Green Residues Research Articles

The Role of Organic Amendments and Their Impact on Soil Restoration: A Review

Soil organic matter (SOM) plays a pivotal role in maintaining soil health by enhancing its physical, chemical, and biological properties. It improves soil structure, water retention, nutrient availability, and microbial activity, contributing significantly to sustainable agriculture. Organic amendments, including animal manure, compost, biosolids, crop residues, and various organic by-products, are widely used to restore degraded soils by increasing SOM content. These amendments not only supply essential nutrients but also promote biological aggregation, suppress soil-borne pathogens, and improve soil's resistance to environmental stressors such as drought and heavy metal toxicity. The positive impacts of organic amendments on soil properties are well-documented, with key benefits including increased soil organic carbon (SOC), improved nutrient cycling, enhanced microbial diversity, and greater water-holding capacity. Organic materials such as compost and animal manure have been shown to significantly improve soil fertility and restore degraded soils. The application of green manure and crop residues also boosts soil biodiversity, enhances rhizospheric processes, and supports overall ecosystem resilience. This paper emphasizes the importance of adopting holistic soil management practices that include organic amendments, conservation tillage, and sustainable cropping systems to address soil degradation. By focusing on replenishing SOM, improving nutrient availability, and increasing soil biodiversity, these practices can contribute to the long-term sustainability of agricultural systems and environmental health. The restoration of soil organic matter is essential for enhancing soil quality and mitigating degradation, ultimately ensuring food security and ecosystem stability for future generations.

Evaluation of green residues management of selected grape varieties

The paper presents the possibilities of energy management of residues from the cultivation of grapes of the ‘Regent’, ‘Rondo’ and ‘Seyval Blanc’ cultivars. The research was conducted in southeastern Poland in the Sandomierska Upland in 2022. The aim of the research was to demonstrate the influence of grape variety on yield capacity in relation to the extraction of biomass residues in the form of leaves. An attempt was made to identify the variety that is characterised by obtaining the most effective and average parameters, i.e. yield size and quality, leaf mass and surface area, and their impact on energy and fuel parameters. The study analysed the following crop parameters, i.e. number and mass of grapes, number and mass of berries; leaf quality parameters, i.e. mass including petioles and area. An energy assessment in Laboratory in Department of Power Engineering and Transportation was carried out by performing proximate and ultimate analysis and estimating emission factors and volumetric composition of exhaust gas. The study showed that the material with the highest energy potential was characterised by ‘Regent’, while the lowest potential was shown for ‘Rondo’. Grapevines of the ‘Rondo’ cultivar were characterised by the highest obtained biomass among the evaluated varieties. The research showed that the most effective in practical cultivation is the use of the Regent variety, which was characterised by the average parameters of the obtained yield and growth values, and the highest fuel energy potential.

Magnetic covalent organic framework as an absorbent coupled with a portable mass spectrometer for rapid detection of malachite green and its metabolite residues

It is important to develop specific adsorbents for malachite green and other fish drug residues. Herein, a simple strategy for synthesizing a novel magnetic covalent organic frameworks (rFe3O4@Py-COF) has been studied, and the materials were used as a magnetic absorbent for solid phase extraction (MSPE) of malachite green (MG) and its metabolite as leucomalachite green (LMG) in fishes. In this study, the mild reduction program of formic acid replacing traditional sodium borohydride as a reducing agent has been adopted to increase the stability of the framework, which can maintain the original high crystallinity and surface area of the reduced COF. The secondary amine bond is expected to be used as the reaction center for further functionalization of COF pore wall. Subsequently, rFe3O4@Py-COF (rmCOF) obtained after reduction was used as MSPE materials to detect MG and LMG by a portable mass spectrometer. After optimizing the conditions, the linearity is good within the range of 1.25∼100 μg/kg (R2≥0.9954), the limits of detection (LODs) are 0.31∼0.44 μg/kg with satisfactory recovery (85.0 %∼106.0 %). These results indicate that the assay is suitable for monitoring MG and LMG in complex aquatic foods, providing protection for food safety.

