Preparation of sodium alginate grafted itaconic acid green flocculant and its application in clarification of sugarcane juice.

The performance of ultrafiltration (UF) membranes with molecular weight cut off (MWCO) of 1000 and 3500 Da in clarifying sugar cane juice was investigated, as well as the performance of a nanofiltration (NF) membrane with MWCO of 200 Da and a reverse osmosis (RO) membrane in concentrating sugar cane juice. For both cases the sugar cane juice had been limed and partially clarified. The UF membranes were found to be effective at clarifying the sugar cane juice in terms of purity rise and reduction in turbidity, colour, starch and protein. A purity rise of approximately 6 was achieved by both UF membranes at trans-membrane pressures (TMP) from 15 to 25 bar. However, Brix reduction in the permeate was between 14.5 and 41.85% and 12.11 and 26.52% for 1000 Da and 3500 Da membranes respectively. For the 200 Da and RO membranes the Brix in the concentrate was increased from 7.65 to 12.3 after 3 hours of operation for the 200 Da membrane at a TMP of 10 bar, whilst the Brix in the concentrate was increased from 15.65 to 27.6 after 3 hours of operation for the RO membrane at a TMP of 35 bar. Overall, UF membranes were found to be unsuitable for clarification of sugar cane juice since significant amount of Brix is reduced in the permeate, whilst RO membranes were found to be effective for concentration of sugar cane juice.

A comparative investigation of adding milk of lime (MOL) versus lime saccharate (SACCH) in the hot lime clarification of juice at a U.S. sugarcane factory was undertaken to quantify performance across the 2009 processing season, after a preliminary factory study in 2008. SACCH was prepared by adding hydrated lime to hot clarified juice (CJ) in a greater than 1:7 ratio. The lime treatment was added to flash heated limed juice (FHLJ) to obtain a target CJ pH of 7.3. Samples of FHLJ and CJ were collected six times every 30 min, taking into account the retention time of the clarification tank. Results from the preliminary study suggested that SACCH caused lower turbidity in CJs with better control, as well as higher and better controlled CJ pHs. Across the 2009 season, SACCH factory mud volumes tended to be slightly (no significant difference) higher than for MOL, but no greater than 8.5%. In 2009, CJ turbidities with SACCH were, generally, lower and better controlled than MOL. Lower median particle sizes in CJs with MOL across the season at least partially explain the higher CJ turbidities with MOL than SACCH. For the same amount of hydrated lime added, SACCH produced a higher pH than MOL and this, generally, allowed SACCH to achieve the target CJ pH better than MOL and reduce sucrose losses from acid inversion. No significantly (P < 0.05) extra lime had to be added in the SACCH than MOL treatment, and there were no significant differences between the color of either FHLJ or CJ from SACCH or MOL. Overall, the use of SACCH over MOL improved hot lime clarification especially with respect to the achievement and control of target pH values that saved a considerable amount in sucrose losses and improved turbidity values of clarified juices. Practical Applications This paper is highly practical because in recent years there has been a shift in the U.S.A. and worldwide from the harvesting of burnt to green (unburnt) sugarcane, which has meant that more sugarcane leaves and tops are being processed at factories and have made clarification and sucrose losses worse. The work represented here offers a solution to this by proving that the addition of lime saccharate (SACCH) instead of the traditional milk of lime (MOL), during clarification of sugarcane juice, can improve turbid particle removal and be used as a tool by sugar processors to reduce expensive sucrose losses. This paper reports the performance of MOL and SACCH lime treatments on both the laboratory and factory clarification of sugarcane juices and puts forward explanations for the differences observed.

Most of the white sugar production is based on the clarification of sugarcane juice through sulfitation. In this work, alternative clarification technologies, namely ozonation and the electrochemical advanced oxidation process using the DSA® anode, are compared for the first time. In the first case, the effects of temperature and ozone concentration in the gas bubbled into raw sugarcane juice were investigated; for the electrochemical process, the effects of applied electric potential and temperature were considered. Central composite experimental designs were used to study the effects of these process variables on ICUMSA color removal, remaining sucrose content, rheology of the juice and energy consumption. For ozonation, the highest ICUMSA color removals at the end of 60 min were 75% (55 °C; 22.9 mg O3 L−1), 71.4% (33.7 °C; 14.5 mg O3 L−1), and 57.6% (55 °C; 14.5 mg O3 L−1), with energy consumptions of 532, 442 and 642 kWh m−3 order−1, respectively. In contrast, the highest ICUMSA color removal achieved by anodic electrooxidation was around 35%, at 33.8 °C and 18 V or 40 °C and 28 V, with 199 and 587 kWh m−3 order−1, respectively. In both cases, no losses of sucrose or appreciable variation in juice viscosity were observed. Considering equivalent clarification performances, the electrochemical process was shown to be more energy-efficient. Conversely, given the best performances achieved in each case, the clarification technologies studied did not reveal significant differences regarding energy consumption, sounding promising for industrial application, while further detailed process design and economic evaluation are needed.

