Artichoke Residues Research Articles

Novel Nanomaterials Made of Humic Substances from Green Composts and Chitosan Exerting Antibacterial Activity

Green compost represents a sustainable source of humic substances (HS), which are supramolecular associations of heterogeneous natural compounds bearing a variety of functional groups. Novel humic-chitosan nanoconjugates (NC) were synthesized by using HS from three green composts [coffee husks (HS-COF), artichoke residues (HS-CYN), and fennel residues (HS-FEN)]. Solid-state NMR spectra showed that HS-CYN and HS-FEN contained the largest relative amount of polysaccharidic and phenolic carbons, whereas HS-COF had the greatest relative content of alkyl and carboxyl groups. While size and z-potential of NC depended upon the HS origin, NC-HS-FEN revealed the greatest thermal stability, followed by NC-HS-CYN and NC-HS-COF. Scanning electron microscopy and transmission electron microscopy analyses suggested the formation of spherical nanoparticles only for NC-HS-FEN and NC-HS-CYN. This was explained by more stable conformations of HS-FEN and HS-CYN that enabled regular spherical nanoparticles, as assessed by high-pressure size-exclusion chromatography measurements. NC bioactivity against bacterial human pathogens was strain-specific, and the inhibition of bacterial development was attributed to the positive z-potentials that facilitated NC adhesion on bacterial cell walls, smaller nanosizes favoring cell penetration, and subsequent release in the cell of NC toxic components that altered microbial biochemical functions. This study indicates that not only novel NCs can be obtained by humic matter derived from recycled biomass, such as green compost, but they can also be employed as effective and sustainable antimicrobial agents.

Bioethanol Production from Globe Artichoke Residues: from the Field to the Fermenter

Bioethanol Production from Globe Artichoke Residues: from the Field to the Fermenter

A study on structural evolution of hybrid humic Acids-SiO2 nanostructures in pure water: Effects on physico-chemical and functional properties

Humic acids (HA) are considered a promising and inexpensive source for novel multifunctional materials for a huge range of applications. However, aggregation and degradation phenomena in aqueous environment prevent from their full exploitation. A valid strategy to address these issues relies on combining HA moieties at the molecular scale with an inorganic nanostructured component, leading to more stable hybrid nanomaterials with tunable functionalities. Indeed, chemical composition of HA can determine their interactions with the inorganic constituent in the hybrid nanoparticles and consequently affect their overall physico-chemical properties, including their stability and functional properties in aqueous environment. As a fundamental contribution to HA materials-based technology, this study aims at unveiling this aspect. To this purpose, SiO2 nanoparticles have been chosen as a model platform and three different HAs extracted from composted biomasses, manure (HA_Man), artichoke residues (HA_Art) and coffee grounds (HA_Cof), were employed to synthetize hybrid HA-SiO2 nanoparticles through in-situ sol-gel synthesis. Prepared samples were submitted to aging in water to assess their stability.Furthermore, antioxidant properties and physico-chemical properties of both as prepared and aged samples in aqueous environment were assessed through Scanning Electron Microscopy (SEM), N2 physisorption, Simultaneous Thermogravimetric (TGA) and Differential Scanning Calorimetric (DSC) Analysis, Fourier Transform Infrared (FT-IR), Nuclear Magnetic Resonance (NMR), Electron Paramagnetic Resonance (EPR) spectroscopies.The experimental results highlighted that hybrid HA-SiO2 nanostructures acted as dynamic systems which exhibit structural supramolecular reorganization during aging in aqueous environment with marked effects on physico-chemical and functional properties, including improved antioxidant activity. Obtained results enlighten a unique aspect of interactions between HA and inorganic nanoparticles that could be useful to predict their behavior in aqueous environment.Furthermore, the proposed approach traces a technological route for the exploitation of organic biowaste in the design of hybrid nanomaterials, providing a significant contribution to the development of waste to wealth strategies based on humic substances.