Dual-color immunochromatographic test strip for simultaneous sensitive detection of malachite green and leucomalachite green residues in fish and shrimp meat samples

A sensitive dual immunochromatographic test strip (dual-ICTS) was developed to detect malachite green (MG) and its metabolite, leucomalachite green (LMG), using two types of gold nanoparticles: round-shaped (red) and star-shaped (blue). The detection limits were determined to be 0.221 μg L−1 for MG and 0.214 μg L−1 for LMG, respectively. The dual-ICTS provided a cut-off value of 1.8 μg L−1 for MG and LMG detection. The dual-ICTS successfully detected MG and LMG in food samples, with recovery rates ranging from 86 % to 116 %. The dual-ICTS was evaluated by correlation analysis between the proposed assay and the well-established enzyme-linked immunosorbent assay in the MG and LMG detection. This is the first report on the development of the ICTS that can detect both MG and LMG at the same time within only 5 min, making it a sensitive and rapid tool for on-site detection.

Effects of Extraction Processes on Recovery, the Phenolic Profile, and Antiglycation Activity from Green Coffee Residues (Coffea arabica and Coffea canephora Pierre)

Effects of Extraction Processes on Recovery, the Phenolic Profile, and Antiglycation Activity from Green Coffee Residues (<i>Coffea arabica</i> and <i>Coffea canephora Pierre</i>)

Effect of steam explosion pretreatment on the fermentation characteristics of polysaccharides from tea residue

Green tea residues are the by-product of tea processing and they contain a large number of bioactive ingredients. Steam explosion has been recognized as one of the most innovative pretreatments for modifying the physicochemical characteristic of polysaccharides from lignocellulosic materials. However, the comparison of biological activity of steam exploded (SE-GTR) and unexploded (UN-GTR) green tea residue polysaccharides was still unclear, which prompted the determination of the efficacy of steam explosion in tea residue resource utilization. In this study, the effects of two extracted polysaccharides UN-GTR and SE-GTR on human gut microbiota in vitro fermentation were conducted. The results showed that after steam explosion pretreatment, SE-GTR displayed more loose and porous structures, resulting in higher polysaccharide content (2483.44±0.5 μg/mg) compared to UN-GTR (1903.56±2.6 μg/mg). In addition, after 24 h fermentation, gut microbiota produced more beneficial metabolites by SE-GTR. The largest SCFAs produced among samples was acetic acid, propionic acid and butyric acid. Furthermore, SE-GTR could regulate the composition and diversity of microbial community, increasing the abundance of beneficial bacteria, such as Bifidobacterium. These results revealed that steam explosion pretreatment could be a promising and efficient approach to enhance the antioxidant activity and bioavailability of polysaccharides isolated from tea residues.

Hydrothermal Carbonization of Green Harvesting Residues (GHRs) from Sugar Cane: Effect of Temperature and Water/GHR Ratio on Mass and Energy Yield.

The Valle del Cauca region in Colombia is a significant producer of sugar cane, resulting in large quantities of agricultural residues (green harvesting residues (GHRs)). To ensure sustainable management of these residues, it is crucial to implement proper treatment and disposal technologies while also reusing waste to produce biogas, bioelectricity, or biofuels. The biomass hydrothermal carbonization process offers a means to convert these residues into useful products that serve as fuels or valuable energy materials. This thermal treatment involves the use of water as a solvent and reagent within the biomass's internal structure. In this study, sugar cane cutting residues were collected with relatively high moisture content of 8.5% wt. These residues were subjected to carbonization temperatures ranging from 200 to 300 °C, along with water/GHR ratios between 5/1 and 10/1. The properties of the resulting hydrocarbons were analyzed by using proximate and ultimate analysis. The objective was to produce hydrochar samples with the highest higher heating value (HHV) and energy density compared with the GHRs. The HHV value of the hydrochar showed a significant increase of 69.6% compared with that of the GHRs, reaching 43.5 MJ/kg. Besides, process parameters were optimized for mass yields, energy yields, and ash content. This exploration led us to investigate a new temperature range between 280 and 320 °C, allowing us to establish an optimal value for the hydrochar's properties.

