Recovery Of Aroma Compounds Research Articles

Pervaporative recovery of aroma compounds in the production of non-alcoholic beers: Incorporation of different condensation strategies into the conceptual design of the process

The study carried out in the present work focused on the conceptual design of the aroma recovery stage of from a lager beer by pervaporation with a PDMS membrane taking into account the condensation step.First, using laboratory-scale experiments, the performance of the Pervatech PDMS membrane was measured in terms of aroma recovery, ratio of higher alcohols to esters (A/E ratio), ethanol flux and overall flux for different operating conditions. In addition, model was obtained that adequately characterized the fluxes through the membrane as a function of temperature and permeate pressure. This model allowed estimating the membrane area requirements for different operating conditions.Secondly, the possibility of using two partial condensers in the condensation stage to approximate the A/E ratio of a lager beer was explored through simulations. Influence of operating conditions and presence of CO2 and air on values for the A/E ratio, the overall fractional recovery of aroma compounds and the economics of the process were modeled. Both the case of mixing condensates obtained from the two condensers and that of an optimal combination of condensates were taken into account in order to approximate the A/E ratio of the lager beer.The best alternative for this variant was the one corresponding to the operating conditions of 30 °C temperature and a pressure of 2.13 kPa for the pervaporation stage, with two partial condensers in series operating at −5 °C and −46 °C, respectively. In this way, two condensates would be obtained which, when combined in a 0.43/1 ratio for subsequent reincorporation into the dealcoholized beer, would result in a product maintaining the (A/E) ratio of the original beer. Under these conditions, a recovery of 14.1% of aromas would be achieved with a total cost of 0.1070 USD/L.Finally, the state-of-the-art alternative consisting of two total condensers condensers in parallel working out of phase was also considered. Results indicate that, if properly designed, the A/E ratio obtained at lab scale level would coincide with that achieved after total condensation and thus, the adjustability of the ratio of higher alcohols to esters would decrease with respect to that achieved when partial condensers are used. Although the use of a total condenser results in more expensive designs, this alternative is very advantageous in terms of overall aroma recovery and process feasibility.From the results obtained, the importance of developing conceptual models that make use of both experimental runs of the aroma recovery process at laboratory scale and simulations of the condensation process from parameters corresponding to the vapour-liquid equilibrium of the multi-component system can be deduced.

Formation, Losses, Preservation and Recovery of Aroma Compounds in the Winemaking Process

A wine’s aroma profile is an important part of the criteria affecting wine acceptability by consumers. Its characterisation is complex because volatile molecules usually belong to different classes such as alcohols, esters, aldehydes, acids, terpenes, phenols and lactones with a wide range of polarity, concentrations and undesirable off-aromas. This review focused on mechanisms and conditions of the formation of individual aroma compounds in wine such as esters and higher alcohols by yeast during fermentation. Additionally, aroma losses during fermentation are currently the subject of many studies because they can lead to a reduction in wine quality. Principles of aroma losses, their prevention and recovery techniques are described in this review.

Recovery of Aromatics from Orange Juice Evaporator Condensate Streams by Reverse Osmosis.

The aim of this work was to analyze the potential of reverse osmosis (RO) membranes in the recovery and concentration of aroma compounds from orange juice evaporator condensate (EC) streams. Concentration experiments were performed by using three RO spiral-wound aromatic polyamide membranes (SG1812C-34D, SC1812C-34D and SE1812) with different NaCl rejections. The effect of transmembrane pressure, axial feed flowrate and volume concentration ratio (VCR) on permeate flux was studied. Rejections of the investigated membranes towards specific aroma compounds (octanol, α-terpineol, terpinen-4-ol, cis-carveol, karvon, linalool) in selected operating conditions were also evaluated. The concentrations of the aroma compounds were determined by gas chromatography coupled with mass spectrometry (GC-MS) using headspace solid-phase microextraction (HS-SPME) as a sample preparation approach. For all selected membranes, the permeate flux increased linearly by increasing the operating pressure from 5 to 25 bar; on the other hand, the feed flowrate did not have any significant effect on the permeate flux. High retention values towards aroma compounds (>80%) were measured for all selected membranes. However, the SC membrane showed the highest rejection values (>96%) and the best correlation between concentration factor of aroma compounds and VCR.

