural populations. This paper proposes a sustainability-first architecture for vaccine and blood component logistics that combines World Health Organization and the United Nations International Children’s Emergency Fund Effective Vaccine Management (EVM 2.0) criteria with energy-aware transport planning, solar-hybrid edge refrigeration, phase-change materials, and digital temperature monitoring compliant with ISO 23412 for temperature-controlled delivery services. In this study, a mixed-methods methodology was employed, including (1) route and mode optimization under temperature risk and carbon intensity constraints; (2) equipment right-sizing using duty-cycle energy models and IEC 60068 environmental tests as design baselines; (3) governance with real-time earned value management (EVM) and key performance indicators (KPIs); and (4) scenario analysis for riverine, road, air, and drone last-mile segments relevant to remote East Malaysian communities. Results from realistic logistic scenarios indicate a 45–65% reduction in dose-weighted temperature-excursion minutes, 28–41% reduction in CO₂e per successful dose delivered, and 35–52% reduction in product loss compared with status quo planning. For blood components, solar-hybrid storage and mixed-mode routing reduced breach risk by 37% while maintaining red cells (2–6 °C), platelets (20–24 °C, continuous agitation surrogate), and fresh frozen plasma (≤−18 °C) requirements aligned with WHO guidance and Malaysia’s national transfusion policies. We provide a reference architecture, implementation bill of materials, and an EVM-aligned KPI dashboard to guide scale-up. Full article

Ram semen is highly susceptible to cold shock, which induces irreversible damage to the integrity and fluidity of membranes. Chilled semen is commonly used within 24 h of collection. However, while its storage at 5 °C extends semen lifespan, it is often accompanied by quality deterioration due to accumulation of reactive oxygen species (ROS). This study evaluated the potential of crocin, a carotenoid with antioxidant properties, to improve the quality of chilled ram semen stored at 5 °C for up to three days in a soybean lecithin–based extender supplemented with two crocin concentrations (0.5 and 1 mM). Sperm motility, viability, glutathione levels, the expression of proteins involved in the heat stress response (HSR), and apoptosis were assessed at 24 h intervals. Crocin preserved motility (up to Day 1), viability (up to Day 2,) and kinematic parameters (up to Day 3). In addition, crocin enhanced intracellular glutathione and Hsp70 levels and inhibited apoptotic levels dose-dependently, indicating the antioxidant and cytoprotective role of crocin. Despite 0.5 mM being effective up to Day 1, 1 mM crocin augmented antioxidant capacity, modulated stress response mechanisms, and preserved sperm quality during chilled storage up to Day 3, highlighting its potential as a valuable additive of ram semen extenders. Full article

Kiwifruit, classified as a respiratory climacteric fruit, faces challenges due to its limited resistance to storage and transportation. Although low-temperature storage is a cost-effective and widely used method, the cold injury it induces poses significant hurdles to industrial development. In this study, we selected ‘Taishan 1’, the dominant kiwifruit cultivar in Shandong Province, as the experimental material. Through transcriptome sequencing, we identified the key gene AcMYC2, which plays a crucial role in the kiwifruit’s response to low-temperature stress. Subsequently, virus-induced gene silencing (VIGS) was performed on ‘Taishan 1’ kiwifruit, and gene overexpression was validated in tomatoes. The results demonstrated that AcMYC2 enhances cold tolerance in kiwifruit accompanied by multiple physiological processes, including antioxidant activity, lipid metabolism, and cell wall degradation. These findings offer significant insights into mitigating cold injury during low-temperature storage of kiwifruit and provide a theoretical foundation for advancing postharvest preservation techniques. Full article

Microfibrillated cellulose (MFC) derived from wood sources is a biodegradable and eco-friendly reinforcing material for polymer composites. However, the high polarity of MFC is a challenge in homogeneous distribution into the hydrophobic PLA matrix, which limits its reinforcing efficiency. In this study, lignin-containing MFC (LMFC) with different residual lignin contents was prepared to investigate its dispersion behavior and reinforcing effect in polylactic acid (PLA). The aspect ratio and neutral sugar composition of LMFC remained similar regardless of lignin content, whereas the dispersion degree in PLA, quantified using a log-normal distribution model, increased from 24.2% to 35.1% with increasing lignin content. Mechanical testing showed that LMFC incorporation enhanced tensile strength and elastic modulus while reducing elongation at break. Higher residual lignin content in LMFC positively affected the tensile strength of the LMFC–PLA composites. Dynamic mechanical analysis revealed an increase in storage modulus and a decrease in loss factor with higher lignin content and LMFC loading (1–10 wt%), indicating enhanced interfacial interactions. Differential scanning calorimetry showed reductions in glass transition temperature (5–8 °C) and cold crystallization temperature (8–16 °C) compared to neat PLA. These findings indicate that residual lignin in LMFC enhances dispersion and interfacial interactions in PLA, leading to improved mechanical and thermal performance and highlighting its potential as an effective reinforcing component in sustainable biocomposites. Full article