Browsing by Author "Bankar, Sandip"
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Item 1-Butanol Separation from Aqueous Acetone-Butanol-Ethanol (ABE) Solutions by Freeze Concentration(American Chemical Society, 2023-06-07) Osmanbegovic, Nahla; Chandgude, Vijaya; Bankar, Sandip; Louhi-Kultanen, Marjatta; Department of Chemical and Metallurgical Engineering; Department of Bioproducts and Biosystems; Chemical Engineering in Aqueous Systems; Bioprocess engineeringThe suspension freeze crystallization of aqueous 1-butanol solutions, synthetic acetone-butanol-ethanol (ABE) solutions, and ABE fermentation broth was studied as a novel concentration method that requires less energy than evaporation for water removal. The equimolar aqueous ABE solutions in a total molality range of 0–5.05 mol/kg(water) were proven to be ideal solutions based on the freezing point depression obtained. An aqueous solution of 8 wt % 1-butanol and three different types of aqueous ABE solutions (3:8:1:88 ABEW, 6:16:2:76 ABEW, and 10:17:2:71 ABEW (wt %)) were concentrated for 80 min by suspension freeze crystallization in a subcooling range from 0.24 to 1.15 °C. Freeze crystallization enabled 1-butanol separation from the generated mother liquor, which split into two liquid phases after ice separation, i.e., a water-enriched phase and a 1-butanol-enriched phase. Ice yield values were higher for higher subcooling degrees and higher initial water content in the feed solutions. 1-Butanol yields separated from the mother liquors were 9.85%, 59.46%, and 22.46% for 3:8:1:88 ABEW, 6:16:2:76 ABEW, and 10:17:2:71 ABEW, respectively, whereas two-stage freeze crystallization of the fermentation broths resulted in water removal with a maximum relative percentage of 29.5%.Item Advanced processes for biobutanol production(2019-01-03) Huotari, Mikko; Chandgude, Vijaya; Kemiantekniikan korkeakoulu; Bankar, SandipItem Ammonia recycling after soaking ensiled grass in aqueous ammonia for improved hydrolysability(2017-10-03) Poikkimäki, Sakari; Pihlajaniemi, Ville; Kemian tekniikan korkeakoulu; Bankar, SandipEnsiled grass is a potential low-cost biorefinery feedstock with surplus production capacity in Europe and properties suitable for advanced animal feed applications and biochemical production. In a typical biorefinery concept, pretreatment of lignocellulosic biomass is required for facilitating enzymatic hydrolysis of carbohydrates in biorefineries. However, due to its cost intensive nature, pretreatment is one of the main reasons why lignocellulose has not yet been utilised fully. Soaking in aqueous ammonia (SAA) is a promising pretreatment process that is being improved for more cost-effective lignocellulose saccharification. Still, the recovery and recycling of ammonia in this process has not been thoroughly researched on to improve the feasibility of the process. The current thesis aimed to study the recovery of ammonia from ammonia pretreated grass silage with simple distillation methods and to determine the effects the recovery has on the yield of enzymatic hydrolysis. A larger scale single-reactor process for ammonia soaking, recovery and enzymatic hydrolysis was demonstrated. Three different ammonia loading ratios in SAA were used to find out the effects on the hydrolysis and ammonia yield in the recovery process. The recovery of ammonia was successful and the best results were gained in the single-reactor study where 66 % of the ammonia was recovered by only evaporating 12 % of the total liquid. The ammonia was recovered as an aqueous solution at a concentration sufficiently high for efficient recycling. The recovery process did not have any detrimental effects on the enzymatic hydrolysis and 10 % ammonia loading was sufficient for efficient pretreatment, leading to hydrolysis yields up to 86 %. The study carried out in this thesis concluded that the recovery of ammonia from SAA can be efficiently performed with simple equipment under atmospheric pressure. Especially the single-reactor process combined with simple recycling method could potentially be utilised in local and decentralised processing of ensiled grass.Item Biobutanol production from sugarcane straw : Defining optimal biomass loading for improved ABE fermentation(Elsevier, 2020-06-01) Pratto, Bruna; Chandgude, Vijaya; de Sousa, Ruy; Cruz, Antonio José Gonçalves; Bankar, Sandip; Department of Bioproducts and Biosystems; School services, CHEM; Biohybrid Materials; Bioprocess engineering; Universidade Federal de São CarlosKey objective of this work was to evaluate the use of cellulosic fraction from