Search Results (618)

This study evaluated productive performance, nutrient use efficiency, and nitrogen and phosphorus mass balance in an intensive aquaponic polyculture system combining Nile tilapia (Oreochromis niloticus), channel catfish (Ictalurus punctatus), lettuce (Lactuca sativa), and spinach (Spinacia oleracea) under high biomass density (40 kg m⁻³). Nine treatments were established through a 3 × 3 factorial combination of fish (tilapia:catfish = 75:25, 50:50, 25:75) and plant (lettuce:spinach = 75:25, 50:50, 25:75) species ratios and evaluated over three consecutive 60-day production cycles. Nitrogen and phosphorus use efficiencies differed significantly among treatments, reaching maximum values above 50% for NUE and 47% for PUE in catfish-dominant systems with higher spinach proportions, indicating improved nutrient recovery and reduced losses. These treatments also produced greater fish biomass, whereas lettuce-dominant combinations favored plant yield. Water quality remained within acceptable ranges, although higher catfish proportions were associated with lower dissolved oxygen and increased nitrogen availability. Overall, results demonstrate that optimizing fish–plant species ratios enhances nutrient retention and sustainable productivity in intensive aquaponic systems. Future research should explore adaptive species ratio management and economic feasibility to support large-scale implementation of polyculture aquaponics. Full article

The increasing demand for environmentally benign inorganic pigments has stimulated interest in sustainable synthesis routes for iron oxide nanoparticles that minimize toxic reagents and energy-intensive processing. In this study, a plant-mediated approach for the synthesis of hematite (α-Fe₂O₃) nanoparticles using Spinacia oleracea (spinach) leaf extract is presented, with particular emphasis on pigment-relevant material characteristics. An aqueous spinach extract was employed as a natural reducing and stabilizing medium for ferric ions under ambient conditions. The formation of iron oxide nanoparticles was indicated by a characteristic color change and confirmed by structural and morphological characterization. X-ray diffraction revealed phase-pure crystalline hematite, while transmission electron microscopy showed quasi-spherical nanoparticles with sizes in the range of 20–50 nm. The synthesis avoids hazardous chemicals, high-temperature calcination, and organic solvents, offering a low-energy and environmentally compatible route. Although the yield per batch is modest, the simplicity, non-toxicity, and pigment-suitable properties of the synthesized nanoparticles highlight the potential of this method for sustainable pigment and coating applications. Full article

Toxic Cd (cadmium) pollution in agricultural soil has been drawing global attention. Using exogenous regulators to detoxify Cd in crops is a promising approach to alleviate Cd stress and prevent Cd accumulation in human bodies through the food chain. Natural compounds show great potential due to their environmentally friendly properties. We have found that thymol (a plant-derived natural compound) protects plants from Cd stress. To extend the application of thymol in agriculture, further studies are needed to understand the detailed mechanism by which thymol induces Cd tolerance and limits Cd accumulation in crops. In this study, hydroponic experiments using the roots of Brassica rapa L. exposed to a nutrient solution containing Cd (3 µM) and thymol (15 µM) were conducted to investigate the mechanism of thymol-induced Cd tolerance. Pot experiments with different vegetables (B. rapa, water spinach, and pepper) growing in Cd-polluted soil (0.5 µM Cd) were carried out to investigate the role of foliar spraying of thymol (15 µM) in decreasing the Cd content in vegetables. In the hydroponic study, thymol enhanced the shoot fresh weight and root fresh weight of B. rapa by 313% and 125%, respectively, upon Cd exposure. Thymol detoxifies Cd-induced ROS accumulation by increasing the activity of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in B. rapa by 8.9–33.6%, 12.9–31.6%, and 57.8–135%, respectively. The thymol-activated AsA-GSH (ascorbic acid-glutathione) cycle also contributed to the decrease in ROS level. Thymol also reduced the Cd content in the shoots and roots of B. rapa by 55.7% and 46.6%, respectively, which was associated with the modulation of the expression of a set of genes accounting for Cd accumulation and transport. In the pot study, foliar spraying of thymol significantly decreased the Cd content in various vegetables, including leafy vegetables (B. rapa and two water spinach varieties, with leaf Cd decreasing by 40.5–45.9%) and solanaceous fruits and vegetables (three pepper varieties, with fruit Cd decreasing by 26.9–35.8%), which was accompanied by a growth-promoting effect. The results from this study elucidate the multifaceted function of thymol in helping vegetables detoxify Cd and decrease Cd bioaccumulation, shedding new light on developing thymol as a potential plant regulator to safeguard agroproduct security in Cd-polluted environments. Full article

