Juice Evaporation Research Articles

Simulation of single-effect and triple-effect evaporator for fruit juice concentration using Aspen HYSYS

Abstract One of the most popular methods of fruit juice preservation is concentration since it offers a variety of advantages, like decreased volume, weight, packing, simpler transportation and handling, and a longer shelf life. The present paper studied the evaporation of fruit juice in single- and triple-effect evaporators using Aspen HYSYS software. The amount of juice was 3000 kg/h, and its concentration was raised from 10 to 50 °Brix. Four evaporator layouts were estimated and optimized: single-effect, modified single-effect, forward triple-effect, and triple-effect in parallel. It is a study of the effect of the temperature of saturated steam (120–300 °C) used to concentrate the juice and the pressure of the product (15–50 kPa) on the mass flow rate of steam required, economy, and overall heat transfer coefficient times area (UA) of the evaporator. The best operating conditions for each type of evaporation system were 15 kPa of the product’s pressure for all types of evaporators, 192, 240, 182, and 210 °C of the single-effect, modified single-effect, forward triple-effect, and parallel triple-effect, respectively. These operating conditions are equivalent to the steam required, economy, UA, and steam cost as follows: for each type, they were (3075, 338.4, 1224, and 1100 kg/h), (0.78, 7.1, 1.96, and 2.15), (40,182, 74,505, 539,987, 152,173 kJ/°C h), and (12.68 × 103, 12.76 × 103, 12.65 × 103, and 12.73 × 103 $/h), respectively.

Optimisation of pH for minimising juice degradation during evaporation

During juice evaporation, sucrose loss can occur due to degradation reactions that are influenced by heat, pH, residence time, and dry substance content. The impacts of heat can be controlled through process and equipment design, and juice pH could be optimised to reduce its effects on degradation reactions. A factory sampling program was conducted with juices collected across an evaporator station comprised of six Robert (rising film) effects in series for a range of juice pH levels and analysed for sucrose loss and overall pH drop from clarified juice to syrup. Measured losses were compared to predictive correlations and showed strong agreement. Using the factory data, two pH control strategies to minimise sucrose degradation and the subsequent impacts on downstream processing were simulated with predictive correlations. The modelling results highlight the potential benefits that can be achieved.

MATHEMATICAL MODELING OF THE PROCESS EVAPORATION OF MULBERRY FRUITS JUICE

When evaporating the juice of mulberry fruits, a differential equation was obtained for changing the amount of liquid over time, expressed as a material balance, converted to the liquid level in the separator of the evaporator, an expression for the density of the liquid, its flow rates at the inlet and outlet of the apparatus, the differential equation for changing the temperature of the liquid over time. Using the reference data of the state of water and steam, equations for the temperature, enthalpy of liquid and dry steam are obtained. A system of equations has been obtained - a mathematical model of the dynamics of the process of liquid evaporation in a single-vessel vacuum evaporator. Using the SIMULINK part of the MATLAB program, a computer model for solving equations was compiled. Some results of studies of the evaporation of mulberry juice on a five-case vacuum evaporator are given, the optimal number of stages of the complex is found.
 Since the calculation of the process of evaporation of water vapor is associated with the thermodynamic parameters of the state of water, it is necessary to obtain equations for the dependence of the boiling point of water, the heat of vaporization of water, the enthalpy of steam, the enthalpy of water on pressure. Experimental data have been obtained for a long time, they are successfully used, however, there are no uniform empirical equations used by all researchers.
 Using the capabilities of the MATLAB program, by statistical processing of tabular data, we obtain empirical equations in the form of polynomials for the state of water and water vapor, describing the real picture with an accuracy of 98% or more.

