Generation of key aroma compounds in Beijing roasted duck induced via Maillard reaction and lipid pyrolysis reaction

This study explores the evolution of key aroma compounds and the chemical changes of their precursors, including reducing sugars, free amino acids, free fatty acids, thiamine and proximate compositions in Beijing roasted duck during roasting for 0-80 min. The results showed that the amounts and contents of 9 key aroma compounds in roasted ducks first quickly increased (p < 0.05) and subsequently remained constant (p > 0.05) after 50 min, except for a slight decrease between 70 and 80 min. Cysteine, cystine and methionine were the main free amino acids and could react with glucose and ribose to generate 2-furfurylthiol, dimethyl trisulfide and methional. Linoleic acid, α-linolenic acid and arachidonic acid had important effects on the increase of hexanal, octanal and nonanal together with the emergence and formation of heptanal, (E, E)-2,4-decadienal and 1-octene-3-ol. However, thiamine might not be the main precursor of the key aroma compounds in Beijing roasted duck.

Pitfalls in the 3, 5-dinitrosalicylic acid (DNS) assay for the reducing sugars: Interference of furfural and 5-hydroxymethylfurfural

Transformation of renewable biomass into value-added chemicals and biofuels has evolved to be a vital field of research in recent years. Accurate estimation of reducing sugars post pretreatment of lignocellulosic biomass has been very inconsistent. For a few decades, 3,5-dinitrosalicylic acid (DNS) assay has been widely employed for the estimation of reducing sugars derived from pretreatment of lignocellulosic biomass. This assay tests for the presence of free carbonyl group (C=O), the so-called reducing sugars. This involves the oxidation of the aldehyde functional group present to the corresponding acid while DNS is simultaneously reduced to 3-amino-5-nitrosalicylic acid under alkaline conditions. However, the presence of other active carbonyl groups can potentially also react with DNS leading to incorrect yields of reducing sugars. Therefore, a detailed study has been carried out to evaluate the influence of active carbonyl compounds like furfural and 5-hydroxymethylfurfural (5-HMF) in the overall estimation of reducing sugars (glucose, xylose and arabinose) by DNS assay. In addition to this, reducing sugars estimation in the presence of furans were also investigated, it reveals that reducing sugars estimation was found to be 68% higher than actual sugars. Therefore, current findings strongly indicate that the employment of DNS assay for quantifying the reducing sugars in the presence of furans is not appropriate.

Concomitant use of Azolla derived bioelectrode as anode and hydrolysate as substrate for microbial fuel cell and electro-fermentation applications

The potential of deoiled Azolla pinnata biomass (DAB) as electrode and substrate was evaluated for microbial fuel cell (MFC) operation. The anode electrode was fabricated using biochar obtained by subjecting DAB to pyrolysis at 600 °C, while the reducing sugars after hydrolysis of DAB by acid pretreatment was used as substrate. The post pyrolyzed biochar (P-DAB) was characterized for structural and elemental functionalities using SEM, XRD and Raman spectroscopy, whereas the reducing sugar obtained from hydrolyzed DAB (H-DAB) was analyzed for its composition. Experimental results indicated that at a given 3 g COD/L resulted in a voltage of 382 mV with 65.6% of COD reduction in closed circuit (CC) mode of operation. Cyclic voltammetric analysis depicted maximum oxidative and reductive peak currents of 3.42 mA and -4.0 mA. Noticeable peaks were also identified in CC (-0.2 V to +0.2 V and -0.19 V to -0.3 V) and OC (+0.2 V to +0.4 V and -0.1 V to -0.3 V) corresponding to complex IV cytochrome c couples (cytochrome C_ox (Cyt C_ox)/cytochrome C_rd (Cyt C_rd)), signifying the participation of electron carriers during electron transfer. The microbiome diversity showed dominance of Proteobacteria, a phylum known for exo-electrogenic bacterial species. The DAB-derived products account to environmental sustainability and support circular bioeconomy in a biorefinery mode.