B vitamins are essential micronutrients for human health with prominent antioxidant properties, capable of scavenging reactive oxygen species (ROS) and maintaining redox homeostasis, protecting cells from oxidative damage. To address global nutrient deficiencies and identify plant-based antioxidant sources, this study quantified seven B vitamins (B₁, B₂, B₃, B₅, B₆, B₉, B₁₂) in seeds, leaves, and seedlings of five oilseeds (sesame, peanut, soybean, rapeseed, perilla) and two leafy vegetables (spinach, lettuce) via LC-MS/MS, revealing distinct species- and tissue-specific patterns. Notably, sesame seeds exhibited exceptional vitamin B₃ (niacin, 39.3 μg/g), surpassing other oilseeds1.6–8.2-fold; its leaves contained outstanding vitamin B₆ (2.88 μg/g), 2.57–8.31-fold higher than spinach (1.12 μg/g) and lettuce (0.34 μg/g), and vitamin B₁₂ (0.44 μg/g) levels ~13–20 times higher than other leaf samples. Sesame seedlings recorded high vitamin B₆ (1.6 μg/g) and B₁₂ (0.1 μg/g) among the oilseed crops seedlings. These findings highlight sesame as a multifunctional B vitamin resource for antioxidant nutrition, supporting dietary optimization, crop biofortification, and mitigation of global B vitamin inadequacies via plant-based solutions. Full article

Objective: This study evaluated the effects of a 12-week High-Intensity Functional Training (HIFT) program combined with thylakoid supplementation on plasma adipo-myokine levels (Decorin, Myostatin, Follistatin, Activin A, and TGF-β1) in men with obesity. Secondary outcomes included anthropometric indices, lipid profiles, and insulin resistance markers. Methods: Sixty men with obesity (age: 27.6 ± 8.4 years; BMI: 32.6 ± 2.6 kg/m²) were randomly assigned to four groups (n = 15 per group): Placebo (PG), Supplement (SG), HIFT + placebo (TPG), and HIFT + supplement (TSG). To ensure robustness against the 27% attrition rate, statistical analyses included both per-protocol and intention-to-treat (ITT) models. HIFT was performed for 3 sessions/week (Borg scale: 15–17). Results: Following Bonferroni correction for multiple endpoints, repeated-measures ANOVA showed significant Time × Group interactions for most adipo-myokines and metabolic markers. Both training groups (TPG and TSG) demonstrated improvements in body composition and insulin sensitivity compared to PG (p < 0.05). While no significant differences were observed between TPG and TSG for systemic metabolic markers, preliminary data suggested that thylakoid supplementation might provide modest complementary modulations in specific myokines (e.g., decorin and follistatin). However, these observed trends did not reach clinical superiority over exercise alone in the broader metabolic profile. Conclusions: Twelve weeks of HIFT is an effective primary driver for modulating the adipo-myokine network in obese men. Although thylakoid supplementation showed potential for selective complementary effects on certain myokines, these findings are exploratory given the small sample size. The clinical significance and long-term complementary value of thylakoid-exercise interactions require further validation in larger, more diverse cohorts. Full article

Fresh baby leaves are commercially marketed in various mixing ratios and packaging amounts, creating very distinct microenvironmental conditions that significantly affect the postharvest quality of the fresh product. This study investigated the synergistic effect of mixing ratio (50LB, 50% lettuce + 50% spinach; 75LB, 75% lettuce + 25% spinach; 100LB, 100% lettuce) and packaging amount (125F, 125 g; 250F, 250 g) on the antioxidant qualities of baby lettuce and spinach mixes during 9 days of storage at 4 °C. The results showed that 50LB × 250F inhibited the degradation of chlorophyll and carotenoids and preserved 28% higher total antioxidant capacity (TAC), 43% higher total phenolic compounds (TPC), and 20% higher vitamin C (Vit.C) than the mean values of all samples, resulting in 0.8% lower O₂ and 14.7% higher CO₂ levels at the end of storage. TPC, Vit.C, and carotenoids were the main contributors to TAC, with strong correlations (p < 0.001). The total bacterial (TB) and yeast + mold (Y + M) counts were only affected by the mixing ratios, with TB increasing by only 1 Log₁₀ cfu g⁻¹ FW, and Y + M remaining within the same order of magnitude over time. After 9 days of storage, the leaves were still fresh and marketable. This study not only provides a practical strategy for the fresh-cut industry to enhance product quality but also underscores the significance of multifactorial synergism in salad mix packaging. Full article

