Ultrasonically enhanced fractionation of milk fat in a litre-scale prototype vessel

The ultrasonic fractionation of milk fat in whole milk to fractions with distinct particle size distributions was demonstrated using a stage-based ultrasound-enhanced gravity separation protocol. Firstly, a single stage ultrasound gravity separation was characterised after various sonication durations (5–20 min) with a mass balance, where defined volume partitions were removed across the height of the separation vessel to determine the fat content and size distribution of fat droplets. Subsequent trials using ultrasound-enhanced gravity separation were carried out in three consecutive stages. Each stage consisted of 5 min sonication, with single and dual transducer configurations at 1 MHz and 2 MHz, followed by aliquot collection for particle size characterisation of the formed layers located at the bottom and top of the vessel. After each sonication stage, gentle removal of the separated fat layer located at the top was performed.Results indicated that ultrasound promoted the formation of a gradient of vertically increasing fat concentration and particle size across the height of the separation vessel, which became more pronounced with extended sonication time. Ultrasound-enhanced fractionation provided fat enriched fractions located at the top of the vessel of up to 13 ± 1% (w/v) with larger globules present in the particle size distributions. In contrast, semi-skim milk fractions located at the bottom of the vessel as low as 1.2 ± 0.01% (w/v) could be produced, containing proportionally smaller sized fat globules. Particle size differentiation was enhanced at higher ultrasound energy input (up to 347 W/L). In particular, dual transducer after three-stage operation at maximum energy input provided highest mean particle size differentiation with up to 0.9 μm reduction in the semi-skim fractions. Higher frequency ultrasound at 2 MHz was more effective in manipulating smaller sized fat globules retained in the later stages of skimming than 1 MHz. While 2 MHz ultrasound removed 59 ± 2% of the fat contained in the initial sample, only 47 ± 2% was removed with 1 MHz after 3 ultrasound-assisted fractionation stages.     

Design parameters for the separation of fat from natural whole milk in an ultrasonic litre-scale vessel

The separation of milk fat from natural whole milk has been achieved by applying ultrasonic standing waves (1 MHz and/or 2 MHz) in a litre-scale (5 L capacity) batch system. Various design parameters were tested such as power input level, process time, specific energy, transducer–reflector distance and the use of single and dual transducer set-ups. It was found that the efficacy of the treatment depended on the specific energy density input into the system. In this case, a plateau in fat concentration of ∼20% w/v was achieved in the creamed top layer after applying a minimum specific energy of 200 kJ/kg. In addition, the fat separation was enhanced by reducing the transducer reflector distance in the vessel, operating two transducers in a parallel set-up, or by increasing the duration of insonation, resulting in skimmed milk with a fat concentration as low as 1.7% (w/v) using raw milk after 20 min insonation. Dual mode operation with both transducers in parallel as close as 30 mm apart resulted in the fastest creaming and skimming in this study at ∼1.6 g fat/min.     

Cavitation and non-cavitation regime for large-scale ultrasonic standing wave particle separation systems – In situ gentle cavitation threshold determination and free radical related oxidation

We here suggest a novel and straightforward approach for liter-scale ultrasound particle manipulation standing wave systems to guide system design in terms of frequency and acoustic power for operating in either cavitation or non-cavitation regimes for ultrasound standing wave systems, using the sonochemiluminescent chemical luminol. We show that this method offers a simple way of in situ determination of the cavitation threshold for selected separation vessel geometry. Since the pressure field is system specific the cavitation threshold is system specific (for the threshold parameter range). In this study we discuss cavitation effects and also measure one implication of cavitation for the application of milk fat separation, the degree of milk fat lipid oxidation by headspace volatile measurements. For the evaluated vessel, 2 MHz as opposed to 1 MHz operation enabled operation in non-cavitation or low cavitation conditions as measured by the luminol intensity threshold method. In all cases the lipid oxidation derived volatiles were below the human sensory detection level. Ultrasound treatment did not significantly influence the oxidative changes in milk for either 1 MHz (dose of 46 kJ/L and 464 kJ/L) or 2 MHz (dose of 37 kJ/L and 373 kJ/L) operation.     