Bacterial cellulose from kombucha: Assessing inoculum age and concentration, and its conversion via enzymatic hydrolysis into cellobiose and glucose

Kombucha-type fermentation yields significant amounts of bacterial cellulose alongside the fermented beverage. This study evaluated the effects of inoculum age and concentration in kombucha-type fermentation using green acerola residue as an extract. The findings revealed that lower inoculum concentrations (2.5 and 5%) resulted in decreased bacterial cellulose (BC) yield. Conversely, increasing the inoculum concentration to 7.5% and 10% led to a 3.2-fold increase in BC yield. Inoculums aged just 3 days exhibited the lowest BC production, followed by older inoculums (9 and 12 days), suggesting reduced metabolic activity in the latter case. The optimal combination was found to be an inoculum age of 6 days and a concentration of 7.5%, resulting in a BC yield of up to 2.2 g/L using 70 g/L of carbon source. BC obtained from fermentation underwent enzymatic hydrolysis to yield cellobiose. Multi-stage hydrolysis - 1 stage (48 h), 2 (24 h, 24 h), 3 (12 h, 24 h, 24 h), and 4 (6 h, 6 h, 12 h, 24 h) - utilizing a methodology that anticipates the adsorption of endoglucanases onto the BC itself was employed to mitigate the inhibition of cellobiose on endoglucanases. The stages demonstrated an increase in cellobiose yield corresponding to the greater number of cycles, with 4 stages yielding 12.4% compared to 8.6% for hydrolysis conducted in a single stage. Despite the observed increase, the yield can be considered low and attributed to the loss of adsorbed enzymes between cycles due to the high crystallinity of the BC.

Application of green tea residue-derived carbon dots in the detection of Fe3+ ions and imaging of Caco-2 cells

In this study, we successfully synthesized green luminescent carbon dots by using green tea residue as the precursor of carbon source. Based on the internal filter effect (IFE), the fluorescence emission intensity of the probe decreased significantly with the increase of Fe3 + concentration. Based on this, a linear relationship between Fe3 + concentration and the fluorescence emission intensity of the probe was established to semi-quantitatively detect Fe3 +. The results showed that the linear range was 1–400 μM, and the detection limit was 3.58 μM. In addition, the probe was further applied to actual samples, and it was found that the recovery rate was between 97.75% and 104.59%, and the relative standard deviation was below 1.81%. These findings underscore the considerable potential of the carbon dots for practical Fe3+ detection applications. In a further application, the fluorescent carbon dots were diluted and directly employed to stain Caco-2 cells. Remarkably, even after 10 and 20-fold dilutions, the Caco-2 cells displayed vivid fluorescence at the green excitation wavelength. This outcome suggests a promising avenue for the application of fluorescent carbon dots in the field of biology.

DESCOMPOSICIÓN Y LIBERACIÓN DE NITRÓGENO DE LOS RESIDUOS DE CAÑA DE AZÚCAR (Saccharum officinarum L.) COMBINADOS CON EL FOLLAJE DE PLANTAS LOCALES

