The citrus seeds are one of the principal residues in the juice industry and their utilization can decrease significantly the problems of their final disposal. In this work the thermal degradation of ...three Mexican citrus seeds: orange (
Citrus sinensis), lemon (
Citrus Limon) and grapefruit (
Citrus paradisi) was studied in nitrogen atmosphere. The two components (embryo and husk) of the seeds were characterized separately. The results showed that the thermal effects are very similar between the three embryos and the three husks. The embryos show higher degradability, superior content of nitrogen and higher heating value than the husks. The thermal degradation of the components of the three seeds is completed at 600
°C and it is considered to be a global process derived from the decomposition of their principal components (cellulose, hemicellulose and lignin). The results suggest that mixing the three entire seeds will not lead to a severe deviation from their individual thermal behavior and that the industry could apply them for carbonization purposes.
A new biorefining process is presented that embodies green processing and sustainable development. In the spirit of a true biorefinery, the objective is to convert agricultural residues and other ...biomass feedstocks into value-added products such as fuel ethanol, dissolving pulp, and lignin for resin production. The continuous biomass fractionation process yields a liquid stream rich in hemicellulosic sugars, a lignin-rich liquid stream, and a solid cellulose stream. This paper generally discusses potential applications of the three streams and specifically provides results on the evaluation of the cellulose stream from corn stover as a source of fermentation sugars and specialty pulp. Enzymatic hydrolysis of this relatively pure cellulose stream requires significantly lower enzyme loadings because of minimal enzyme deactivation from nonspecific binding to lignin. A correlation was shown to exist between lignin removal efficiency and enzymatic digestibility. The cellulose produced was also demonstrated to be a suitable replacement for hardwood pulp, especially in the top ply of a linerboard. Also, the relatively pure nature of the cellulose renders it suitable as raw material for making dissolving pulp. This pulping approach has significantly smaller environmental footprint compared to the industry-standard kraft process because no sulfur- or chlorine-containing compounds are used. Although this option needs some minimal post-processing, it produces a higher value commodity than ethanol and, unlike ethanol, does not need extensive processing such as hydrolysis or fermentation. Potential use of low-molecular weight lignin as a raw material for wood adhesive production is discussed as well as its use as cement and feed binder. As a baseline application the hemicellulosic sugars captured in the hydrolyzate liquor can be used to produce ethanol, but potential utilization of xylose for xylitol fermentation is also feasible. Markets and values of these applications are juxtaposed with market penetration and saturation.
In coastal sandy soils, the establishment of a plant cover is fundamental to avoid degradation and desertification processes. A better understanding of the ability of plants to promote soil microbial ...process in these conditions is necessary for successful soil reclamation. The current study was to investigate the ability of four different plant species to regenerate the microbiological processes in the rhizosphere soil and to discuss which species were the most effective for the reclamation of the coastal zone. The rhizosphere soils were studied by measuring microbial abundance (bacteria, fungi, actinomycetes, and ammonifiers), enzyme activities (invertase, catalase, urease, and phosphatase) and their relationship. Microbial abundance greatly varied among rhizospheres of different plant species (p < 0.05). Phragmites australis supported the highest amount of bacterial, actinomycetes, and ammonifiers abundance, and Echinochloa crusgalli supported the highest fungi abundance. In addition, the significant differences in rhizosphere enzyme activities of different plant species were also observed. There was a significant linear correlation between rhizosphere soil microbial abundances and enzyme activities between bacteria and urease and between fungi and catalase, but no such significant relationship was found between all rhizosphere soil microbial abundance and phosphatases. It was concluded that different plant species in coastal areas have different rhizosphere soils due to the impact of the different root exudates and plant residues of the microbial properties. In addition, natural grasslands (P. australis and E. crusgalli) are the most effective for revegetating coastal sandy soils.
An incubation experiment was carried out with maize (
Zea mays L.) leaf straw to analyze the effects of mixing the residues with soil and N amendment on the decomposition process. In order to ...distinguish between soil effects and nitrogen effects for both the phyllospheric microorganisms already present on the surface of maize straw and soil microorganisms the N amendment was applied in two different placements: directly to the straw or to the soil. The experiment was performed in dynamic, automated microcosms for 22 days at 15
°C with 7 treatments: (1) untreated soil, (2) non-amended maize leaf straw without soil, (3) N amended maize leaf straw without soil, (4) soil mixed with maize leaf straw, (5) N amended soil, (6) N amended soil mixed with maize leaf straw, and (7) soil mixed with N amended maize leaf straw.
