Recovery Of Lactose Research Articles

The administration route of indigestible gut permeability markers modulates urinary marker recovery in calves

Indigestible gut permeability markers are used to assess gut integrity and can be administered to calves via a milk meal (MM) or orally pulsed (OP). This study investigated how marker administration route (ADM_R) affects the estimation of gut permeability in relation to MR fat inclusion. Thirty-two male Holstein calves were blocked based on their arrival sequence at the facility. Within each block of 4 calves, calves were randomly assigned to one of 2 treatments (n = 16/ treatment): a MR high in lactose (HL) and a MR high in fat (HF). During the first 5 d, calves were fed 6.0 L/d followed by 7.0 L/d offered in 2 meals per day at 15% solids. To evaluate gut permeability, indigestible markers (lactulose, D-mannitol, and chromium (Cr)-EDTA) were administered in 2 periods, on Tuesday and Thursday in the third week after arrival. Within each block, calves with different MR treatments were randomly assigned to a different marker ADM_R order: MM in the first period and OP in the second (n = 16) or the opposite order (n = 16). Thus, one block of 4 calves included all combinations of MR and ADM_R. Following marker administration, urine was collected over 2 sampling periods: the first from 0 to 6 h and the second from 6 to 24 h. Measurements included weekly BW and daily MR intake and fecal scoring. Intake, growth, and fecal consistency were not affected by dietary treatments nor by ADM_R. The urinary recovery of lactulose was greater in calves fed HF during the 6–24 h and the overall 24-h collection period. Consistently, D-mannitol recovery tended to be greater in calves fed HF during the 24-h collection. With OP administration, the urinary recovery of all markers was greater between 0 and 6 h, whereas in the 6–24 h period, the recovery of lactose and D-mannitol were lower. Over 24-h of collection, Cr-EDTA recovery was greater with OP. No interaction between ADM_R and MR composition was detected. This suggests that both ADM_R were equivalent in assessing the effects of dietary interventions on gut permeability. However, different ADM_R affected the trajectory and time spent by the markers in each section of the gut.

Recovery of lactose from acid whey by nanofiltration: An experimental study

The flowsheet of an overall process to recover valuable products from raw acid whey is proposed. It considers typical pretreatments, an ultrafiltration step to remove proteins, a decalcification step to remove calcium and magnesium by precipitation, and a nanofiltration/diafiltration step for demineralization and deacidification of lactose. The performance of each step is evaluated and the characteristics of the main streams are estimated. The feasibility of lactose recovery after the decalcification step by nanofiltration is demonstrated by using a spiral wound module. Membrane characterization was performed at pH 4 and 50 °C, with an artificial solution containing lactose, lactic acid and sodium chloride, prepared to mimic the clarified supernatant from the decalcification unit. The feasibility of the simultaneous concentration and deacidification of lactose is finally validated by processing a real solution. With the real solution, the maximum removal of lactic acid, close to 87%, is obtained by operating with a nanofiltration (NF) step (at a concentration factor of 3.5) followed by a NF step operated in diafiltration mode (DF) at constant volume (at a dilution factor of 1.8). A lactic acid/lactose ratio of 0.018 g/g is achieved, with an overall lactose purity and yield of 93.6% and 98.2%, respectively, when operating at low pressure values (up to 12–14 bar). A preliminary process simulation is finally performed to identify the premises for process optimization of the NF+DF configuration. The success of the integrated NF+DF process is contingent upon the correct balance between the choice of the membrane and the operating conditions, which ensure lactose rejections exceeding 98.5% and lactic acid rejections falling below 20–30%, while maintaining transmembrane fluxes between 8 and 15 dm3/(hm2).