&lt;p&gt;&lt;strong&gt;Background&lt;/strong&gt;: Green post-harvest sugarcane residues (&lt;em&gt;Saccharum officinarum&lt;/em&gt;) present low rates of decomposition and N release in the short term when integrated into the production system. Combining &lt;em&gt;S. officinarum&lt;/em&gt; residues with the foliage of local plants rich in nitrogen could be an alternative to accelerate the decomposition process of residues with a positive impact on soil conservation. &lt;strong&gt;Objective&lt;/strong&gt;: To evaluate and compare the decomposition patterns and potential release of N to the soil of the residues of &lt;em&gt;S. officinarum&lt;/em&gt; variety MEX 69-290, with the addition of different foliage such as &lt;em&gt;Clitoria ternatea&lt;/em&gt;, &lt;em&gt;Leucaena leucocephala&lt;/em&gt; and &lt;em&gt;Tithonia diversifolia&lt;/em&gt;, in southern Quintana Roo. &lt;strong&gt;Methodology&lt;/strong&gt;: The treatments evaluated were the following: Clitoria + MEX 69-290, Leucaena + MEX 69-290, Tithonia + MEX 69-290, and MEX 69-290 (control). The materials were placed in decomposition bags and incubated on the ground in four periods (15, 30, 60 and 120 days), in a completely randomized design. The contents of dry matter, nitrogen and lignin were determined for the initial and remaining material in each period. &lt;strong&gt;Results&lt;/strong&gt;: With the integration of local plants, a significant increase in the percentage of decomposition and release of N was obtained. After 120 days of evaluation, the decomposition values were 71.3, 50.4, 48.1 and 33.5%, for the Tithonia + MEX 69-290, Clitoria + MEX 69-290, Leucaena + MEX 69-290, and MEX 69-290 control, respectively. Likewise, the potential N release values were 98.2, 95.3, 92.9 and 58.7%, for Tithonia + MEX 69-290, Leucaena + MEX 69-290, Clitoria + MEX 69-290, and MEX 69-290 control. The Tithonia + MEX 69-290 treatment had the highest relative decomposition rate (0.009 g g&lt;sup&gt;-1&lt;/sup&gt; day&lt;sup&gt;-1&lt;/sup&gt;) and a high potential N release rate (0.053 g g&lt;sup&gt;-1&lt;/sup&gt; day&lt;sup&gt;-1&lt;/sup&gt;), compared to the other treatments. &lt;strong&gt;Implications&lt;/strong&gt;: The integration of N-rich plants can increase the decomposition and release of N from sugarcane residues, with potential in plant assimilation from the first crop cycle, reduce the application of nitrogen fertilizer and increase sugarcane yields. in the region. &lt;strong&gt;Conclusion&lt;/strong&gt;: The combination of &lt;em&gt;S. officinarum&lt;/em&gt; residues with foliage of local plants, particularly &lt;em&gt;T. diversifolia&lt;/em&gt;, could be considered a viable strategy to accelerate the decomposition process and release of N in residues on the edaphoclimatic conditions of southern Quintana Roo.&lt;/p&gt;

Enchytraeid-stimulation of nitrogen mineralization from green plant residues in an organic soil

Faunal-mediated nutrient cycling, especially N mineralization, has the potential to make a significant contribution to nutrient supply to crop plants in production systems involving e.g. green manure cover crops. We investigated the effects of enchytraeids on N mineralization from mung bean residues in microcosm experiments using an organically-farmed soil with an inherently large population of enchytraeids. Enchytraeids promoted N mineralization by 23% after a distinct lag of between four and 12 weeks, concomitant with a substantial increase in population size followed by an almost complete collapse. Nitrogen release from the necromass would have contributed a small but significant fraction of the N mineralized, and the result suggested the presence of other mechanisms. Enchytraeids suppressed nematode populations, while did not affect the mean weight diameter (MWD) of soil aggregates, although mung bean residues increased MWD. We conclude that enchytraeids have potential to play significant roles in mediating N supply to crops but matching supply-and-demand periods may be challenging.

Green manure incorporation enhanced soil labile phosphorus and fruit tree growth.

The incorporation of green manures substantially enhances the conversion of external phosphorus (P) fertilizers and soil-reserved P into forms readily available to plants. The study aims to evaluate the influence of green manure additions on soil phosphorus dynamics and citrus growth, considering different green manure species and initial soil phosphorus levels. Additionally, the research seeks to elucidate the microbiological mechanisms underlying the observed effects. A citrus pot experiment was conducted under both P-surplus (1.50 g·P·kg-1) and P-deficient (0.17 g·P·kg-1) soils with incorporating legume (Leg), non-legume (Non-Leg) or no green manure residues (CK), and 18O-P labeled KH2PO4 (0.5 g, containing 80‰ δ18Op) was additionally introduced to trace the turnover characteristics of chemical P fertilizer mediated by soil microorganisms. In P-surplus soil, compared with the CK treatment, the Leg treatment significantly increased soil H2O-Pi (13.6%), NaHCO3-Po (8.9%), NaOH-Pi (9.5%) and NaOH-Po (30.0%) content. It also promoted rapid turnover of P sources into H2O-Pi and NaHCO3-Pi pools by enhancing the phoC (576.6%) gene abundance. In contrast, the Non-Leg treatment significantly augmented soil H2O-Pi (9.2%) and NaHCO3-Po (8.5%) content, facilitating the turnover of P sources into NaHCO3-Pi pools. Under P-deficient soil conditions, compared with the CK treatment, the Leg treatment notably raised soil H2O-Pi (150.0%), NaHCO3-Pi (66.3%), NaHCO3-Po (34.8%) and NaOH-Pi (59.0%) content, contributing to the transfer of P sources into NaHCO3-Pi and NaOH-Pi pools. This effect was achieved through elevated ALP (33.8%) and ACP (12.9%) activities and increased pqqC (48.1%), phoC (42.9%), phoD (21.7%), and bpp (27.4%) gene abundances. The Non-Leg treatment, on the other hand, led to significant increases in soil NaHCO3-Pi (299.0%) and NaHCO3-Po (132.6%) content, thereby facilitating the turnover of P sources into NaHCO3-Pi and NaOH-Pi pools, except for the phoC gene abundance. Both Leg and Non-Leg treatments significantly improved citrus growth (7.3-20.0%) and P uptake (15.4-42.1%) in P-deficient soil but yielded no substantial effects in P-surplus soil. In summary, introducing green manure crops, particularly legume green manure, emerges as a valuable approach to enhance soil P availability and foster fruit tree growth in orchard production.