15NH
4
15NO
3 (5
at%) was added. Gas emissions (CO
2,
13CO
2 and N
2O) were continuously recorded throughout the experiment. Microbial biomass C, biomass N, ergosterol, δ
13C of soil organic C and of microbial biomass C as well as
15N in soil total N, mineral N and microbial biomass N were determined in soil samples at the end of the incubation. The CO
2 evolution rate showed a lag-phase of two days in the non-amended maize leaf straw treatment without soil, which was completely eliminated when mineral N was added. The addition of N generally increased the CO
2 evolution rate during the initial stages of maize leaf straw decomposition, but not the cumulative CO
2 production. The presence of soil caused roughly a 50% increase in cumulative CO
2 production within 22 days in the maize straw treatments due to a slower decrease of CO
2 evolution after the initial activity peak. Since there are no limitations of water or N, we suggest that soil provides a microbial community ensuring an effective succession of straw decomposing microorganisms. In the treatments where maize and soil was mixed, 75% of microbial biomass C was derived from maize. We concluded that this high contribution of maize using microbiota indicates a strong influence of organisms of phyllospheric origin to the microbial community in the soil after plant residues enter the soil.
Herb decoctions—the aqueous extract of rosemary, sage and thyme, left as by-product after steam distillation of essential oils, were investigated as a source of antioxidants in marinades for turkey ...thigh meat. Lipid oxidation after marinating, cooking and chill storage (warmed over flavour, WOF) was assessed by thiobarbituric acid-reactive substances (TBARS), GC-MS and sensory judgement on marinated and untreated meat. Results showed that marinating with herb decoctions, which exerted antioxidant activity (free radical scavenging), was an effective means of retarding lipid oxidation in raw and cooked meat. Meat from the rosemary marinade had the lowest TBARS values and volatile levels, while the control samples showed the highest values throughout the marinating, cooking and storage period. Oxidative changes in meat marinated with thyme and sage were significantly more advanced than in meat marinated with rosemary decoction. The partial least squares regression (PLS-R) showed that control samples were strongly related to the oxidation variables (volatiles, TBARS, rancidity) while the marinated meat had high scores for spicy and acidic odour and flavour. Results indicated that antioxidants contained in herb decoction, could be exploited in marinades to prevent rancidity in stored, heat-treated turkey meat products.
The presence of foreign matter in cotton seriously affects the cotton grade and thus the price per bale paid by the spinner to the grower, the efficiency of the spinning and ginning operations, and ...the quality of the final woven product. Rapid identification of the nature of the extraneous matter in cotton at each stage of cleaning and processing is necessary to permit actions to eliminate or reduce its presence and improve efficiency and quality. Although several instruments are being successfully employed for the measurement of contamination in cotton fibers based on particle size/weight, no commercial instrument is capable of accurate qualitative identification of contaminants. To this end, ATR/FT-IR spectra of retrieved foreign matter were collected and subsequently rapidly matched to an authentic spectrum in a spectral database. The database includes contaminants typically classified as “trash”, cotton plant parts (hull, shale, seed-coat fragments, bract, cacyx, leaf, bark, sticks, and stems) and grass plant parts (leaf and stem); “foreign objects and materials”, synthetic materials (plastic bags, film, rubber, bale wrapping and strapping); organic materials (other fibers, yarns, paper, feathers, and leather); plus entomological and physiological sugars and inorganic materials (sand and rust). The spectral matching resulted in consistently high-score identification of the foreign matter based on chemical composition, irrespective of its particle size. The method is envisioned to be employed with stand-alone rugged infrared instrumentation to provide specific identification of extraneous materials in cotton as opposed to only general classification of the type by particle size or shape. Keywords: Attenuated total reflectance; mid-infrared; FT-IR; spectral matching; upland cotton (Gossypium hirsutum L.); Pima cotton (Gossypium barbadense L.); cotton trash; foreign matter; ginning; spinning
Elephant grass and castor cake when combined can make a promising organic fertilizer. However, castor cake contains potentially toxic chemicals, such as ricin and ricinine. To test potential effects ...of these chemicals, compost piles of elephant grass ( Pennisetum purpureum Schum.) with castor cake were prepared with different C:N ratios (T1 = 40, T2 = 30, T3 = 20; T4 = 30 control, elephant grass + crotalaria) to evaluate colonization by edaphic fauna and any suppressive effects of castor cake. Soil organisms were collected with Berlese-Tullgren funnels. There were temporal differences between the treatments, and the epigeous fauna was mainly represented by members of the Acari and Entomobryomorpha. Elapsed time is the major factor in determining the composition of the epigeous fauna community associated with composting, indicating that castor cake has no suppressive effect.