Process parameters of microwave heating-assisted vacuum evaporation of tomato juice: quality, energy consumption, exergy performance, and kinetic processing

Increasing heating performance and preservation of product quality are critical factors in the food industry. Although microwave-vacuum heating is applied in many food processes, there are many unanswered questions about its effects on sensitive foods. In this study, the tomato juice was concentrated in microwave-vacuum heating system and results compared with conventional and conventional-vacuum heating methods. The effect of pressure and microwave power was investigated on quality parameters, energy consumption, exergy performance, and processing kinetics of tomato juice concentration. The processing time in the microwave-vacuum method was 2.3 to 6.3-fold lower than conventional and conventional-vacuum methods. The exergy performance was obtained in the range of 7.16–13.29% for microwave-vacuum heating and 2.04–2.99% for conventional methods. Microwave vacuum heating could reduce energy consumption by 30–71%, compared with conventional-vacuum methods. The minimum decline in ascorbic acid and total phenol content of tomato juice concentrate was observed for microwave-vacuum evaporation. Microwave-vacuum heating was an excellent concentration technique that provided tomato paste with improved nutritional quality, increasing exergy efficiency, reducing processing time and energy consumption compared to conventional and conventional vacuum processes.

System thinking in the analysis of the juice evaporation plant in the food industry

The article is devoted to the system analysis of evaporation of solutions. The existing evaporation apparatus has been studied by dividing into quasi-apparatuses: the heating chamber, the wall of the boiling pipes of the heat-transmitting evaporation apparatus, the vapor-liquid space - the inner part of the boiling pipes of the evaporation apparatus. Studies of the evaporation object have a stable character with a change in the concentration of the outgoing solution.

Thermostability of thin juice

The initial thin juice pH value usually changes during juice evaporation. As long as the pH value of the final thick juice differs maximal ±0.5 pH units, preferably ±0.2 pH units, from that of thin juice, the thin juice is considered thermostable. The observed change of the juice pH value depends on the ratio between dissolved ammonia and carbon dioxide in thin juice. During the juice concentration both volatile components will evaporate at which they have opposite effects with respect to the pH value change. Ammonia is dissolved as ammonium ion in the juice and leaves a proton in the juice upon evaporation, whereas carbon dioxide is dissolved mainly as bicarbonate and delivers alkali upon evaporation. This paper explains why a thermostable thin juice is crucial for the effectiveness of the following process steps evaporation and crystallization. Details about the origin of ammonia and carbon dioxide will be presented, as well as possible ways to control the thin juice thermostability by influencing the ammonia to carbon dioxide ratio.

Efficacy of mass of energy storage material on the performance of a solar driven stepped series system during sugarcane juice concentration

In this experimental study, the effect of mass of paraffin wax as ESM is studied during solar evaporation of sugarcane juice in a sustainable energy recovery system (SERS) having series of stepped solar stills. In this research work, three systems are taken under experiments viz. SERS-ESM15, SERS-ESM30 and SERS-ESM60, respectively laden with 675 g, 1350 g and 2700 g of paraffin wax. The distillate production and brix content of final product are found to increase with mass of ESM and SERS-ESM60 gives optimum results (2175.6 g and 25.8 oB). SERS-ESM60 is found thermally more efficient having energy efficiency of 245.32 % which is respectively, 330.8 % and 159.4 % higher than those of SERS-ESM15 and SERS-ESM30. The exergy efficiency of SERS-ESM60 is also observed maximum (16.78 %). The carbon credits earned by SERS-ESM60 are evaluated as $123.92 and it is found to mitigate 8.26 tonnes of CO2 per year that makes it environmentally friendlier among the tested systems. Also SERS-ESM60 is found economical with total productive cost of $124.12/year. It is inferred that SERS becomes more sustainable and stable with increase in mass of ESM and could be used in NCS industry for its sustainable transition.