Green Manuring and Irrigation Strategies Positively Influence the Soil Characteristics and Yield of Coriander (Coriandrum sativum L.) Crop under Salinity Stress

This study shows the influence of soil salinity and irrigation dose on biomass production and its impact on some edaphic indicators and functions. For this purpose, an experiment was carried out in two representative soils from Murcia (SE Spain), one slightly saline (LS) and the other saline (S), where an oat–vetch green manure was intercalated between a spinach cycle and a coriander cycle; the latter being subjected to three different irrigation doses (deficient, optimum and surplus). Rapid response indicators (ECext, cations and anions in the soil solution, etc.) were monitored, as well as the material balances, in particular C and salts. Green manure and crop residues increased soil OC by 12.5% and reduced Na+ and NO3− concentrations. Total biomass production was also affected by salinity, both in oat–vetch, 35.9 and 31. 9 tm ha−1 in LS and S, respectively, and in the coriander crop, where the irrigation dose was decisive, obtaining around 29 tm ha−1 with the optimum and surplus doses and significantly lower amounts with the deficit dose: 20.4 tm ha−1 in LSD and 14. 0 in SD. Therefore, it is necessary to adjust the irrigation doses, since deficit irrigation significantly reduces production and the surplus does not lead to an increase with respect to the optimum, while also causing ions to leach to depth horizons, as is the case for NO3−, Cl− and Na+, with the consequent risk of contaminating the water table.

HAuCl4/K4Fe(CN)6 reaction mediated silver nanosol as SERS substrate for robust detection of malachite green residue in seafood

Irreproducibility is considered as a significant obstacle to the widespread use of surface enhanced Raman spectroscopy (SERS) as a sensing platform. However, in terms of the SERS performance in applications, less attention has been paid on the stability, i.e., repeatability and reproducibility compared to sensitivity. Here, based on HAuCl4/K4Fe(CN)6 reaction and silver nanosol (Ag NS), a reaction mediated SERS (R-SERS) platform was proposed for the detection of malachite green residue (MG) in aquatic products, aiming to improve both the sensitivity and stability of SERS. Wherein, the HAuCl4/K4Fe(CN)6 reaction produced Au0 grows on Ag NPs and provided additional “hot spots” to enhance signal intensity. Meanwhile, the reaction system released cyano group (-C≡N) will cap on the surface of Ag or Au NPs and act as an internal signal at ∼2100 cm−1 to adjust the background signal. As a proof of principle, adenine (Ade, 730 cm−1), ceftriaxone (Cef, 1345 cm−1) and MG (1170 cm−1) were selected as targets to discuss the detection performance, with linear ranges of 0.1 ∼ 20 μM, 0.1 ∼ 10 μM and 0.1 ∼ 2 μM and limit of detection (LOD, 3σ/M) of 0.079 μM, 0.050 μM and 0.032 μM, respectively. In practical applications, MG residue in aquatic products were detected with the recoveries ranged from 85 % to 98 % and the coefficient of variations of intra-assay below 6.6 %. The R-SERS platform, therefore, was demonstrated to enhance SERS intensity and stability with in situ growth of label on Ag NPs, suggesting its potential applications in SERS sensing.

