Utilizing peanut husk (Arachis hypogaea L.) in the manufacture of medium-density fiberboards

The main objective of this study was to investigate the potential of peanut husk (Arachis hypogaea L.) as a fiber–peanut mixture to produce fiberboards for general purposes. For panel production, the addition of peanut husk at various percentages to the wood fiber was the only variable. Panels produced utilizing peanut husk were compared to panels produced using 100% wood fiber. The chemical properties of peanut husk; holocellulose and lignin content, alcohol–benzene, hot and cold water, and dilute alkali (1% NaOH) solubility, were also determined. Results indicated that panels could be produced utilizing up to 30% peanut husk without affecting the usability of the panels. It was not possible to meet the minimum IB strength standards when peanut husk was added to the mixture. Higher additions resulted in panels having lower elastic and rupture moduli than the minimum requirements according to TS-EN standards.     

Characterization of humic materials extracted from hazelnut husk and hazelnut husk amended soils

This study was carried out to determine effects of composted hazelnut husk (CHH) on some chemical properties of soil and soil humic acid (HA). Compost application increases organic matter (OM) content of the soil considerably, OM value of 3.18% became 3.89% in 3 years time interval. Before application of compost, the soil pH was found to be 5.37, while after compost application it became 5.61. FTIR characteristics of humic acid/humic acid-like materials extracted from the original hazelnut husk, composted hazelnut husk and composted hazelnut husk amended soil have been investigated. C and O content of humic acid-like/humic acid materials were in the range of 41.4–50.8% and 37.8–50.5%, respectively. The N content of the humic acid/humic acid-like materials are in the expected range for humic materials which is 2–6%. Comparison of FTIR spectra of hazelnut husk and composted hazelnut husk humic acid-like fractions shows that both exhibit similar but not identical series of IR bands indicating the presence of the same functional groups in both samples. The only difference in the spectra seemed to be a decrement in the peak intensities of composted sample compared to uncomposted one. The similar differentiation of the intensities of IR bands of compost applied soil sample has also been observed. The FTIR spectral results show that the characteristics of composted material tend to become similar to that of soil humic acids characteristics in time.     

Influences of composted hazelnut husk on some physical properties of soils

Some physical properties of clay loam and sandy loam soils amended with hazelnut husk (HH) were investigated. HH collected from hazelnut trees were dried, ground and composted for four months. Before use the composted material obtained was separated to three different aggregate sizes, smaller than 0.84 mm, 0.84-2.38 mm and bigger than 2.38 mm. Then these fractions were mixed with soil samples, at 0%, 1%, 2%, 4% and 8% by weight.Huzelnut husk compost-soil mixtures were placed to plastic pots and kept in an incubator at 25+/-5 degrees C for 45 and 90 days. At the end of incubation periods, water stable aggregate (WSA), hydraulic conductivity, total porosity, aeration porosity and macro- and micro-pore percentages of the mixtures were determined. Results obtained showed that composted HH increased the WSA, hydraulic conductivity, total porosity and macro-pore percentage in both clay loam and sandy loam soils depending on the incubation time and aggregate sizes.     

Risk Attitudes of Organic and Conventional Hazelnut Producers in Turkey

Understanding farmers’ attitudes and responses to agricultural risks is important for designing financial support services and effective extension activities. Risk attitudes of farmers are also one of the critical barriers for conversion to organic agriculture. Few studies have been conducted to explore and compare risk perceptions between organic and conventional farmers. The purposes of this research were to elicit and compare the risk attitudes of organic and conventional Turkish hazelnut producers and to determine the barriers additional to their risk attitudes toward conversion to organic agriculture in the Terme district of Samsun, Turkey. The Equally Likely Certainty Equivalent (ELCE) model was used to elicit responses from producers. The data used in this study were collected by using a structured questionnaire administered to both 64 randomly selected conventional hazelnut producers and all organic hazelnut producers (39) in the research area. Research results revealed that organic hazelnut producers were less risk averse than conventional producers. It was also found that the variables of education level of operators, farm income, total assets, time allocated outside the farm, farm land area, size of hazelnut orchard, number of hazelnut plots, and total information score were other barriers for conversion to organic hazelnut production, in addition to the producers’ risk attitudes. Providing better extension services and farmers’ training activities relating to organic agriculture and land consolidation, focusing on raising the educational level of producers, facilitating producers with greater access to credit to increase farm land and to enhance farm assets are factors that may accelerate the process of conversion to organic hazelnut production.     

