Rice Bran Acid Research Articles

Comparison of rice bran characteristics fermented by mono- or di-strain probiotics based on omics technology

Rice bran is a premium agricultural byproduct rich in nutrients and bioactive substances. The aim of this study was to compare the effects of fermentation with Bacillus subtilis, Lactobacillus plantarum, and a mixture of both on the bacterial communities and metabolic functions of rice bran based on omics techniques. The results showed that probiotic fermentation decreased crude fiber (CF) content, phytic acid, and trypsin inhibitor activity (TIA), and increased trichloroacetic acid soluble protein (TCA-SP), reducing sugar (RS), and total phenol (TP) in rice bran. Ten dominant genera with relative abundances greater than 1% were successfully identified, and probiotic fermentation significantly reduced the relative abundances of Enterobacter, Kasakonia, and Pantoea. A total of 63 differentially expressed metabolites (DEMs) were identified and further analysis revealed that probiotic fermentation increased essential amino acids, phenolic compounds, and organic acids in rice bran. Additionally, the di-strain probiotic fermentation of Bacillus subtilis and Lactobacillus plantarum facilitated the growth of beneficial microbiota (Limosilactobacillus, Prevotella and Dialister) and the production of bioactive substances (lactic acid, catechol, beta-tyrosine, etc.). In conclusion, co-fermentation of di-strain probiotics is a valuable method to produce functional compounds and enhance the health-promoting properties of rice bran.

Improving nutritional and sensory properties of rice bran by germination and solid-state fermentation with fungi

Rice bran, a by-product of the rice milling industry, is rich in protein, fiber, and other nutrients. However, its utilization in food has been limited due to the presence of unpleasant flavors and anti-nutritional components. The present study investigated the impact of germination and solid-state fermentation with various fungi starters on the nutritional and sensory features of rice bran. The results showed germination can significantly decrease phytic acid content and increase the contents of protein and fibers but had a negligible influence on the sensory characteristics of rice bran. Fungal fermentation demonstrated a notable increase in protein content and effective degradation of insoluble fiber and phytic acid in rice bran. Meanwhile, the sensory characteristics of rice bran after fermentation with different fungal cultures varied according to the instrumental analysis (electronic nose/tongue and GC-IMS) and sensory panelists evaluations. Rice bran fermented with Aspergillus niger, Actinomucor elegans and liquor koji exhibited similar GC-IMS spectra and characteristics of odor. However, A. niger imparted bran a musty smell and A. elegans contributed tastes of bitter and astringency. Mucor racemosus fermentation resulted in the highest score of fruity odor. Additionally, rice bran fermented with soy sauce koji stood out with the highest richness score, distinguishing it from other fermented brans. This research can provide insights into improving nutritional and sensory attributes of rice bran.

Effect of bee pollen on the characteristic of bread incorporated with Monascusfermented durian seeds and rice bran

Bread incorporated with Monascus-fermented durian seeds (MFDS) and rice bran (RB) is a functional food which contains bioactive compounds. Although it is beneficial for human health, it has bitterness and unpleasant aroma that caused by phenolic compounds in MFDS and fatty acids in RB. Incorporation of bee pollen in this bread is one way to improve the sensory properties of bread. The aim of this study was to observe the effect of different bee pollen concentrations on the physicochemical and sensory properties of bread incorporated with MFDS and RB. This study used Randomized Block Design with six levels of treatment starting from 0, 0.075, 0.150, 0.225, 0.300 and 0.375%. Data were analyzed by Analysis of Variance with α = 5%. The results indicated that difference in bee pollen concentration significantly affected on physicochemical and sensory properties of bread incorporated with MFDS and RB (p>0.05). Higher bee pollen concentration significantly increased the preference score for taste, aroma and overall acceptance (p>0.05). The best treatment was obtained by using 0.375% bee pollen.