Selective anomer crystallization from aqueous solution: Monitoring lactose recovery under mutarotation limitation via attenuated total reflection Fourier-transform spectroscopy and theoretical rate analysis

Lactose is typically produced via cooling crystallization either from whey or whey permeate (edible grade) or from aqueous solution (pharmaceutical grade). While in solution, lactose is present in 2 anomeric forms, α- and β-lactose. During cooling crystallization under standard process conditions, only α-lactose crystallizes, depleting the solution of α-anomer. In practice, mutarotation kinetics are often assumed to be much faster than crystallization. However, some literature reports limitation of crystallization by mutarotation. In the present research, we investigate the influence of operating conditions on mutarotation in lactose crystallization and explore the existence of an operation regimen where mutarotation can be disregarded in the crystallization process. Therefore, we study crystallization from aqueous lactose solutions by inline monitoring of concentrations of α- and β-lactose via attenuated total reflection Fourier-transform spectroscopy. By implementing a linear cooling profile of 9 K/h to a minimum temperature of 10°C, we measured a remarkable increase in β/α ratio, reaching a maximum of 2.19. This ratio exceeds the equilibrium level by 36%. However, when the same cooling profile was applied to a minimum temperature of 25°C, the deviation was significantly lower, with a maximum β/α ratio of 1.72, representing only an 8% deviation from equilibrium. We also performed a theoretical assessment of the influence of process parameters on crystallization kinetics. We conclude that mutarotation needs to be taken into consideration for efficient crystallization control if the crystal surface area and supersaturation are sufficiently high.

Lactose recovery from Panela cheese whey: Effect of whey acidification on spontaneous and stirring‐induced crystallisation

This work aimed to investigate the kinetics, yield, size and composition changes in lactose crystals when Panela cheese whey was acidified (pH 3.80) or slightly alkalinised (pH 6.89) before being subjected to spontaneous or stirring‐induced crystallisation. At pH 3.8, the crystallisation was accelerated, and the incorporation of salts and proteins in lactose crystals decreased. Nevertheless, these conditions induced the formation of amorphous lactose. In contrast, at pH 6.89 and under stirring conditions, the amorphous lactose was not formed and gave a high crystallisation yield (∼25 g of lactose per Kg of whey) with ∼80% of lactose recovery.

Recovery of lactose from simulated delactosed whey permeate by a low-temperature crystallization process

Delactosed whey permeate is the mother liquor/by-product of lactose manufacture, but it still contains around 20 wt% lactose. The high mineral content, stickiness, and hygroscopic behavior prevent further recovery of lactose in the manufacturing process. Therefore, its use is currently limited to low-value applications such as cattle feed, and more often it is seen as waste. This study investigates a new separation technique operating at sub-zero conditions. At low temperature, precipitation of calcium phosphate is expected to be reduced and the lower solubility at sub-zero temperature makes it possible to recover a large portion of the lactose. We found that lactose could be crystallized at sub-zero conditions. The crystals had a tomahawk morphology and an average size of 23 and 31 µm. In the first 24 h, the amount of calcium phosphate precipitated was limited, whereas the lactose concentration was already close to saturation. The overall rate of crystallization was increased compared with the crystals recovered from a pure lactose solution. Mutarotation was rate limiting in the pure system but it did not limit the crystallization of lactose from delactosed whey permeate. This resulted in faster crystallization; after 24 h the yield was 85%.

Scaling up continuous eutectic freeze crystallization of lactose from whey permeate: A pilot plant study at sub-zero temperatures

Eutectic freeze crystallization is explored as an alternative to the state-of-the-art evaporation process for the recovery of lactose from whey permeate. At the so-called eutectic freezing point, both water (the solvent) and lactose (the solute) crystallize and can be removed continuously while continuously feeding whey permeate. This continuous process is demonstrated on a pilot scale at sub-zero temperatures. In the first instance, only freeze concentration of whey permeate took place at −4 °C. It was possible to reach a lactose concentration of 30 wt% and hardly any nucleation was observed. The resulting ice had high purity, with a lactose concentration of ±2 wt%. Next, the eutectic phase was reached, and lactose and ice crystallized simultaneously and were continuously removed from the system, the resulting crystals had parallelogram morphology with an average size of 10 µm. Ice was recovered at a rate of 60 kg/h and lactose was recovered at a rate of 16 kg/h, yielding over 80% of the feed lactose. A conceptional design was proposed for an improved yield and reduction of energy. Yields of at least 80% and up till 95% could be achieved. Compared to the state-of-the-art mechanical vapor recompression (MVR), EFC is 80% more energy efficient.