Leafy green vegetables provide important nutrients for human growth; however, human health is highly compromised through consumption of vegetables contaminated by heavy metals. Therefore, the study aimed to investigate the bioaccumulation of heavy metals in five different leafy green vegetables and soils and determine the human health risks that may arise from consuming those vegetables from Tonga town in Mpumalanga province, South Africa. Soils and five edible leafy vegetables (i.e., lettuce, cabbage, rape, pumpkin leaves, and spinach) were assessed for bio-concentration factor, daily intake of metals, health risk, and target hazard quotient across the study sites. The Si, K, Na, Ca, Mg, Al, and Fe concentrations were high in the soils. In general, vegetables exhibited elevated Ca, Fe, Si, Al, and Sr levels, although spinach had high Na concentrations. The bioconcentration factor showed the following trends: Mg > B > Si > V for trace metals and Cr > Co > Mn > Ni > B for heavy metals in lettuce, spinach, and pumpkin leaves. The human risk index for all vegetables showed that all metals were not likely to induce any health hazards to humans, and the target hazard quotient for B, Si, V, Al, Cr, Mn, Fe, Ni, Zn, and Pb showed potential for substantial health risk hazard. The findings of this study generally reveal that the concentrations of the analysed metals exceeded the permissible limits established by the World Health Organisation and the Food and Agricultural Organisation. Given the high levels of metals detected in the soil and vegetables within the study area, it is important to investigate the potential implications for human health and mitigate both acute and chronic health challenges associated with heavy metal exposure. Furthermore, this study will guide policymakers in developing improved regulations and safety standards for agricultural practices and environmental protection, particularly for vulnerable peri-urban and rural communities. Full article

Background: Spinach has a high content of nutrients, proteins, carbohydrates, and vitamins beneficial for human health, that are closely associated with the type of crop, the growing media, the temperature, and lights used for growing. Methods: Two types of light were used: white light (WL) and red light (RL), and also three different growing media: compost without additives (CB), compost with coffee additive (CC), and compost with rockrose additive (CR). Results: Spinach grown under WL, regardless of the treatment, showed greater plant growth than that grown under RL_P. Furthermore, treatments WL_CC and WL_CR increased by 90% and 95%, respectively, compared to WL_P; similarly, treatments WL_CB, WL_CC, and WL_CR increased by 179%, 174%, and 205%, respectively, compared to the RL_P control. The protein content of spinach leaves from growing media WL_CB and WL_CC increased by 50 and 46% respectively compared to WL_P; similarly, growing media RL_CB and RL_CC increased by 82 and 57% respectively compared to RL_P. This contrasted with the carbohydrate content, which was higher in spinach grown under WL_P and RL_P. Spinach grown under WL_P and RL_P showed significantly more free sugars. On the other hand, spinach grown under WL had a higher concentration of organic acids than that grown under RL, regardless of the growing media used. The content of fatty acids, phenolic compounds, and antioxidant activities did not follow a clear pattern with respect to the type of light and growing media. Conclusions: Overall, compost-based substrates combined with white LED light enhanced spinach growth and nutritional quality through a synergistic effect. However, compost reduced phenolic compounds, while red LED light increased phenolic content and antioxidant activity, indicating contrasting effects on spinach quality. Full article