不同品种(系)榛子坚果表型性状差异性分析及其综合评价

该研究以目前主栽的平榛、毛榛及25个平欧杂种榛品种(系)的坚果为研究对象,测定了不同品种(系)榛子坚果的17个表型性状指标,用方差分析、相关性分析、聚类分析和主成分分析方法对其进行差异性分析和综合评价,为国内榛树品种(系)的选优、开发及加工利用提供科学依据。结果表明：(1)不同品种(系)榛子坚果的17个表型性状指标存在显著差异,其中果壳质量、坚果体积和坚果质量差异最为明显,变异系数分别为31.49%、30.44%、27.50%,横纵径比、果形指数、伸长率、圆球度的变异系数均小于10%。(2)平欧杂种榛坚果的纵径、横径、侧径及坚果质量、果仁质量、出仁率等指标显著优于毛榛和平榛,其中杂种榛的平均果仁质量(0.70～1.46 g)和出仁率(31.48%～56.12%)显著高于平榛(0.51 g、35.13%)和毛榛(0.37 g、38.12%)。(3)榛子坚果表型性状指标间的相关性分析表明,榛子坚果体积越大,其质量和果仁质量也越大,果壳越薄则出仁率更高。(4)主成分分析结果发现,影响榛子坚果综合得分的主要指标为坚果的纵径、横径、侧径、质量和果仁质量,其次是果形指数、横纵径比、出仁率、果仁饱满...     

Isolation of potato proteins using simulated moving bed technology

The simulated moving bed (SMB) concept of chromatography was applied to treat potato juice from production of starch. The aim was to harvest proteins. SMB offers possibilities to operate with different process strategies and in this study it was shown possible to harvest up to 80% of the protein in a process utilizing very little extra water besides that already present in the juice. After depleting protein from the juice in the adsorption step, the flow through was used to recondition the column after elution. The present study illustrates a new concept of applying chromatography as a capturing step of bulk products.     

Dehydrogenase activity in Lumbricus terrestris casts and surrounding soil affected by addition of different organic wastes and Zn

A laboratory experiment was conducted to determine the effects of different organic wastes such as wheat straw (WS), tea production waste (TEW), tobacco production waste (TOW), cow manure (CM) and hazelnut husk (HH) on dehydrogenase activity (DHA) in casts of earthworm Lumbricus terrestris and surrounding soil using 5% (dry weight) application rates associated with increasing doses of Zn (0, 50, 100, 250, 500 and 1000 microg g(-1)). Twenty one days after treatment of Zn and organic wastes, the DHA analyses were carried out on collected casts and soil samples. In general, all organic waste treatments influenced the DHA, the contents of organic C, N and available Zn in earthworm L. terrestris casts and the surrounding soil in comparison with the control. DHA in casts exceeded that in the surrounding soil without Zn additions. After Zn application of 50 microg Zn g(-1) in all organic waste treatments and the control, the DHA level in casts and surrounding soil increased significantly. It decreased by application rates of 100, 250, 500 and 1000 microg Zn g(-1) consecutively in all organic waste applications. The addition of wastes with low C/N ratio and high Zn content (TEW, TOW, CM) inhibited the DHA in both cast and surrounding soil.     

New and different lignocellulosic materials from Turkey for laccase and manganese peroxidase production by Trametes versicolor

In the present study, the production of laccase (Lac) and manganese‐dependent peroxidase (MnP) by the white‐rot fungus Trametes versicolor grown in submerged cultures with different agricultural residues was investigated. The lignocellulosic materials studied were almond shells, hazelnut husks, sunflower stems, clover straw and hazelnut cobs, because they are common agricultural wastes in Turkey. Among the different lignocellulosic materials studied, hazelnut cobs provided the highest Lac and MnP activities (47.09 and 109.21 U/L, respectively). The optimum conditions were determined for Lac and MnP production in submerged cultures of T. versicolor by using hazelnut cobs as substrate. For Lac production, the optimum incubation time, hazelnut cob concentration, pH, and shaking rate were found as 4 days, 2% w/v, 6.0 and 130 rpm, respectively. For MnP production, the optimum incubation time, hazelnut cob concentration, pH and shaking rate were found as 5 days, 2% w/v, 6.0 and 90 rpm, respectively.     