sugarcane straw pretreated by liquid hot water (LHW) for butanol production via acetone-butanol-ethanol (ABE) fermentation. Separated hydrolysis and fermentation (SHF), and pre-saccharification and simultaneous saccharification and fermentation (PSSF) were investigated at 10 and 15 % w/v biomass loading. For 15 % w/v, the synergistic effect of weak acids and phenolic compounds made the sugarcane straw hydrolysate poorly fermentable. The 10 % w/v solid load was more favorable (∼ 4-fold higher) in both SHF and PSSF strategies with respect to the ABE production, without including a detoxification step. However, PSSF achieved higher ABE titer (10.5 g/L – SHF; 13.5 g/L – PSSF) and productivity (0.09 g/(L.h) – SHF; 0.14 g/(L.h) – PSSF) when compared with SHF. Using best condition (PSSF at 10 % w/v), it would be possible to estimate a yield of 169 L ABE per ton pretreated sugarcane straw (or 84.5 L ABE per ton of raw sugarcane straw), containing 65 L acetone, 95 L butanol, and 9 L ethanol. This result represents a process efficiency of 28 %, based on carbohydrates content in raw material.Item Biocatalyst characterization and activity assay development(2018-01-30) Kruus, Satu; Simell, Jaakko; Kemian tekniikan korkeakoulu; Bankar, SandipItem Biodegradability needs and testing methods of water treatment polymers(2020-12-06) Hieta, Ilmari; Bankar, Sandip; Kemiantekniikan korkeakoulu; Kontturi, EeroItem Butter oil process development for ideal cream(2018-12-11) Penttinen, Henna; Partanen, Riitta; Hokkanen, Sanna; Kemian tekniikan korkeakoulu; Bankar, SandipItem Carbohydrate utilization of marine fungi(2018-12-11) Happonen, Petrus; Wiebe, Marilyn; Kemian tekniikan korkeakoulu; Bankar, SandipItem Chemolithoautotrophic growth of Knallgas bacteria in an electrobioreactor using in situ water electrolysis(2017-03-30) Wuokko, Mikko; Pitkänen, Juha-Pekka; Tamminen, Anu; Kemian tekniikan korkeakoulu; Bankar, SandipEver-increasing amounts of carbon dioxide in the atmosphere have urged the development of efficient CO2 fixation methods. Biotechnical methods using algae and cyanobacteria have been studied, but another alternative could be the use of Knallgas bacteria. Hydrogen-oxidizing Knallgas bacteria are capable of using hydrogen as their energy source and converting CO2 into biomass. Chemolithoautotrophic gas fermentation has been studied in literature to determine the production possibilities of Knallgas bacteria. In a few studies the hydrogen and oxygen have also been produced inside an electrobioreactor, using electrolysis of the culture medium. This work established the cultivation of the Knallgas bacterium Rhodococcus opacus in electrobioreactor conditions. Several 70 ml electrobioreactor cultivations were performed to determine the suitability of the organism to the process. In the first cultivations, using platinum electrodes, it was proven that the organism was able to grow with supply of CO2, while generating hydrogen and oxygen via electrolysis of culture medium inside the reactor. Further testing using iridium oxide-coated titanium and stainless steel electrodes enabled to increase electrode surface area and current. In addition, carbonate was added in the medium to decrease the overpotential of electrolysis. Growth-improving factors were concluded to be increased hydrogen formation due to moderately higher current, and increased inoculum growth time under autotrophic conditions. Shake flask cultivations with different substrates showed that chemolithoautotrophic growth was over seven times slower than heterotrophic. Best autotrophic growth in an electrobioreactor was achieved using iridium oxide coated titanium wire as anode and stainless steel as cathode. The applied current was 14 mA in 70 ml culture volume. The maximum cell density was 3.25 g/l. The biomass composition of R. opacus was analysed, and the average protein content was 63 % of total biomass. The composition was comparable to other single-cell protein sources, as well as soybean, indicating possible uses for animal feed. The biomass-based protein price was calculated to be 3.4 €/kg, based on the electricity consumption alone. Further process improvements and cheaper electricity could result in R. opacus biomass being a viable product alternative for soybean meal as animal feed.Item Effect of media composition on functional properties of dip slide tests(2018-07-31) Mäkeläinen, Iida; Aro, Leena; Kemian tekniikan korkeakoulu; Bankar, SandipItem Endoglucanase-assisted refining of bleached chemical birch pulp(2021-12-14) Nuutinen, Inkeri; Hultholm, Tom; Bankar, Sandip; Kemian tekniikan