Nitrogen Levels Research Articles

Soil organic matter and total nitrogen as key driving factors promoting the assessment of acid-base buffering characteristics in a tea (Camellia sinensis) plantation habitat.

The issue of soil acidification in tea plantations has become a critical concern due to its potential impact on tea quality and plant health. Understanding the factors contributing to soil acidification is essential for implementing effective soil management strategies in tea-growing regions. In this study, a field study was conducted to investigate the effects of tea plantations on soil acidification and the associated acid-base buffering capacity (pHBC). We assessed acidification, pHBC, nutrient concentrations, and cation contents in the top 0-20cm layer of soil across forty tea gardens of varying stand ages (0-5, 5-10, 10-20, and 20-40years old) in Anji County, Zhejiang Province, China. The results revealed evident soil acidification due to tea plantation activities, with the lowest soil pH observed in tea gardens aged 10-20 and 20-40years. Higher levels of soil organic matter (SOM), total nitrogen (TN), Olsen phosphorus (Olsen-P), available iron (Fe), and exchangeable hydrogen (H+) were notably recorded in 10-20 and 20-40years old tea garden soils, suggesting an increased risk of soil acidification with prolonged tea cultivation. Furthermore, prolonged tea cultivation correlated with increased pHBC, which amplified with tea stand ages. The investigation of the relationship between soil pHBC and various parameters highlighted significant influences from soil pH, SOM, cation exchange capacity, TN, available potassium, Olsen-P, exchangeable acids (including H+ and aluminum), available Fe, and available zinc. Consequently, these findings underscore a substantial risk of soil acidification in tea gardens within the monitored region, with SOM and TN content being key driving factors influencing pHBC.

Influence of Various Nitrogen Levels and Herbicides Application on Nutrient Uptake and Quality Parameters of Rice (Oryza sativa L.)

The present study determines the Influence of Various Nitrogen Levels and Herbicides Application on Nutrient Uptake and Quality Parameters of Rice (Oryza sativa L.). A field experiment was conducted during Kharif season 2022 and 2023 at Agronomy research farm, Acharya Narendra Deva University of Agriculture and Technology Kumarganj, Ayodhya Uttar Pradesh, (India), which consisted of three levels of nitrogen 80, 120 and 160 Kg/ha in main plot and five weed management practices Pyrazosulfuron ethyl 10 % WP @ 20g a.i/ha (PE) at 0-3 DAT, Bispyribac sodium 10 % SC @ 25g a.i/ha (PoE) at 25 DAT, Pyrazosulfuron ethyl 10 % WP @ 20g a.i/ha (PE) at 0-3 DAT fb Bispyribac sodium 10 % SC @ 25g a.i/ha (PoE) at 25 DAT, Weed free and Weedy check in subplot thereby, making fifteen treatment combinations and replicated thrice in split plot design . Results indicated that protein content and protein yield, N, P and K content in grain and straw and their uptake after harvest were maximum recorded with the application of 160 Kg N ha-1 and Pyrazosulfuron ethyl 10 % WP @ 20g a.i/ha (PE) at 0-3 DAT fb Bispyribac sodium 10 % SC @ 25g a.i/ha (PoE) at 25 DAT which was comparable to weed free during both the years of investigation on transplanting rice.

Effect of Different Planting Density in Cocoa (Theobroma cacao l.) on Leaf Macro and Micronutrient Levels Grown under Coconut Ecosystem

An experiment investigating the impact of different cocoa densities on leaf macro and micronutrient levels within a coconut ecosystem was conducted at the Coconut Farm of the Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore. The study employed a Randomized Block Design (RBD) comprising eight treatments, each replicated three times. Notably, among the various spacing configurations, T1 (3m x 1.2m) exhibited the highest levels of leaf nitrogen (1.86%), phosphorus (0.084%), potassium (1.39%), and boron (91.33 ppm) content. This suggests that under Tamil Nadu conditions, high-density planting in the T1 treatment not only resulted in elevated nutrient levels but also correlated with a notable increase in revenue. These findings underscore the potential benefits of adopting high-density planting practices in cocoa cultivation within coconut ecosystems. Further research is warranted to explore the long-term implications of spacing configurations and nutrient interactions on crop productivity and profitability.

A new technique for the treatment of ureteric stricture after kidney transplantation.