Fate of Nitrogen from Artichoke (Cynara cardunculus L. var. scolymus (L.)) Crop Residues: A Review and Lysimeter Study

The goal of the European Nitrate Directive 91/676/CEE is to mitigate or prevent water pollution associated with the nitrogen (N) cascade. Vegetable crops have a high risk of nitrate leaching during autumn and winter. Information about the fate of N from artichoke (Cynara cardunculus L. var. scolymus (L.)) residues is reviewed and then supplemented with a three-year study with 15N-labelled residues in an artichoke-cauliflower (Brassica oleracea L. cv. botrytis) rotation in six lysimeters. After three years, 6% of N in artichoke residues was leached, 8% was exported by crops, while 86% remained in the lysimeter. Summed over the rotation, 16% of artichoke-residue N was absorbed by artichoke and 14% by cauliflower. Total aboveground N uptake by all crops during the entire rotation ranged from 370 to 534 kg N ha−1, of which 207–311 kg N ha−1 returned to the soil as residues. Increasing N-recycling efficiency and reducing the risk of N leaching while conserving crop productivity requires capturing N mineralized from soil organic N. Cauliflower performs this capture effectively during the drainage period. A break crop should be introduced after the first and second harvests of artichoke to further synchronize N mineralization and uptake and reduce leaching risk during the rotation.

Improvement of physico-chemical properties and microbiome in different salinity soils by incorporating Jerusalem artichoke residues

Soil salinization is becoming increasingly serious, threatening the development of ecological agriculture that aims at high yield, high efficiency and closed-loop cycles. In this study, residues of Jerusalem artichoke were incorporated in three soils differing in salinity, and the physical and chemical properties of soil and soil microbial community were characterized over time. After residue incorporation, the soil pH fluctuated between 6.8 and 8, trending toward neutrality; the soil salinity decreased significantly. The total nitrogen content increased significantly, whereas the soil organic matter content increased initially and then decreased. Soil microbiome abundance and diversity increased, with a significant increase in the population of moderate halophiles and cellulose-decomposing bacteria in soil. Compared with the genera adapted to medium-to-high salt concentration, the abundance and diversity of the low-salt genera were higher. The degradation rate of residues increased with time, with cellulose degradation being strongest, followed by hemicellulose, and finally lignin. In summary, incorporation of Jerusalem artichoke residues can improve soil physical and chemical properties and the microbial community structure, which provides a theoretical basis for improving saline-alkali soils, rational utilization of crop residues and promoting sustainable development of modern agriculture.

Sustainable management of lignocellulosic wastes: Temperature strategies for anaerobic digestion of artichoke

Lignocellulosic residues are a widely available energy resource, but their conversion into biogas through biomethanation may be hindered by a chemical structure with strong bonds. A strategy based on temperature-phased anaerobic digestion (TPAD) is here applied to optimize anaerobic digestion of artichoke as a representative lignocellulosic waste. The experiments consist of a first thermophilic stage conducted at 55 °C (7 and 5 days), followed by a second mesophilic stage at 35 °C. In addition, for comparison, single-stage temperature trials are carried out within the most common conditions for biomethanation (mesophilic at 35 °C, and thermophilic at 55 °C), as well as at the intermediate range (42 °C). In general, biomethanation of artichoke residues under TPAD configuration provides better performance than single-stage systems. Particularly, the best performance is observed for the TPAD arrangement using a thermophilic phase of 7 days. Thus, at this optimal configuration, volatile solids (VS) removal of 54%, and biogas and methane yields of 442 mL/g-VS and 375 mL-CH4/g-VS were reached, respectively. Moreover, a kinetic model coupling biogas generation and substrate consumption has been applied. Good agreement is found for both variables in each system tested. The calculated non-biodegradable substrate (S∞) is lower in TPAD systems (mean 49.6%) compared with that of single-stages (average 53.9%). The maximum specific growth rate of biomass (μM) is higher for TPAD digesters (mean 0.0625 d−1), although the thermophilic single-stage reactor reaches a close value (0.0615 d−1). The biogas yield (α) is similar for all conditions (0.358 L/g-VS), but with a maximum value of 0.428 L/g-VS for the TPAD digester with the 7-days thermophilic period. Therefore, temperature-phased anaerobic digestion has proved to be an efficient strategy for sustainable management of artichoke wastes.

Phenolic Composition of Artichoke Waste and its Antioxidant Capacity on Differentiated Caco-2 Cells.