In this study, Cu2+-chelated magnetic silicon dioxide nanoparticles were synthesized as carriers for laccase immobilization. The prepared magnetic immobilized laccase was applied in the clarification of sugarcane juice. The optimal conditions for the clarification of sugarcane juice with magnetic immobilized laccase in a shake flask were determined to be as follows: a temperature of 35 °C, pH of 5.5, rotation speed of 150 r/min, and immobilized laccase dosage of 1.0 mg/mL. The sucrose in the sugarcane juice inhibited both free and immobilized laccase. The inhibitory effect was characterized as mixed inhibition, wherein competitive inhibition played a dominant role. An alternating magnetic field was introduced into the catalysis process using magnetic immobilized laccase, and the catechin degradation rate was improved to 77.2% under a magnetic field intensity of 80 Gs and magnetic field frequency of 400 Hz. Under the optimal alternating magnetic field conditions, the treatment time of sugarcane juice was reduced to 20 min when catalyzed by the magnetic immobilized laccase, wherein a decolorization rate of 54.4%, reduction in turbidity of 89.7%, and total phenol degradation rate of 43.4% were achieved. Compared with the shaking condition, the assistance of alternating magnetic fields can shorten the clarifying time, increase the clarifying effect, and enhance the catalyst reusability. These results reveal useful information about the enzymatic treatment of high-sugar juice and provide a potential strategy for juice clarification with magnetic immobilized enzymes.

The clarification of sugar cane juice is a major unit operation in producing white sugar. In Brazil, the traditional method for this process is sulfitation, a technique that uses gaseous SO 2 and lime. However, this process has shown some restrictions in its use due to environmental and food safety standards. An alternative process is carbonation, which improves sugar quality and reduces environmental damage commonly related to the former process. For optimization and process design purposes, the study of the variables is a prior step. In this work, the clarification of sugar cane juice was carried out using carbon dioxide and the pH effect on parameter of greatest relevance in clarified juice was investigated in the range from 5 to 9, highlighting especially the content of sucrose, reducing sugars, starch, phosphate, turbidity, color ICUMSA, %CaO and ash. Results show that there was no degradation of sucrose, and clarification at pH 9 removes the starch, phosphate and turbidity and increases the degradation of reducing sugars. In the experimental conditions, carbonation with pH lower than 7 were not effective in removing impurities from sugar cane juice.

Highly alkali-stable and cellulase-free xylanases from Fusarium sp. 21 and their application in clarification of orange juice

Characterization of pectinase from Geotrichum candidum AA15 and its potential application in orange juice clarification

This study aimed to characterize an exo-PG from Aspergillus terreus PA3A5T and evaluate its application in the clarification of fruit juices. Exo-PG was obtained by submerged fermentation and it was purified by ion-exchange chromatography and gel filtration. The enzyme presented molecular mass of 95.2 kDa, with maximum activity at 70 °C in a pH of 4.0 and remaining stable in an acid pH at 60°C. FeCl2, SnCl2, CoCl2, ZnSO4, NaCl, Al2(SO4)3, MgCl2, MnCl2, and CuSO4 ions activated the enzymatic activity, and PbCl2 inhibited it completely. The value of Km was 1.83 mg mL-1 and Vmax was 335 U mg-1. The A. terreus PA3A5T exo-PG proved to be very effective in the clarification process of the juices, significantly reducing viscosity and color.

Sugar cane biomass is one of the most viable feedstocks for the production of renewable fuels and chemicals. Therefore, processing the whole of crop (WC) (i.e., stalk and trash, instead of stalk only) will increase the amount of available biomass for this purpose. However, effective clarification of juice expressed from WC for raw sugar manufacture is a major challenge because of the amounts and types of non-sucrose impurities (e.g., polysaccharides, inorganics, proteins, etc.) present. Calcium phosphate flocs are important during sugar cane juice clarification because they are responsible for the removal of impurities. Therefore, to gain a better understanding of the role of calcium phosphate flocs during the juice clarification process, the effects of impurities on the physicochemical properties of calcium phosphate flocs were examined using small-angle laser light scattering technique, attenuated total reflectance Fourier transformed infrared spectroscopy, and X-ray powder diffraction. Results on synthetic sugar juice solutions showed that the presence of SiO2 and Na(+) ions affected floc size and floc structure. Starch and phosphate ions did not affect the floc structure; however, the former reduced the floc size, whereas the latter increased the floc size. The study revealed that high levels of Na(+) ions would negatively affect the clarification process the most, as they would reduce the amount of suspended particles trapped by the flocs. A complementary study on prepared WC juice using cold and cold/intermediate liming techniques was conducted. The study demonstrated that, in comparison to the one-stage (i.e., conventional) clarification process, a two-stage clarification process using cold liming removed more polysaccharides (≤19%), proteins (≤82%), phosphorus (≤53%), and SiO2 (≤23%) in WC juice but increased Ca(2+) (≤136%) and sulfur (≤200%).