Non-Centrifugal Sugar (NCS) and Health: A Review on Functional Components and Health Benefits

Non-centrifugal sugar (NCS) is the scientific term the Food and Agriculture Organization (FAO) uses to define a solid product, produced by sugarcane juice evaporation, which is unrefined or minimally refined. NCS is referred to in various names globally, the most significant ones are whole cane sugar, panela (Latin America), jaggery (India) and kokuto (Japan). NCS contains minerals, bioactive compounds, flavonoids and phenolic acids, which have therapeutic potentials from time immemorial. Even though the bioactive property is dependent on the composition, which relies mainly on the agronomic conditions and production process, NCS possesses antioxidant and anti-inflammatory properties. Hence, substituting the consumption of refined sugar with NCS might be helpful in the control of chronic diseases generally connected to oxidative stress and inflammation. Experimental facts from in vitro and in vivo models have proven that NCS plays an essential role in weight management, maintaining insulin sensitivity and preventing neurodegenerative diseases. NCS has also shown hypoglycemic and hypolipidemic effects. This review aims to synopsize the recent literature pertaining to the benefits of NCS in human health. The NCS can be considered a nutraceutical and functional food. However, detailed and regulated studies are important to enhance the beneficial effects in human and animal interventions.

Sustainable juice evaporation unit selection for noncentrifugal sugar production by multicriteria evaluation methods

AbstractIn the conventional practice of producing noncentrifugal sugar (NCS), many technologies are available for juice evaporation, all of which may not be sustainable. The sustainability of these units is dependent on multiple criteria belonging to resources, technical, economic, process‐output, and environmental parameters. This paper presents the work undertaken to identify the most sustainable juice evaporation unit (to produce NCS) among 10 alternatives using three multicriteria evaluation (MCE) techniques, namely TOPSIS, PROMETHEE II, and VIKOR. The analyses were based on 11 evaluation criteria covering four sustainability elements. Analytic hierarchy process (AHP) and entropy weight approaches were used to assess the importance of each criterion for the ranking of evaporation units. The necessary data were obtained from three different decision‐maker groups, namely academics and sustainability promoters, NCS manufacturers, and NCS plant suppliers. The resulting criteria weights indicate that capital cost (with AHP analysis based weights as 16.81, 12.51, 15.30% for decision‐makers groups I, II, III, and a weight of 23.28% from entropy method) is found to be the most crucial criterion. With assessment values of 0.741, 0.186, and 0.048 in TOPSIS, PROMETHEE II, and VIKOR, respectively, “single pan with the improved furnace” emerged to be the most sustainable option. This result is also substantiated by a group priority index of 1.08 obtained through the geometric mean method of analysis. This suggests that “single pan with the improved furnace” is the most sustainable one for NCS production. Furthermore, sensitivity analyses undertaken indicate that “single pan with the improved furnace” is most and least sensitive to “greenhouse emissions” and “process time,” respectively. With these outcomes, this paper demonstrates that the methodology adopted herein could be considered for assessing the sustainability of other process units involved in NCS production.Practical ApplicationsIn the conventional practice of producing NCS, there are various technologies available for the evaporation of juice. This paper narrates the MCE‐based work to identify a sustainable juice evaporation unit. It can be suggested that the most sustainable unit is “single pan with improved furnace” and the least sustainable is “multi‐effect evaporator.” The results of the present analysis suggested that the use of the other nine units for the production of NCS is to be subjected to thorough scrutiny, specifically regarding their sustainability. The methodology taken up for this analysis could be extended for other subprocesses in the NCS production process line to get the most sustainable process line.

An experimental study on solar evaporation of sugarcane juice

AbstractIn this study, an attempt is made to obtain concentrated sugarcane juice and distilled water using solar radiations that would save energy as well as environment. In this study work, the experimental performance of a sugarcane juice solar evaporation system (SJSES) is investigated for the evaporation of water from sugarcane juice. To check the influence of flow rate on the performance of SJSES units, experiments are carried out at 20, 25, 30, and 35 ml/min. The flow of sugarcane juice at 25 ml/min in SJSES unit is found optimum that resulted in highest energy saving, distilled water, and relatively more brix content of final product. The performance of SJSES unit loaded with paraffin wax at optimum flow rate (unit IV) resulted in maximum distilled water (605.1 g) which is 82.4%, 14.8%, and 39.4% higher than other units. Paraffin wax loading in SJSES increased its distillate output, brix of juice, and working time by 78.3 g, 7.9%, and 1 h, respectively. Thermal and exergy efficiencies are found maximum for unit IV having values 58.56% and 4.53%, respectively. The amount of energy saved is observed maximum for this unit along with least distillate cost and payback period.