Artichoke waste represents a huge amount of discarded material. This study presents the by-products (bracts, exterior leaves, and stalks) of the “Blanca de Tudela” artichoke variety as a potential source of phenolic compounds with promising antioxidant properties. Artichoke residues were subjected to different extraction processes, and the antioxidant capacity and phenolic composition of the extracts were analyzed by spectrophotometric methods and high performance liquid chromatography (HPLC) analyses, respectively. The most abundant polyphenols in artichoke waste were chlorogenic acid, luteolin-7-O-rutinoside, and luteolin-7-O-glucoside. Minor quantities of cynarin, luteolin, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, and naringenin-7-O-glucoside were also found. The antioxidant activity of the obtained extracts determined by ABTS [2, 2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)], DPPH (2,2-diphenyl-1-pycrilhydracyl), and FRAP (Ferric Ion Reducing Antioxidant Power) was highly correlated with the total concentration of phenolic compounds. Chlorogenic acid, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside, the most abundant compounds in 60% methanol extracts, are the components most responsible for the antioxidant activity of the artichoke waste extracts. The extract with the best antioxidant capacity was selected to assay its antioxidant potential on a model intestinal barrier. This action of the hydroxycinnamic acids on intestinal cells (Caco-2) was confirmed. In summary, artichoke waste may be considered a very interesting ingredient for food functionalization and for therapeutic purposes.

Rheological behavior of soluble dietary fiber fractions isolated from artichoke residues

Cynara cardunculus var. scolymus agroindustrial by-products (stems, outer bracts, leaves) constitute 80% of the plant. These by-products may be recovered for the extraction of food additives and nutraceuticals. In this research, the rheological behavior of soluble dietary fiber fractions isolated from bracts (B) and stems (S) of artichoke was studied. Fractions were isolated by means of a heat treatment followed by processing with sodium citrate buffer (S1, B1) or buffer/protease (S2, B2) or hemicellulase (S3, B3) or both enzymes (S4, B4). They were composed, mainly, by pectin (degree of methylation, DM ≤ 53%) and inulin. When dissolved in water (2.00% w/v) with Ca2+ (40 mg/g pectin), fractions were sensitive to the ion showing shear thinning flow, with initial yield stress in the case of B2, B3 or S3. Citrate buffer extracted fractions (B1, S1) showed the highest viscosities, whereas extraction with buffer and both enzymes (B4, S4) produced the least viscous fiber fractions. At rest assays revealed the formation of gel-like networks that were stronger, in general, in the presence of higher pectin and inulin content, homogalacturonan proportion, and low methylation degree. Leftovers of artichoke can be used to extract soluble dietary fiber fractions that might be utilized as natural thickeners and gelling agents in foods, pharmaceutical and cosmetics, helping to add value to raw materials and to close the bioeconomy loop in relation to this plant.

Evaluation of soil enzyme activities and microbial communities in tomato continuous cropping soil treated with jerusalem artichoke residues

ABSTRACT Jerusalem artichoke (JY) (Helianthus tuberosus L.) has been reported to have a strong inhibitory effect on weed growth and root knot nematodes, but little information is available on the effects on soil ecosystems, especially soil microorganisms and soil enzyme activities. Understanding the dynamics of soil microbes and soil enzyme activities in cropping systems can help determine how agricultural practices influence soil processes mediated by JY residues. This study used a pot experiment, with five-year continuous cropping soil of tomato plants as the experimental material and 2% (w/w) JY residue as the treatment material in the soil. The treatment was compared to continuously monocropped tomato soil that was not treated with JY residues. The results of 16S high-throughput sequencing showed that both fungal and bacterial community structure and composition varied significantly at each stage of JY treatment. The analysis showed that the major phyla in the soil fungal community included Ascomycota, Zygomycota and Basidiomycota. Chytridiomycota was dominant in only the JY-treated soil. At the genus level, the abundances of Mortierella, Cephaliophora, Cryptococcus and Fusarium notably changed at each stage of JY treatment. In the bacterial community in the JY-treated group, the abundance of Proteobacteria increased significantly, while that of Firmicutes decreased significantly, compared to the control group. JY enhanced the activity of soil sucrase and urease. In addition, the soil sucrase activity showed a strong negative correlation with Fusarium and Bacillus. Overall, our results revealed that JY residues changed both the soil bacterial and fungal community composition and the soil enzyme activities.

