Unveiling the impact of high-pressure processing on anthocyanin-protein/polysaccharide interactions: A comprehensive review.

Anthocyanins, natural plant pigments responsible for the vibrant hues in fruits, vegetables, and flowers, boast antioxidant properties with potential human health benefits. However, their susceptibility to degradation under conditions such as heat, light, and pH fluctuations necessitates strategies to safeguard their stability. Recent investigations have focused on exploring the interactions between anthocyanins and biomacromolecules, specifically proteins and polysaccharides, with the aim of enhancing their resilience. Notably, proteins like soy protein isolate and whey protein, alongside polysaccharides such as pectin, starch, and chitosan, have exhibited promising affinities with anthocyanins, thereby enhancing their stability and functional attributes. High-pressure processing (HPP), emerging as a non-thermal technology, has garnered attention for its potential to modulate these interactions. The application of high pressure can impact the structural features and stability of anthocyanin-protein/polysaccharide complexes, thereby altering their functionalities. However, caution must be exercised, as excessively high pressures may yield adverse effects. Consequently, while HPP holds promise in upholding anthocyanin stability, further exploration is warranted to elucidate its efficacy across diverse anthocyanin variants, macromolecular partners, pressure regimes, and their effects within real food matrices.

Insight into the humification and carbon balance of biogas residual biochar amended co-composting of hog slurry and wheat straw.

The impact of biogas residual biochar (BRB) on the humification and carbon balance process of co-composting of hog slurry (HGS) and wheat straw (WTS) was examined. The 50-day humification process was significantly enhanced by the addition of BRB, particular of 5% BRB, as indicated by the relatively higher humic acid content (67.28 g/kg) and humification ratio (2.31) than other treatments. The carbon balance calculation indicated that although BRB addition increased 22.16-46.77% of C lost in form of CO2-C, but the 5% BRB treatment showed relatively higher C fixation and lower C loss than other treatments. In addition, the BRB addition reshaped the bacterial community structure during composting, resulting in increased abundances of Proteobacteria (25.50%) during the thermophilic phase and Bacteroidetes (33.55%) during the maturation phase. Combined these results with biological mechanism analysis, 5% of BRB was likely an optimal addition for promoting compost humification and carbon fixation in practice.

Synergistic effect of two bacterial strains promoting anaerobic digestion of rice straw to produce methane.

A large amount of agricultural waste causes global environmental pollution. Biogas production by microbial pretreatment is an important way to utilize agricultural waste resources. In this study, Sporocytophaga CG-1 (A, cellulolytic strain) was co-cultured with Bacillus clausii HP-1 (B, non-cellulolytic strain) to analyze the effect of pretreatment of rice straw on methanogenic capacity of anaerobic digestion (AD). The results showed that weight loss rate of filter paper of co-culture combination is 53.38%, which is 29.37% higher than that of A. The synergistic effect of B on A can promote its degradation of cellulose. The cumulative methane production rate of the co-culture combination was the highest (93.04 mL/g VS substrate), which was significantly higher than that of A, B and the control group (82.38, 67.28 and 67.70 mL/g VS substrate). Auxiliary bacteria can improve cellulose degradation rate by promoting secondary product metabolism. These results provide data support for the application of co-culture strategies in the field of anaerobic digestion practices.

Heavy metals drive microbial community assembly process in farmland with long-term biosolids application.

Biosolids are considered an alternative to chemical fertilizers due to their rich nutrients. However, long-term biosolids application can lead to heavy metals accumulation, which severely affects soil microbial community compositions. The factors influencing soil microbial community assembly were explored under a 16-year long-term experiment with biosolids applications. Our results indicated that biosolids application significantly increased fungal richness while not for bacterial and arbuscular mycorrhizal (AM) fungal richness. Besides, biosolids application significantly affected soil bacterial, fungal compositions and AM fungal community. Soil microorganisms were clustered into different modules with bacterial and AM fungal communities were affected by both organic matter and heavy metals, while fungal communities were affected by heavy metals (Cr, Ni, and As). The soil bacterial community assembly was dominated by stochastic processes while the fungal and AM fungal community assemblies were mainly driven by deterministic processes. Random forest analysis showed that heavy metals were identified as major drivers (Hg, Cu, Cd, and Zn for bacteria, Pb and Cr for fungi, and As and Ni for AM fungi) of the community assembly process. Overall, our study highlights the significant role of heavy metals in shaping microbial community dynamics and gives a guide for controlling biosolids application.