Intensification of dilute acid hydrolysis of spent tea powder using ultrasound for enhanced production of reducing sugars

Spent tea (ST) powder is one of the potential sustainable sources available abundantly and can be utilized to produce reducing sugars required for production of platform chemicals. The current study aims at intensifying the reducing sugars production based on ultrasound assisted dilute acid hydrolysis (UADAH). The effects of reaction time, solid liquid ratio, acid concentration and temperature on the yield of reducing sugars were investigated initially for UADAH process based on ultrasonic (US) horn. The highest yield of 24.75 g/L for the reducing sugars was obtained at solid liquid ratio of 1:8, acid concentration of 1% w/v and temperature of 60 °C within 120 min. Use of oxidants like hydrogen peroxide (H₂O₂) and Fenton's reagent to further intensify the production has also been studied. Use of H₂O₂ at optimum loading of 0.75 g/L resulted in reducing sugars yield of 26.2 g/L within 75 min while using same H₂O₂ loading with FeSO₄ at loading of 0.75 g/L along with UADAH reduced the reaction time to 60 min for almost similar yield. Large scale studies performed using US flow cell revealed that yield of reducing sugars as 22.4 g/L is obtained in 120 min in the case of only UADAH, while in the case of UADAH along with H₂O₂ and Fenton's reagent, similar yield of reducing sugars was obtained in only 90 and 60 min respectively. UADAH in combination with oxidants has been demonstrated as an effective and intensified approach to produce reducing sugars from spent tea powder available as sustainable source.

Effect of temperature on the formation of acrylamide in cocoa beans during drying treatment: An experimental and computational study

The aim of this work was to determine the effect of temperature on the formation of acrylamide in cocoa beans during drying treatment by an experimental and computational study, in order to assess the presence of this neoformed compound from postharvest stage. The computational study was conducted on the reaction between fructose, glyoxal from glucose, and on asparagine at the M06-2X/6-31+G(d,p) level, under cocoa bean drying conditions at 323.15 to 343.15 K. The proposed reaction for acrylamide formation consisted of seven steps, which required to progress a via cyclic transition state of the four members. In addition, step III (decarboxylation) was considered to be the rate-determining step. Glucose followed an E1-like elimination and fructose exhibited an E1cb-like elimination. Computational model showed that the reaction of acrylamide formation was favored by fructose rather than glucose. The content of reducing sugars, asparagine and acrylamide in fermented and dried cocoa from two subregions of Antioquia-Colombia, as well as roasted cocoa, were evaluated by UHPLC-C-CAD and UHPLC-QqQ. The concentrations of monosaccharides measured at the end of the fermentation and drying process of cocoa nibs showed greater decreases in the levels of fructose as compared to glucose, supporting the main model hypothesis. Acrylamide formation only occurred in Bajo Cauca due to the presence of both precursors and fast drying time (72 h). Finally, it was possible to find the conditions to which acrylamide can be formed from the drying process and not only from roasting, information that can be used for future control strategies.

Effect of osmo priming on sucrose metabolism in spring maize, during the period of grain filling, under limited irrigation conditions

The present study was undertaken to study the effect of osmo priming on sucrose metabolism of spring maize, under limited irrigation conditions. Osmo priming increased the activities of acid invertase, alkaline invertase and sucrose synthase (cleavage) and the contents of reducing sugars and starch in the grains of stressed plants. There was also an increase in sucrose phosphate synthase activity with a parallel increase in sucrose content in leaves of stressed plants in comparison with those of hydro priming treatment. It showed that osmo priming helped in improving sucrose phosphate synthase activity in leaves of plants, leading to higher sucrose content, under stress conditions.