The sugar‐energy industries are highlighted in Brazil for exercising fundamental roles in the economy, being responsible for the production of products and by‐products considered essential in the daily life of a society, such as sugar, alcohol and energy. One of the processes used in the production of sugar is the clarification of sugar by sulfur. Due to the high toxicity of sulfur and its derivatives, harmful to both the human and the environment, there is a great and constant concern in reducing the consumption and emissions of these compounds. Seeking a method of clarification of sugarcane juice that uses less harmful clarifying agents and provides less loss of sugars, the present work investigated how ozonation affects certain parameters of the sugarcane juice, which are turbidity and color (International Commission for Uniform Methods of Sugar Analysis). In the experiment, the samples were divided into two lots and submitted to ozonation with ozone generation rates of 13, 17, and 21 mg O3/min, temperatures of 30, 60, and 90 °C and duration of 0, 30, and 60 min. A complete factorial design with three factors was used, in three equidistant levels (33), totaling 27 samples for each lot. The experiments were performed randomly, submitted to analysis of variance using the STATISTICA software. The results presented in this work are better than those obtained in real situations and similar to others in experimental situation by ozonation; when compared with traditional methods of clarification, our results are at least equal to them.Practical applicationsA method of obtaining better quality sugar is presented from the point of view of clarification. This method does not use chemical agents harmful to human health and the environment.

Polygalacturonase from Aspergillus japonicus (PGAj): Enzyme production using low-cost carbon source, biochemical properties and application in clarification of fruit juices

Clarification of sugarcane juice is one of the most important steps in the sugar manufacturing process, considering that an efficient clarification may result in highly beneficial effects on the quality and yield of the final product, crystal or refined sugar. Currently, depending on the industrial plant and intended product, the use of calcium hydroxide, phosphoric acid and sulfur dioxide as auxiliary agents for clarification has been consolidated, the latter being questioned for causing adverse health reactions. In this context, the present study evaluated the performance of the natural black Acacia (Acacia mearnsii) tannin extract as an alternative for the sugarcane juice clarification. The results showed that tannin dosages between 300 and 500 ppm along with liming applied at pH 7.3 and 3 ppm of anionic flocculant provided the best performance, resulting in 32–34% of color removal and 89–93% of turbidity removal. Under these conditions, starch and dextran removal increased, 90 and 98%, as compared to 69% and 96%, obtained with conventional treatment. The performance of the tannin also reduced the calcium hardness of clarified juice by up to 18% compared to the conventional treatment, which in turn may prevent fouling in the subsequent steps.

The energy and exergy analyses of raw juice production and juice clarification units are carried out using the operational data from M/s Triveni Engineering & Industries Ltd, Deoband (Dist: Saharanpur, Uttar Pradesh), India. All the stages are considered as a steady state open thermodynamic system and the analysis is done by employing the first and second laws of thermodynamics. The results are analysed and discussed in this paper. The causes and location of energy loss and irreversibilities are identified. The exergy and energy efficiencies of raw juice production stage are found as 59.27% and 83.05% and those of juice clarification stage are 71.23% and 80.65%, respectively. Based on the analysis, it is recommended that the energy and exergy efficiencies of the process can be improved, if the irreversibilities generated during the process are minimised.

In this study, grafting of itaconic acid (IA) onto sodium alginate (NaAlg) using cerium(IV) ammonium nitrate/nitric acid (CAN/HNO3) as redox system was carried out by free radical polymerization. The structures of the grafted copolymers (NaAlg-g-PIA) were characterized by ATR-FTIR spectroscopy, NMR spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The reaction conditions for maximum grafting were optimized by varying the reaction time, temperature, percentage of sodium alginate, monomer, initiator, and nitric acid concentrations. The optimum reaction conditions were obtained with reaction time of 5 h, reaction temperature of 30 °C, IA concentration of 0.92 M, CAN concentration of 1.368 × 10−1 M, HNO3 concentration of 0.094 M and percentage of NaAlg 0.5 g/dL. The solubility test of NaAlg-g-PIA was also investigated using solvents. The results indicate that prepared graft copolymer was non-soluble in the various solvents, while it was soluble only in saturated solution of NaOH and promising as an adsorbent.

Processing of juice expressed from green sugar cane containing all the trash (i.e., tops and leaves, the nonstalk component) of the sugar cane plant during sugar manufacture has been reported to lead to poor clarified juice (CJ) quality. Studies of different liming techniques have been conducted to identify which liming technique gives the best clarification performance from juice expressed from green cane containing half of all trash extracted (GE). Results have shown that lime saccharate addition to juice at 76 °C either continuous or batchwise gives satisfactory settling rates of calcium phosphate flocs (50-70 cm/min) and CJ with low turbidity and minimal amounts of mineral constituents. Surprisingly, the addition of phosphoric acid (≤ 300 mg/kg as P₂O₅), prior to liming to reduce juice turbidity (≤ 80%), increased the Mg (≤ 101%) and Si (≤ 148%) contents particularly for clarified GE juices. The increase was not proportional with increasing phosphoric acid dose. The nature of the flocs formed, including the zeta potential of the particles by the different liming techniques, has been used to account for the differences in clarification performance. Differences between the qualities of the CJ obtained with GE juice and that of burnt cane juices with all trash extracted (BE) have been discussed to provide further insights into GE processing.