Optimization of agricultural biogas supply chains using artichoke byproducts in existing plants

The development of biogas production exacerbated the competition for land availability between crops dedicated to human consumption and those intended for energy production. Residual biomasses have been often proposed for their positive outcomes in terms of reduced pressure on land use. However, literature did not assess optimization options for existing biogas plants feeding. This paper developed a bio-economic model for the optimization of agricultural biogas supply chains using artichoke byproducts in existing plants. A multiple goal linear programming approach was adopted, using two objective functions, calculating respectively net present value and land use from energy crops, associated to a regional biogas network. Three scenarios were defined using primary and secondary data on the residues of a specific artichoke variety - globe - and an Italian region - Sardinia. In the Business As Usual scenario, net present value is about 7 million € with a land use of about 2720 ha. When using artichoke residues, the economic impact increases by 28% and land use is reduced by 83% if net present value is optimized. When land use is optimized, the economic impact still grows by 25% and land use is reduced by 100%. Results from this study confirm that, under certain conditions, locally available residual biomasses can replace energy crops in existing biogas networks, coupling viability and sustainability.

Potential Biogas Production from Artichoke Byproducts in Sardinia, Italy

The paper aims at evaluating the potential biogas production, both in terms of CH4 and theoretical energy potential, from globe artichoke agricultural byproducts in Sardinia. Field data about the productivity of byproducts were collected on five artichoke varieties cultivated in Sardinia, to assess the biomethane production of their aboveground non-food parts (excluding the head). Moreover, secondary data from previous studies and surveys at regional scale were collected to evaluate the potential biogas production of the different districts. Fresh globe artichoke residues yielded, on average, 292.2 Nm3·tDOM−1, with dissimilarities among cultivars. Fresh samples were analyzed in two series: (a) wet basis; and (b) wet basis with catalytic enzymes application. Enzymes proved to have some beneficial effects in terms of anticipated biomethane availability. At the regional level, ab. 20 × 106 Nm3 CH4 could be produced, corresponding to the 60% of current installed capacity. However, districts potentials show some differences, depending on the specific biomass partitioning and on the productivity of cultivated varieties. Regional assessments should encompass the sensitiveness of results to agro-economic variables and the economic impacts of globe artichoke residue use in the current regional biogas sector.

Artichoke (Cynara scolymus L.) as cash-cover crop in an organic vegetable system

In organic vegetable systems green manure crops play an important role as a nitrogen source, but they cover the soil for several months without producing a direct income. Globe artichoke (Cynara scolymus L.) provides both heads to be harvested and particularly abundant plant residues to be possibly incorporated into the soil, so it may play a double role of cash and cover crop. This paper describes an on-farm study in which seed-propagated artichoke, cultivated as an annual crop, preceded zucchini squash and lettuce cultivated in sequence within a vegetable organic system. Artichoke produced about 7 t ha-1 of saleable heads and left, after harvest, 50.3 t ha-1 of fresh biomass usable as green manure. Zucchini squash and lettuce following artichoke showed a significant increase in yield when artichoke residues were incorporated into the soil. Furthermore, a residual positive effect of green manure on soil fertility was detected after lettuce harvest.

Environmental consequences of the conversion from traditional to energy cropping systems in a Mediterranean area

The bioenergy production greatly runs around the controversial interconnections among food, energy and environment that have noteworthy implications in various spheres. Using a cropping system approach, this study aimed at evaluating environmental impact variations associated to switching from traditional cereal, forage and horticultural systems to food/energy ones under Mediterranean conditions. The alternative scenarios included the introduction of rapeseed as dedicated energy crop in the cereal cropping systems, the valorization of artichoke residuals for energy production in the horticultural system and the shift from forage to biomass for energy production in the forage systems. A “cradle to farm gate” consequential Life Cycle Assessment approach was used that allowed to identify the environmental “hot spots” of the agricultural practices. The introduction of rapeseed into cereal crop systems and, to a lesser extent the conversion of forage systems into energy systems, showed positive effects on the environmental farming sustainability, with a variation of −32% and −8% burdens on land basis, respectively. The harvesting of artichoke residues for energy production required additional energy inputs leading to an increased impact compared to the solely edible heads harvest (+88%) on land basis.These findings provide useful information for improving agricultural practices and designing land allocation options among crops of these Mediterranean cropping systems aiming to minimize food/energy competition and environmental burdens.