Quantitative trait loci for starch-corrected chip color after harvest, cold storage and after reconditioning mapped in diploid potato

The objective of this study was to map the quantitative trait loci (QTLs) for chip color after harvest (AH), cold storage (CS) and after reconditioning (RC) in diploid potato and compare them with QTLs for starch-corrected chip color. Chip color traits AH, CS, and RC significantly correlated with tuber starch content (TSC). To limit the effect of starch content, the chip color was corrected for TSC. The QTLs for chip color (AH, CS, and RC) and the starch-corrected chip color determined with the starch content after harvest (SCAH), after cold storage (SCCS) and after reconditioning (SCRC) were compared to assess the extent of the effect of starch and the location of genetic factors underlying this effect on chip color. We detected QTLs for the AH, CS, RC and starch-corrected traits on ten potato chromosomes, confirming the polygenic nature of the traits. The QTLs with the strongest effects were detected on chromosomes I (AH, 0 cM, 11.5% of variance explained), IV (CS, 43.9 cM, 12.7%) and I (RC, 49.7 cM, 14.1%). When starch correction was applied, the QTLs with the strongest effects were revealed on chromosomes VIII (SCAH, 39.3 cM, 10.8% of variance explained), XI (SCCS, 79.5 cM, 10.9%) and IV (SCRC, 43.9 cM, 10.8%). Applying the starch correction changed the landscape of QTLs for chip color, as some QTLs became statistically insignificant, shifted or were refined, and new QTLs were detected for SCAH. The QTLs on chromosomes I and IV were significant for all traits with and without starch correction.

Developmental patterns of enzyme activity, gene expression, and sugar content in sucrose metabolism of two broomrape species

A better understanding of broomrape physiological features opens up new perspectives for developing specific management strategies. For this purpose, activities of key enzymes involved in osmoregulation (SAI1, CWI, M6PR, and SUS1) were considered at developmental stages of two important broomrape species (Egyptian and branched broomrape) on tomato. While Egyptian broomrape tubercles had high activities of invertases, branched broomrape shoots revealed high activities of M6PR and SUS1 during both pre- and post-emergence stages except for M6PR at post-emergence stages of P. aegyptiaca. Interestingly, the main accumulation of total reducing sugars was detected in tubercle during pre- and in shoot during post-emergence. Unlike low levels of genes expression (except for CWI) before parasite emergence, significantly higher expression levels of SAI1, SUS1 and M6PR were detected after parasite emergence. Matching the expression levels of SAI1 and SUS1 genes with their corresponding enzymes activities makes them as the suitable candidates for gene silencing strategies.

Dilute acid hydrolysis of spoiled wheat grains: Analysis of chemical, rheological and spectral characteristics

In this work, hydrolysis of spoiled wheat grains using dilute acid (5, 10%; 1 N HCl) was investigated and the effect of hydrolysis conditions on reducing sugars, soluble proteins, rheology and infrared spectra of the hydrolysates was determined. Hydrolysis with 10% acid concentration released more quantities of reducing sugar (16.47 mg/mL) at shorter hydrolysis times whereas 5% acid concentration produced higher protein content (28.74 mg/mL) for similar durations. Flow characteristics demonstrated an increased apparent viscosity of the hydrolysates retrieved after 4.5 h of hydrolysis possibly due to breakdown of hemicelluloses and lignin into sugars. Infrared spectroscopy showed release of carbonates after 1.5 h and 5.5 h of hydrolysis perhaps due to oxidation of lignin or a reaction between acid and sugars. The study highlights that acid hydrolysis would be a rapid and cost effective approach to produce fermentable hydrolysates for bio-processing industry applications while generating an avenue for waste grain utilization.

Microalgae-biorefinery with cascading resource recovery design associated to dairy wastewater treatment

The potential of microalgae for the treatment of dairy wastewater (DWW) was studied by integrating with bioethanol production. At the end of treatment, organic carbon removal was observed to be 90% with simultaneous removal of nutrients. Biomass concentration increased from 3^rd day and reached to a maximum of 1.4 g L^-1 by the end of cycle. The biomolecular composition of microalgae comprised of 38% carbohydrates, 15% proteins and 22% lipids. Reducing sugars extracted from deoiled microalgae showed highest percentage of glucose (54.12%) than other monomers. The reducing sugars obtained were utilized for the production of bioethanol via yeast fermentation using Saccharomyces cerevisiae. This resulted in the production of ethanol (3G) upto 116.2 mg g^-1 with simultaneous decrease in reducing sugars upto 92 mg g^-1. The results obtained indicate potential of microalgae to produce multiple biobased products in a biorefinery framework.