To evaluate the safety and effectiveness of endoscopic treatments with Allium® metal ureteric stent (AMUS) for ureteric strictures after kidney transplantation (KT). In a prospective manner, we gathered clinical data from 68 patients who underwent endoscopic treatments with AMUS for ureteric strictures after KT between January 2019 and March 2022. The definition of surgical success was the unobstructed drainage of the AMUS, or in cases where there was AMUS migration, occlusion or encrustation and subsequently removed, there is no worsening of renal hydronephrosis in the patient during the follow-up period. Based on the specific circumstances of the ureteric strictures, three distinct types of surgery were selected for treatment. The overall success rate of endoscopic treatments for ureteric strictures following KT was 90% (61/68) during a follow-up period of 1 year. Surgical complications included haematuria (18%), pain (10%), urinary tract infections (7.4%), and lower urinary tract symptoms (7.4%). The incidences of stent migration, occlusion, and encrustation were 10%, 2.9%, and 1.5%, respectively. Postoperatively, significant improvements were observed in various parameters. At 1 month after surgery, there was a notable decrease in blood creatinine levels (105.5 vs 90.4 mol/L), urea nitrogen levels (6.6 vs 5.4 mmol/L), and hydronephrosis volume (64.4 vs 43.9 mL). Additionally, the serum estimated glomerular filtration rate increased from 49.5 to 64.4 mL/min/1.73 m2. The follow-up results of patients at 1 year after surgery were similar to those observed at 1 month after surgery. Systemic endoscopic treatments with AMUS were found to be safe and effective for ureteric strictures after KT with short-term follow-ups. This technique offers a novel option for the treatment of post-KT strictures.

Effect of nitrogen and phosphorus on growth and yield of mungbean

Nutrient management and their balance application are crucial for the high productivity of the crops; nitrogen and phosphorus are the essential nutrients, which are often deficient in the soil and must be supplied to the crops through various sources. The excessive application of these nutrients can lead to increased emissions of greenhouse gases and contribute to eutrophication, water pollution, and many other issues. To determine the optimal application rate of these nutrients, a field experiment was conducted in ANASTU research farm, Kandahar, in 2023 to evaluate the effects of different nitrogen and phosphorus levels on the growth and yield of mungbean (Vigna radiata L.). Treatments comprised three levels of nitrogen (0, 20, and 40 kg ha-1) and four levels of phosphorous (0, 40, 60 and 80 kg P2O5 ha-1). The study was carried out using an RCBD design with three replications. The results showed that 20 kg N ha-1 and 40 kg P2O5 ha-1, together and separately, enhanced growth parameters (Plant height, leaf area, dry matter, branches plant-1), yield attributes (Pods plant-1, grains pod-1, 100-grain weight and pod length) and grain, stover and total yield, significantly. Overall, this study indicates that the mungbean should be fertilized with 20 kg N ha–1 and 40 kg P2O5 ha–1 in Dand district of Kandahar province.

Can a naturally depauperate Ephemeroptera, Plectoptera and Trichoptera (EPT) fauna track river degradation in south-western Australia?

Freshwater aquatic ecosystems are threatened globally. Biological monitoring is required to deliver rapid and replicable assessment of changes in habitat quality. The Ephemeroptera, Plectoptera, Trichoptera (EPT) index is a globally recognised rapid bioassessment that measures taxa richness of three insect orders whose larvae are considered sensitive to freshwater habitat degradation. South-western Australia contains threatened freshwater ecosystems but has depauperate EPT fauna and high endemism, potentially reducing the capacity of the EPT index to track degradation. This study investigated if EPT species richness, composition or individual species tracked physical or chemical river degradation in three catchments in south-western Australia. We sampled EPT fauna and measured water chemistry, erosion, sedimentation, riparian vegetation cover and instream habitat at 98 sites in the winters of 2007 and 2023. We found 35 EPT taxa across the study area with a median number of species per site of two. EPT species richness had weak positive associations with a composite water quality index and dissolved oxygen and weak negative associations with electrical conductivity and total nitrogen. No association was found between physical and fringing zone degradation measures and EPT species richness. EPT community structure generally did not distinguish between sites with high or low degradation levels. The presence of the mayfly Nyungara bunni tracked salinity, dissolved oxygen and nitrogen levels, but its usefulness as a bioindicator could be limited by its restricted range. This study suggests that the EPT index would need modification or combination with other indices to be a useful rapid bioassessment in south-western Australia.

The Ameliorative and Neuroprotective Effects of Dietary Fiber on Hyperuricemia mice：A perspective from Microbiome and Metabolome.