Saline soil represents an important reserve of cultivated land in China, yet poor soil conditions and low-nitrogen use efficiency constrain crop production. Biochar has been widely applied to improve soil properties; however, its interactive effects with nitrogen fertilization in saline soils remain unclear. A pot experiment using coastal saline soil collected from the northern Jiangsu province was conducted to evaluate the combined effects of biochar (0%, 4%, and 8% w·w⁻¹) and nitrogen fertilizer (0, 150, and 200 mg·kg⁻¹) on the growth performance, photosynthetic indices, yield, quality, and nitrogen use efficiency of water spinach (Ipomoea aquatica Forssk.). Moderate biochar application significantly improved vegetative growth of water spinach, as indicated by higher plant height, stem diameter, leaf area index, and SPAD values. In addition, biochar substantially enhanced photosynthetic performance, dry matter accumulation, and yield, whereas excessive biochar or nitrogen application generally inhibited plant performance. The combined application of 4% biochar with 150 mg·kg⁻¹ nitrogen consistently produced the highest yield and nitrogen partial factor productivity, while simultaneously increasing soluble protein, soluble sugar, and vitamin C contents and reducing nitrite accumulation. These research results demonstrated a clear synergistic interaction between biochar and nitrogen fertilization. In coastal saline soils, reducing the usage of nitrogen fertilizer moderately and adding approximately 4% of biochar is an effective strategy. Full article

Recently, the EU approved RENURE-criteria materials to be used as substitutes for synthetic N fertilisers. Several studies have been performed on the agronomic efficacy and potential environmental impacts of different bio-based fertilisers (BBFs) from biomass recovery, including the RENURE-criteria materials. But information is lacking about their effectiveness under abiotic stress conditions like salinity and drought. The predictions for climate change-induced increased drought and soil salinisation for the European soils have also increased, making it inevitable to understand BBF performance in these impending situations. Two RENURE-criteria top-priority materials (ammonium nitrate (AN) and ammonium sulphate (AS) and another commercially used BBF—an evaporator concentrate (CaE)) were evaluated in a pot trial growing spinach under salinity and drought stress with a reference ‘no stress’ condition to examine crop growth, nutrient uptake, and nitrogen fertiliser replacement value (NFRV). Agronomically, BBFs performed at par with the synthetic fertiliser (SF) under unstressed and salt-stressed conditions, whereas, under drought stress, BBFs outperformed the SF treatment. AS exhibited the highest yield and nutrient uptake, displaying an NFRV of 3.1 and 1.8 under no-stress and salt-stress conditions, respectively. Salt stress did not negatively impact the crops grown in this trial, potentially due to the higher potassium content in the system, which alleviated the possible negative impacts of high sodium. This study delves into the agronomic response, without evaluating crop physiological changes, and, hence, should be taken as a preliminary step into further investigation of observed elemental interactions (that could be potentially driving stress mitigation) while also examining the crop physiology during the duration of stress. Full article

Elevated atmospheric CO₂ is known to alter plant physiology, yet its specific effects on nutrient-rich leafy vegetables remain insufficiently quantified. This study aimed to examine how eCO₂ influences yield and nutritional quality in kale (Brassica oleracea) and spinach (Spinacia oleracea) through the first meta-analysis focused exclusively on these crops. Following the Collaboration for Environmental Evidence (CEE) guidelines, we systematically reviewed eligible studies and conducted a random-effects meta-analysis to evaluate overall and subgroup responses based on CO₂ concentration, crop type and exposure duration. Effect sizes were calculated using Hedges’ g with 95% confidence intervals. The analysis showed that eCO₂ significantly increased biomass in spinach (g = 1.21) and kale (g = 0.97). However, protein content declined in both crops (spinach: g = −0.76; kale: g = −0.61), and mineral concentrations, particularly calcium and magnesium, were reduced, with spinach exhibiting stronger nutrient losses overall. The variability in response across different CO₂ concentrations and exposure times further underscores the complexity of eCO₂ effects. These results highlight a trade-off between productivity and nutritional quality under future CO₂ conditions. Addressing this challenge will require strategies such as targeted breeding programmes, biofortification, precision agriculture and improved sustainable agricultural practices to maintain nutrient density. This research provides critical evidence for policymakers and scientists to design sustainable food systems that safeguard public health in a changing climate. Full article