Subcritical liquified dimethyl ether and supercritical fluid carbon dioxide extraction of gamma oryzanol from rice bran acid oil

Gamma oryzanol (γ-oryzanol) is a bioactive compound in rice bran acid oil, a by-product of the rice bran oil refining process that possesses various pharmacological properties. This study investigated the effect of green technology supercritical fluid carbon dioxide extraction (SF–CO2) and subcritical liquified dimethyl ether extraction (SUBLDME) of γ-oryzanol from rice bran acid oil. Results showed that subcritical liquified dimethyl ether extracted oryzanol at 4865.25 mg/100 g from rice bran acid oil without pretreatment by hexane and ethyl acetate compared with supercritical fluid carbon dioxide extraction (2569.04 mg/100 g), with high extraction efficiency (62.73 vs 18.86%). Further extraction of the filter cake remaining from supercritical fluid carbon dioxide extraction from rice bran acid oil without pretreatment using subcritical liquified dimethyl ether extraction gave the highest percentage yield and γ-oryzanol contents (8128.51 mg/100 g). Supercritical fluid carbon dioxide extraction together with subcritical liquified dimethyl ether extraction showed promise as a green technology to extract γ-oryzanol from rice bran acid oil. Further studies are required to optimize both SF-CO2 and SUBLDME extraction methods to increase the γ-oryzanol content.

Enzymatic esterification/transesterification of rice bran acid oil for subsequent γ-oryzanol recovery

This study recovered γ-oryzanol from rice bran acid oil (RBAO), following an initial enzymatic esterification/transesterification to selectively convert its glyceride impurities into fatty acid ethyl esters (FAEEs) or biodiesel. γ-oryzanol was then deprotonated and separated from the biodiesel into the resulting aqueous phase via acid-base extraction. Herein, we determine the effects of varying reaction conditions, i.e., ethanol:RBAO molar ratio, temperature, reaction time, enzyme loading, and agitation speed, on the degrees of glyceride removal, γ-oryzanol loss, free fatty acid (FFA) remaining, and biodiesel content. Up to 100% glyceride removal was achieved with a relatively high biodiesel yield (84%) and γ-oryzanol loss as low as 26% under our most suitable reaction conditions (5:1 ethanol:RBAO molar ratio, 40 °C, 24 h reaction time, 10%wt enzyme loading, 200 rpm agitation). Furthermore, of the remaining oryzanol, up to 94% was recovered by the acid-base extraction with 2-4 M ethanolic NaOH solution. Our results suggest that a combination of enzymatic esterification/transesterification with subsequent acid-base extraction offers an efficient alternative approach to the simultaneous production of biodiesel and γ-oryzanol recovery from low-cost RBAO. Based on our analysis of techno-economic and environmental sustainability, integration of the present method into a rice bran oil refinery would make the process profitable, with the minimum use of toxic chemicals and energy.

Enzymatic hydrolysis as a green alternative for glyceride removal from rice bran acid oil before γ-oryzanol recovery: Statistical process optimization

Rice bran acid oil (RBAO) is a byproduct of rice bran oil refinery, comprising of free fatty acids (FFAs), glycerides, and considerable amount of the natural antioxidant, γ-oryzanol. As a primary step to recover γ-oryzanol from RBAO, glycerides must be removed by conversion into more easily separable components such as FFAs. In this study, enzymatic hydrolysis was proposed as a green alternative to conventional base-catalyzed hydrolysis for glyceride removal from RBAO. The face-centered central composite rotatable design was used to investigate the effects of three independent variables: time, temperature, and water:RBAO ratio, and their interactions on the responses: glyceride removal, γ-oryzanol loss, and FFA production, and to determine the statistical models describing their relationships. In addition, by applying the desirability function approach, the optimal location was identified, corresponding to maximal glyceride removal with an imposed upper limit of 35% γ-oryzanol loss. At an established optimal condition of 22 h, 48.5 °C and 1:1 water:RBAO ratio, the experiments in which the enzymatic hydrolysis was carried out at 1x and 10x reaction scales confirmed the validity of the models: glyceride removal approached completion (99%), γ-oryzanol loss was as low as 32%, and the FFA production was 73–75%, falling within the 95% prediction interval. The results of this study demonstrated that the enzymatic hydrolysis is a promising method for glyceride removal prior to recovery of γ-oryzanol from RBAO, and that the statistical models gave accurate predictions of responses and would be useful further industrial design of the process.

Method Development for Purification of γ-oryzanol from Hydrolyzed Rice Bran Acid Oil by Semi-preparative Chromatography.