Creaming enhancement in a liter scale ultrasonic reactor at selected transducer configurations and frequencies

Recent research has shown that high frequency ultrasound (0.4–3 MHz), can enhance milkfat separation in small scale systems able to treat only a few milliliters of sample. In this work, the effect of ultrasonic standing waves on milkfat creaming was studied in a 6 L reactor and the influence of different frequencies and transducer configurations in direct contact with the fluid was investigated. A recombined coarse milk emulsion with fat globules stained with oil-red-O dye was selected for the separation trials. Runs were performed with one or two transducers placed in vertical (parallel or perpendicular) and horizontal positions (at the reactor base) at 0.4, 1 and/or 2 MHz (specific energy 8.5 ± 0.6 kJ/kg per transducer). Creaming behavior was assessed by measuring the thickness of the separated cream layer. Other methods supporting this assessment included the measurement of fat content, backscattering, particle size distribution, and microscopy of samples taken at the bottom and top of the reactor. Most efficient creaming was found after treatment at 0.4 MHz in single and double vertical transducer configurations. Among these configurations, a higher separation rate was obtained when sonicating at 0.4 MHz in a vertical perpendicular double transducer setup. The horizontal transducer configuration promoted creaming at 2 MHz only. Fat globule size increase was observed when creaming occurred. This research highlights the potential for enhanced separation of milkfat in larger scale systems from selected transducer configurations in contact with a dairy emulsion, or emulsion splitting in general.     

Ultrasound improves the renneting properties of milk

The effects of ultrasound application on skim milk (10% w/w total solids at natural pH 6.7 or alkali-adjusted to pH 8.0) prior to the renneting of milk at pH 6.7 were examined. Skim milk, made by reconstituting skim milk powder, was sonicated at 20 kHz and 30 °C (dissipated power density 286 kJ kg⁻¹) in an ultrasonic reactor. The rennet gelation time, curd firming rate, curd firmness, and the connectivity of the rennet gel network were improved significantly in rennet gels made from milk ultrasonicated at pH 8.0 and re-adjusted back to pH 6.7 compared to those made from milk sonicated at pH 6.7. These renneting properties were also improved in milk sonicated at pH 6.7 compared to those of the non-sonicated control milk. The improvements in renneting behavior were related to ultrasound-induced changes to the proteins in the milk. This study showed that ultrasonication has potential to be used as an intervention to manipulate the renneting properties of milk for more efficient manufacturing of cheese.     

Lipid oxidation volatiles absent in milk after selected ultrasound processing

Ultrasonic processing can suit a number of potential applications in the dairy industry. However, the impact of ultrasound treatment on milk stability during storage has not been fully explored under wider ranges of frequencies, specific energies and temperature applications. The effect of ultrasonication on lipid oxidation was investigated in various types of milk. Four batches of raw milk (up to 2 L) were sonicated at various frequencies (20, 400, 1000, 1600 and 2000 kHz), using different temperatures (4, 20, 45 and 63 °C), sonication times and ultrasound energy inputs up to 409 kJ/kg. Pasteurized skim milk was also sonicated at low and high frequency for comparison. In selected experiments, non-sonicated and sonicated samples were stored at 4 °C and were drawn periodically up to 14 days for SPME–GCMS analysis. The cavitational yield, characterized in all systems in water, was highest between 400 kHz and 1000 kHz. Volatile compounds from milk lipid oxidation were detected and exceeded their odor threshold values at 400 kHz and 1000 kHz at specific energies greater than 271 kJ/kg in raw milk. However, no oxidative volatile compounds were detected below 230 kJ/kg in batch systems at the tested frequencies under refrigerated conditions. Skim milk showed a lower energy threshold for oxidative volatile formation. The same oxidative volatiles were detected after various passes of milk through a 0.3 L flow cell enclosing a 20 kHz horn and operating above 90 kJ/kg. This study showed that lipid oxidation in milk can be controlled by decreasing the sonication time and the temperature in the system depending on the fat content in the sample among other factors.     

Physicochemical characterization of black seed oil-milk emulsions through ultrasonication

The ultrasonic formation of stable emulsions of a bioactive material, black seed oil, in skim milk was investigated. The incorporation of 7% of black seed oil in pasteurised homogenized skim milk (PHSM) using 20 kHz high intensity ultrasound was successfully achieved. The effect of sonication time and acoustic power on the emulsion stability was studied. A minimum process time of 8 min at an applied acoustic power of 100 W was sufficient to produce emulsion droplets stable for at least 8 days upon storage at 4 ± 2 °C, which was confirmed through creaming stability, particle size, rheology and color analysis. Partially denatured whey proteins may provide stability to the emulsion droplets and in addition to the cavitation effects of ultrasound are responsible for the production of smaller sized emulsion droplets.     