korkeakoulu; Louhi-Kultanen, MarjattaPulp refining is a prerequisite in the production of high-quality papers and boards while it is also one of the most energy consuming steps in the manufacturing process. Enzymatic refining has been identified as a potentially feasible and sustainable method for reducing the refining energy demand while preserving or even improving specific pulp and paper properties. However, enzymatic refining of birch pulp has not been addressed in the literature. The present work addresses this research gap and studies the applicability of endoglucanases for the refining of bleached birch sulfate pulp. The thesis includes a theoretical framework conducted as a literature acquisition and experimental laboratory-scale refining trials with four enzymes conducted as a case study in conditions corresponding to the conditions of the case paper machine. The results of this study indicate that endoglucanase-assisted refining of birch pulp caused similar or even enhanced effects compared to corresponding studies conducted with softwoods in the literature. The most suitable treatments were determined to be enzyme IV with 40 g/t of pulp dose for quality improvements at an equal specific refining energy (SRE), enzyme III with 50 g/t of pulp dose for quality improvements at an equal drainage resistance, and enzyme I with 50 g/t of pulp dose for refining energy reductions and quality improvements at an equal tensile index. The most important enzyme-induced changes were the enhanced development of tensile index and internal bond strength, which took place without significantly impairing drainability, water retention value or tear index. These changes were determined to be mostly due to increased external fibrillation and modest fines content formation compared to the reference. A tensile index of 80 Nm/g was reached with 12.0–28.5% lower SRE when enzymes were utilized. At 60 kWh/t, the tensile index, internal bond strength and Gurley air resistance of paper were increased by 2.3–9.0%, 20.0–63.1%, and 30.9–341.2%, respectively, compared to the enzymatically untreated reference. However, since hardwoods require lower SRE compared to softwoods, the achieved absolute refining energy savings were lower in the case of birch compared to corresponding studies conducted with softwoods in the literature. The break-even price for enzyme I (50 g/t of pulp) was calculated to be 0.75€ per ton of pulp when refined to a tensile index of 80 Nm/g. With this price, the increased chemical costs could be fully covered with the savings generated from the reduced refining energy. The improved quality and the potential possibility to run paper machine with a higher velocity are additional benefits that could improve the feasibility. Currently, the method is not net positive from the perspective of the case paper machine. The key issue with industrial-scale enzymatic refining was concluded to be the inadequate availability of well-controlled enzymes and their price. However, with the advances in protein engineering and enzyme production technologies, the availability of different enzyme preparations for refining applications is expected to improve and the price to decrease, which may help in the industrial-scale breakthrough of the method. Additionally, the tightening of environmental regulations may increase the interest in enzymatic refining in the future.Item Enhanced activity of hyperthermostable Pyrococcus horikoshii endoglucanase in superbase ionic liquids(SPRINGER, 2022-08) Hebal, Hakim; Hämäläinen, Joonas; Makkonen, Laura; King, Alistair W.T.; Kilpeläinen, Ilkka; Bankar, Sandip; Boucherba, Nawel; Turunen, Ossi; Department of Bioproducts and Biosystems; Bioprocess engineering; University of Béjaïa; St1 Biofuels Oy; Aalto University; University of Helsinki; University of Eastern FinlandObjectives: Ionic liquids (ILs) that dissolve biomass are harmful to the enzymes that degrade lignocellulose. Enzyme hyperthermostability promotes a tolerance to ILs. Therefore, the limits of hyperthemophilic Pyrococcus horikoschii endoglucanase (PhEG) to tolerate 11 superbase ILs were explored. Results: PhEG was found to be most tolerant to 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc) in soluble 1% carboxymethylcellulose (CMC) and insoluble 1% Avicel substrates. At 35% concentration, this IL caused an increase in enzyme activity (up to 1.5-fold) with CMC. Several ILs were more enzyme inhibiting with insoluble Avicel than with soluble CMC. Km increased greatly in the presence ILs, indicating significant competitive inhibition. Increased hydrophobicity