Evaluation of Torrefaction on the Quality of Bio-Oil Obtained by Pyrolisis of Green Coconut Wastes

Pyrolysis of green coconut residues is considered a promising source of biomass for transforming energy and generating value-added products from thermochemical processes such as pyrolysis, mainly due to the high volume of this material in the Northeast region. For better pyrolytic results, some pre-treatments of the biomass can be used. In this work, the pre-treatment technique of oxidative and non-oxidative torrefaction was applied, using temperatures of 200 and 250 °C. These torrefied biomasses were subsequently subjected to fast pyrolysis at 700 °C. GC/qMS characterized the bio-oil obtained, and an increase in the content of phenolic compounds was observed in the torrefied biomass samples when compared to the raw biomass, indicating that the process is viable and adds value to the bio-oil obtained by pyrolysis.

Evaluating the persistence of malachite green residues in tilapia and pacu fish

Although banned in food-producing animals, residues of malachite green (MG) and its primary metabolite, leucomalachite green (LMG), have been found in fish due to illegal use in aquaculture and the release of industrial wastewater, which represent a serious risk to food and environmental securities. This study aimed to investigate the residue depletion profile of MG and LMG in edible tissues of Nile tilapia (Oreochromis niloticus) and pacu (Piaractus mesopotamicus) cultured simultaneously under the same environmental conditions to support control measures in case of abuse. An analytical method involving QuEChERS sample preparation and liquid chromatography coupled to tandem mass spectrometry was developed, validated, and applied to quantify MG and LMG residues in fish fillets from two depletion experiments after treatment by immersion bath (MG at 0.10 mg L-1 for 60 min). During the experiment, the average water temperature was 30 ºC, while the pH was 6.9. The method is selective, precise (CV = 0.4 - 22%) and accurate (recovery 92 - 114%). The limits of detection and quantification are 0.15 and 0.5 ng g-1, respectively. In both species, the sum of MG and LMG residues were quantified up to the 32nd day post-exposure, and the concentrations were significantly higher in the pacu fillets (up to 3284 ng g-1) than in Nile tilapia (up to 432 ng g-1). The sums of MG and LMG residues were below 2 ng g-1 at 44 days and 342 days for Nile tilapia and pacu, respectively – the Minimum Required Performance Limit (MRPL) for analytical methods intended to monitor forbidden substances in food according to old European Commission guidelines. The persistence of MG residues in pacu may be attributed to its higher lipid content, which favors the accumulation of the non-polar metabolite LMG. These results provide insights into the concern about human, animal, and environmental health risks resulting from unauthorized use or aquatic contamination by industrial wastewater containing MG residues.

Sustainable papaya plant waste and green tea residue composite films integrated with starch and gelatin for active food packaging applications

This study explores the sustainable utilization of wastes from a papaya plant (papaya peels (PP), papaya seeds (PS), leaf-stem (PL)) and dried green tea residues (GTR) for the synthesis of bioplastics. The dried GTR were individually blended with each papaya waste extract and then boiled in water to get three composite papaya plant waste-green tea supernatants. Potato starch and gelatin-based functional films were prepared by integrating each with the composite papaya waste-green tea supernatant liquid. This work introduces a dissolved organic matter (DOM) study to the field of bioplastics, with the goal of identifying the organic components and macromolecules inherent in the PW supernatants. When compared with the films prepared solely from papaya waste (PW) supernatants, PW-GTR composite supernatant films prevent UV light transmission with superior antioxidant and mechanical properties. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction spectroscopy (XRD), and atomic force microscopy (AFM) were utilized to characterize the starch and gelatin PW-GTR films. Owing to the exceptional antioxidant, UV barrier, and remarkable biodegradable properties of the starch/PW/GTR and gelatin/PW/GTR composite films, make them ideal for use in food packaging applications.