Water and lipid diffusion MRI using chemical shift displacement-based separation of lipid tissue (SPLIT)

PurposeTo obtain water and lipid diffusion-weighted images (DWIs) simultaneously, we devised a novel method utilizing chemical shift displacement-based separation of lipid tissue (SPLIT) imaging.Materials and methodsSingle-shot diffusion echo-planar imaging without fat suppression was used and the imaging parameters were optimized to separate water and lipid DWIs by chemical shift displacement of the lipid signals along the phase-encoding direction. Using the optimized conditions, transverse DWIs at the maximum diameter of the right calf were scanned with multiple b-values in five healthy subjects. Then, apparent diffusion coefficients (ADCs) were calculated in the tibialis anterior muscle (TA), tibialis bone marrow (TB), and subcutaneous fat (SF), as well as restricted and perfusion-related diffusion coefficients (D and D*, respectively) and the fraction of the perfusion-related diffusion component (F) for TA.ResultsWater and lipid DWIs were separated adequately. The mean ADCs of the TA, TB, and SF were 1.56 ± 0.03 mm²/s, 0.01 ± 0.01 mm²/s, and 0.06 ± 0.02 mm²/s, respectively. The mean D*, D, and F of the TA were 13.7 ± 4.3 mm²/s, 1.48 ± 0.05 mm²/s, and 4.3 ± 1.6%, respectively.ConclusionSPLIT imaging makes it possible to simply and simultaneously obtain water and lipid DWIs without special pulse sequence and increases the amount of diffusion information of water and lipid tissue.     

Ultrasound assisted enzymatic pre-treatment of high fat content dairy wastewater

This paper illustrates the application of ultrasound in a dairy waste water treatment for the removal of fat using enzyme as a catalyst. Lipase Z was used to perform the enzymatic pre-hydrolysis of a synthetic dairy wastewater containing around 2000 mg/L of fat content coupled with ultrasound irradiation. Different process parameters like effect of enzyme loading, temperature, ultrasound power, frequency, duty cycle and speed of agitation are optimized. The maximum hydrolysis of 78% is achieved at 0.2% enzyme loading (w/v), 30 °C temperature, 165 W of ultrasonication power at 25 kHz and 66% duty cycle. It was observed that the enzymatic pre-hydrolysis under the influence of ultrasound drastically reduces the reaction time from 24 h to 40 min as compared to conventional stirring with improved yield.     

Advances in high frequency ultrasound separation of particulates from biomass

In recent years the use of high frequency ultrasound standing waves (megasonics) for droplet or cell separation from biomass has emerged beyond the microfluidics scale into the litre to industrial scale applications. The principle for this separation technology relies on the differential positioning of individual droplets or particles across an ultrasonic standing wave field within the reactor and subsequent biomass material predisposition for separation via rapid droplet agglomeration or coalescence into larger entities. Large scale transducers have been characterised with sonochemiluminescence and hydrophones to enable better reactor designs. High frequency enhanced separation technology has been demonstrated at industrial scale for oil recovery in the palm oil industry and at litre scale to assist olive oil, coconut oil and milk fat separation. Other applications include algal cell dewatering and milk fat globule fractionation. Frequency selection depends on the material properties and structure in the biomass mixture. Higher frequencies (1 and 2 MHz) have proven preferable for better separation of materials with smaller sized droplets such as milk fat globules. For palm oil and olive oil, separation has been demonstrated within the 400–600 kHz region, which has high radical production, without detectable impact on product quality.     

Atomic structure of Cs grown on Si(0 0 1)(2×1) surface by coaxial impact collision ion scattering spectroscopy

The atomic structure and the saturation coverage of Cs on the Si(0 0 1)(2×1) surface at room temperature have been studied by coaxial impact collision ion scattering spectroscopy (CAICISS). For the atomic structure of saturated Cs/Si(0 0 1)(2×1) surface, it is found that Cs atoms occupy a single adsorption site at T3 on the Si(0 0 1) surface. The height of Cs atoms adsorbed at T3 site is 3.18±0.05 Å from the second layer of Si(0 0 1)(2×1) surface. The saturation coverage estimated from the measured CAICISS intensity ratio and the proposed atomic structure is found to be 0.46±0.06 ML.     