Membrane-Based Operations in the Fruit Juice Processing Industry: A Review

The fruit juice industry is one of the food sectors that has invested the most in the implementation of new technologies, such as non-thermal technologies. Among them, membrane processes are considered today well-established separation techniques to support the production and marketing of innovative fruit juices designed to exploit the sensory characteristics and nutritional peculiarities of fresh fruits. Pressure-driven membrane operations, membrane distillation, osmotic distillation and pervaporation have been widely investigated in the last few decades to replace conventional technologies used in fruit juice processing industry (i.e., clarification, stabilization, concentration and recovery of aroma compounds). This paper will review the significant progresses on the use of membrane-based operations in fruit juice processing industry in the light of the growing interest towards products with improved safety, quality and nutritional value and sustainable processes characterized by low energy consumption and low environmental impact.

Concentration of aroma compounds by pervaporation process using polyvinyl chloride membrane

AbstractThe organoleptic properties of beverage products have an important role in consumption and commercial success. Nowadays aroma recovery with high efficiency is an important process. Hydrophobic pervaporation is an alternative process for the recovery of aroma compounds in the food industry. The purpose of this study was to determine the effects of operation temperature, feed concentration, and driving force on the recovery of different aroma compounds such as propyl acetate, pentyl acetate, and octyl acetate by pervaporation. Pervaporation was operated using a Polyvinyl Chloride hydrophobic membrane. As the process temperature and the feed concentration increased, the flux increased, but separation factor values of binary aqueous solutions of the aroma components propyl acetate, pentyl acetate, and octyl acetate decreased. Polyvinyl Chloride possessed a higher separation factor value for propyl acetate than octyl acetate and pentyl acetate. This situation was also confirmed with swelling tests and solubility parameters. Low‐swelling degree results in a high separation factor. The highest separation success was observed for propyl acetate. The flux and separation factor of propyl acetate were obtained as 1.57 kg m−2 h−1 and 158, respectively. It has been found that the pervaporation is an efficient process for aroma recovery from water and that the polyvinyl chloride membrane exhibits good separation performance from the removal of propyl acetate, pentyl acetate, and octyl acetate from the water.

Adsorption and recovery of aroma compounds from wastewater of clove oil distillation using coffee husk biosorbent

Adsorption and recovery of aroma compounds from wastewater of clove oil distillation using coffee husk biosorbent

Characteristic of aroma compounds recovery from binary and ternary (alcohol-ester-water) aqueous solutions with use of pervaporation

The aim of this study was to examine and quantitatively describe how the coupling phenomenon affects the pervaporation. In the first stage binary water-alcohol (ethanol; isopentanol) and water-ester (methyl butyrate; butyl acetate) mixtures were examined. In the second stage three different ternary water-ester-alcohol solutions have been separated with the use of commercially available PDMS (polydimethyl siloxane) membrane and the effect of separation was expressed with the semi-empirical Arrhenius-like equation and strictly empirical Response Surface Methodology (RSM). Modelling results show that the coupling phenomenon is very case-specific, and the addition of another species to the separated solution could have both a negative and positive impact on the productivity and separation efficiency, depending on the characteristic of penetrant-penetrant and membrane-penetrant interactions. The relationship between process parameters and coupling effects strongly affects pervaporation performance, and yields dissimilar results for various concentrations of feed components in multicomponent systems.

Simulation of spirits distillation for a better understanding of volatile aroma compounds behavior: Application to Armagnac production

A methodology for the simulation of spirits continuous distillation was developed and applied to the analysis of an Armagnac unit, using the software ProSimPlus®. Distillation data for 66 aroma compounds were acquired during an experimental campaign and 32 of these species were simulated with the NRTL model, using interaction parameters estimated from equilibria data at high dilution.Validation of static simulations against reconciled experimental data showed that the recovery of aroma compounds from wine to distillate can be predicted with good precision. Considering relative volatilities and composition profiles, three main groups of aroma compounds were proposed: (I) light compounds (recovered in distillate), (II) intermediary compounds (distributed between distillate and vinasse) and (III) heavy compounds (recovered in vinasse).After validation of the nominal point, the influence of some operating parameters was investigated. According to simulation, three parameters, namely, tails extractions, ethanol concentration in distillate and distillate temperature, have a real impact on Spirit composition. They permit a preferential reduction of intermediary and heavy species with respect to ethanol. Comparison with experimental and literature data confirms that simulation is a powerful and reliable approach to analyze the synergy between process operation, its performance and Spirit composition.