RESUMO: O composto inteiramente vegetal, a partir da mistura de capim elefante e torta-de-mamona, apresenta-se promissor como adubo orgânico. No entanto, há preocupações quando se consideram os compostos químicos potencialmente tóxicos contidos na torta-de-mamona, como a ricina e ricinina. Assim, foram montadas pilhas de compostagem com diferentes relações C:N (T1 = 40; T2 = 30; T3 = 20; T4 = 30 (tratamento controle composto por Capim elefante + crotalária )) com o objetivo de avaliar, ao longo do tempo, a colonização da fauna edáfica e se a torta-de-mamona causa algum efeito supressor. A avaliação foi realizada com funis de Berlese-Tullgren. Houve diferenças pontuais entre os tratamentos, sendo a fauna epígea representada principalmente pelos grupos Acari e Entomobryomorpha. Verificou-se que o tempo é o principal fator na determinação da comunidade de fauna epígea associada à compostagem, indicando que o uso da torta-de-mamona não tem efeito supressor sobre a fauna edáfica ao longo do processo de compostagem.
The content and chemical forms of P in compost are essential variables for its proper management with an agricultural purpose, especially considering the increasing P over-fertilization in ...agrosystems. In this study, the estimation of P content and dynamics in different composting scenarios was developed using near infrared reflectance spectroscopy (NIRS) coupled with a statistical tool for calibration, a penalized signal regression. Samples were analyzed on total P and partitioned using NaOH-solution
31P NMR spectroscopy quantifying pyrophosphate, orthophosphate, orthophosphate diesters, phospholipids, and orthophosphate monoesters pools. According to the results obtained, total P content (
r
2
=
0.99 and root mean square error of cross-validation
=
0.53) and P forms can be estimated during composting using NIRS, as well as in the mature product, orthophosphate and orthophosphate monoesters being the most abundant P forms throughout the experiment. Penalized signal regression allows detecting the significant wavenumbers in each composting period, and also with the different P pools in the composting pile depending on time.
Mechanically deboned meat (MDM) contains about 10 times more polyunsaturated fatty acids (PUFAs) and also more hemoproteins than hand deboned meat (HDM) and is essentially more susceptible to both ...chemical and biochemical oxidation. The oxidation, leading to the formation of potentially mutagenic and carcinogenic derivatives of PUFAs, can be inhibited by berry extracts rich in antioxidant polyphenols. Using the 2-thiobarbituric acid reactive substances (TBARS) method, we have established that the ethanol slurry of the juice-free solid residue of sea buckthorn (
Hippophae rhamnoides – SB) berries inhibits oxidation of unsaturated fatty acids, of both chicken and turkey MDM. The polyphenols, mainly flavonols, responsible for this inhibition, are comparatively stable during short-term cooking and 6-day storage of cooked SB-MDMs at +6
°C. About half of the polyphenols are lost, obviously oxidised, during the storage of the uncooked samples of turkey 2%SB-MDM at +6
°C. The loss of polyphenols is much smaller in the case of chicken MDM, which is characterised by an
in situ lower content of fatty acids, including the polyunsaturated ones. The liquid chromatography–diode array detection–tandem mass spectrometry (LC–DAD–ESI-MS/MS) method was used for identification and ranking of the potent polyphenolic antioxidants in the berry residue.
Earlier versions of the Revised Universal Soil Loss Equation, version 2 (RUSLE2) calculated vegetative residue production only during periods of canopy decline or in response to management ...operations. This resulted in underestimation of residue amounts and overestimation of soil erosion from pasture and hay lands. To solve this problem, new vegetation routines were implemented in RUSLE2. These modifications were designed to better reflect the amount of residue added by perennial vegetation during its growth and to make it is easier to model haying and grazing scenarios. The new routines were based on the assumption that all unharvested aboveground biomass growth will die after its life span is reached, and this biomass will be added to a standing residue pool. Trained specialists can define the characteristics of a vegetation assemblage in terms of total annual potential production under good management, monthly production percentages reflecting expected fertility and irrigation levels, average vegetation lifespan, maximum canopy height, cutting height for optimal yield, and the tendency of the vegetation to thicken at lower heights (form a sod) in response to repeated defoliations. Users will specify actual harvest management and an underlying model predicts plant growth responses in terms of the amount of harvested forage and the amount of above- and belowground residues returned to the soil. The USDA-NRCS is developing extensive databases so that the new version of RUSLE2 will allow erosion estimates to be a factor considered as part of forage and grazing planning.
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