Effects of processing parameters in the sonic assisted water extraction (SAWE) of 6-gingerol

The use of water in subcritical conditions for extraction has several drawbacks. These include the safety features, higher production costs and possible degradation of the bioactive compounds. To overcome these problems, sonic energy and an entrainer were used as external interventions to decrease the polarity of water at milder operating conditions. The effect of low (28 kHz) and high (800 kHz) frequencies of sonication in the extraction of the main ginger bioactive compound (6-gingerol) were compared. Six parameters were studied: mean particle size (MPS, mm), time of extraction, applied power, sample to solvent ratio (w/v), temperature of extraction, and the percentage of entrainer. The optimum conditions for high frequency SAWE prototype were MPS 0.89–1.77 mm, 45 min, 40 W applied power, 1:30 (w/v), 45 °C, and 15% of ethanol as entrainer. Two-way analysis of variance (ANOVA) gave the most significant parameter, which was power with F (1, 45.07), p < 2.50 × 10⁻⁹. Although the effect of low frequency was stronger than high frequency, at the optimum conditions of the sample to solvent ratio 1:30 (w/v) with 700 mL solvent and temperature 45 °C, the concentration and recovery of 6-gingerol from high frequency of SAWE prototype was 2.69 times higher than at low frequency of SAWE. It was found that although the effects of high frequency (800 kHz) were negligible in other studies, it could extract suitable compounds, such as 6-gingerol, at lower temperature. Therefore, the effects of sonication, which cause an enlargement in the cell wall of the ginger plant matrix, were observed using a Scanning Electron Microscope (SEM). It was found that the applied power of sonication was the most significant parameter compared to the other parameters.     

Formulation of saponin stabilized nanoemulsion by ultrasonic method and its role to protect the degradation of quercitin from UV light

The objective of the present study was to prepare quercitin (QT) loaded o/w nanoemulsion using food grade surfactants (saponin and tween 80). The prepared nanoemulsion) was stable up to 30 days. The average particle size of the nanoemulsion was 52 ± 10 nm. The formation of saponin stabilized nanoemulsion was confirmed by transmission electron microscopy. Quercitin (QT) trapped nanoemulsion showed higher stability on exposure to UV light (254 nm) as compared to water/ethanol system. The degradation rate was found to decrease from 9 ± 1%, 11 ± 1% at pH 7.4, 8.0 respectively as compared to 42 ± 2% in water/ethanol system. Attempt was also made to study the interaction of QT with two different bile salts (sodium cholate and sodium taurocholate). The free radical scavenging activity of DPPH quercitin and curcumin was compared in NEm media. The obtained IC₅₀ value of quercitin, curcumin and ascorbic acid are 28.88 ± 1, 45.53 ± 2 and 51.51 ± 2 μM respectively. The values of binding constant for sodium cholate (NaC) and sodium taurocholate (NaTC) are 2.66 × 10⁵ and 2.72 × 10⁴ M⁻¹ respectively. Sodium cholate (NaC) was found to show strong interaction towards quercitin (QT) due to more electron density on oxygen atom of carboxylate ion.     

Connection between biomechanics and cytoskeleton structure of lymphocyte and Jurkat cells: An AFM study

The mechanical properties of cells are important for many cellular processes. Here, atomic force microscopy (AFM) and laser scanning confocal microscopy (LSCM) were carried out to characterize lymphocyte and Jurkat cells. The average elastic modulus of lymphocyte is 1.24 ± 0.09 kPa, which is almost twofold higher than that of Jurkat cell (0.51 ± 0.06 kPa). LSCM images of sub-membrane cytoskeleton showed a significant difference in the organization of their F-actin structures. Lymphocyte cells had more and thicker actin bundles than that of Jurkat cells. Lymphocyte and Jurkat cells after adding the F-actin destabilizing agent Cytochalasin-B (Cyt-B) were also investigated by AFM. A decrease in the elastic modulus of lymphocyte from a value of 1.24 ± 0.09 kPa down to 0.34 ± 0.04 kPa for 24 h was observed, and that of Jurkat cell decreased from 0.51 ± 0.06 kPa to 0.23 ± 0.04 kPa. We really believe that this technology will be used for cancer detection and opens a door to study the biophysical properties of signaling domains extending from the cell surface to deeper parts of the cell.     