Enzymatic hydrolysis of starch into sugars is influenced by microgel assembly

The use of alginate and chitosan polymer in the immobilization of Aspergillus oryzae ATCC 3940 fungal crude enzyme extract (CEE) amylase was presented. The assembly results change in the application of optimal pH and temperature hydrolysis to convert starch to sugar. Bead arrangement in three microgel supports: the internal support phase (IP), the external support phase (EP), and the internal and external support phase (UP). The best results were obtained using IP and EP. Reusing beads evaluated the stability of immobilized enzymes on IP support, remained active and bound during three cycles of reuse. For free and immobilized (IP) activity showed pH ranged from 5.0 to 7.0; optimum thermal enzymatic greater activity at 45 °C. The method of building the microgel influencing sugar reduction, in a single-step way to immobilize crude fungal amylase extracts can be used in industry.

WCl6 catalyzed cellulose degradation at 80 °C and lower in [BMIM]Cl

Degradation of cellulose to reducing sugar is the key step for the conversion of cellulose to valuable chemicals. Cellulose was degraded by WCl₆ in 1-butyl-3-methyl imidazole chloride at 80 °C and lower. 83% and 85.5% yield of total reducing sugar was gotten at 70 and 80 °C, respectively. Compared with inorganic acid, heteropoly acid, acidic ionic liquid and other metal chlorides, WCl₆ has shown better catalytic performance for degradation of cellulose to reducing sugar. The effect of reaction temperature, reaction time, WCl₆ amount and cellulose concentration were investigated. Degradation of cellulose by WCl₆ in 1-butyl-3-methyl imidazole chloride is a zero reaction. WCl₆ also showed excellent catalytic performance for the degradation of nature cellulose and lignocellulose. Catalyst can be reused at least 5 times without decrease of reducing sugar yield. The mechanism of degradation of WCl₆ was also suggested.

Isolation of cellulase enzyme from brown garden snail (Cornu aspersum) for the saccharification of waste paper materials

Garden snails (Cornu aspersum) have been sacrificed by drowning the snails overnight in water. The visceral organs (inside the shell organs) have been separated from the foot as well as the shell and homogenized using tris-HCl buffer, pH 5. The homogenate of visceral organs was dialysed in distilled water at 4 °C for 18 h where after the dialysed material was used to bio-convert the cellulose component of various waste paper materials into fermentable sugars such as glucose. Saccharification of the waste cellulose materials was performed with the extracted snail cellulase during ten consecutive incubation periods of 2 h each. The amount of sugars produced during cellulase action on waste cellulose was determined by the dinitrosalicylic acid (DNS) method. All incubations were performed in triplicate and the percent saccharification of each paper material was determined as a fraction of the paper material exposed to cellulase action. •Cellulase extracted from brown garden snail•Saccharification of waste paper using garden snail cellulase.

Aluminum directly inhibits alternative oxidase pathway and changes metabolic and redox parameters on Jatropha curcas cell culture