The effect of single dietary fiber (DF) on lowering uric acid (UA) level has been reported in the literature. However, the potential protective mechanism of dietary fibre against potassium oxybate-induced hyperuricaemia (HUA), as modelled by prophylactic administration, remains unclear.The data demonstrates that DF significantly decreased serum and cerebral tissue UA concentrations, inhibited xanthine oxidase (XOD) expression and activity in the liver, and reduced levels of creatinine (Cr) and urea nitrogen (BUN) in the serum. Additionally, it mitigated the deposition of amyloid-β (Aβ) in cerebral tissue. Correlation analysis showed that DF modulated the TLR4/NF-κB signaling pathway, attenuating oxidative stress and inflammatory responses in HUA mice. Additionally, DF helps to maintain the composition of the gut microbiota, reducing harmful Desulfovibrio and enriching beneficial Akkermansia and Ruminococcus populations.The results of the faecal metabolomics analysis indicate that DF facilitates the regulation of metabolic pathways involved in oxidative stress and inflammation. These pathways include pyrimidine metabolism, tryptophan metabolism, nucleotide metabolism, and vitamin B6 metabolism. Additionally, the study found that DF has a preventive effect on anxiety-like behaviour induced by HUA. In summary, DF shows promise in mitigating HUA and cognitive deficits, primarily by modulating gut microbiota and metabolites.

Cottonseed meal protein hydrolysate influences growth performance, carcass characteristics, serum biochemical indices, and intestinal morphology in yellow-feather broilers.

This study investigated the effects of cottonseed meal protein hydrolysate (CPH) on the growth performance, carcass characteristics, serum biochemical indices, intestinal morphology, and enzyme activities of yellow-feather broilers. We randomly divided 240 chicks into four groups, each with six replicates: a basal diet with 0% (CON), 1% (LCPH), 3% (MCPH), or 5% (HCPH) CPH. The trail spanned 63 days and included three phases: Days 1-21, 22-42, and 43-63. Increased average daily gain (ADG) and decreased ratio of feed to gain (F/G) with LCPH were observed in 21-day-old broilers (P < 0.05). MCPH led to higher ADG and average daily feed intake (ADFI) in 42-day-old broilers (P < 0.05). Additionally, CPH supplementation resulted in increased dressing percentage, percentage of half-eviscerated yield, percentage of eviscerated yield, breast muscle rate, and leg muscle rate were observed (P < 0.05) with diet. The serum levels of total protein (TP), high-density lipoprotein cholesterol (HDL-C), calcium (Ca), and phosphorus (P) were enhanced, and blood urea nitrogen (BUN) and triglyceride (TG) levels decreased with diet and CPH (P < 0.05). CPH increased the length of the jejunum and ileum and the weight of the duodenum, jejunum, and ileum in 21-day-old broilers (P < 0.05). Alterations in the duodenal villus structure in broilers occurred on Days 21 and 42, and the CPH groups performed better; however, a similar change occurred in the jejunum on Days 42 and 63 (P < 0.05). MCPH and HCPH enhanced trypsin activity in the duodenum of 21-day-old and 63-day-old broilers (p < 0.05). Chymotrypsin activity increased (P > 0.05) in the duodenum of 63-day-old broilers fed MCPH. Lipase activity increased (P < 0.05) in the jejuna of 21-day-old broilers treated with HCPH. CPH increased trypsin activity in the ilea of 21-day-old broilers (P < 0.05). These results showed that CPH influenced the growth performance, carcass characteristics, serum biochemical indices, and intestinal morphology of yellow-feather broilers, which are related to growth stage. The recommended CPH level in broilers is 1% before 21 days of age and 3% after 21 days of age.

Effect of different level of nitrogen on different plant spacing on growth, yield and quality of kale

Effect of different level of nitrogen on different plant spacing on growth, yield and quality of kale

Association between metabolic parameters and embryo production in superovulated dairy cattle.

This study aims to investigate the relationship between metabolic parameters and the number of embryos produced in superovulated cows with high genetic characteristics in milk yield. Eighteen Holstein donors were treated with classic superovulation protocols, AI and flushing. During superovulation, decreasing doses of FSH (follicle-stimulating hormone) were administered at 12-h intervals for 4 days. Plasma insulin-like growth factor (IGF1), glucose (GLU), beta-hydroxybutyric acid (BHB), non-esterified fatty acid (NEFA), blood urea nitrogen (BUN) and total protein (TP) levels were determined by using an autoanalyzer. The mixed model analysis of variance was used for statistical analysis. As a result, plasma IGF1, BHB and BUN had significant interactions with both groups and days (p < .05). Additionally, plasma TP-days interactions were significant (p < .05). Furthermore, there was a negative correlation between the number of embryos and plasma BHB levels (p < .05). In conclusion, under appropriate environmental conditions, metabolic profile control of donors can contribute to the embryo production process and to the studies on the metabolic infrastructure.