Vacuum-Assisted Block Freeze Concentration Studies in Cheese Whey and Its Potential in Lactose Recovery.

Block freeze concentration (BFC) is considered an emerging technology which allows the acquiring of high quality organoleptic products, due to the low temperatures employed. In this study we have outlined how the vacuum-assisted BFC of whey was investigated. The effects of vacuum time, vacuum pressure, and the initial solids concentration in whey were studied. The results obtained show that the three variables significantly affect each of the following parameters analysed: solute yield (Y) and concentration index (CI). The best Y results were obtained at a pressure of 10 kPa, 7.5 °Bx, and 60 min. For CI parameter, the highest values were given at 10 kPa, 7.5 °Bx, and 20 min, respectively. In a second phase, by applying the conditions that provide higher solute yield to three different types of dairy whey, Y values of 70% or higher are reached in a single step, while that the CI of lactose are higher than those of soluble solids. Therefore, it is possible to recover, in a single step, at least 70% of the lactose contained in the initial whey samples. This suggests that vacuum-assisted BFC technology may be an interesting alternative for the recovery of lactose contained in whey.

Progressive freeze concentration of cheese whey for protein and lactose recovery

Cheese whey (CW) is one of the main problematic waste streams in the dairy industry. CW and its protein and lactose content was concentrated through progressive freeze concentration (FC). The screening of different operating conditions was performed to set the agitation rate and cooling temperature resulting in optimal concentration efficiencies (600 rpm and −5 °C). In each screening assay 50% of the initial CW volume was frozen and the influence of the operating conditions on protein and lactose phase distribution (ice and concentrated liquid) and content. Additionally, a four-stage FC procedure was also performed under optimal conditions resulting in a concentration up to 20.52% (w/w) of total solids, with 13.93% of protein content in the concentrated fraction and 6.24% (w/w) of lactose in the ice fraction. The present study demonstrated the potential behind FC to concentrate and valorise waste streams such as cheese whey.

Continuous lactose recovery from acid whey by mixed suspension mixed product removal (MSMPR) crystallizer in the presence of impurities

The continuous crystallization approach provides the opportunity to intensify production and improve the quality of crystals manufacturing. This study examined the effect of impurities on lactose crystallization in the continuous mixed suspension mixed product removal (MSMPR) crystallizer. Two impurities usually present in acid whey, protein and lactic acid, were examined. The continuous process was evaluated based on the time required to reach a steady state operation, particle size distribution (PSD), purity, and yield. Impurities increased the time for the continuous system to achieve a steady state condition. This effect was more pronounced in the presence of protein (>13 residence time). In the acidic environment, lactose crystals tended to promote caking and agglomeration during the filtration process, resulting in the formation of larger crystals and a wider PSD. The protein incorporation in the continuous process was 1.5 times higher than in the batch process due to the inefficiency of the filtration stage caused by the aggregated denatured protein particles, which entrapped the mother liquor between the void area of the agglomerated crystals. Understanding impurity effects on lactose crystals in continuous crystallization can be used as a fundamental study to intensify the process and improve the quality of the crystals.

Cooling crystallization of lactose in the presence of whey protein and lactic acid impurities

Whey protein and lactic acid are two main impurities affecting the crystallization recovery of lactose from acid whey solutions. This study systematically examined the individual and combined effect of whey protein and lactic acid on the purity of the recovered lactose. From batch cooling stirred tank crystallization experiments, whey protein affected the purity by co-precipitation from the denaturation of protein. In contrast, lactic acid affected the purity by incorporation into the lactose crystal structure. This was primarily due to the similarity in the molecular structure between lactic acid and lactose. The presence of both impurities led to an undesired synergistic effect, which led to a significant increase in the impurity level. The low acidity and enhanced aggregation of protein were the main cause of this undesired synergistic effect. This study highlights the importance of the effective separation of whey protein in acidic whey solutions prior to the recovery of lactose by crystallization. • Denaturation of protein at high temperature was co-precipitated with lactose. • Denatured protein at pH of 4.5 resulted in a larger particle size distribution due to aggregation. • The combination of protein and lactic acid yielded the lowest purity.