Aluminum (Al) toxicity has been recognized to be a main limiting factor of crop productivity in acid soil. Al interacts with cell walls disrupting the functions of the plasma membrane and is associated with oxidative damage and mitochondrial dysfunction. Jatropha curcas L. (J. curcas) is a drought resistant plant, widely distributed around the world, with great economic and medicinal importance. Here we investigated the effects of Al on J. curcas mitochondrial function and cell viability, analyzing mitochondrial respiration, phenolic compounds, reducing sugars and cell viability in cultured J. curcas cells. The results showed that at 70 μM, Al limited mitochondrial respiration by inhibiting the alternative oxidase (AOX) pathway in the respiratory chain. An increased concentration of reducing sugars and reduced concentration of intracellular phenolic compounds was observed during respiratory inhibition. After inhibition, a time-dependent upregulation of AOX mRNA was observed followed by restoration of respiratory activity and reducing sugar concentrations. Cultured J. curcas cells were very resistant to Al-induced cell death. In addition, at 70 μM, Al also appeared as an inhibitor of cell wall invertase. In conclusion, Al tolerance in cultured J. curcas cells involves a inhibition of mitochondrial AOX pathway, which seems to start an oxidative burst to induce AOX upregulation, which in turn restores consumption of O₂ and substrates. These data provide new insight into the signaling cascades that modulate the Al tolerance mechanism.

The effect of peeling and cooking processes on nutrient composition of Oromo dinich (Plectranthus edulis) tuber

The effects of peeling and cooking processes (boiling, steaming and baking) on the proximate, amino acids, mono, and disaccharides content of Oromo dinich (Plectranthus edulis) tubers from selected landraces were investigated. The effect of peeling on the crude protein, reducing sugars and sucrose content of the tuber was not consistent across the landraces. Crude protein reduced in landraces DHSer, IWsh, DGArr, and DGArw but increased in landrace CWsh. Reducing sugars (fructose, glucose, and maltose) increase in landraces LWsh, CWsh, DGArr, and DOJiw but reduced in landrace DOSu. Sucrose reduced in landraces IWsh and LWsh but increased in landrace CWsh on dry matter basis. Peeling significantly reduced the dry matter, ash and crude fiber content of the tubers. Dry matter reduced in landraces CWsh, DGArr, and DGArw; ash reduced in landraces DHSer and DGArw; crude-fiber reduced in landraces DOSu, DOSer, LWsh, CWsh, DGArr, and DGArw. On contrary, peeling significantly increased the crude fat, sum of total amino acids content and energy density of the tubers. Crude fat increased in landrace DOSu, IWsh, CWsh, DGArr, and DOJiw. Sum of total amino acids increased in landraces DOSu, DOJiw, and DGArw. Energy density (KJ/100 g dm) increased in landraces DOSu, DHSer, IWsh, and DOJiw. Boiling and steaming significantly increased the ash content of the tubers in landrace LWsh. Steaming and baking significantly increased crude fiber in landraces IWch and CWsh, and carbohydrate content of the tubers in landrace LWsh. Boiling, steaming and baking significantly reduced the crude fiber and the energy density of the tubers in landrace LWsh. Baking significantly reduced the moisture content of the tubers in landraces IWch, LWsh and CWsh. Boiling significantly reduced reducing sugars and crude fat content of the tubers in landraces IWch, LWsh and CWsh. The reduction in reducing sugar and crude fat content most likely is due to leaching and the presence of essential oils respectively. Thus to get the best possible nutritional benefits from P.edulis tubers, cooking with their skin under optimized operation recommended.

Effect of glucose on the morpho-physiology, photosynthetic efficiency, antioxidant system, and carbohydrate metabolism in Brassica juncea

The present experiment was conducted to investigate the promotive effects of exogenous glucose (Glc) on the morpho-physiology in Brassica juncea. L. cv. RGN-48. The plants were treated with the different concentrations (0, 2, 4, and 8%) of glucose as foliar spray at 25 days after sowing (DAS) for 5 days consecutively. The plants were collected to analyze various growth and photosynthetic parameters at 30, 45, and 60 DAS. After 5 days exposure to Glc, the level of carbohydrate, total reducing sugars, proline, plant water status, chlorophyll content, as well as that of activities of peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6), and superoxide dismutase (EC 1.15.1.1) were increased. Glc application also enhanced the gaseous exchange parameters, i.e., stomatal conductance (g_s), internal CO₂ concentration (Ci), transpiration rate (E), and net photosynthetic rate (P_N) in intact leaf. Other enzymes, such as nitrate reductase (EC 1.7.99.4) and carbonic anhydrase (EC 4.2.1.1) were also increased. Additionally, microscopic studies further reveal a remarkable increase in the stomatal aperture on Glc exposure. Moreover, exogenous Glc decreases the levels of malondialdehyde (MDA), superoxide radical (O₂^·-) and hydrogen peroxide (H₂O₂). This indicates that exogenous Glc application has a positive effect on Brassica juncea plants.