Potential and benefits of biochar production: crop straw management and carbon emission mitigation in Shaanxi Province, China.

Shaanxi Province is an important agricultural province in western China. Its profit-oriented management of crop residues remains a concern in the agriculture sector. Aiming to accelerate the valorization of agricultural straw and offer potential solutions for profit-oriented use of crop residues in Shaanxi, this study estimated the quantity of resources and collectable amount of crop straw by using the grain-to-straw ratio, analyzed the carbon emission reduction potential considering biochar energy and soil uses with the help of a life cycle assessment (LCA) model, and calculated the economic benefits of biochar production using waste and abandoned straw in Weinan (a city of Shaanxi). The theoretical resources and collectible amount of crop straw in Shaanxi showed an overall growth trend from 1949 to 2021, reaching 1.47 × 107 and 1.26 × 107 t in 2021 respectively. In 2021, straw from corn, wheat, and other grains accounted for 94.32% of the total straw. Among the 11 cities in Shaanxi, Weinan had the largest straw resources of 2.82 × 106 t, Yulin had the largest per capita straw resources of 0.72 t/person, and Yangling had the highest resource density of 7.60 t/hm2. The total carbon emission reduction was 3.11 × 104 t under scenario A with crop straw used for power generation. The emission reduction ranged from 1.25 × 107 to 1.27 × 107 CO2e t under scenario B with biochar production for energy and soil use. By using waste and abandoned straw in Weinan for biochar production, carbon emissions could be reduced by up to 2.07 × 105 t CO2e. In terms of the economic benefit from straw pyrolysis, the actual income was estimated to range from 0.67 × 108 to 1.33 × 108 ¥/a with different carbon prices. This study sheds light on the economic and environmental benefits of agricultural straw valorization through pyrolysis in Shaanxi, and provided an important basis for promoting the agricultural straw utilization in view of its potential for carbon emission reduction.

Comparison analysis of microbial agent and different compost material on microbial community and nitrogen transformation genes dynamic changes during pig manure compost.

This study aimed to assess the impact of microbial agent and different compost material, on physicochemical parameters dynamic change, nitrogen-transfer gene/bacterial community interaction network during the pig manure composting. Incorporating a microbial agent into rice straw-mushroom compost reduced the NH3 and total ammonia emissions by 25.52 % and 14.41 %, respectively. Notably, rice straw-mushroom with a microbial agent reduced the total ammonia emissions by 37.67 %. NH4+-N and pH emerged as primary factors of phylum-level and genus-level microorganisms. Microbial agent increased the expression of narG, nirK, and nosZ genes. Rice straw-mushroom elevated the content of amoA, nirK, nirS, and nosZ genes. Alcanivorax, Luteimonas, Pusillimonas, Lactobacillus, Aequorivita, Clostridium, Moheibacter and Truepera were identified as eight core microbial genera during the nitrogen conversion process. This study provides a strategy for reducing ammonia emissions and analyzes the potential mechanisms underlying compost processes.

Strategy to enhance the semicontinuous anaerobic digestion of food waste via exogenous additives: experimental and machine learning approaches.

The anaerobic digestion (AD) of food waste (FW) was easy to acidify and accumulate ammonia nitrogen. Adding exogenous materials to the AD system can enhance its conversion efficiency by alleviating acidification and ammonia nitrogen inhibition. This work investigated the effects of the addition frequency and additive amount on the AD of FW with increasing organic loading rate (OLR). When the OLR was 3.0 g VS per L per day and the concentration of the additives was 0.5 g per L per day, the stable methane yield reached 263 ± 22 mL per g VS, which was higher than that of the group without the additives (189 mL per g VS). Methanosaetaceae was the dominant archaea, with a maximum abundance of 93.25%. Through machine learning analysis, it was found that the optimal daily methane yield could be achieved. When the OLR was within the range of 0-3.0 g VS per L per day, the pH was within the range of 7.6-8.0, and the additive concentration was more than 0.5 g per L per day. This study proposed a novel additive and determined its usage strategy for regulating the AD of FW through experimental and simulation approaches.