Improved enzyme production by bio-pellets of Aspergillus niger: targeted morphology engineering using titanate microparticles

The present study describes the design of bio-pellet morphologies of the industrial working horse Aspergillus niger strains in submerged culture. The novel approach recruits the intended addition of titanate microparticles (TiSiO(4), 8 μm) to the growth medium. As tested for two recombinant strains producing fructofuranosidase and glucoamylase, the enzyme titer by the titanate-enhanced cultures in shake flasks was increased 3.7-fold to 150 U/mL (for fructofuranosidase) and 9.5-fold to 190 U/mL (for glucoamylase) as compared to the control. This could be successfully utilized for improved enzyme production in stirred tank reactors. Stimulated by the particles, the achieved final glucoamylase activity of 1,080 U/mL (fed-batch) and 320 U/mL (batch) was sevenfold higher as compared to the conventional processes. The major reason for the enhanced production was the close association between the titanate particles and the fungal cells. Already below 2.5 g/L the micromaterial was found inside the pellets, including single particles embedded as 50-150 μm particle aggregates in the center resulting in core shell pellets. With increasing titanate levels the pellet size decreased from 1,700 μm (control) to 300 μm. Fluorescence based resolution of GFP expression revealed that the large pellets of the control were only active in a 200 μm surface layer. This matches with the critical penetration depth for nutrients and oxygen typically observed for fungal pellets. The biomass within the titanate derived fungal pellets, however, was completely active. This was due a reduced thickness of the biomass layer via smaller pellets as well as the core shell structure. Moreover, also the created loose inner pellet structure enabled a higher mass transfer and penetration depths for up to 500 μm. The creation of core-shell pellets has not been achieved previously by the addition of microparticles, for example, made of talc or alumina. Due to this, the present work opens further possibilities to use microparticles for tailor-made morphology design of filamentous fungi, especially for pellet based processes which have a long and strong industrial relevance for industrial production.     

A novel approach for the production of natural aroma compounds using agro-industrial residue

Experiments were carried out to study the production of aroma compounds from coffee husk by a fungal culture of C. fimbriata in solid state fermentation. Hot water treated coffee husk seemed to be useful substrate for aroma production in comparison to whole coffee husk or its water extract. Raw data were integrated in order to calculate the total volatiles (TV) accumulated during the fermentation using the Gompertz model. Glucose addition between 20-35% increased significantly the yields of aroma compounds. Supplementation of leucine further improved the TV production significantly (about 58%), specially the esters. When soybean oil was added, TV production was similar to the control, showing that the fungus was not able to use soybean oil for its primary metabolism, nor it acted as precursor for the synthesis of methyl ketones as reported for other fungi. Addition of saline solution drastically decreased the volatile production. Under optimized conditions, a total of 13 compounds were produced which included alcohols (2), aldehyde (1), ketones (2) and esters (8). Ethyl acetate was the prominent compound, followed by ethanol.     

Production of activated carbon from bagasse and rice husk by a single-stage chemical activation method at low retention times

The production of activated carbon from bagasse and rice husk by a single-stage chemical activation method in short retention times (30-60min) was examined in this study. The raw materials were subjected to a chemical pretreatment and were fed to the reactor in the form of a paste (75% moisture). Chemicals examined were ZnCl2, NaOH and H3PO4, for temperatures of 600, 700 and 800 degrees C. Of the three chemical reagents under evaluation only ZnCl2 produced activated carbons with high surface areas. BET surface areas for rice husk were up to 750m2/g for 1:1 ZnCl2:rice husk ratio. BET surface areas for bagasse were up to 674m2/g for 0.75:1 ZnCl2:bagasse ratio. Results were compared to regular two-stage physical activation methods.     

Optimization of conditions for the production of lignocellulolytic enzymes by Sphingobacterium sp. ksn-11 utilizing agro-wastes under submerged condition

Abstract

The present work was aimed at studying the production of lignocellulolytic enzymes, namely cellulase, xylanase, pectinase, mannanase, and laccase by a newly isolated bacterium Sphingobacterium sp. ksn-11, utilizing various agro-residues as a substrate under submerged conditions. The production of lignocellulolytic enzymes was found to be maximum at the loading of 10%(w/v) agro-residues. The enzyme secretion was enhanced by two-fold at 2?mM CaCO_3, optimum pH 7, and temperature 40°. The Field Emission Gun-Scanning Electron Microscope (FEG-SEM) results have shown the degradative effect of lignocellulases; cellulase, xylanase, mannanase, pectinase, and laccase on corn husk with 3.55?U/ml, 79.22?U/ml, 12.43?U/ml, 64.66?U/ml, and 21.12?U/ml of activity, respectively. The hydrolyzed corn husk found to be good adsorbent for polyphenols released during hydrolysis of corn husk providing suitable conditions for stability of lignocellulases. Sphingobacterium sp. ksn is proved to be a promising candidate for lignocellulolytic enzymes in view of demand for enzymes in the biofuel industry.     