A sub-zero crystallization process for the recovery of lactose

In industry, lactose is generally produced by concentrating whey permeate by evaporation followed by a slow cooling process where lactose is crystallized. Here, an alternative method is presented whereby the concentration and crystallization steps are combined at sub-zero temperatures, so-called eutectic freeze crystallization. It was discovered that simultaneous crystallization of lactose and water (ice) is possible. The obtained lactose crystals had an average size of 10 μm and a thin triangular or tomahawk morphology. The process was analyzed in detail in two steps: freeze concentration and lactose crystallization at sub-zero temperatures. Freeze concentration experiments showed that concentrating to supersaturation was possible without excessive lactose crystallization. In the second step, lactose was crystallized at temperatures below zero from a 30 wt% lactose solution, without observation of significant primary or secondary nucleation. The amount of seed material had a large influence on the final yield, crystal size and morphology. The optimum seed amount was found to be at 0.08% of the total lactose; the resulting crystals had an average size of 26 μm and a tomahawk morphology. Although highly supersaturated conditions are present in the sub-zero crystallization of lactose, crystal growth is found to be the predominant process rather than nucleation.

Recovery of lactose from aqueous solution by application of ultrasound through millichannel

Abstract Instead of direct disposal of whey, extraction of valuable products from it may reduce the environmental pollution. In the present study, the effect of ultrasound irradiation through millichannel on recovery of lactose was investigated. The ultrasonic baths of varying amplitude (20–40%) and frequency (25–35 kHz), two different configurations of millichannel i.e., coil and serpentine, were used to know their individual and combined effect on the lactose yield. Box-Behnken design was employed to examine the interactive effect of different operating conditions. The recovery of lactose was enhanced approximately by 5–53% and induction time was reduced by 1.79–1.85 times in comparison to the conventional process. The size of the lactose crystals was reduced from 139.5 to 42.486 μm at 40% amplitude and 49.879 μm at 35 kHz frequency. Optimized condition showed 63% yield of lactose at 3.6 supersaturation, 35 kHz frequency, and 45 min of sonication time.

Regularities of the transition of substances from permeate to molasses in the process of lactose recovery

Crystalline lactose is produced all over the world in large quantities. The main raw material used for crystalline lactose manufacturing is permeate obtained by ultrafiltration of milk and whey. It is believed that it is better to use sweet whey permeate, but the modern world has adapted to use other sources rich in lactose. Molasses is a by-product of crystalline lactose production. Its composition varies depending on the characteristics of the feedstock, the parameters of crystallization, the use of various methods required in the technological process. In foreign countries, molasses is considered as complex raw material, but at the same time it is used for various purposes, used for feeding animals and fertilizing soils, as a nutrient medium for microorganisms’ cultivation. In Russia, molasses as a by-product of dry lactose manufacturing is practically not widespread; it was mainly used to obtain feed additives for animals. Food and pharmaceutical lactose production development gives an impetus to start studying and creating new products based on dairy molasses. Molasses has a significant good quality, which allows it to be used as a raw material in the development of functional products based on lactose and its derivatives.