Exploring carbon conversion and balance with magnetite-amended during pig manure composting.

This study was designed to explore the magnetite in maturation and humification during pig manure (PM) and wolfberry branch fillings (BF) composting. Different proportions of magnetite (T1, 0%; T2, 2.5%; T3, 5%; T4, 7.5%;) were blended with PM for 50 days of composting. The findings indicated magnetite amendment has no influence on the maturity, and the 5% ratio significantly promoted humic acid (HA) formation and fulvic acid (FA) decomposition compared to other treatments. Compared to T1, magnetite addition significantly increased CO2 and CH4 emissions by 106.39%-191.69% and 6.88-13.72 times. The further analysis suggested that magnetite improved Ruminofilibacter activity were significantly positively associated with HA, and C emissions. The further PICRUSt 2 analysis showed membrane transport may enhance environmental information processing by magnetite. Overall, these results demonstrated higher organic matter (OM) degradation and HA formation with an additional increase in microbial activity highlighted advantages of using magnetite during PM composting.

From feedstock to digestion: Unraveling the impact of humic acid composition on anaerobic digestion.

In the anaerobic digestion (AD) process, the effects of humic acid (HA) derived from different feedstocks on AD are influenced by the variations in their structural composition and oxygen-containing functional groups. Thus, clarifying the structural differences of HA obtained from different feedstocks is crucial for understanding their impact on AD. In this study, the structure of five humic acids (HAs) derived from liquid digestate, food waste, silage corn straw, lignite and commercial HA, and their effects on AD were investigated. The study found that HA from food waste had more carboxyl groups, while straw-derived HA had more phenolic hydroxyl groups. Both types of HA had higher aromaticity and humification degree and showed significant inhibition effect on AD. HA from food waste had an average methanogenic inhibition rate of 43.5 % with 1 g/L HA added. In addition, commercial HA and HA derived from lignite had similar functional group types and aromaticity, with an average methanogenic inhibition rate of about 20 %. The study revealed that HAs with more carboxyl groups exhibited greater effectiveness in inhibiting AD, thereby confirming the influence of HA structures derived from different feedstocks on AD. In conclusion, this study provides valuable insights into the mechanism of HA effect on AD and offers guidance for future research focused on enhancing AD efficiency.

Mechanisms and effects of novel ammonifying microorganisms on nitrogen ammonification in cow manure waste composting.

It is essential to reduce nitrogen losses and to improve nitrogen conversion during organic waste composting because of environmental protection and sustainable development. To reveal newly domesticated ammonifying microorganisms (AM) cultures on the ammonification and nitrogen conversion during the composting, the screened microbial agents were inoculated at 5 % concentration (in weight basis) into cow manure compost under five different treatments: sterilized distilled water (Control), Amm-1 (mesophilic fungus-F1), Amm-2 (mesophilic bacterium-Z1), Amm-3 (thermotolerant bacterium-Z2), and Amm-4 (consortium: F1, Z1, and Z2), and composted for 42 days. Compared to control, AM inoculation prolonged the thermophilic phases to 9-19 days, increased the content of NH4+-N to 1.60-1.96 g/kg in the thermophilic phase, reduced N2O and NH3 emissions by 22.85-61.13 % and 8.45-23.29 %, increased total Kjeldahl nitrogen, and improved cell count and viability by 12.09-71.33 % and 66.71-72.91 %. AM was significantly associated with different nitrogen and microbial compositions. The structural equation model (SEM) reveals NH4+-N is the preferable nitrogen for the majority of bacterial and fungal growth and that AM is closely associated with the conversion between NH3 and NH4+-N. Among the treatments, inoculation with Amm-4 was more effective, as it significantly enhanced the driving effect of the critical microbial composition on nitrogen conversion and accelerated nitrogen ammonification and sequestration. This study provided new concepts for the dynamics of microbial in the ammonification process of new AM bacterial agents in cow manure compost, and an understanding of the ecological mechanism underlying the ammonification process and its contribution to nitrogen (N) cycling from the perspective of microbial communities.