Allelopathic persistence of Helianthus tuberosus L. residues in the soil

Helianthus tuberosus (Jerusalem artichoke) has been reported to be highly invasive in European cropping systems; simultaneously, there is a growing interest in it as a cultivated crop in middle and southern Europe. This study investigated the allelopathic effect of Jerusalem artichoke residues on the germination and early growth of crop and weed species with two experiments carried out in greenhouse. Experiment 1 was conducted by incorporating 0.5, 1.0 or 2.0tha−1 of dried H. tuberosus leaf tissue into pots filled with sand at 0, 7, 14, 21, 28, and 35 days prior to seeding lettuce, pea, or Digitaria sanguinalis. Experiment 2 was carried out by incorporating 2.5 or 5.0tha−1 of total plant residues into pots filled with naturally infested soil collected from H. tuberosus-free fields. Of the species considered, D. sanguinalis showed the highest sensitivity to the allelopathic activity of Jerusalem artichoke; germination reductions of more than 30% were observed in almost all residue incorporation times. Weed community experiment provided good evidence of the allelopathic potential of H. tuberosus residues. Incorporating various amounts of H. tuberous remains into sand planted with test seeds showed weed development and growth were progressively more inhibited with increasing residue substrate exposure time. The results of this study do not only increase the knowledge on the allelopathic potential of H. tuberosus, but also bring the attention to the residual effect overtime.

How the nitrogen fertilization dose affects the biochemical composition and net mineralization of the artichoke residues

In Egypt, recycling of vegetable and crop residues is improving of environmen- tal and efficiency of nitrogen use. In this study, artichoke (Cynara cardunculus L.) plants have been grown in field for nine months at three rates of nitrogen fertiliza - tion: 0 (N0), 250 (N250), 500 (N500) kg ha -1 . The aims of this study are to assess effect of nitrogen fertilization of previous treatments on the chemical composition and mineralization of the artichoke. The results showed that the artichoke residues of the treatment N500 contained higher amounts of lignin, cellulose, hemicellulose and soluble C at 100°C and a lower soluble fraction Van Soest than N0 and N250 treatments. Artichoke residues contained 129.3, 89.2 and 57.4 kg N ha -1 for N500, N250 and N0, respectively. Carbon of artichoke residues was mineralized above 60% at 50 days in the incubation experiment, and then slowly CO 2 release. Net N immobilization was observed during the first days of incubation in N0 and N250 treatments. While, the N500 treatment was mineralized immediately. The study demonstrated that the net N mineralization ranged from 38.26 mg N kg -1 dry soil for

Allelochemicals identified from Jerusalem artichoke ( Helianthus tuberosus L.) residues and their potential inhibitory activity in the field and laboratory

Weed management systems often seek biological solutions to minimize the environmental impacts related to the use of herbicides in agricultural systems. The suppressive effects of allelochemicals can sometimes be used effectively to provide biological pest and weed control. Jerusalem artichoke ( Helianthus tuberosus L.) has been reported to be a highly invasive weed in European cropping systems, but this plant is also gaining interest as a cultivated crop in Italy. The aim of this study was to investigate the impact of Jerusalem artichoke and its extracts upon the germination and growth of seedling weeds and crops. HPLC coupled to MS was used for identification of the compounds associated with the observed growth inhibition. The weed suppressive activity of local biotypes of Jerusalem artichoke on weed growth and establishment was also evaluated in a field experiment. Shoot extracts of the cultivar Fuseau were consistently most inhibitory to germination and seedling growth of lettuce, particularly the diethyl ether extract. Solvent partitioning of the aqueous extracts of dried artichoke shoots resulted in greater inhibition in comparison to the aqueous extract itself. The diethyl ether extract provided 2-fold greater growth inhibition, in comparison to the aqueous extract, at concentrations of less than 0.5 mg extract per Petri dish. HPLC MS evaluation of the diethyl ether extract led to the identification of salicylic acid ( o-hydroxybenzoic acid), and the closely related compound p-hydroxybenzaldehyde, as well as minor quantities of o-coumarinic acid and coumarin in the active fraction inhibiting lettuce seedling growth. Field observations provided further evidence for the allelopathic potential of H. tuberosus residues, as significant weed growth inhibition was observed in Jerusalem artichoke-infested plots with soil-incorporated residues in comparison to non-infested field sites, both in terms of weed seedling emergence and growth. The allelopathic potential of H. tuberosus may be of interest in the implementation of integrated weed management programmes by considering the suppressive ability of this plant and its residues for weed management in the field.