Obtaining fermentable sugars and bioproducts from rice husks by subcritical water hydrolysis in a semi-continuous mode

This work aimed at producing fermentable sugars and bioproducts from rice husks by subcritical water hydrolysis at 25 MPa in a semi-continuous mode. The influences of temperature (180 °C; 220 °C; 260 °C) and liquid/solid ratio (7.5 g water/g husks; 15 g water/g husks) on reducing sugar yield (Y_RS), efficiency (E), kinetic profiles (0-15 min), composition of sugars, inhibitors and organic acids, and physicochemical characteristics of the remaining solid material were evaluated and discussed in the work. The highest Y_RS (18.0 ± 2.9 g/100 g husks) and E (39.5 ± 1.7 g sugars/100 g carbohydrates) were obtained at 220 °C and 7.5 gwater/g husks. In such condition, the hydrolyzed solutions presented cellobiose (18.0 g/L), xylose 17.7 g/L), arabinose (3.6 g/L), glucose (1.5 g/L), and levulinic acid (0.7 g/L). The fermentable sugars and bioproducts can be applied in several industrial fields, especially for the production of bioethanol and other higher value-added chemical compounds.

Defatted algal biomass as feedstock for short chain carboxylic acids and biohydrogen production in the biorefinery format

The objective of the study was to evaluate the potential application of defatted algal biomass (DAB) residue as a resource for biobased product synthesis in the biorefinery framework. Acid-catalyzed pretreatment of DAB residue resulted in higher reducing sugars (RS) solubilization (0.26 g RS/g DAB) than corresponding base method (0.19 g RS/g DAB). Subsequently, resulting RS were acidogenically fermented for the production of Bio-H₂ and short chain carboxylic acids (SCA)/volatile fatty acids (VFA) at varying redox conditions (pH: 6, 7 and 10). Biosystem with pH-6 resulted in higher SCA (0.54 g SCA/g RS) and Bio-H₂ production (0.83  l) followed by pH-10 (0.43 g SCA/g RS, 0.71  l) and pH-7 (0.27 g SCA/g RS, 0.48  l). Higher SCA production in pH-6 system resulted in maximum acidification (23%). Algal biomass majorly derived from CO₂ and its residues after lipids extraction accounted as major feedstock for acidogenic product synthesis. Evaluation of these studies using DAB residues offers sustainability to algal refineries on its entirety use.

Effects of USDA quality grade and cooking on water-soluble precursors of beef flavor

The objective of the current study was to determine the effects of three USDA quality grades and cooking on the water-soluble flavor precursors of beef Longissimus lumborum. Raw and cooked steaks from beef strip loins of USDA Prime (PR; n = 8), Low-Choice (LC; n = 8), and Standard (ST; n = 8) were analyzed for extractable free amino acids, reducing sugars, and other nitrogenous organic compounds (NOCs). Overall, two-way quality grade × cooking interactions were found for the contents of most water-soluble precursors (P_{quality grade × cooking} < 0.05), which were greater in raw LC and ST and were changed more in ST and LC steaks by cooking. The magnitude of those changes suggested that cystine, a dimer of cysteine, glucose, and glucose 6-phosphate might play more important roles in beef flavor development than previously thought.