Synergetic effect and mechanism of elementary sulphur, MgSO4 and KH2PO4 progressive reinforcement on pig manure composting nitrogen retention.

The potential of sulphur (S), MgSO4 (Mg), and KH2PO4 (P) in nitrogen retention, ammonia emission decrease, and microbial community succession during composting needs to be investigated. To achieve this, different levels of S (0, 0.2, 0.4, 0.6, and 0.8% in dry weight) plus Mg and P (S + Mg + P) were progressively added in 70 days pig manure aerobic composting. The results revealed that the amendment increased salinity and lowered pH and dephytotoxication of the product with the increase of S amount. However, no significant inhibition effects were observed on the evolution of the thermophilic phase and product maturity. In addition, the amendment significantly reduced the total NH3 and N2O emissions by 29.66%-58.81% and 20.6%-56.7%, increased NH4+ level by 17.22%-73.21% in thermophilic phase and NO3- content by 26.17%-57.48% in a mature phase, and elevated the total Kjeldahl nitrogen content by 34.28%-46.6% during the composting. In addition, compared to the control, the supplement markedly encouraged the formation of guanite in the compost product. The S addition stimulated the growth of Anseongella, Actinomadura, Chelativorans, Castellaniella, Luteimonas, and Steroidobacter microbial communities which functioned well in the degradation of nitrogen-containing compounds and organic matter. Evidence from Redundancy Analysis, Firmicutes, Myxococcus, Chloroflexi, Gemmatimonadota, and Deinococcota showed positive correlations with pH. These results imply that adding S-Mg-P amendment encourages the population and activity of specific functional microorganisms, and facilitated the ammonia emission reduction by lowering pH and thus reserved nitrogen through the formation of guanite during composting. The investigation of bacterial community abundance and environmental variables at the phylum and genus levels over time revealed that adding of 0.6% S in conjunction with P and Mg minerals was suitable for nitrogen loss mitigation in composting. The findings suggest using S + Mg + P supplement to conserve nitrogen in pig dung aerobic composting.

Current and emerging applications of saccharide-modified chitosan: a critical review.

Chitin, as the main component of the exoskeleton of Arthropoda, is a highly available natural polymer that can be processed into various value-added products. Its most important derivative, i.e., chitosan, comprising ß-1,4-linked 2-amino-2-deoxy-ß-d-glucose (deacetylated d-glucosamine) and N-acetyl-d-glucosamine units, can be prepared via alkaline deacetylation process. Chitosan has been used as a biodegradable, biocompatible, non-antigenic, and nontoxic polymer in some in-vitro applications, but the recently found potentials of chitosan for in-vivo applications based on its biological activities, especially antimicrobial, antioxidant, and anticancer activities, have upgraded the chitosan roles in biomaterials. Chitosan approval, generally recognized as a safe compound by the United States Food and Drug Administration, has attracted much attention toward its possible applications in diverse fields, especially biomedicine and agriculture. Despite some favorable characteristics, the chitosan's structure should be customized for advanced applications, especially due to its drawbacks, such as low drug-load capacity, low solubility, high viscosity, lack of elastic properties, and pH sensitivity. In this context, derivatization with relatively inexpensive and highly available mono- and di-saccharides to soluble branched chitosan has been considered a "game changer". This review critically scrutinizes the emerging technologies based on the synthesis and application of lactose- and galactose-modified chitosan as two important chitosan derivatives. Some characteristics of chitosan derivatives and biological activities have been detailed first to understand the value of these natural polymers. Second, the saccharide modification of chitosan has been discussed briefly. Finally, the applications of lactose- and galactose-modified chitosan have been scrutinized and compared to native chitosan to provide an insight into the current state-of-the research for stimulating new ideas with the potential of filling research gaps.

Ozonation-pelleting of nitrogen-enriched wheat straw: Towards improved pellet properties, enhanced digestibility, and reduced methane emissions.