of the IL cation or anion was associated with the strongest enzyme inhibition and activation. Surprisingly, PhEG activity was increased 2.0–2.5-fold by several ILs in 4% substrate. Cations exerted the main role in competitive inhibition of the enzyme as revealed by their greater binding energy to the active site. Conclusions: These results reveal new ways to design a beneficial combination of ILs and enzymes for the hydrolysis of lignocellulose, and the strong potential of PhEG in industrial, high substrate concentrations in aqueous IL solutions.Item Enhancing Biobutanol Production from biomass willow by pre-removal of water extracts or bark(ELSEVIER SCI LTD, 2021-12-10) Dou, Jinze; Chandgude, Vijaya; Vuorinen, Tapani; Bankar, Sandip; Hietala, Sami; Lê, Huy Quang; Department of Bioproducts and Biosystems; Wood Chemistry; University of HelsinkiAiming to understand the importance of debarking on the controlled utilization of phenolic-rich willow biomass, biobutanol was produced from it by using Clostridium acetobutylicum. Acid-catalysed steam explosion and enzymatic hydrolysis (EH) were investigated before the acetone-butanol-ethanol (ABE) fermentation. The hydrolysable sugar yield and ABE fermentation efficiency were found to decline progressively from willow wood (WW) to HWE WB (hot water extracted willow biomass), WB (willow biomass) and the WW + HWE (willow wood plus the artificial willow bark water extracts), indicating that the pre-removal of water extracts or the bark can significantly improve ABE yield. Notably, the ABE productivity of WW achieved 12.7 g/L at the solvent yield of 31%, and the butanol concentration (i.e. 8.5 g/L) generated by WW is relatively high among the reported lignocellulosic-derived biomass. Additionally, it is hypothesized that under acidic conditions and high temperatures the fructose present in willow water extractsform hydroxymethylfurfural during steam explosion, which then spontaneously condenses with phenolic substances of willow bark to form a solid furanic precipitate. The formed furanic precipitates play inhibitory role in the enzymatic hydrolysis and are thereby deleterious to the ABE fermentation.Item Enzyme-aided solubilization of faba bean nutrients(2021-12-14) Haikonen, Hannamari; Wilhelmson, Annika; Kemian tekniikan korkeakoulu; Bankar, SandipItem Expression, purification and characterization of proteins with unknown function homologous to a novel carbohydrate esterase(2018-01-30) Kutiavina, Vera; Master, Emma; Jurak, Edita; Kemian tekniikan korkeakoulu; Bankar, SandipRecently, FjoAcXE, a novel acetyl xylan esterase was characterised to deacetylate internal xylose residues of glucuronoxylan at all positions displaying low susceptibility to steric hindrance of the substrates. In this thesis eight unknown proteins homologous to FjoAcXE that shared from 47 to 98% sequence similarity to FjoAcXE were studied (K392DRAFT_2214, FF52_18088, EW79DRAFT_2436, T426DRAFT_00687, WP_035683315.1, AlkimDRAFT_0871, ZPR_3026 and CHSO_3300). Six of selected proteins (K392DRAFT_2214, FF52_18088, EW79DRAFT_2436, T426DRAFT_00687, WP_035683315.1, AlkimDRAFT_0871) were successfully expressed and purified. Additionally, pH optimum and temperature stability were determined for the studied proteins. In this work FjoAcXE- homologues showed ability to deacetylate simple synthetic substrates (pNP-acetate and 4MU-acetate). Further characterisation demonstrated that the enzymes were capable of deacetylating per-acetylated xylo-oligosaccharide mixture and branched feruloylated xylo-oligosaccharides from corn fibre and thereby revealed acetyl xylan esterase activity. Following comparison of FjoAcXE and six homologous to it proteins showed analogous level of acetic acid release from xylo-oligosaccharide mixtures.Item Functional characterization of diverse GH43 enzymes encoded in metagenomes of lignocellulose-active microbial communities(2017-12-12) Kataja, Kim; Jurak, Edita; Kemian tekniikan korkeakoulu; Bankar, SandipCarbohydrates are the main carbon source in plants and, as a photosynthetically renewable form of fixed carbon, plant biomass is considered as a prime target for replacing the petroleum derived fuels and for producing renewable chemicals and materials. The utilization of plant biomass requires degradation, through debranching and depolymerization, of the complex carbohydrate structures. Carbohydrate active enzymes (CAZymes) catalyze the breakdown, biosynthesis or modification of carbohydrates. The sequence based classification of the CAZymes began in 1991. In 2016, the CAZy database already comprised over 