Use of various coffee industry residues for the cultivation of Pleurotus ostreatus in solid state fermentation

Studies were carried out to evaluate the feasibility of using coffee industry residues, viz. coffee husk, coffee leaves and spent coffee ground as substrates in solid state fermentation (SSF) to cultivate edible mushrooms Pleurotus. Eight strains of Pleurotus ostreatus and two strains of Pleurotus sajor‐caju were screened on a medium prepared from aqueous extract of coffee husk and agar. Based on best mycelial growth (9.68 mm/day) and biomass production (43.4 mg/plate in 9 days at 24°C), the strain P. ostreatus LPB 09 was selected for detailed studies. SSF was carried out using these substrates under different moisture conditions (45–75%) and spawn rates (2.5–25%). In general, although a 25% spawn rate appeared superior, the 10% spawn rate was recommended for all the three substrates in view of the process economics, as there was not any significant difference in the increase with 10 to 15%. The ideal moisture content for mycelial growth was 60–65% for coffee husk and spent coffee ground, and 60–70% for coffee leaves. The biological efficiency (BE), which is defined as the ratio of the weight of fresh fruiting bodies to the weight of dry substrate, multiplied by 100, and which indicates the fructification ability of the fungus for utilizing the substrate, was best with coffee husk. With coffee husk as the substrate, the first fructification occurred after 20 days of inoculation, and the biological efficiency reached about 97% after 60 days. When coffee leaves were used as the substrate, no fructification was observed even upon prolonged cultivation. With spent ground as the substrate, the first fructification occurred 23 days after inoculation and the biological efficiency reached about 90% in 50 days. There was a significant decrease in the caffeine and tannin contents (61 and 79%, respectively) of coffee husk after 60 days. It was remarkable to observe that caffeine was adsorbed onto the fruiting body (0.157%), indicating that it was not completely degraded by the fungal culture. However, no tannins were found in the fruiting body, indicating that the fungal strain was capable of degrading them. The results showed the feasibility of using coffee husk and spent coffee ground as substrates without any pre‐treatment for the cultivation of edible fungi in SSF, and provided one of the first steps towards an economical utilization of these otherwise unutilized or poorly utilized residues.     

Early nut development as a resistance factor to the attacks of Curculio nucum (Coleoptera: Curculionidae)

The nut weevil Curculio nucum (Coleoptera: Curculionidae) is responsible for high yield losses in several hazelnut‐growing areas of Europe and Turkey, if not regularly controlled using pesticides. The resistance of hazelnut varieties to the nut weevil is known but poorly investigated so far. Thus a 2‐year study was carried out to investigate factors affecting C. nucum attacks on two cultivars [Tonda Gentile delle Langhe (TGL), Ennis] and four selections (Daria, 101, B6, L35) in a 15‐year‐old orchard of northwestern Italy. Nut developmental stages and shell characteristics, such as hardness and thickness, were measured and correlated to the biological cycle of the nut weevil and to the damage by its larvae. During the 2‐year sampling, nut weevil adults were collected on all cultivars and selections, but in greater quantities on TGL and Daria, and in lower quantities on 101 and B6. In 2005, by female dissection, mature eggs were observed from late June, when the mean temperature exceeded 18°C. Differences between cultivars and selections were found in nut and kernel development, and in shell hardening; in particular, the kernel development was directly related with the shell hardness. At harvest, the damage varied on average from 2.57% in cultivar TGL to 51.84% in selection 101 of total nuts harvested, so independently of the numbers of the collected weevil adults. These two varieties were the earliest and the latest in kernel development and shell hardening, respectively. Therefore, the susceptibility to nut weevil attacks was strictly related to shell hardening; in fact, a rapid hardening of the shell can hamper the oviposition of C. nucum females. By contrast, no correlation was found between shell thickness and damage at harvest.     

Degradation of toxaphene by Bjerkandera sp. strain BOL13 using waste biomass as a cosubstrate

The white-rot fungus Bjerkandera sp. strain BOL13 was capable of degrading toxaphene when supplied with wood chips, wheat husk or cane molasses as cosubstrates in batch culture experiments. Approximately 85% of toxaphene was removed when wheat husk was the main substrate. The production of lignin peroxidase was only stimulated when wheat husk was present in the liquid medium. Although xylanase was always detected, wheat husk supported the highest xylanase production. A negligible amount of β-glucosidase and cellulase were found in the batch culture medium. To the best of our knowledge, this is the first reported case of toxaphene degradation by white-rot fungi.     