Nitrogen Fertilization Strategies for Forage Maize Genotypes: Agronomic Performance, Nitrogen use Efficiency and Economic Assessment and Deter- mination of Economical N Fertilizer Rate

A field investigation was conducted using factorial experiment in randomized block design with seven genotypes and three nitrogen (N) levels (80, 120 and 160 kg N/ha) with three replications at Dr Rajendra Prasad Central Agricultural University, Pusa, Bihar, India during kharif season, 2022. The objective of the study was to assess the nitrogen use efficiency, productivity and profitability of forage maize genotypes under different N levels. Among, the genotypes, J-1006 and among N levels, application of 120 kg ha-1 registered the maximum green and dry fodder yield and crude protein yield (CPY). The highest partial factor productivity of N fertilizer (PFPN) was recorded with J-1006 (103.3 kg DM/kg N applied) and application of lowest dose i.e. 80 kg/ha (99.1 kg DM/kg N applied) among genotypes and N levels, respectively. J-1006 (Rs 78109 ha-1 and 3.62) and application of 120 kg N ha-1 (Rs 65716 ha-1 and 3.21) was profitable in terms of net returns and B:C ratio among genotypes and N levels, respectively. The economic optimum dose of N for tested fodder maize genotypes was found to be 139 kg/ha.

Nutrient levels control root growth responses to high ambient temperature in plants

Global warming will lead to significantly increased temperatures on earth. Plants respond to high ambient temperature with altered developmental and growth programs, termed thermomorphogenesis. Here we show that thermomorphogenesis is conserved in Arabidopsis, soybean, and rice and that it is linked to a decrease in the levels of the two macronutrients nitrogen and phosphorus. We also find that low external levels of these nutrients abolish root growth responses to high ambient temperature. We show that in Arabidopsis, this suppression is due to the function of the transcription factor ELONGATED HYPOCOTYL 5 (HY5) and its transcriptional regulation of the transceptor NITRATE TRANSPORTER 1.1 (NRT1.1). Soybean and Rice homologs of these genes are expressed consistently with a conserved role in regulating temperature responses in a nitrogen and phosphorus level dependent manner. Overall, our data show that root thermomorphogenesis is a conserved feature in species of the two major groups of angiosperms, monocots and dicots, that it leads to a reduction of nutrient levels in the plant, and that it is dependent on environmental nitrogen and phosphorus supply, a regulatory process mediated by the HY5-NRT1.1 module.

Effects of the Mixed Seeding Rate of Milkvetch on Fertilizer Substrate, Growth, and Carotenoid Levels of Baby Leaf Vegetables in Vertical Indoor Farming

During this study, an indoor experiment was conducted to determine the effect of mixed seeding rates of legumes used as green manure on the substrate fertilizer, growth characteristics, and bioactive compounds of baby leaf vegetables. The mixed seeding treatment was designed for milkvetch (Astragalus sinicus L.), tatsoi (Barassica rapa L.), kale (Brassica oleracea var. sabellica L.), and spinach (Spinacia oleracea L.) using five rates for each. Accordingly, a total of 15 treatments (3 baby leaf species × 5 mixed seeding rates) were constructed using a randomized complete block design with three replications for each treatment. During the baby leaf vegetable harvest, we evaluated the macronutrient levels (nitrogen, phosphorus, and potassium) in the substrate as well as the growth parameters and carotenoid contents. The substrate in the treatment mixed with milkvetch showed significantly higher levels of nitrogen, phosphorus, and potassium compared with those of tatsoi and kale sown alone (P ≤ 0.05). However, there were no significant differences in macronutrients observed in substrate-sown spinach with or without the milkvetch mixture. The growth and carotenoid levels of each baby leafy vegetable sown alone were significantly higher than those of each baby leafy vegetable sown with the mixed seeding treatment (P ≤ 0.05). Sowing the milkvetch–vegetable mixtures did not result in a significant increase in the growth and carotenoid levels of the three baby vegetables. The results showed that planting milkvetch with tatsoi and kale had a significant impact on substrate fertilization. However, regarding short-term vertical indoor farming, the growth and carotenoid responses of the three greens may be different. Nonetheless, we still believe that the combined interactions of legumes can provide long-term benefits by enhancing the biological functionality of the growing medium for balanced indoor agriculture production.