Improving Energy Efficiency of Cogeneration System in Cane Sugar Industry by Steam Dryer

Cogeneration system in the cane sugar industry produces not only molasses and raw sugar but also exportable electrical power. Main components of the system are boiler, steam turbine, condenser, and sugar juice evaporation process. Bagasse is used as fuel for boiler. Bagasse is a by-product of sugar juice extraction process. It is characterized by a high moisture content, which leads to the inefficiency of energy conversion. The integration of steam dryer in cogeneration system to reduce bagasse moisture content before combustion will improve the system performance. The moisture content of bagasse is reduced in a steam dryer due to heat transfer from steam condensation. Saturated steam supplied to steam dryer is obtained by mixing superheated steam extracted from steam turbine with the appropriate amount of cooling water in desuper-heater. The objective of this paper is to evaluate the performance of this cogeneration system quantitatively. Models of boiler and steam dryer are used for this purpose. Simulation results show that the cogeneration system integrated with steam dryer generates more power output than the reference cogeneration system without steam dryer under the conditions that sugar juice processing capacity and bagasse consumption are the same. Furthermore, the cogeneration system integrated with steam dryer requires 20% less heating surface area than the reference cogeneration system under the condition that temperatures of flue gas exhausted from boilers of both systems are the same.

A study on electrical conductivity and performance evaluation of ohmic evaporation process of grape juice

Examination of the Ohmic evaporation process in terms of electrical conductivity value and laws of thermodynamics is limited in the literature. In this study, the moisture content of the grape juice sample was concentrated from 5.75 kg water/kg Dry-Matter (DM) to approximately 2 ± 0.3 kg water/kg DM by an ohmic evaporator. Evaporation process was applied in three different voltage gradients (16–24 V/cm) by Ohmic evaporator. The electrical conductivity value was found to be between 0.21 and 0.77 S/m during the heating process while it was between 0.77 and 1.01 S/m during the evaporation process. In addition, when evaluating this process concerning thermodynamic laws, it was stated that increasing voltage gradient had a positive effect on energy efficiency, exergy efficiency, and improvement potential values. To conclude, it was achieved that the ohmic heating-assisted evaporation process could be used in the concentration of grape juice and an effective system with an average of 80% energy efficiency. Practical applications As the ohmic heating process is known as a homogeneous, rapid, and efficient heating technique, its use in food applications is gradually increasing in recent years. Evaporation process is one of the preservation methods used especially in the fruit juice industry. An alternative evaporation method has been obtained by integrating the ohmic heating process into the evaporation process. It was determined that the voltage gradient used and foam formation were an effect on the electrical conductivity and performance analyses. It was determined that as the voltage gradient increased, the amount of water removed from the grape juice increased (kg/s) and the total processing time shortened. It is considered that this study may be a data source in the literature related to pilot and industrial-scale production lines by determining electrical conductivity value during the evaporation of grape juice and investigating energy efficiencies.