Understanding the role of different operating modes and ultrasonic reactor configurations for improved sonocrystallization of lactose

The current work focuses on understanding the effect of different ultrasonic reactors on the recovery of lactose using crystallization. Three different scales of operations selected in the work include laboratory scale, medium scale and pilot scale based on the different reactor configurations. Ultrasonic bath (25 kHz) showed higher recovery of 90.3 ± 0.3 % for 20 min of sonication as compared to ultrasonic horn (20 kHz) with recovery of 88.8 ± 0.6 % with a standing time of 24 h in both the cases. Analysis of variance (ANOVA) demonstrated the significant dominance of all the factors studied on the response (recovery). The dual frequency ultrasound reactor (22 + 44 kHz) proved to be more efficient in delivering higher recovery values as compared to ultrasonic bath in the case of large scale systems with maximum recovery of 91.3 ± 0.9 %. The recovery of ethanol used as antisolvent was performed using distillation and the reusability of ethanol was studied. It was demonstrated that ethanol could be very well recycled, which is an important aspect at large scale operation. Overall, a systematic study helped in elucidating the role of ultrasonic parameters and reactor configuration in deciding an energy efficient and economical approach for maximum lactose recovery.

Recovery of lactose and proteins from cheese whey with poly(ethylene)glycol/sulfate aqueous two-phase systems

Cheese whey is an environmental problem as an effluent, but also a source of valuable raw materials, namely proteins and lactose. In this work, Aqueous Two-Phase Systems (ATPS) were studied for the recovery of lactose, BSA, β-lactoglobulin and α-lactalbumin, key components of cheese whey. ATPS formed by PEG (molecular weights: 200–8000 g.mol−1) with sodium or ammonium sulfate were investigated. Partitioning of the selected solutes was experimentally addressed in different ATPS and pH values. Partition behavior showed that ATPS formed by PEG1500/ammonium sulfate is able to separate lactose from proteins, while PEG300/sodium sulfate ATPS may be used for protein fractionation. These separation strategies were then tested with simulated and real cheese whey. Under optimized conditions, PEG 1500/ammonium sulfate ATPS allows efficient recovery of > 95% proteins (precipitate) and 80% of lactose (bottom phase), as confirmed for both simulated and real cheese whey. The results found indicate that the proposed polymer/salt ATPS can be used to design scalable and cost-effective separation strategies to apply in cheese whey and other related wastes.

On the valorization of lactose and its derivatives from cheese whey as a dairy industry by-product: an overview

The resulting whey from cheese manufacture consists mainly of water and lactose, a sugar with little sweetening and fermentable power and low commercial value. Aiming at valorizing the whey and faced with the challenge to reduce and treat an industrial wastewater present at high volumes and composed of high organic load, several ways to enhance the commercial value lactose have been sought. Thanks to the functional and technological traits of lactose and to the biotechnological advances, several applications have been proposed either for direct use or for the production and application of chemical and enzymatic derivatives or by-products from microbiological processes. Nowadays, lactose has numerous potential applications in food, feed, nutraceutical, pharmaceutical and cosmetic industry, an overview of which is given in this review. On the other hand, many compounds of high added value are produced from lactose, such as oligosaccharides with prebiotic properties, lactobionic acid with antioxidant properties, lactitol as sweetener with dietetic and prebiotic functions, and lactulose as prebiotic ingredient. Nevertheless, the implementation of industrial processes for whey collection and lactose recovery and valorization faces practical difficulties, particularly of logistical and financial investment nature. This communication aims at giving an overview with respect to the problems associated with the high volumes of whey produced in the dairy industry and some of the foremost technological routes for its commercial exploitation through the use of lactose and its derivatives. It also presents a set of considerations regarding the main bottlenecks to overcome towards the creation and implementation of integrated systems tailored for collecting and processing cheese whey in an efficient, sustainable and cost-effective approach.