Potential Allelopathic Effects of Jerusalem Artichoke (Helianthus tuberosus) Leaf Tissues

Jerusalem artichoke has been reported to colonize several ecological niches and agronomic crops in southern Europe. This plant is also of interest because of its high biomass production and its potential to produce ethanol for biofuel. Allelopathy may be an advantageous trait in Jerusalem artichoke under cultivation, as it potentially reduces weed interference with the crop, theoretically allowing a reduction of mechanical or chemical input required for weed management. However, this trait may also be unfavorable if other crops are cultivated in rotation with Jerusalem artichoke or in areas infested by this species. The aim of this study was to investigate the sensitivity of selected diverse crops (wheat, lettuce, corn, tomato, rice, and zucchini) and weeds (barnyardgrass, black nightshade, common lambsquarters, common purslane, large crabgrass, and pigweed) to the presence of Jerusalem artichoke dried leaf tissues in laboratory experiments performed under controlled conditions. The simulated soil incorporation of different Jerusalem artichoke residues (four cultivars and a weedy population) was carried out in a series of laboratory and greenhouse experiments. Jerusalem artichoke reduced the radicle growth of seedling lettuce (60%), tomato (30%), large crabgrass (70%), and barnyardgrass (30%), whereas total germination of these species was less affected. Sensitivity to Jerusalem artichoke residues was species dependent; germination and initial growth of corn were not affected, whereas winter wheat, lettuce, tomato, rice, and zucchini seedlings were more sensitive to residue presence. Our experiments show that both wild and cultivated decomposing Jerusalem artichoke residues, particularly leaves and stems, possess phytotoxic potential. Additional field experimentation remains to be conducted to determine if allelopathy in the field contributes to its invasibility.

Stimulation of nitrogen fixation in soddy-podzolic soils with fungi

Stimulation of nitrogen fixation in soddy-podzolic soils is related to the hydrolytic activity of fungi decomposing plant polymers. It was found that the rate of nitrogen fixation upon the simultaneous inoculation of the strains of nitrogen-fixing bacteria Bacillus cereus var. mycoides and the cellulolytic fungus Trichoderma asperellum into a sterile soil enriched with cellulose or Jerusalem artichoke residues is two to four times higher than upon the inoculation of the strains of Bacillus cereus var. mycoides L1 only. The increase in the nitrogen fixation depended on the resistance of the substrates added into the soil to fungal hydrolysis. The biomass of the fungi decomposing plant polymers increased by two–four times. The nitrogen-fixing activity of the soil decreased when the growth of the fungi was inhibited with cycloheximide, which attested to a close correlation between the intensity of the nitrogen fixation and the decomposition of the plant polymers by fungi. The introduction of an antifungal antibiotic, together with starch or with plant residues, significantly (by 60–90%) decreased the rate of nitrogen fixation in the soll.

Diluted acid hydrolysis pretreatment of agri-food wastes for bioethanol production

Because of its environmental benefits, bioethanol is regarded as a promising biofuel substitute for gasoline in the transportation sector. To make it competitive with fossil fuels, it is necessary to reduce production costs by using new, alternative biomass feedstocks. As a result of its strong agricultural growth, Spain has seen increased development of its vegetable canning industry which produces approximately 450,000 tonnes of waste a year. Solutions must be developed in order to diminish the environmental impact from this increasing amount of waste. For this study, wastes from fresh and processed vegetables were used as feedstocks for a diluted acid hydrolysis process using sulphuric acid as a catalytic agent. The maximum ratios of single sugar recovery in the liquid fraction from dilute acid hydrolysis assays were 40.29 and 50.20% (w/w) for tomato and red pepper residues, respectively (Table 3). More intensive pretreatment was necessary to maximise sugar recovery in the case of pulse food (legumes such as beans, lentils and chickpeas) and artichoke residues because of their high starch and inulin content. Finally, for cardoon residues a maximum single sugar recovery of 78.18% (w/w) was obtained in the liquid fraction (Table 4). The suitability of these pretreatments has also been evaluated by corroborating the low levels of sugar degradation compounds detected in the samples, which are significantly lower than the concentrations reported in previous studies. In conclusion, because the sugars in fresh and processed vegetable wastes are widely available and easily obtainable, they can be considered as potential feedstocks for bioethanol production.