Assessing the influence of pod storage on sugar and free amino acid profiles and the implications on some Maillard reaction related flavor volatiles in Forastero cocoa beans

The practice of pod storage (PS) has been applied in many cocoa producing countries, especially by Ghanaian farmers over the years. However, the study of PS has not received much attention, hence, until now, its potential impact on specific flavor precursor development and implications on the flavor of cocoa beans still remains uncovered. The study was therefore aimed at exploring this possibility through physico-chemical and flavor precursor analyses, carried out on equally fermented and dried pod stored (0, 3 and 7 days) Ghanaian cocoa beans. Flavor analysis was also conducted on equally roasted pod stored cocoa beans. Through visual assessment of the pods, pulp and beans, the compelling impact of PS on fermentation index (FI) and nib acidity could be demonstrated by the various biochemical and physical changes such as respiration, moisture reduction, and cellular degradation, occurring during the process. Whereas the entire reaction of sugar degradation may be deemed complex, a clear relationship between the FI, nib acidity and the glucose content was observed. Also, PS was found to increase with marginal increase in total reducing sugars (glucose and fructose). Although the concentration of free amino acids was directly proportional to the duration of PS, within the framework of this study, a significant difference (p < .05) was only observed in the case of extended duration (7 days). Overall, 7 PS seemed to have enhanced the formation of more volatiles. This was followed by 0 PS and finally 3 PS. Suggestively, these findings could provide some indications in explaining the typical flavor profiles of the Ghanaian cocoa beans, considering the fact that 87.8% of Ghanaian farmers adhere to this practice. Meanwhile, for the chocolate industry, the surging demand for cocoa/chocolate products exhibiting unique flavors, could be partly addressed by adopting PS as a tool for varietizing the flavor capacity of "bulk" cocoa through the expression or suppression of specific flavor precursors in the raw material on the farm level, which comes with almost no additional cost.

Magnesium and organic biostimulant integrative application induces physiological and biochemical changes in sunflower plants and its harvested progeny on sandy soil

Magnesium (Mg) often leaches down in sandy soils due to high mobility and its foliar application proves to be beneficial. Organic biostimulants also prove to be helpful to affect plant physio-biochemistry and antioxidative defense system. The present study evaluated the beneficial effects of seed soaking in maize grain extract (MGE; 3%) in integration with or without foliar Mg (1 mM) in comparison to control (no treatment) on growth, yield performance, seed oil and fatty acid profile including physiological and biochemical basis of Hysun-336 sunflower hybrid grown on a sandy soil under greenhouse conditions. The integrative treatment (seed soaking in MGE + foliar spray with Mg) elevated growth traits, plant water status and membrane stability index, and reduced electrolyte leakage. Improved leaf contents of chlorophylls, carotenoids, total soluble sugars and proline, activities of non-enzymatic and enzymatic antioxidants were also observed. In addition, enhanced uptake of N, P, K including Mg and endogenous levels of plant hormones IAA, GA₃ and zeatin were recorded with the integrative treatment. Seed yield and oil contents including oleic (mono-unsaturated) and linoleic (poly-unsaturated) fatty acids also increased; however, a decrease in other saturated, mono-unsaturated and poly-unsaturated fatty acids was noticed. Improved seed and seedling vigor traits were also observed in progeny of sunflower that harvested from the integrative treatment. In summary, improved plant performance by the integrative treatment may be attributed to improved activities of antioxidants contributing to improved plant water content, nutrient uptake and endogenous hormonal levels in sunflower plants grown under sandy soil conditions.

Microbial lipid production by Cryptococcus curvatus from vegetable waste hydrolysate