530 000 sequences from 5 enzyme classes. The era of large-scale genome and metagenome sequencing analysis has opened possibilities for deeper understanding of biological systems while at the same time highlighting the vast gap between the sequencing and the lagging characterization of encoded proteins. With readily available expression hosts, such as E. coli, genes of interest, particularly from bacterial sources, can be expressed and produced for biochemical characterization. Glycoside hydrolase family 43 (GH43) is one of the biggest GH families in the CAZy database, comprising 8498 GH43s in 34 subfamilies. However, from the 8498 sequences, only less than 2 % are biochemically characterized. The family includes a range of debranching, already biochemically characterized, CAZymes that promote the degradation of hemicellulose, especially arabinoxylans and pectin. In this work, the GH43 family was mined from six metagenomes of enriched lignocellulose active microbial communities. Five novel predicted GH43 proteins (GH43-GH95, GH43-GH16, CE12-GH43, GH43_18, and GH43-GH43_17) were successfully produced, purified, and screened on 26 substrates at three pH conditions. Based on the results, the GH43 from the completely uncharacterized subfamily 18, was studied in more detail as it showed clear exo activity with pNP-α-L-arabinofuranoside. The GH43_18 (aka AG-PHAbf43_18J) was screened further with six xylooligosaccharides and it was observed that the protein selectively releases 1-3 linked α-L-arabinose from the terminal xylosyl residue on the non-reducing end of the xylooligomers. Based on a literature survey, this type of highly selective α-L-arabinofuranosidase activity has not been previously reported.Item Gas-liquid mixing in a stirred tank bioreactor with gas-exchange means(2019-05-07) Qian, Franco; Lee, Cheng-Kang; Mou, Duen-Gang; Kemian tekniikan korkeakoulu; Bankar, SandipMicroorganisms are very tiny creatures that play an important part in the biotechnology industry. In certain environmental conditions, microbes metabolize and convert carbohydrates into alcohol or organic acids, a process known as fermentation. Different factors, such as temperature, air composition, nutrients and pH affects microbial growth. The purpose of this thesis was to study oxygen transfer behaviour and its influence on fermentation in a baffleless flask -fermentor-hybrid stirred-tank reactor (STR) (US patented Pat. 8,162,295) of Moubio Knowledge Co. The innovative design and portability of this tank make it a potentially important piece of laboratory equipment. The off-center impeller, the plastic vent tube and the thermometer well work together to create a possible mechanism for continuous gas exchange between the tank and the surrounding air. The tank (kLa = 29.57 h-1, 925 rpm) had 3 times oxygen transfer of Zoro’s [1] reactor (kLa = 10 h-1, 1000 rpm). In addition, this stirred tank reactor could grow microbes even at room temperature with 64 % of the same results as a shake flask incubating at an optimal temperature of 37 oC. In this project, Escherichia coli BL21 was used to produce green fluorescent protein (GFP) in the aerobic system. Oxygen transfer rate (OTR) was observed by iodometric titration, which was then used to calculate kLa values to form kLa correlations. OTR values changed based on the stirring speed, the depth of the plastic vent tube, and the depth of the thermometer well in the working volume. kLa correlation curves can be utilized in future tank design and gas-exchange research.Item Hemicellulose cross-linked nanocellulose as immobilization matrix for photosynthetic solid-state cell factories(2021-08-24) Virkkala, Tuuli; Tammelin, Tekla; Arola, Suvi; Kemian tekniikan korkeakoulu; Bankar, SandipPhotosynthetic microorganisms can be utilized to produce sustainable fuels and chemicals. These photosynthetic cell factories constitute a promising alternative to non-renewable fossil resources. However, technical challenges associated with suspension cultures, most prominently the light-to-product ratio coupled with high water and energy consumption, limits the realization of their theoretical potential. Immobilization i.e. binding the cells within a gel-like matrix is an interesting new technique that could be used to overcome these difficulties. It is vital that the matrix material used to immobilize the photosynthetic cells has sufficient wet mechanical properties to endure the submerged production conditions in addition to expressing biological compatibility with the cells. Recently, TEMPO-oxidized cellulose nanofibers (TCNFs) cross-linked