The livestock industry needs to use crop straws that are highly digestible to improve feed productivity and reduce ruminal methane emissions. Hence, this study aimed to use the ozonation and pelleting processes to enhance the digestibility and reduce the ruminal methane emissions of wheat straw enriched with two nitrogen sources (i.e., urea and heat-processed broiler litter). Various analyses were conducted on the pellets, including digestibility indicators, mechanical properties, surface chemistry functionalization, chemical-spectral-structural features, and energy requirements. For comparison, loose forms of the samples were also analyzed. The nitrogen-enriched ozonated wheat straw pellets had 43.06 % lower lignin, 28.30 % higher gas production for 24 h, 12.28 % higher metabolizable energy, 13.78 % higher in vitro organic matter digestibility for 24 h, and 28.81 % higher short-chain fatty acid content than the nitrogen-enriched loose sample. The reduction of methane emissions by rumen microorganisms of nitrogen-enriched wheat straw by ozonation, pelleting, and ozonation-pelleting totaled 89.15 %, 23.35 %, and 66.98 %, respectively. The ozonation process resulted in a 64 % increase in the particle density, a 5.5-time increase in the tensile strength, and a 75 % increase in the crushing energy of nitrogen-enriched wheat straw. In addition, ozone treatment could also reduce the specific and thermal energy consumption required in the pelleting process by 15.10 % and 7.61 %, respectively.

Potential application of polysaccharide mucilages as a substitute for emulsifiers: A review.

Mucilages are natural compounds consisting mainly of polysaccharides with complex chemical structures. Mucilages also contain uronic acids, proteins, lipids, and bioactive compounds. Because of their unique properties, mucilages are used in various industries, including food, cosmetics, and pharmaceuticals. Typically, commercial gums are composed only of polysaccharides, which increase their hydrophilicity and surface tension, reducing their emulsifying ability. As a result of the presence of proteins in combination with polysaccharides, mucilages possess unique emulsifying properties due to their ability to reduce surface tension. In recent years, various studies have been conducted on using mucilages as emulsifiers in classical and Pickering emulsions because of their unique emulsifying feature. Studies have shown that some mucilages, such as yellow mustard, mutamba, and flaxseed mucilages, have a higher emulsifying capacity than commercial gums. A synergistic effect has also been shown in some mucilages, such as Dioscorea opposita mucilage when combined with commercial gums. This review article investigates whether mucilages can be used as emulsifiers and what factors affect their emulsifying properties. A discussion of the challenges and prospects of using mucilages as emulsifiers is also presented in this review.

Recent developments in improving the emulsifying properties of chitosan.

Chitosan is one of the valuable products obtained from crustacean waste. The unique characteristics of chitosan (antimicrobial, antioxidant, anticancer, and anti-inflammatory) have increased its application in various sectors. Besides unique biological properties, chitosan or chitosan-based compounds can stabilize emulsions. Nevertheless, studies have shown that chitosan cannot be used as an efficient stabilizer because of its high hydrophilicity. Hence, this review aims to provide an overview of recent studies dealing with improving the emulsifying properties of chitosan. In general, two different approaches have been reported to improve the emulsifying properties of chitosan. The first approach tries to improve the stabilization property of chitosan by modifying its structure. The second one uses compounds such as polysaccharides, proteins, surfactants, essential oils, and polyphenols with more wettability and emulsifying properties than chitosan's particles in combination with chitosan to create complex particles. The tendency to use chitosan-based particles to stabilize Pickering emulsions has recently increased. For this reason, more studies have been conducted in recent years to improve the stabilizing properties of chitosan-based particles, especially using the electrostatic interaction method. In the electrostatic interaction method, numerous research has been conducted on using proteins and polysaccharides to increase the stabilizing property of chitosan.

Chitosan nanocarriers containing essential oils as a green strategy to improve the functional properties of chitosan: A review.