Techniques for the recovery of volatile aroma compounds from biochemical broth: A review

AbstractFlavours, fragrances, or aromas are valuable chemicals, with a broad range of industrial applications. The consumer's preference for ‘naturally’ manufactured aromas drives the development of biochemical production, which requires suitable product recovery. In this study, different industrially established recovery techniques, their advantages and limitations, and their possible application for aroma recovery from crude fermentation broth are reviewed. Among several techniques discussed, absorption, adsorption, and pervaporation appear to be particularly suitable for the recovery of aromas from highly diluted biochemical mixtures.

Use of pervaporation process for the recovery of aroma compounds produced by P. fermentans in sugarcane molasses.

Natural fruity aroma was produced during submerged fermentation by Pichia fermentans using sugarcane molasses as a cultivation broth. The aroma compounds were recovered from the fermentation by a pervaporation process using a polydimethylsiloxane membrane (Pervap 4060-Sulzer). Isoamyl acetate, a characteristic compound associated with fruity aromas, was the major compound produced. The pervaporation module was fed at three different temperatures to test the best conditions to recover the natural fruity aroma. The total flux (J T), partial fluxes of each component (J i), and enrichment factors (β) were determined within the tested ranges. The process was performed at 45 °C, a feed flow of 1.5mL/min and 0.1kPa, for a duration of 13h to concentrate the natural flavor. The pervaporation process can concentrate the isoamyl acetate from fermented broth from 9 to 61.8mg/L in the first hour of pervaporation. As a single step of downstream operation, pervaporation was efficient for recovering and concentrating the natural fruity aroma. The obtained product was colorless and had a characteristic banana flavor.

Simulation of Recovery of Aroma Compound from Aqueous Solutions by Batch Pervaporation Coupled with Permeate Decantation and Water Phase Recycle

In this work, the dynamic (batch) models of recovery of low soluble aroma compounds from aqueous solutions by pervaporation coupled with permeate decantation and water phase recycle was derived and simulated. The model was run to simulate the pervaporation of propyl propionate-water separation using PEBA membrane. The effect of two parametric models (i.e. ratio of feed mass over membrane area (F0/Am) and the aroma solubility in water) on the aroma compound recovery was studied. As compared to the conventional pervaporation, the application of water phase recycle was known to be able to enhance the recovery of aroma compounds in various extents, depending on the operating time and aroma solubility. The larger membrane area used (or smaller (F0/Am)) did not affect the maximum aroma compound recovery, but only shortened the operating time. For the aroma solubility of 0.56, 1, and 5 wt.%, referring to the optimum operating time in the conventional mode, the extent of improvement in recovery can be around 7, 10 and 16%, respectively. The modified pervaporation process also offered another advantage that the process would not be strictly restricted by the operating time due to permanent increase in cumulative mass of aroma compound recovered in the product.

Mathematical modeling of aroma compound recovery from natural sources using hollow fiber membrane contactors with small packing fraction

A numerical simulation was carried out in order to investigate aroma compounds recovery from aqueous phase using an organic solvent. A hollow-fiber membrane contactor with small packing fraction was selected to be used in the study. Momentum, continuity and mass transfer equations were solved simultaneously utilizing finite element method. The simulation results showed that solving the Navier–Stokes equations has significantly diminished average deviation about 55% compared to Happle’s velocity model. Simulation results revealed that mass transfer resistance increases along the contactor length in both tube and shell sides. It seems that it is due to the increasing thickness of the boundary layer. Enhancement of the solvent velocity could result in increasing mass transfer rate through the membrane. However, it reduced the extraction efficiency of aroma compounds. Moreover, recovery of 2-hexanal was higher than benzaldehyde due to its higher partition coefficient. Furthermore, n-hexane has higher extraction efficiency than miglyol because of lower Schmidt number.