Optimization of ultrafiltration of whey using Taguchi method for maximizing recovery of lactose

The current work focuses on establishing optimized conditions for operating parameters of ultrafiltration such as whey source, transmembrane Pressure (TMP), retentate to permeate ratio, membrane type, molecular weight cut-off (MWCO) and temperature so as to maximize lactose recovery. Orthogonal L16 array created by Taguchi method using MINITAB 19 software was used for obtaining a compact experimental design to analyse the effect of all the operating parameters and their levels on the associated important responses as permeate recovery, permeate flux, fouling and recovery of lactose after crystallization. Whey source was found to be most imperative parameter for reduction in fouling and for maximizing the lactose recovery after crystallization. The dominant effect of whey source was attributed to the variation in pH of whey with different sources. The permeate recovery and permeate flux were found to be highly dependent on the TMP and membrane type respectively with considerable desirability for membrane MWCO as well. For permeate recovery, use of acid whey at 1.5 bar with 1:3 as the retentate to permeate ratio, hydrosart membrane of 10 kDa cut off and temperature of 30 °C were found to be the optimum conditions which was also the case for permeate flux except with different value of the optimum ratio as 1:1. The response of fouling showed slight deviation in optimum levels which was also observed for lactose recovery after crystallization. Overall, a systematic study with the help of statistical analysis demonstrated the best possible operating conditions and their influence on desired output.

Investigations in physical mechanism of ultrasound-assisted antisolvent batch crystallization of lactose monohydrate from aqueous solutions.

Sonication is known to enhance crystallization of lactose from aqueous solutions. This study has attempted to reveal the mechanistic features of antisolvent crystallization of lactose monohydrate from aqueous solutions. Experiments were conducted in three protocols, viz. mechanical stirring, mechanical stirring with sonication and sonication at elevated static pressure. Mechanical stirring provided macroconvection while sonication induced microconvection in the system. Other experimental parameters were initial lactose concentration and rate of antisolvent (ethanol) addition. Kinetic parameters of crystallization were coupled with simulations of bubble dynamics. The growth rate of crystals, rate of nucleation, average size of crystal crop and total lactose yield in different protocols were related to nature of convection in the medium. Macroconvection assisted nucleation but could not give high growth rate. Microconvection comprised of microstreaming due to ultrasound and acoustic (or shock) waves due to transient cavitation. Sonication at atmospheric static pressure enhanced growth rate but reduced nucleation. However, with elimination of cavitation at elevated static pressure, sonication enhanced both nucleation and growth rate resulting in almost complete lactose recovery.

Effect of process parameters on the recovery of lactose in an antisolvent acetone/acetone-ethanol mixture: A comparative study based on sonication medium.

Recovery of lactose from the whey using sonocrystallization was studied experimentally. The effect of sonication medium and irradiation power levels was evaluated using three different ultrasonic equipments. Effects of various parameters such as sonication time, pH of the medium, antisolvent (acetone and acetone-ethanol mixture) and concentration of lactose were determined. The optimal parametric conditions were analyzed using differential scanning calorimetry, thermogravimetric analysis, particle size distribution, and zeta potential measurements. Overall, the highest lactose recovery was obtained using a mixture of acetone and ethanol as antisolvent in bath sonication as well as atomization process.

Fuzzy-assisted ultrafiltration of whey by-products recovery

It is well known that wastewaters from the food industry are a potential source of valuable compounds, such that these wastewaters may be considered by-products awaiting the development of appropriate treatment methodologies. Whey is one of the most important polluting effluents from the milk industry because of its very high biological oxygen demand (BOD). Nevertheless, whey is rich in by-products such as whey proteins and lactose, both of which are widely used industrially. Integrated processes could permit the selective recovery of these by-products in conjunction with the generation of clean, reusable water, thus reducing the environmental impact of this wastewater. Ultrafiltration is a crucial step in the separation and recovery of whey protein and lactose, but this technology suffers from fouling problems that can reduce its performance. New technologies assisted by smart modeling and control systems could improve this ultrafiltration step. In this work, a novel system that allows the recovery of the whey protein in milk industry effluent and the disposal of wastewater was developed and tested. This system utilizes an ultrafiltration process, as this permits the purification of the effluent at room temperature, ensuring the preservation of the recovered proteins. A specially designed autoadaptive fuzzy logic controller evaluates the level of filter membrane fouling and controls a mechanical device that induces filter regeneration. Experimental testing showed that this approach permits process intensification.