Impact of tops and green leaves on sugarcane processing: laboratory testing

In Réunion, changes in harvesting practices have led to increased amounts of sugarcane tops and leaves delivered to factories. To anticipate the changes in sugar recovery processing, laboratory trials were undertaken. Samples with known quantities of tops or green leaves were prepared and cane processing was simulated at laboratory scale: juice extraction, clarification and evaporation with operating parameters similar to those in the factory. Juice and syrup were collected and analyzed for sugar quality parameters, as well as parameters that impact sugar recovery or processing quality: ash and reducing sugars contents were monitored to estimate the sucrose loss to molasses, while calcium, phosphate and oxalate contents were monitored to evaluate the risk of fouling in evaporator. Results highlight a degradation of juice composition with increasing quantities of tops and leaves, an increase in lime consumption, and color. An increase in residual calcium in syrup was observed thus increasing the risk of evaporator fouling. The mixed juice, clear juice and syrup qualities declined in the same proportion and the composition of the juice did not get worse with juice treatment.

The relationship between soil chemical properties and phytochemical contents of non-centrifugal cane brown sugar in Thailand

In Thailand, NCS products from sugarcane are traditionally produced by the evaporation of raw cane juice obtained from a pressing machine. NCS products enhance flavor and supply both energy and nutritional value through the vitamins, minerals and bioactive compounds which occur naturally in sugarcane produced without molasses removal. Soil quality and choice of cane cultivar affect the nutraceutical components of brown cane sugar products grown in diverse areas. Differences in nutraceutical components of NCS products obtained by traditional processes were investigated form sugarcane planted in two different areas of Sukhothai Province, with varied soil qualities based on the same cane variety (LK-92-11). The soil classification was carried out according to the Staff Soil Survey (2014) and classified as Aquic Haplustalfs and Aeric Endoaquepts soil types. NCS products from sugarcane planted in Aquic Haplustalfs contained high nutraceuticals and antioxidant activities compared with sugarcane planted in Aeric Endoaquepts. EC and potassium content of the soils showed significant negative correlation with policosanols, total phenolics, total flavonoid contents, and antioxidant activities of the NCS products. Pearson’s correlation indicated that higher electrical conductivity and potassium content of the soils were attributable to lower amounts of policosanols, total phenolics, and total flavonoid contents as well as antioxidant activities. We suggested that electrical conductivity and potassium content of soil should be concerned and monitored to obtain high level of nutraceutical of NCS product made from sugarcane

Harnessing the osmotic energy of cane molasses by forward osmosis: process studies and implications for a sugar mill

ABSTRACT The osmotic energy of cane molasses was used to drive the partial dewatering of sugarcane juice by Forward Osmosis. The studies were conducted at low molasses to juice ratio considering their relative abundances. Studies in recirculation mode provided insight into the maximum possible extent of dewatering and the variation of permeate flux () with bulk osmotic pressure difference. Operation in continuous single pass (CSP) mode helped maximise the throughput and . Data on permeation selectivity, back diffusion and osmotic energy use efficiency were additionally obtained for both modes of operation. The optimised CSP mode process was evaluated in a sugar mill employing commercial process streams. Energy saving – owing to reduced juice evaporation load – and freshwater saving – owing to simultaneous dilution of molasses – were the twin gains from the process considering sugar and ethanol as the final products. Areas of process improvement were identified.

Modification of Conventional Sugar Juice Evaporation Process for Increasing Energy Efficiency and Decreasing Sucrose Inversion Loss

The evaporation process, boiler, and turbine are the main components of the cogeneration system of the sugar factory. In the conventional process, the evaporator requires extracted steam from the turbine, and bled vapor from the evaporator is supplied to the juice heater and the pan stage. The evaporation process may be modified by using extracted steam for the heating duty in the pan stage. This paper is aimed at the investigation of the effects of this process modification. Mathematical models of the conventional and modified processes were developed for this purpose. It was found that, under the conditions that the total evaporator area is 13,000 m2, and the inlet juice flow rate is 125 kg/s, the optimum modified evaporation process requires extracted steam at a pressure of 157.0 kPa. Under the condition that the fuel consumption rate is 21 kg/s, the cogeneration system that uses the optimum modified evaporation process yields 2.3% more power output than the cogeneration system that uses a non-optimum conventional cogeneration process. Furthermore, sugar inversion loss of the optimum modified process is found to be 63% lower than that of the non-optimum conventional process.