Mathematical modeling of sorption step in pervaporative aroma compounds recovery from the multicomponent solution

The present work describes sorption characteristics of volatile aroma compounds in pervaporation of the multicomponent aroma solution. A better understanding of the mass transfer mechanism is essential in that, among other it improves the process of designing new pervaporation membranes or that it lends itself to be used for scale-up studies. One of the two mass transport stages that are reported to have the predominant effect on pervaporation efficiency and selectivity is aroma compounds sorption in membrane material. The objective of this study was to examine the applicability of the Flory Huggins (F–H) theory and its three modifications in the modeling of sorption equilibria in hydrophobic pervaporation of a model multicomponent solution. The sorption experiments of isopentanol–methyl butyrate–polydimethylsiloxane were conducted in a wide range of feed concentrations and temperatures. The results of the experiments were used to ascertain parameters of models based on the original Flory–Huggins theory and on modifications proposed in the scientific literature. Three different models were used for data fitting, yielding the values of the coefficients of determination that range between 0.73 and 0.98. The influence of both, temperature and concentration on the model parameter was determined and the sorption separation factors were compared with pervaporation experimental results.

Recovery of aroma compounds from model solution by pervaporation membrane

The aim of our study was to examine applicability of pervaporation in reference to the apple aroma recovery and the effects of the operating parameters on the process. Based on performed experiments the pervaporation, as membrane process, may be capable to reduce the loss of aroma compounds in the beverages production, due to its low operating temperature and high aroma recovery efficiency so organoleptic characteristics of the products would satisfy the growing consumer expectations as well. The studied main aroma compounds were i-amyl-alcohol, ethanol, butanol, i-butanol, ethyl-acetate, which could be separated with high selectivity. The values of activation energy of investigated compounds follow their order of polarity that requires further investigation. The data were analysed statistically, which showed negligible effects of flow-rate and initial concentration on the process.

Recovery of aroma compounds from seafood cooking juices by membrane processes

Cooking juices are fish industry effluents with high organic and salt contents, typically 10–20gCODL−1 and 20–30gsaltL−1. They contain valuable substances (mainly aromas and proteins) that can be recovered, thereby significantly lowering treatment cost and offering a commercial gain for the food industry.The use of membrane processes to concentrate aromas in the cooking juices of fish and shellfish/crustaceans is reviewed, and some issues related to the technical and economic feasibility of industrial processes are highlighted.The issue of process design and economic evaluation is illustrated by a case study of a batch process concentrating shrimp aromas by reverse osmosis, and desalting juices by electrodialysis. The analysis shows that the sizing of this integrated process does not require systematic evaluations of CAPEX and OPEX, but can be done by considering only two simple criteria, namely minimizing energy consumption and the total membrane surface installed. In addition, when the characteristics of the processed juices change in time, the best solution should be determined by considering not only the process costs but also the ability of the process to adequately treat juices with different characteristics.

Computational fluid dynamics modeling of mass transfer for aroma compounds recovery from aqueous solutions by hydrophobic pervaporation

In this work, a mass transfer study on aroma compound recovery by pervaporation process was performed using a model based on solution–diffusion theory. CFD method was employed to solve the governing mass transfer equations by considering the flux coupling. Concentration profiles of penetrants inside the membrane as well as permeation flux and aroma permeate concentration through the membrane were determined. The modeling results were validated by the experimental data obtained for pervaporative recovery of isopentyl acetate and n-hexanol from their binary aqueous solutions with composite PDMS membrane. The influence of key operating parameters such as feed aroma concentration and temperature on the flux and permeate concentration was also investigated theoretically and experimentally. The results showed that the aroma permeate concentration as well as the total and partial fluxes increased with an increase in the feed aroma content and feed temperature. The predicted results were in good agreement with experimental data.