Effective collection of protein-enriched cells from green tea residue: An innovative process for leaf protein production

Green tea residue (GTR) contains a high protein content. However, the protein in GTR can't be effectively extracted using traditional methods. Thus, a novel method using ethylenediamine tetraacetic acid (EDTA), ammonium oxalate, or Celluclast® 1.5 L were used to disperse leaf tissues and to collect mesophyll cells to enrich the protein. Compared with EDTA or ammonium oxalate treatment, Celluclast® 1.5 L treatment achieved the highest amounts of mesophyll cells, about 2.7 × 106 g−1 of GTR. The number of collected mesophyll cells was positively and linearly correlated with the extraction rate of glucose and xylose, indicating that cellulose and hemicellulose were key components influencing cell collection. Celluclast® 1.5 L treatment enriched the protein content by 1.65 times in collected mesophyll cells to 50% protein content with a protein recovery of 88%, providing a novel scheme to obtain high-quality leaf protein for the food industry.

Application of Italian ryegrass residue changes the soil biochemical properties and bacterial communities in Southern China

Green manure application is a feasible agricultural practice to effectively improve soil fertility. However, our understanding of the effects and mechanisms of different green manure residue amounts on soil fertility improvement remains insufficient. Regarding a new type of Italian ryegrass (Lolium multiflorum L.)-rice (Oryza sativa L.) rotation (IRR) system in Southern China, the effects of six Italian ryegrass residue amounts (IRR0: 15,700 kg·ha−1, IRR1: 30,700 kg·ha−1, IRR2: 35,400 kg·ha−1, IRR3: 40,100 kg·ha−1, IRR4: 44,800 kg·ha−1, IRR5: 49,500 kg·ha−1) on the soil nutrient contents, soil enzyme activities, and bacterial communities were evaluated. Compared to the CK, appropriate amounts of Italian ryegrass residue application increased total nitrogen (36.45–37.38 %), soil organic carbon (15.34–26.55 %), microbial biomass carbon (14.07–33.93 %) and microbial biomass nitrogen (30.20–47.65 %) (P < 0.05). The activities of soil polyphenol oxidase, urease, β-glucosidase, peroxidase, cellulase, and total enzyme were also improved significantly in comparison with the CK (P < 0.05). Bacterial community structures in response to IRR were different from those in the CK. The application of Italian ryegrass residue significantly enhanced the relative abundance of beneficial taxa, including Acinetobacter, Pseudomonas, and Arenimonas (P < 0.05). The 30,700–35,400 kg·ha−1 Italian ryegrass residue exhibited the most practical amounts for enhancing soil fertility, soil enzyme activities, and altering soil microbial communities, suggesting that the improvement effects of green manure application on soil were dependent on the residue returning amounts. These findings suggest that the returning of Italian ryegrass residue is an effective land management measure to realize efficient and sustainable utilization of paddy fields.

Simultaneous saccharification and fermentation residues as potential sources of phenolics by fast pyrolysis (Py-GC/MS) and alkaline hydrolysis

Unlike 1 G bioethanol, the success of 2 G technology faces difficulties. The economic difficulties of 2 G bioethanol can be solved with an additional income in by-products, mainly from lignin. The present study investigated the generation of phenolics via fast pyrolysis and alkaline hydrolysis using residues from saccharification and simultaneous fermentation (SSF) as substrate. The SSF residues were obtained from schemes with green coconut fiber (without chemical pretreatment) and corn cob (with previous acid pretreatment). Chemical composition, FTIR, and XRD analyses confirmed that the processing undergone by SSF residues altered the lignocellulose structure. Due to extractives removal and lignin increase, the fast pyrolysis experiments with SSF residues favored the generation of phenolics over C1-C4 products. Phenol was the main product in the pyrolysis of untreated green coconut fiber (14.64%) and SSF residue (13.51%), while the 2-methoxy-4-vinylphenol content in the bio-oil was doubled with the SSF corn cob residue (from 12.87% to 27.01%). SSF corn cob residue showed a high yield of hydroxynamic acids after alkaline hydrolysis with sodium hydroxide. The p-coumaric acid yield reached 4337 mg/100 g in experiments at 60 °C. Based on the results, the conversion of SSF residues appears as an alternative to obtain commercially appealing phenolics and may be attractive for 2 G bioethanol technology.