Hederagenin Improves Adriamycin-induced Nephropathy by Inhibiting the JAK/STAT Signaling Pathway

ABSTRACT Background: Glomerulonephritis, a common kidney disease and major cause of end-stage renal disease, lacks effective treatment options. Hederagenin (HDG) exerts potent anti-inflammatory and protective effects on the kidneys and exhibits promise for the treatment of glomerulonephritis. This study aimed to investigate the therapeutic effects and mechanism of action of hederagenin in the context of adriamycin-induced nephropathy (ADN). Methods: C57BL/6 mice were randomly divided into 5 groups that included the control, model, low-dose HDG (20 mg/kg), high-dose HDG (40 mg/kg), and positive control (10 mg/kg irbesartan) groups. ADN was established in mice by administering a single injection of 10 mg/kg adriamycin. Renal pathology and fibrosis were assessed using haematoxylin and eosin (H &amp; E) and Masson’s trichrome staining, whereas in vitro studies were conducted using cultured mouse podocytes (MPC5). Immunofluorescence staining and western blotting were performed to detect inflammation and the protein levels of signaling pathways. Results: The results revealed that HDG significantly improved adriamycin-induced abnormal serum creatinine, albumin, and urea nitrogen levels. HDG treatment reduced glomerular injury and fibrosis, particularly at high doses. Additionally, HDG effectively reduced adriamycin-induced activation of Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling and renal fibrosis while suppressing CD4+/CD8+ cell ratios in the kidneys and enhancing the immune response. Interestingly, when the JAK/STAT signaling pathway was activated by an agonist, the ameliorative effects of HDG on ADN were inhibited, thus suggesting that JAK/STAT signaling is a key target of HDG. Conclusion: HDG may represent a promising treatment option for glomerulonephritis by inhibiting JAK/STAT-mediated immune-inflammatory responses.

Assigning strategic COD flow to enhance denitrification coupled with anaerobic digestion and anammox for systematic upgradation of advanced nitrogen removal from food waste digestate

Anammox is a low-carbon and efficient technology for treating high-strength ammonium in food waste digestate (FWD). However, achieving superior low-nitrogen effluent levels to meet strict discharge standards remains challenging. This study proposes an anammox-based process that integrates simultaneous denitrification and methanogenesis (SDM), partial nitrification (PN), and simultaneous anammox and denitrification (SAD) to realize advanced nitrogen removal from FWD by strategically utilizing influent organic matter. The SAD process achieved an inorganic nitrogen removal efficiency of 94.0 %, with the anammox reaction contributing 96.0 %. Residual nitrate in the SAD effluent was recirculated into SDM, maintaining a removal efficiency of 95 %–97 %. Profiling wastewater and material flows in the integrated process showed a 97.2 % nitrogen removal efficiency, with effluent nitrogen levels meeting discharge standards (<70 mg/L for municipal sewer systems). 3D-fluorescence analysis indicated that quasi-humic acid was effectively removed through SDM. Soluble microbial by-products of FWD served as carbon source for the denitrifying bacteria in SAD. Controlling influent bypass flow and effluent recirculation allowed for strategic allocation of chemical oxygen demand (COD) flow, achieving a total removal efficiency of 71.8 %. SDM removed 45.8 % COD, followed by PN at 13.4 % and SAD at 12.6 %. Compared with those of conventional nitrification and denitrification process, the economic cost, greenhouse gas emission, and total environmental impact of this integrated process were reduced by 85.8 %, 35.8 %, and 84.1 %, respectively. This study provides new insights into the application of anammox-based process for attaining advanced nitrogen removal while minimizing environmental impact.

Internet of Things(IoT) Application for Crop Prediction and Fertilizer Suggestion Using Machine Learning Techniques

Abstract: Agriculture serves as the primary source of income globally, particularly in regions like the Indian subcontinent. However, modern challenges such as unpredictable weather patterns, water scarcity, and market fluctuations necessitate the adoption of advanced farming techniques. Soil fertility depletion, caused by various factors, further exacerbates these challenges, leading to decreased crop yields. To solve these problems, our project utilizes modern technology, specifically leveraging machine learning techniques. By integrating an NPK sensor with a web application, our goal is to give farmers practical insights into their soil's nutrient composition. Upon collecting nitrogen, phosphorus, potassium, and pH levels from the soil, these values are entered into the application. Compared to traditional farming methods, our project offers several advantages. Firstly, it empowers farmers with accurate and timely information about their soil's nutrient levels, giving them the ability to make wise decisions.