The increasing demand for sustainable agriculture requires innovative strategies to enhance nitrogen use efficiency while minimizing environmental losses associated with conventional fertilizers. This study aimed to develop and compare ammonium chloride- and ammonium nitrate-modified nanobiochar as controlled-release nitrogen carriers and to elucidate their effects on nitrogen retention, soil properties, and physiological nitrogen utilization in spinach (Spinacia oleracea L.). Nitrogen-modified nanobiochar was synthesized using ammonium chloride (NB-AC) and ammonium nitrate (NB-AN) at three nitrogen rates (0.03, 0.06, and 0.12 g N g⁻¹ NB) and applied to soil at 1% (w/w). Soil properties, nutrient dynamics, and plant growth and physiological traits were analyzed after 15 and 30 days. Nitrogen modification significantly improved soil nitrogen retention and nutrient availability compared with unmodified nanobiochar. The highest nitrogen loading treatments (NB-AC3 and NB-AN3) notably improved spinach growth, photosynthetic efficiency, pigment content, nitrogen metabolism enzymatic activities, and accumulation of key metabolites (soluble sugars, flavonoids). Nitrogen-release assessments indicated a pronounced controlled-release with reduced nitrogen leaching and greater retention, particularly under NB-AN3. Overall, this study demonstrates that nitrogen-modified nanobiochar functions as an effective nitrogen carrier that enhances nitrogen utilization and growth. These findings provide mechanistic insights into its potential as a sustainable alternative to conventional nitrogen fertilizers. Full article

Valorizing fruit and vegetable residues as renewable sources of bioactive compounds (BCs) is critical for advancing sustainable biotechnology. This review (i) assesses the occurrence, diversity and functionality of BCs in 20 edible plant residues; (ii) compares and classify them by botanical family and residue type; (iii) reviews and evaluates the efficiency of conventional and green extraction and characterization techniques for recovering phytochemical and isolating phenolics (e.g., flavonoids and anthocyanins), carotenoids, alkaloids, saponins, and essential oils; and (iv) examines the BCs’ environmental, medical, and industrial applications. It synthesizes current knowledge on the phytochemical potential of these crops, highlighting their role in diagnostics, biomaterials, and therapeutic platforms. Plant-derived nanomaterials, enzymes, and structural matrices are employed in regenerative medicine and biosensing. Carrot- and pumpkin-based nanoparticles accelerate wound healing through antimicrobial and antioxidant protection. Spinach leaves serve as decellularized scaffolds that mimic vascular and tissue microenvironments. Banana fibers are used in biocompatible composites and sutures, and citrus- and berry-derived polyphenols improve biosensor stability and reduce signal interference. Agro-residue valorization reduces food waste and enables innovations in medical diagnostics, regenerative medicine, and circular bioeconomy, thereby positioning plant-derived BCs as a cornerstone for sustainable biotechnology. The BCs’ concentration in fruit and vegetable residues varies broadly (e.g., total phenolics (~50–300 mg GAE/g DW), anthocyanins (~100–600 mg C3G/g DW), and flavonoids (~20–150 mg QE/g DW)), depending on the crop and extraction method. By linking quantitative food waste hotspots with phytochemical potential, the review highlights priority streams for the circular-bioeconomy interventions and outlines research directions to close current valorization gaps. Full article

Remediating cadmium (Cd) contamination in aquatic and terrestrial environments has become an urgent environmental priority. Biochar has been widely employed for heavy metal removal due to its wide availability, strong adsorption capacity, and potential for recycling agricultural waste. In this study, samples of alkali–Fe-modified biochar (Fe@NaOH-SBC, Fe@NaOH-HBC, and Fe@NaOH-MBC) were prepared from agricultural wastes (ginger straw, Sichuan pepper branches, and kiwi leaves) through NaOH and FeCl₃·6H₂O modification. A comprehensive characterization confirmed that the alkali–Fe-modified biochar exhibits a higher specific surface area, richer functional groups, and successful incorporation of the iron oxides Fe₃O₄ and α-FeOOH. The fitting parameter qmax from the Langmuir model indicates that the alkali–Fe modification of carbon significantly enhanced its maximum capacity for Cd²⁺ adsorption. Furthermore, a synergistic effect was observed between iron oxide loading and alkali modification, outperforming alkali modification alone. Furthermore, a 30-day soil incubation experiment revealed that the application of alkali–Fe-modified biochar significantly increased soil pH, SOM, and CEC while reducing the available cadmium content by 13.34–33.94%. The treatment also facilitated the transformation of highly bioavailable cadmium species into more stable, less bioavailable forms, thereby mitigating their potential entry into the food chain and the associated human health risks. Moreover, short-term spinach seed germination experiments confirmed that treatments with varying additions of alkali–Fe-modified biochar mitigated the inhibition of seed physiological processes by high concentrations of available cadmium to varying degrees. Overall, this study provides a sustainable and effective strategy for utilizing agricultural waste in the remediation of cadmium-contaminated water and soil systems. Full article