The objective of this study was to develop a method for isolation and purification of γ-oryzanol from hydrolyzed rice bran acid oil (RBAO) using semi-preparative chromatography by first applying silica coated-thin layer chromatography (TLC) to determine the suitable mobile phase. Subsequently, column chromatography was carried out to determine the effects of purification conditions such as the amount of and particle sizes of the sample silica gel, and elution modes, on the percentage of γ-oryzanol yield and recovery. The results from the TLC suggested that 75:25 (v/v) hexane to ethyl acetate mixture was a suitable mobile phase. The semi-chromatographic results indicated that the column containing 10 g of 25-40 μm silica gel with isocratic elution gave the highest yield (84%) of purified γ-oryzanol (> 95% purity). Further application of a step-gradient elution with 85:15 (v/v), followed by 75:25 (v/v) hexane to ethyl acetate mixture increased chromatographic resolution (Rs), resulting in enhanced separation efficiency, which in turn led to a higher yield of purified γ-oryzanol of 90%.

Rice Bran and Its Potential To Complement the Nutritional Needs of Children and Elderly.

Rice bran is an agro-industrial by-product of low added value that can be used to complement human nutritional needs. In this work, the profile of minerals, fatty acids and amino acids in brown rice bran was determined, aiming to evaluate its potential to complement the nutritional needs of different age groups, according to recommendations of regulatory agencies. The brown rice bran was supplied by a rice processing industry located in the south of the state of Rio Grande do Sul. Minerals were quantified using an emission spectrometer; the fatty acid profile was determined by gas chromatography and the amino acids were quantified by high-performance liquid chromatography with fluorescence (HPLC-FL). The main minerals were phosphorus (P), magnesium (Mg), potassium (K) and calcium (Ca) (2,933, 1,029, 211 and 56mg / 100g of rice bran). Saturated, monounsaturated and polyunsaturated fatty acids in rice bran were 22.4, 36.2 and 34.5% of lipid content, respectively. The polar, neutral and charged amino acids represented 8.8, 9.3 and 12.8% of the protein content, respectively. The composition of this co-product of rice supply chain is a good alternative to the new demand on plant-based food supplying the recommended daily intake (RDI) of national and international food polices.

Ruminal degradability of bypass fat and protein of certain commonly used feedstuffs in dairy rations

Studies were conducted to determine the rumen degradability of protein of certain commonly used feed ingredients and degradability of bypass fat used in dairy rations. In situ crude protein (CP) disappearance of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0.9% (of CP) formaldehyde treated soybean extraction, and in situ fat disappearance of bypass fat in the rumen at different incubation periods were determined by nylon bag technique using 3 adult crossbred steers. The effective degradability was calculated for an assumed outflow rate of 5%/h. The effective CP degradability of groundnut cake, soybean extraction, cottonseed cake, maize gluten meal, wheat bran, rice bran, maize, 0.3, 0.6 and 0. 9% (ofCP) formaldehyde treated soybean extraction was 86, 74, 66, 21, 73, 65, 63, 66, 48 and 26%, respectively. The effective fat degradability of bypass fat was 86%. The results indicated that maize gluten meal is a good source of bypass protein. Soybean extraction although extensively degraded in the rumen, contribute fairly more amount of undegradable protein than rumen degradable protein at an outflow rate of 5%/h, when it is treated with 0.6 and 0.9% (of CP) formaldehyde. The bypass fat supplement prepared from rice bran acid oil is a good source of energy in which about 86% of fat would be available at the lower tract of ruminants. Therefore, maize gluten meal, 0.9% formaldehyde treated soybean extraction and protected fat can be included in the rations of dairy animals forimproved productive performance

Optimizing modified rice bran for treating aqueous solutions polluted by Cr (VI) ions: isotherm and kinetics analyses

This study investigated the possibility and efficiency of absorbing chromium (VI) (Cr [VI]) ions from the polluted solutions by employing the chemically modified adsorbents (alkali, biochar, and acid rice bran), focusing on the possible impacts of the solution’s pH values, adsorbent’s dosages, concentrations, and contact times. The colori-metric method was used for Cr determination by employing an ultraviolet/visible spectrophotometer. The scanning electron microscope and Fourier transform infrared spectroscopy were used to analyze the characteristics of the modified adsorbents. The findings indicated that the optimized acid, biochar, alkali, and unmodified rice bran removal efficiency for Cr (VI) were 94.50%, 94.27%, 88.60%, and 90.18%, respectively. The increase of adsorbent dosage up to 2 g/L led to a rise in removal effectiveness (82.06%). Furthermore, the highest removal efficiency was obtained (94%) at the pH of 2.0, the contact duration of 100 min, Cr (VI) concentration of 50 mg/L, and dosage of 2 g/L, which was statistically the optimal condition for the modified rice bran. The adsorption kinetics was agreeably suited to pseudo-second-order, whereas the Freundlich isotherm equation was also suitably expounded the study’s findings. The findings implied that the acid and biochar rice bran performed remarkably in the reme-diation of the wastewater compared with alkali rice bran for reuse for industrial, agricultural, and environmental purposes.