Large amounts of agricultural waste, especially marine product waste, are produced annually. These wastes can be used to produce compounds with high-added value. Chitosan is one such valuable product that can be obtained from crustacean wastes. Various biological activities of chitosan and its derivatives, especially antimicrobial, antioxidant, and anticancer properties, have been confirmed by many studies. The unique characteristics of chitosan, especially chitosan nanocarriers, have led to the expansion of using chitosan in various sectors, especially in biomedical sciences and food industries. On the other hand, essential oils, known as volatile and aromatic compounds of plants, have attracted the attention of researchers in recent years. Like chitosan, essential oils have various biological activities, including antimicrobial, antioxidant, and anticancer. In recent years, one of the ways to improve the biological properties of chitosan is to use essential oils encapsulated in chitosan nanocarriers. Among the various biological activities of chitosan nanocarriers containing essential oils, most studies conducted in recent years have been in the field of antimicrobial activity. It was documented that the antimicrobial activity was increased by reducing the size of chitosan particles in the nanoscale. In addition, the antimicrobial activity was intensified when essential oils were in the structure of chitosan nanoparticles. Essential oils can increase the antimicrobial activity of chitosan nanoparticles with synergistic effects. Using essential oils in the structure of chitosan nanocarriers can also improve the other biological properties (antioxidant and anticancer activities) of chitosan and increase the application fields of chitosan. Of course, using essential oils in chitosan nanocarriers for commercial use requires more studies, including stability during storage and effectiveness in real environments. This review aims to overview recent studies on the biological effects of essential oils encapsulated in chitosan nanocarriers, with notes on their biological mechanisms.

Tree-based machine learning model for visualizing complex relationships between biochar properties and anaerobic digestion.

The ideal conditions for anaerobic digestion experiments with biochar addition are challenging to thoroughly study due to different experimental purposes. Therefore, three tree-based machine learning models were developed to depict the intricate connection between biochar properties and anaerobic digestion. For the methane yield and maximum methane production rate, the gradient boosting decision tree produced R2 values of 0.84 and 0.69, respectively. According to feature analysis, digestion time and particle size had a substantial impact on the methane yield and production rate, respectively. When particle sizes were in the range of 0.3-0.5 mm and the specific surface area was approximately 290 m2/g, corresponding to a range of O content (>31%) and biochar addition (>20 g/L), the maximum promotion of methane yield and maximum methane production rate were attained. Therefore, this study presents new insights into the effects of biochar on anaerobic digestion through tree-based machine learning.

Topological charge-density-vector method of identifying filaments of scroll waves.

Scroll waves have been found in a variety of three-dimensional excitable media, including physical, chemical, and biological origins. Scroll waves in cardiac tissue are of particular significance as they underlie ventricular fibrillation that can cause sudden death. The behavior of a scroll wave is characterized by a line of phase singularity at its organizing center, known as a filament. A thorough investigation into the filament dynamics is the key to further exploration of the general theory of scroll waves in excitable media and the mechanisms of ventricular fibrillation. In this paper, we propose a method to identify filaments of scroll waves in excitable media. From the definition of the topological charge of filaments, we obtain the discrete expression of the topological charge-density vector, which is useful in calculating the topological charge vectors at each grid in the space directly. The set of starting points of these topological charge vectors represents a set of phase singularities, thereby forming a line of phase singularity, that is, a filament of a scroll wave.

Composting pig manure with nano-zero-valent iron amendment: Insights into the carbon cycle and balance.

The effectiveness of nano-zero-valent-iron (NZVI) addition during composting of pig manure (PM) was investigated. Different dosages of NZVI were mixed with PM substrate during a 50 days composting process. The results revealed that the higher share of NZVI addition, the higher OM degradation rate is. On contrary, it was observed that the higher share of NZVI addition, the lower the fulvic acid and the humin degradation rate is. Meanwhile, NZVI amendment increased the CO2 and CH4 emissions by 29-47 % and 53-57 %, respectively. The in-depth analysis showed that NZVI addition increased the activity of Sphaerobacter and Luteimonas, which eventually led to the degradation of hard-to-degrade OM faster. Additionally, NZVI was found to increase the filtration of microorganisms, reducing the toxicity and hygiene of compost products. No significant improvement in humic substance enhancement was observed during composting with NZVI addition but improved OM degradation.