Using multivariate analysis to predict carcass characteristics of lambs grazing and supplemented with different levels of non-protein nitrogen

Using multivariate analysis to predict carcass characteristics of lambs grazing and supplemented with different levels of non-protein nitrogen

Nitrogen Addition Mitigates Drought by Promoting Soybean (Glycine Max (Linn.) Merr) Flowering and Podding and Affecting Related Enzyme Activities

Drought at the flower and pod stage, which is the most moisture-sensitive stage of soybean development, is the main cause of yield loss in soybean. Nitrogen is a vital nutrient for soybeans. The objective of this study was to assess the potential of post-drought nitrogen fertilization at the soybean (Heihe 45) pod stage to (1) reduce pod shedding and increase yield, and (2) elucidate the mechanisms by which nitrogen fertilization regulates soybean growth under drought stress. The pot experiment was designed with two moisture levels and three nitrogen levels, resulting in a total of six treatments. The results show that nitrogen reduces cellular oxidation by regulating key enzymes of sucrose metabolism, such as sucrose synthase and sucrose phosphate synthase; and regulates cellulase to reduce shedding and mitigate drought. Comparison of low and high nitrogen conditions under drought conditions showed that the number of flowers and pods in soybean increased by 30% and 32.94%, respectively, malondialdehyde content decreased by 24%, cellulase activity in flowers and pods decreased by 15.07% and 12.31%, respectively, and yields increased by 29.98% under high nitrogen conditions. The high nitrogen treatment performed optimally and the differences between treatments reached the significant level.

Relation of myocardial dysfunction to biomarkers, COVID-19 severity and all-cause mortality.

The COVID-19 infection has been described as affecting myocardial injury. However, the relation between left ventricular global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS), disease severity and all-cause mortality in COVID-19 is unclear. The study consisted of 220 patients with COVID-19, including 127 (57.5%) with mild, 43 (19.5%) with moderate and 50 (22.7%) with severe/critical conditions. Myocardial dysfunction was analysed by GLS, GCS and GRS using two-dimensional speckle-tracking echocardiography. Hazard ratios and Kaplan-Meier curves were produced to assess the association between strains and cardiac biomarker indices with a composite outcome of all-cause mortality. With an average follow-up period of 11days, 19 patients reached the endpoint (death). Significant associations were found for the three strain parameters and the levels of blood urea nitrogen (BUN) (r=0.206, 0.221 and 0.355, respectively). Cardiac troponin I (cTnI) was closely related to the GLS and GCS (r=0.240 and 0.324, respectively). In multivariable Cox regression, GCS>-21.6% was associated with all-cause death {hazard ratio, 4.007 [95% confidence interval (CI), 11.347-11.919]}. GLS, GCS and GRS are significantly related to myocardial dysfunction in patients with COVID-19. Worsening GCS poses an increased risk of death in COVID-19.

The Effect of Japanese Papaya Leaf Powder (Cnidoscolus aconitifolius) as a Natural Preservative of Block Fish During Cold Temperature Storage

Mackerel (Rastelliger Sp.) is a small pelagic fish commonly consumed as a source of animal protein. Due to its high susceptibility to spoilage, effective storage and the use of natural preservatives are essential to extend its shelf life. Japanese papaya leaf powder, which contains alkaloids, flavonoids, tannins, and saponins, has potential as a natural preservative due to its antimicrobial properties. This study aims to evaluate the optimal combination of Japanese papaya leaf powder concentration and storage duration on the quality of mackerel stored at low temperatures. A completely randomized factorial design was employed, with two factors: the concentration of Japanese papaya leaf powder (0%, 6%, 8%, and 10%) and storage duration (0, 2, 4, and 6 days). Data were analyzed using ANOVA at a 5% significance level, followed by Duncan's Multiple Range Test (DMRT) at the same significance level. The results indicated that the best treatment combination was 10% Japanese papaya leaf powder and 4 days of storage. This combination yielded a moisture content of 64.51%, a total microbial count of 6.6 cfu/g, a total volatile basic nitrogen (TVBN) level of 23.28 mg/100g, a pH of 5.34, a trimethylamine (TMA) level of 6.15 mg/100g, and a water holding capacity (WHC) of 53.11%. The organoleptic assessment showed that the mackerel maintained acceptable color and aroma, indicating effective preservation.