Quantitative Dixon MRI sequences to relate muscle atrophy and fatty degeneration with range of motion and muscle force in brachial plexus injury

BackgroundAssessment of muscle atrophy and fatty degeneration in brachial plexus injury (BPI) could yield valuable insight into pathophysiology and could be used to predict clinical outcome. The objective of this study was to quantify and relate fat percentage and cross-sectional area (CSA) of the biceps to range of motion and muscle force of traumatic brachial plexus injury (BPI) patients.MethodsT1-weighted TSE sequence and three-point Dixon images of the affected and non-affected biceps brachii were acquired on a 3 Tesla magnetic resonance scanner to determine the fat percentage, total and contractile CSA of 20 adult BPI patients. Regions of interest were drawn by two independent investigators to determine the inter-observer reliability. Paired Students' t-test and multivariate analysis were used to relate fat percentage, total and contractile CSA to active flexion and biceps muscle force.ResultsThe mean fat percentage 12 ± 5.1% of affected biceps was higher than 6 ± 1.0% of the non-affected biceps (p < 0.001). The mean contractile CSA 8.1 ± 5.1 cm² of the affected biceps was lower than 19.4 ± 4.9 cm² of the non-affected biceps (p < 0.001). The inter-observer reliability was excellent (ICC 0.82 to 0.96). The contractile CSA contributed most to the reduction in active flexion and muscle force.ConclusionQuantitative measurement of fat percentage, total and contractile CSA using three-point Dixon sequences provides an excellent reliability and relates with active flexion and muscle force in BPI.     

Submillimeter-wave measurements of N2 and O2 pressure broadening for HO2 radical generated by Hg-photosensitized reaction

The N₂ and O₂ pressure broadening coefficients of the pure rotational transitions at 625.66 GHz (N_KaKc=10_1?9–10_0?10, J=10.5–10.5) and 649.70 GHz (N_KaKc=10_2?9–9_2?8, J=9.5–8.5) in the vibronic ground state X²A′ of the perhydroxyl (HO₂) radical have been determined by precise laboratory measurements. For the production of HO₂, the mercury-photosensitized reaction of the H₂ and O₂ precursors was used to provide an optimum condition for measurement of the pressure broadening coefficient. The Superconducting Submillimeter-wave Limb Emission Sounder (SMILES) was designed to monitor the volume mixing ratio of trace gases including HO₂ in the Earth's upper atmosphere using these transitions. The precise measurement of pressure broadening coefficient γ in terms of the half width at half maximum is required in order to retrieve the atmospheric volume mixing ratio. In this work, γ coefficients of the 625.66 GHz transition were determined for N₂ and O₂ at room temperature as γ(N₂)=4.085±0.049 MHz/Torr and γ(O₂)=2.578±0.047 MHz/Torr with 3σ uncertainty. Similarly, the coefficients of the 649.70 GHz transition were determined as γ(N₂)=3.489±0.094 MHz/Torr and γ(O₂)=2.615±0.099 MHz/Torr. The air broadening coefficients for the 625.66 GHz and 649.70 GHz lines were estimated at γ(air)=3.769±0.067 MHz and 3.298±0.099 MHz respectively, where the uncertainty includes possible systematic errors. The newly determined coefficients are compared with previous results and we discuss the advantage of the mercury-photosensitized reaction for HO₂ generation. In comparison with those of other singlet molecules, the pressure broadening coefficients of the HO₂ radical are not much affected by the existence of an unpaired electron.     

Fabry–Pérot cavities based on chemical etching for high temperature and strain measurement

In this paper, two hybrid multimode/single mode fiber Fabry–Pérot (FP) cavities were compared. The cavities fabricated by chemical etching are presented as high temperature and strain sensors. In order to produce this FP cavity a single mode fiber was spliced to a graded index multimode fiber with 62.5 μm core diameter. The Fabry–Pérot cavities were tested as a high temperature sensor in the range between room temperature and 700 °C and as strain sensors. A reversible shift of the interferometric peaks with temperature allowed to estimate a sensitivity of 0.75 ± 0.03 pm/°C and 0.98 ± 0.04 pm/°C for the sensor A and B respectively. For strain measurement sensor A demonstrated a sensitivity of 1.85 ± 0.07 pm/μ? and sensor B showed a sensitivity of 3.14 ± 0.05 pm/μ?. The sensors demonstrated the feasibility of low cost fiber optic sensors for high temperature and strain.     