Apparent total and ileal digestibility of rice bran with or without multicarbohydrase and phytase in weaned piglets

In the first 2 weeks after weaning, the piglets' digestive system cannot efficiently digest the new diet with vegetal ingredients. This study evaluated the effects of multicarbohydrase – MC (700 U α-galactosidase, 2200 U galactomannanase, 3000 U xylanase and 22 000 U β-glucanase per kilogram of diet), and phytase – Phy (500 phytase units – FTU/kg of diet) supplementation on the nutritive value of rice bran (RB) in weaned piglets. Twenty-five weaned piglets, 21 days old, were individually caged to determine the apparent digestibility of dry matter (DM), crude protein (CP), ash, digestible (DE), metabolisable (ME) energy, methane production, as well as apparent (AID) and standardised (SID) ileal amino acid digestibility in RB. Treatments were applied in a completely randomised experimental design with a 2 × 2 (0 and 200 mg/kg MC; 0 and 50 mg/kg Phy) factorial arrangement. An additional group of five piglets was fed a corn-basal diet (BD) during apparent digestibility evaluation of nutrients and a 5% casein-corn starch basal (BD1) diet during apparent and standardised ileal digestibility (SID) of amino acid evaluation. Ileal digesta were collected at slaughtering (38 days old). Test diets were made by mixing the basal diets and RB 7: 3 (w/w), with or without MC, Phy-or the combination. There was a positive interaction (P < 0.05) between MC and Phy-in the balance of CP and energy. An effect of Phy (P < 0.05) was observed on DM, CP and ash digestibility, whereas MC only improved N retention (P < 0.05). The pronounced effect of Phy-on ash digestibility of RB confirmed what was expected; however, it had no equivalent effect on amino acid digestibility. Based on literature data, the nutrient balance and digestible energy of RB without enzymes were lower than those using older pigs; AID and SID values for indispensable amino acids were 39 and 17% lower, respectively. The combination MC + Phy-showed an effect (P < 0.05) on Ile, Leu, Thr, Trp-and Val-digestibility. Isolated or combined, the enzymes increased the AID and SID averages of all amino acids in RB (P < 0.05). Enzyme combination provided a positive synergy for energy and protein digestibility of RB. The MC + Phy-RB test diet produced less methane, followed by Phy-and MC diets.

Comparative study on physicochemical hydrolysis methods for glycerides removal from rice bran acid oil for subsequent γ-oryzanol recovery

A comparative study on physicochemical hydrolysis methods, including acid-catalyzed, base-catalyzed, and subcritical water hydrolysis, for glycerides removal prior to subsequent γ-oryzanol purification from rice bran acid oil (RBAO), is presented. The effects of hydrolysis conditions on the residual levels of glycerides and γ-oryzanol in RBAO were first investigated for each method. It can be concluded that the acid-catalyzed hydrolysis was not a suitable hydrolysis method for this application as it provided a low glycerides conversion level of ca. 30% using 2 N H2SO4 at 80–100 °C, despite the long reaction time (> 60 min). For the base-catalyzed hydrolysis, 100% glycerides removal was achieved at the most suitable condition, which was suggested to be at 2.5 N NaOH, 90 °C and 5–10 min. At this condition, a relatively high residual level of γ-oryzanol of ca. 57–66% was obtained. For the subcritical water hydrolysis, the results suggested that γ-oryzanol was hydrolyzed more rapidly than glycerides, and the most suitable condition for subcritical water hydrolysis was at 220 °C for 10 min. At this condition, high glycerides removal of > 95% was achieved while the remaining amount of γ-oryzanol was still acceptable (50%).