This study primarily evaluated the effect of pre-treatment on release of reducing sugars (RS) from vegetable waste (VW). Different acids and alkalis viz., H₂SO₄, HCl, HNO₃, H₃PO₄, NaOH and KOH were evaluated at varied concentration (0.5, 1.0, 1.5 and 2.0%) for pretreatment. The highest RS yield of 472.36 ± 1.89 g/l and 439.13 ± 1.04 g/l was obtained with 1.5% H₂SO₄ and 2% HCl respectively. Secondly, pre-treated vegetable waste hydrolysates (PT-VWH) were evaluated for yeast fermentation using Cryptococcus curvatus MTCC 2698 for lipid production. Maximum biomass (9.46 ± 0.1 g/l and 8.12 ± 0.1 g/l) and lipid (28.3 ± 0.5% and 26 ± 0.5%) was obtained with 1.5% H₂SO₄ PT-VWH and 2% HCl PT-VWH respectively. The FAME profiling revealed the predominance of palmitic, stearic, oleic and linoleic acid. The presence of these fatty acids in majority has beneficial effect on the biodiesel quality.

Enhancing digestibility of Miscanthus using lignocellulolytic enzyme produced by Bacillus

In this study an effective bacterial pretreatment method was developed to improve digestibility of Miscanthus. Seven new bacterial isolates, which showed excellent xylanase production ability using Miscanthus as carbon source, were used to perform the pretreatment experiments. After pretreatment, the hemicellulose content and crystallinity index of Miscanthus were decreased, while the reducing sugars released from Miscanthus were significantly increased by 30.8-87.8% after enzymatic hydrolysis. Bacillus sp. G0 was selected to optimize the pretreatment parameters via response surface methodology due to its high reducing sugars released from Miscanthus. According to the optimal model, the pretreatment parameters were set as citrate buffer/G0 fermentation broth ratio at 0.34, pretreatment time at 100h and Tween-20 concentration at 1.73%. The reducing sugars released from Miscanthus pretreated by optimal parameters were 305mgg^-1 dry biomass. The results suggested our bacterial pretreatment approaches have great potential to increase digestibility of bioenergy crops.

Treatment of supermarket vegetable wastes to be used as alternative substrates in bioprocesses

Fruits and vegetables have the highest wastage rates at retail and consumer levels. These wastes have promising potential for being used as substrates in bioprocesses. However, an effective hydrolysis of carbohydrates that form these residues has to be developed before the biotransformation. In this work, vegetable wastes from supermarket (tomatoes, green peppers and potatoes) have been separately treated by acid, thermal and enzymatic hydrolysis processes in order to maximise the concentration of fermentable sugars in the final broth. For all substrates, thermal and enzymatic processes have shown to be the most effective. A new combined hydrolysis procedure including these both treatments was also assayed and the enzymatic step was successfully modelled. With this combined hydrolysis, the percentage of reducing sugars extracted was increased, in comparison with the amount extracted from non-hydrolysed samples, approximately by 30% in the case of tomato and green peeper wastes. For potato wastes this percentage increased from values lower than 1% to 77%. In addition, very low values of fermentation inhibitors were found in the final broth.

Enhanced saccharification of lignocellulosic agricultural biomass and increased bioethanol titre using acclimated Clostridium thermocellum DSM1313

Consolidated bioprocess assures an efficient lignocellulosic conversion to fermentable sugars and subsequently to bioethanol. Such a single-step hydrolysis and anaerobic fermentation was achieved with acclimated Clostridium thermocellum DSM 1313 on different mildly pre-treated agricultural lignocellulosic residues without any additional enzymes/and strains. Acclimation was achieved by serially sub-culturing in increasing concentration of individual substrates, such as rice husk, sugarcane bagasse, and banana pseudostem in the standard media, with cellobiose as an adjunct. The acclimated cellulolytic thermophile exhibited an early log phase entry with enhanced growth compared to the direct inoculation experiments with unacclimated culture. Around 672 mg/g of reducing sugar was produced from sugarcane bagasse media and 636 mg/g from rice husk media and 513 mg/g from banana pseudostem media with the acclimated organism. Bioethanol production also doubled in experiments with serially acclimated cultures, with a maximum of 1.21 and 1.0 g/L ethanol titre from sugarcane bagasse and rice husk, respectively. The serial acclimation experiments have increased the saccharification potentials of the organism towards the respective lignocellulosic substrates and also enhanced the bioethanol production.