Hazelnut husk as a substrate for the cultivation of shiitake mushroom (Lentinula edodes)

The possibility of using hazelnut husk (HH) as a new basal ingredient for substrate preparation in Lentinula edodes cultivation was investigated. Some chemical properties of the substrates prepared by HH alone and its mixtures with wheat straw (WS), beech wood-chip (BWC) and wheat bran (WB) in different ratios were compared, and their effects on spawn run time, days to first harvest (earliness), yield and biological efficiency (BE) were determined. The N content of the substrate prepared from HH alone was very high (0.82%), and thus the C:N ratio of substrates decreased with an increase in the rate of HH in the mixtures. Yield and BE in the HH alone substrate was considerably low compared with the controls (80BWC:10WS:10M and 60BWC:20WS:20WB), and decreased with an increase in the rate of HH in the mixtures. However, when the HH content in the mixtures was kept below 50%, the yield was relatively high (50HH:50WS and 50HH:50BWC). Even when the HH content increased to 75% in the mixture, the comparable yield and BE to the controls could be obtained by adding 10% of WB as nutrients (75HH:15WS:10WB and 75HH:15BWC:10WB). The results revealed that HH could be used as a new basal ingredient for substrate preparation in L. edodes cultivation.     

Polycyclic aromatic hydrocarbons (PAHs) in bio-crudes from induction-heating pyrolysis of biomass wastes

The aim of this work was to prepare the bio-crudes from agricultural wastes (i.e., rice straw, rice husk, sugarcane bagasse and coconut shell) by using induction-heating pyrolysis at specified conditions. The quantitative analysis of 21 priority pollutant polycyclic aromatic hydrocarbons (PAHs) in bio-crudes examined using gas chromatography/mass spectrometry (GC/MS) revealed that the PAHs in bio-crudes were primarily dominant in the low molecular weight (LMW) PAHs, including naphthalene (1.10-2.45 mg/L) and acenaphthene (0.72-7.61 mg/L). However, by considering carcinogenic potency, the bio-crudes from rice husk and sugarcane bagasse contained higher contents of benzo[a]pyrene (BaP) (0.52 and 0.92 mg/L, respectively) as compared to those from rice straw and coconut shell.     

Production, statistical optimization and application of endoglucanase from Rhizopus stolonifer utilizing coffee husk

Coffee cherry husk (CH) is one of the major by-products obtained from coffee processing industry and accounts to 43 ± 5.9 % of cellulose. Screening of fungal organism for cellulase production was carried out and the potential organism was identified as Rhizopus stolonifer by internal transcribed spacer’s (ITS)—5.8S rDNA analysis. A systematic study with response surface methodology (RSM) based on CCRD was used to study the interactions among the variables such as pH (3–7), moisture (40–80 %) and progression duration (72–168 h) of the fermentation process to maximize the enzyme production. Under the optimized cultivation condition, R. stolonifer synthesized 22,109 U/gds. Model validations at optimum operating conditions showed excellent agreement between the experimental results and the predicted responses with a confidence level of 95 %. Endoglucanase thus produced was utilized for ethanol production by simultaneous saccharification and fermentation and maximum of 65.5 g/L of ethanol was obtained. This fungal cellulase has also reported to be efficient detergent additives and promising for commercial use. The present study demonstrates coffee husk as a significant bioprocess substrate. Statistical optimization with major parameters for cellulase production can be highly applicable for industrial scale. Furthermore, value addition to coffee husk with sustainable waste management leading to environment conservation can be achieved.     

Investigation of ash deposition in a pilot-scale fluidized bed combustor co-firing biomass with lignite

This study presents the results from investigation of ash deposition characteristics of a high ash and sulfur content lignite co-fired with three types of biomass (olive residue, 49 wt%; hazelnut shell, 42 wt%; and cotton residue, 41 wt%) in 0.3 MW(t) Middle East Technical University (METU) Atmospheric Bubbling Fluidized Bed Combustion (ABFBC) Test Rig. Deposit samples were collected on an air-cooled probe at a temperature of 500 degrees C. Samples were analyzed by SEM/EDX and XRD methods. The results reveal that co-firing lignite with olive residue, hazelnut shell and cotton residue show low deposition rates. High concentrations of silicon, calcium, sulfur, iron, and aluminum were found in deposit samples. No chlorine was detected in deposits. Calcium sulfate and potassium sulfate were detected as major and minor components of the deposits, respectively. High sulfur and alumina-silicate content of lignite resulted in formation of alkali sulfates instead of alkali chlorides. Therefore, fuel blends under consideration can be denoted to have low-fouling propensity.