Dynamic modeling and simulation of an alembic pear wine distillation

In this research a phase equilibrium model to predict the recovery of several aroma compounds in spirits distilled in a traditional Charentais alembic has been developed. Due to the congeners’ quasi-infinite dilution, the properties of the mixture are assumed to be dependent on the ethanol mole fraction only. Thus, the system is treated as a quasi-binary mixture; the ethanol recovery, the dynamics of the condensation and the heat transfer processes are modeled independently of the congener's concentration. The model was calibrated with laboratory data obtained during the elaboration of pear distillates. The concentration of ethanol and 15 congeners in the distillate were measured with gas chromatography during the experiments. Fitting just two parameters, one for heating power and one for heat loss, was sufficient to reproduce the experimental ethanol recovery curves. This allowed an accurate prediction of most of the congener's recovery curves. The prediction of the concentration of five congeners, including acetaldehyde and methanol, are not significantly different from measured values. The prediction of the concentration of six congeners was biased but with relatively small errors (ranging between 8% and 25%). Significantly large prediction biases (more than 30%) were observed for ethyl hexanoate, ethyl decanoate and phenethyl alcohol.

Effect of the operating variables on the extraction and recovery of aroma compounds in an osmotic distillation process coupled to a vacuum membrane distillation system

The coupled operation of osmotic distillation (OD) and vacuum membrane distillation (VMD) for concentration of fruit juices and simultaneous recovery of their aroma compounds was studied. The simulated aqueous fruit juices containing four common aroma compounds were concentrated using osmotic distillation where the feed solution was in contact with a brine solution of CaCl2, through a hydrophobic macroporous membrane contactor. Aroma compounds absorbed in the extraction brine were extracted using a membrane evaporator under vacuum and collected into a cold trap. This way, both concentration and aroma recovery of fruit juices were achieved simultaneously using two hollow fiber membrane modules. The transfer of the aroma compounds was evaluated by using different operating variables such as hydrodynamic conditions, brine concentration and vacuum pressure. The experiments show that the loss of aroma compounds during the concentration processes can be avoided by means of extraction of the aroma compounds from the brine separately, resulting in an average of 75% recovery in aroma compounds. In general, the process of aroma removal and recovery is faster than the concentration process of the fruit juices by osmotic distillation at a technical and commercial level (higher than 45°Brix). Thus, the simultaneous operation of these two membrane processes can be used to decrease the energy requirements for a given production capacity.

Supercritical CO 2 extraction applied toward the production of a functional beverage from wine

Supercritical CO 2 extraction has been proved to be a potential tool in the recovery of aroma compounds from different natural sources and in the removal of ethanol from aqueous solutions. In this work, both ideas are combined to develop a two-step process toward the production of a low-alcohol beverage from wine, but maintaining the aroma and the antioxidant activity similar to that of the original wine. First, the recovery of aroma from wine was attained in a countercurrent packed column (white and red wines were investigated) using very low CO 2/wine ratios. Then, the aroma-free wine recovered from the bottom of the extraction column was dealcoholized by applying different extraction conditions. The results obtained from these studies permit the design of a two-step countercurrent CO 2 extraction process at 9.5 MPa and 313 K, in which the different CO 2/wine ratios employed in each step lead to the recovery of aroma or the removal of ethanol. The two-step process was applied to rose wine and the low-alcohol beverage obtained proved to have similar antioxidant activity and similar aroma profile to that of the original wine.

Aroma compound recovery by hydrophobic pervaporation: The effect of membrane thickness and coupling phenomena

In this study, pervaporation experiments were performed with binary and ternary model solutions of pomegranate aroma compounds to investigate the effect of membrane thickness and coupling phenomena on the permeation flux and aroma enrichment factors. Various composite POMS and PDMS membranes were tested for pervaporation and compared for their separation performance. In order to evaluate the significance of mass transfer resistance in the boundary layer with respect to the mass transfer resistance in the membrane, experiments were carried out using membranes with different thickness. The results showed that the permeation flux through both membrane types decreased markedly with increasing the membrane thickness, while the aroma compound enrichment factors increased. Coupling effects was qualitatively evaluated by comparing the aroma partial flux from the binary and ternary feed solutions. It was observed that the permeation of some aroma compounds was affected by presence of other aroma compounds.