Novel fructooligosaccharide conversion from sugarcane syrup using a specialised enzymatic pH-stat bioreactor

Fructooligosaccharides (FOS) have gained significant attention for their prebiotic properties. Given that sugarcane syrup (SS) is sucrose-rich but with other nutritional benefits, its direct transformation into FOS may add value to this product. Therefore, the aims of this study were to develop FOS conversion from SS and to define the kinetic behaviour of FOS synthesized in a 1-L specialized pH-stat bioreactor (SPSB). The SS was composed of sucrose (58.93%) with considerable antioxidant capacities and Ƴ-aminobutyric acid. The developed SPSB process consisted of three stages: evaporation of sugarcane juice into syrup (68–75 °Brix) (stage 1), optimization of the Viscozyme L and SS mixture at different reaction temperatures (47–55 °C) (stage 2), and upscaling of the optimized reaction system under defined conditions in a 1 L-SPSB system (stage 3). In the 1 L-SPSB system, the enzymatic reaction yielded 32.22% of FOS from SS after a 6 h reaction, which is comparable with a pure system containing an equivalent concentration of 10% of sucrose as initial substrate with 39.55% yield. This result demonstrated the efficient conversion of SS into FOS, supporting the utilization of sugarcane juice for its health benefits.

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.

Increased Energy Efficiency of a Backward-Feed Multiple-Effect Evaporator Compared with a Forward-Feed Multiple-Effect Evaporator in the Cogeneration System of a Sugar Factory

The cogeneration system of a sugar factory consists of boiler, steam turbine, and sugar juice evaporation process. The multiple-effect evaporator used for the conventional sugar juice evaporation process is the forward-feed multiple-effect evaporator, in which steam and sugar juice flow in the same direction. The main objective of this paper is to investigate the energy efficiency of the backward-feed multiple-effect evaporator, in which steam and sugar juice flow in opposite directions, compared with that of the forward-feed multiple-effect evaporator. Mathematical models are developed for both multiple-effect evaporators, and used to compare the performances of two cogeneration systems that use the forward-feed and backward-feed multiple-effect evaporators. The forward-feed multiple-effect evaporator requires extracted steam from a turbine at one pressure, whereas the backward-feed multiple-effect evaporator requires steam extraction at two pressures. Both evaporators have the same total heating surface area, process the same amount of sugar juice, and operate at the optimum conditions. It is shown that the cogeneration system that uses the backward-feed multiple-effect is more energy efficient than the cogeneration system that uses the forward-feed multiple-effect because it yields more power output for the same fuel consumption.

Effect of Sugarcane Juice Pre-Treatment on the Quality and Crystallization of Sugarcane Syrup (Treacle)

Treacle (black honey) is liquid syrup produced by heating and evaporation of sugarcane juice. It is rich in sugars including, sucrose, glucose, and fructose, which may crystallize during storage, especially at low temperatures. The crystallization of treacle was the main problem facing treacle producers in the Egyptian traditional food industry and affected negatively in the quality and consumer acceptability. Consequently, the aimed to investigate the effect of sugarcane juice pre-treatments, including the addition of citric acid at concentrations of (1, 2, and 3) g/l alone or in a combination with preheating at (60 or 70)°C for 1 h on physiochemical properties and crystallization of sugarcane syrup during storage for 60 days at room temperature. The results showed that these pre-treatments significantly affected the quality and properties of sugar cane syrup. The combination of the citric acid addition at a concentration of 1 g/l and preheat treatment at 70°C for 1 h resulted in syrup with the greatest overall acceptability. Also, these pretreatments prevented the crystallization of the produced syrup during the storage for 60 days at room temperature (20 ± 5)°C. Therefore, pre-treatment of the sugar cane syrup with a combination of the citric acid addition and heating can be suggested as a promising method for producing a high-quality sugar can syrup and preventing syrup crystallization during storage and handling.