Accelerating MRI fat quantification using a signal model-based dictionary to assess gastric fat volume and distribution of fat fraction

To quantify intragastric fat volume and distribution with accelerated magnetic resonance (MR) imaging using signal model-based dictionaries (DICT) in comparison to conventional parallel imaging (CG-SENSE). This study was approved by the local ethics committee and written informed consent was obtained. Seven healthy subjects were imaged after intake of a lipid emulsion and data at three different time points during the gastric emptying process was acquired in order to cover a range of fat fractions. Fully sampled and prospectively undersampled image data at a reduction factor of 4 were acquired using a multi gradient echo sequence at 1.5T. Retrospectively and prospectively undersampled data were reconstructed with DICT and CG-SENSE. Image quality of the retrospectively undersampled data was assessed relative to the fully sampled reference using the root mean square error (RMSE). In order to assess the agreement of fat volumes and intragastric fat distribution, Bland-Altman analysis and linear regression were performed on the data. The RMSE in intragastric content (ΔRMSE = 0.10 ± 0.01, P < 0.001) decreased significantly with DICT relative to CG-SENSE. CG-SENSE overestimated fat volumes (bias 2.1 ± 1.3 mL; confidence limits 5.4 and − 1.1 mL) in comparison to the prospective DICT reconstruction (bias − 0.1 ± 0.7 mL; confidence limits 1.8 and − 2.0 mL). There was a good agreement in fat distribution between the images reconstructed by retrospective DICT and the reference images (regression slope: 1.01, R² = 0.961). Accelerating gastric MRI by integrating a dictionary-based signal model allows for improved image quality and increases accuracy of fat quantification during breathholds.     

Targeted microbubbles for ultrasound mediated gene transfection and apoptosis induction in ovarian cancer cells

Ultrasound-targeted microbubble destruction (UTMD) technique can be potentially used for non-viral delivery of gene therapy. Targeting wild-type p53 (wtp53) tumor suppressor gene may provide a clinically promising treatment for patients with ovarian cancer. However, UTMD mediated gene therapy typically uses non-targeted microbubbles with suboptimal gene transfection efficiency. We synthesized a targeted microbubble agent for UTMD mediated wtp53 gene therapy in ovarian cancer cells. Lipid microbubbles were conjugated with a Luteinizing Hormone–Releasing Hormone analog (LHRHa) via an avidin–biotin linkage to target the ovarian cancer A2780/DDP cells that express LHRH receptors. The microbubbles were mixed with the pEGFP-N1-wtp53 plasmid. Upon exposure to 1 MHz pulsed ultrasound beam (0.5 W/cm²) for 30 s, the wtp53 gene was transfected to the ovarian cancer cells. The transfection efficiency was (43.90 ± 6.19)%. The expression of wtp53 mRNA after transfection was (97.08 ± 12.18)%. The cell apoptosis rate after gene therapy was (39.67 ± 5.95)%. In comparison with the other treatment groups, ultrasound mediation of targeted microbubbles yielded higher transfection efficiency and higher cell apoptosis rate (p < 0.05). Our experiment verifies the hypothesis that ultrasound mediation of targeted microbubbles will enhance the gene transfection efficiency in ovarian cancer cells.     

Mechanistic study on ultrasound assisted pretreatment of sugarcane bagasse using metal salt with hydrogen peroxide for bioethanol production

This study presents the ultrasound assisted pretreatment of sugarcane bagasse (SCB) using metal salt with hydrogen peroxide for bioethanol production. Among the different metal salts used, maximum holocellulose recovery and delignification were achieved with ultrasound assisted titanium dioxide (TiO₂) pretreatment (UATP) system. At optimum conditions (1% H₂O₂, 4 g SCB dosage, 60 min sonication time, 2:100 M ratio of metal salt and H₂O₂, 75 °C, 50% ultrasound amplitude and 70% ultrasound duty cycle), 94.98 ± 1.11% holocellulose recovery and 78.72 ± 0.86% delignification were observed. The pretreated SCB was subjected to dilute acid hydrolysis using 0.25% H₂SO₄ and maximum xylose, glucose and arabinose concentration obtained were 10.94 ± 0.35 g/L, 14.86 ± 0.12 g/L and 2.52 ± 0.27 g/L, respectively. The inhibitors production was found to be very less (0.93 ± 0.11 g/L furfural and 0.76 ± 0.62 g/L acetic acid) and the maximum theoretical yield of glucose and hemicellulose conversion attained were 85.8% and 77%, respectively. The fermentation was carried out using Saccharomyces cerevisiae and at the end of 72 h, 0.468 g bioethanol/g holocellulose was achieved. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis of pretreated SCB was made and its morphology was studied using scanning electron microscopy (SEM). The compounds formed during the pretreatment were identified using gas chromatography–mass spectrometry (GC–MS) analysis.