with polyvinyl alcohol (PVA) has been reported as a superior alternative matrix material to the traditional alginate-based solutions. The purpose of this Master’s thesis was to investigate mixed-linkage glucan (MLG) as a natural polysaccharide-based alternative to the synthetic PVA with limited biodegradability. MLGs are hemicelluloses found as structural cross-linkers in the cell walls of grassy plants and they have been previously shown to create strong hydrogels with TCNF even with small concentrations. Rheological measurements and photosynthetic activity monitoring were used to study the mechanical properties and biocompatibility of MLG cross-linked TCNF (TCNF-MLGs). Three MLGs with different molecular weights were used in the experiments. All MLGs were shown to cross-link TCNF, and mechanical performance similar to PVA was obtained especially with the low molecular size MLG. TCNF-MLG expressed less variation in the matrix performance with and without the entrapped cyanobacterial cells than TCNF-PVA. The TCNF-MLG matrices were additionally shown to retain cell viability for up to 47 days. Overall, the results demonstrate that all-polysaccharidic matrices are feasible for microalgae immobilization in novel photosynthetic cell factories.Item Inhibition of hyperthermostable xylanases by superbase ionic liquids(ELSEVIER SCI LTD, 2020-08) Hebal, Hakim; Parviainen, Arno; Anbarasan, Sasikala; Li, He; Makkonen, Laura; Bankar, Sandip; King, Alistair W.T.; Kilpeläinen, Ilkka; Benallaoua, Said; Turunen, Ossi; University of Béjaïa; University of Helsinki; Department of Bioproducts and Biosystems; Aalto University; Bioprocess engineeringThe use of enzymes in aqueous solutions of ionic liquids (ILs) could be useful for the enzymatic treatment of lignocellulose. Hydrophilic ILs that dissolve lignocellulose are harmful to enzymes. The toleration limits and enzyme-friendly superbase IL combinations were investigated for the hyperthermophilic Thermopolyspora flexuosa GH10 xylanase (endo-1,4-β-xylanase EC 3.2.1.8) TfXYN10A and Dictyoglomus thermophilum GH11 xylanase DtXYN11B. TfXYN10A was more tolerant than DtXYN11B to acetate or propionate-based ILs. However, when the anion of the ILs was bigger (guaiacolate), GH11 xylanase showed higher tolerance to ILs. 1-Ethyl-3-methylimidazolium acetate ([EMIM]OAc), followed by 1,1,3,3-tetramethylguanidine acetate ([TMGH]OAc), were the most enzyme-friendly ILs for TfXYN10A and [TMGH]+-based ILs were tolerated best by DtXYN11B. Double-ring cations and a large size anion were associated with the strongest enzyme inhibition. Competitive inhibition appears to be a general factor in the reduction of enzyme activity. However, with guaiacolate ILs, the denaturation of proteins may also contribute to the reduction in enzyme activity. Molecular docking with IL cations and anions indicated that the binding mode and shape of the active site affect competitive inhibition, and the co-binding of cations and anions to separate active site positions caused the strongest enzyme inhibition.Item An investigation on changes in composition and antioxidant potential of mature and immature summer truffle (Tuber aestivum)(Springer Verlag, 2020-04-01) Shah, Nirali; Usvalampi, Anne; Chaudhary, Sandeep; Seppänen-Laakso, Tuulikki; Marathe, Sandesh; Bankar, Sandip; Singhal, Rekha; Shamekh, Salem; Institute of Chemical Technology; Biohybrid Materials; VTT Technical Research Centre of Finland; Department of Bioproducts and Biosystems; Juva Truffle CenterSummer truffles (Tuber aestivum) collected from Italy were evaluated for changes in chemical composition and hence in vitro bioactivity on the basis of their maturity. Truffles were classified as immature and mature based on the colour of glebum. Water and methanol extracts of freeze-dried mature truffles demonstrated higher total phenolics, in vitro antioxidant activity, and lower tannins than immature truffle extracts. Phenolics and flavonoids were detected by liquid chromatography–mass spectroscopy (LC–MS) analysis. Gas chromatography (GC)–MS analysis of hexane extracts showed differences in fatty acid composition. Linoleic acid content was highest in both samples, and lauric and myristic acids were prominently detected in hexane extracts of mature truffles. The aroma profiling of truffles by headspace—GC showed an increase in alcohols and decrease in aldehydes. Thus this study comprehends altered chemical composition and its manifestation in in vitro bioactivity on maturation of summer truffles. This would aid in development of techniques for identification of maturity of truffles.