Parametric study of esterification of high free fatty acid rice bran oil using aluminum doped sulfated zirconia

Parametric study of esterification of high free fatty acid rice bran oil using aluminum doped sulfated zirconia

Free fatty acids in rice bran during its storage after a treatment by twin-screw extrusion to prevent possible rapid hydrolytic rancidity of lipids

This research studied the prevention of hydrolytic rancidity during the storage of rice bran stabilized by an extrusion process. A double screw extruder was used, set at 130° C in the barrel and a rotational speed of the screws programmed at 200 RPM. The moisture content of the bran was adjusted at 20%. The treated bran was stored, using two packing methods (with and without vacuum), at two ambient conditions (18° C – 70 % RH and 30° C - 78% RH) for a period of 8 weeks. The content of free fatty acids (FFA) in the rice bran was observed during the storage time period. The extruded treated rice bran stored at 18° C - 70% RH resulted in lower values of FFA in comparison with the values in the bran kept at 30° C - 78% RH. Vacuum packaging showed a significant disadvantage as compared to packaging without vacuum.

Enhanced accumulation of gamma-aminobutyric acid in rice bran using anaerobic incubation with various additives

An anaerobic incubation for the enzymatic production of gamma-aminobutyric acid (GABA) in rice bran with the addition of glutamate, hydrolyzed wheat protein (HWP), yeast extract (YE) and pyridoxal-5-phosphate (PLP) was investigated. Rice bran was moistened (30% moisture content) with an electrolyzed oxidizing water and anaerobically incubated under nitrogen at 40 °C for 8 h. The incubation activated the glutamate decarboxylase (GAD) in rice bran and increased the GABA content from 10.7 to 171.5 mg/100 g. The addition of glutamate and protein hydrolysates further amplified the GABA content in the treated rice bran: 974.9, 487.4, and 372.8 mg/100 g, with 2.25% glutamate, 6% HWP, and 8% YE, respectively. Furthermore, addition of PLP (1.48 mg/100 g) as a coenzyme for GAD, together with 2.25% glutamate addition, could raise the GABA accumulation in rice bran to 2242 mg/100 g. Other amino acids in rice bran were changed in their composition by the anaerobic treatment.

Development of Bigels Based on Stearic Acid–Rice Bran Oil Oleogels and Tamarind Gum Hydrogels for Controlled Delivery Applications

AbstractIn the last few decades, different types of gels have been widely studied as potential drug delivery carriers. In this paper, we propose the synthesis of an oleogel, a tamarind gum hydrogel, and bigels for applications as drug delivery matrices. The oleogel was prepared by mixing stearic acid and rice bran oil, whereas the hydrogel was prepared by mixing tamarind gum with a hydroethanolic solution. Hydrogel‐in‐oleogel and oleogel‐in‐hydrogel bigels were prepared by mixing the hydrogel and the oleogel. The suitability of the formulations for controlled drug release applications was thoroughly examined using microscopy, Fourier transform infrared (FTIR) spectroscopy, as well as mechanical, electrical, thermal, drug release, and antimicrobial studies. An alteration in the microarchitecture of the bigels is observed when the oleogel and the hydrogel are mixed in varying proportions. The associative interactions within the formulations increase with the increase in the hydrogel content. The bigels exhibit the presence of stearic acid melting endotherm (associated with the oleogel) and water evaporation endotherm (associated with the hydrogel). This study suggests that the hydrogel has lowest bulk resistance compared to the other formulations. The structural breakdown of the bigels is composition‐dependent, and the bulk electrical resistance is mainly governed by the oleogel phase. An increase in the diffusion of the moxifloxacin HCl from the formulations is observed with the increase of the hydrogel proportion, which in turn increases the rate of release of the drug. The proposed formulations also exhibit good antimicrobial efficacy. The analysis of these properties suggests that specific formulations can be tailored by need‐based applications of the drug release rate.

Recovery of γ-Oryzanol from Rice Bran Acid Oil by an Acid-base Extraction Method with the Assistance of Response Surface Methodology.

A rapid and low energy consumption method for the recovery of γ-oryzanol from rice bran acid oil (RBAO), a byproduct of rice bran oil (RBO) refining, is presented. The RBAO was converted to the fatty acid ethyl ester (FAEE) and was used as the starting material. The dissolved γ-oryzanol was separated from the FAEE using an acid-base extraction method with alkaline aqueous ethanol and hexane as extraction media. A systematic investigation of the extraction yield was carried out by applying response surface methodology (RSM) based on central composite design (CCD) and Derringer's desirability function. The concentration of NaOH, the percentage of ethanol in water, the hexane content and their interactions showed significant effects on the yield of γ-oryzanol and FAEE. The optimal extraction conditions were as follows: extraction time of 1 min at room temperature (28-32°C); extraction medium: 1.855 M NaOH; 75.91% ethanol in water and 20.59% hexane in the total volume of the extractant; and FAEE to extractant ratio of 1:10 corresponding to a maximum γ-oryzanol yield of 75.82±3.44% and the desired FAEE yield of 54.42±7.80%. The γ-oryzanol-rich fraction was further purified by washing with a 2% Na2CO3 solution, obtaining 69.94% recovery yield with 89.90% purity of γ-oryzanol. The purified γ-oryzanol showed good scavenging activity on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and the ABTS radical and was comparable to the commercial product, clearly suggesting that the presented process was efficient and feasible.

Potential Prebiotic Oligosaccharide Mixtures from Acidic Hydrolysis of Rice Bran and Cassava Pulp.

Two agricultural wastes, rice bran and cassava pulp were subjected to acidic hydrolysis by 2M sulfuric acid which resulted in hemicellulosic oligosaccharide mixtures. Monosaccharide component analysis of these mixtures revealed that the oligosaccharides of rice bran acid hydrolysate (RAHF) composed of glucose and arabinose while cassava pulp acid hydrolysate (CAHF) was found to be comprised of glucose, galactose and arabinose. Both RAHF and CAHF were able to fuel all of the tested threeLactobacillus, five Bifidobacterium and three Bacteroides strains indicating the prebiotic potential of these oligosaccharide mixtures. Moreover, Lb. gasseri grew significantly better on RAHF than on inulin, a benchmark prebiotic oligo- and polysaccharide mixture. When the digestibility of RAHF and CAHF were tested it was found that these oligosaccharide mixtures were only slightly hydrolyzed upon exposure to simulated human gastric (by less than 8%) and pancreatic juices (by less than 3%). Additionally, most sensory attributes of the above obtained oligosaccharide mixtures supplemented two model cereal drink formulations were generally not different from those of the control, while the overall acceptance was not affected significantly in one cereal drink formulation.

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Differential Flotation of Some Egyptian Feldspars for Separation of Both Silica and Iron Oxides Contaminants

An anionic-cationic flotation of two Egyptian feldspar samples, representing Road Ashaab locality of the Eastern Desert of Egypt, was investigated on both laboratory and pilot plant scales. The pegmatites belong to the alkali feldspar granite type, mostly microcline and orthoclase, KAL Si3O8 coarse grained rocks. Quartz, as the main gangue mineral, occurs in two forms as either free grains or as veins intercalating the feldspar crystals or, sometimes, intermingled with them. Iron, on the other hand, is found in three different forms as free magnetite embedded in the feldspar crystals, as microcrystalline crystals, or as magnetite filling cracks in the feldspar. Dissolution of magnetite to hematite is, sometimes, observed. Grinding of the feldspar samples to less than 0.25 mm followed by desliming was optimized in the laboratory, using a ball mill in closed circuit with the screen. Anionic flotation of the iron oxide impurity from the -0.25 + 0.03 mm ground product was successfully conducted using locally produced dodecyl benzene sulphonic acid—rice bran oil/kerosene promoter at pH 3. Cationic flotation of feldspar from this product was then carried out employing a locally produced quaternary ammonium salt in presence of HF acid, as a silica depressant and a feldspar activator at pH 3. Feldspar final concentrates assaying 80.8% - 89.5% feldspar mineral, 0.119% - 0.127% Fe2O3 and 16.84% - 18.65% Al2O3, were obtained at the optimum operating conditions that satisfy the requirements of the ceramic industry. Continuous 200 kg/h pilot plant runs were conducted using the appropriate equipment, based upon the laboratory findings to produce feldspar concentrates assaying 16.38% - 18.13% Al2O3, and 0.13% - 0.15% Fe2O3. Materials’ metallurgical balance and complete chemical analyses were shown.