Effects of instant controlled pressure drop treatment combined with refractance window drying on infusion quality of made green tea.

BACKGROUND: The study aimed to determine the effects of instant controlled decompression of steam pressure, termed as ICPD (instant controlled pressure drop) on fresh tea leaves, when combined with refractance window drying (RWD) of rolled green teas during green tea manufacturing. The ICPD steam treatment pressure (TP; 0.1-0.3 MPa), treatment time (TT; 10-20 s) and refractance window drying temperature (RWDT; 70-90 °C) were used as the processing parameters for manufacturing of green tea. RESULT: Response surface methodology was employed to enumerate the effects of ICPD process conditions and temperature of RWD on total phenolic content (TPC), total flavonoid content (TFC) and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of the green tea infusion. An optimum condition for green tea processing was found at TP 0.2 MPa, TT 20 s with RWDT at 70 °C. In comparison to made green tea manufactured without ICPD treatment, the ICPD treated green tea showed enhanced TPC, TFC and DPPH radical scavenging activity along with better colour and sensory attributes. The microstructural study of ICPD treated green tea samples showed more deformed cell surface integrity, larger stomatal pore size and cracks at the leaf surface in comparison with non-treated green tea sample. CONCLUSION: Present study reveals that an ICPD treatment at 0.2 MPa for 20 s can be used as an alternative to the traditional enzyme inactivation step of hot water treatment, for green tea leaves to improve the infusion quality in terms of increased levels of TPC and TFC and DPPH radical scavenging activity. © 2024 Society of Chemical Industry.

Physicochemical and Quality Properties of Dried Courgette Slices: Impact of Vacuum Impregnation and Drying Methods.

The aim of this study was to determine the effects that the type of impregnating solution and drying method (freeze drying (FD) and vacuum drying (VD) at 45 °C and convective drying (CD) at 50, 60, and 70 °C) had on the physicochemical and quality properties of courgettes. Courgette slices were vacuum-impregnated (6 kPa) in freshly squeezed onion, kale, and onion and kale (50:50) juices with 3% NaCl solution (N). The application of vacuum impregnation (VI) with impregnating solutions from freshly squeezed onions and kale had a beneficial effect on the bioactive values of courgette. The highest contents of quercetin (41.84 µg/g d.m.) and carotenoids (276.04 µg/g d.m.) were found in courgette impregnated with onion juice after freeze drying. The highest values of lutein and zeaxanthin (216.42 µg/g d.m.) were recorded for courgette impregnated with kale juice and convective dried. By analysing the kinetics of convective drying, the best matching of the logistic model was found. Increasing the drying process temperature from 50 to 70 °C reduced the drying time from 15% to 36%, depending on the type of impregnating solution used. Water activity < 0.6 was recorded for courgette dried by freezing, vacuum, and convection at 60 and 70 °C. Conclusions: The vacuum impregnation process and the impregnation solutions from freshly squeezed vegetables can be used to develop new snacks with high levels of bioactive compounds. The FD method is the most appropriate considering both the bioactive compounds content and the obtained colour and water activity.

Preservation of Aloe vera and soybean flour fortified Granny Smith apple through optimised quartz-halogen radiated vacuum drying: kinetics and quality evaluation.

BACKGROUND: Granny Smith (GS) apple has low protein content and poor antimicrobial properties; hence it has been blended with Aloe vera (AV; high ascorbic acid, antimicrobial and antioxidant properties) and soybean flour (SF; rich in phenols, flavonoids, ascorbic acid, total antioxidant and protein) in different proportions to obtain fortified GS, i.e. GSAVSF. Moreover, GS being a perishable fruit, its moisture content should be reduced to enhance shelf life. Accordingly, this GSAVSF was osmotically pre-dehydrated and finally dried through energy-efficient quartz-halogen radiation (QHR) assisted vacuum-drying (QHRVD) to produce dried GSAVSF i.e. (DGSAVSF) under optimized conditions. RESULTS: The optimally dehydrated DGSAVSF product resulted in minimum moisture (4.85% w/w) and maximum protein (6.24 g kg-1 ) content. The application of osmotic dehydration and QHRVD afforded acceptable colour of DGSAVSF compared to GSAVSF (ΔEI * = 10.07 ± 0.21). A parametric drying model was formulated that corroborated well with Fick's equation. QHRVD rendered high moisture diffusivity (1.49 × 10-8 m2 s-1 ) and low activation energy (27.64 kJ mol-1  K-1 ). Appreciable quality improvements with respect to fresh GS concerning ascorbic acid (176.05%), total phenolic (579.07%), total flavonoid (333.33%) contents and 2,2'-diphenyl-1-picrylhydrazyl radical scavenging activity (446.71%) could be achieved. The product demonstrated satisfactory shelf life (1 × 104 CFU g-1 : aerobic mesophilic; 1 × 104 CFU g-1 : mould and yeast) and high rehydration ratio (4.25 ± 0.1). CONCLUSION: The enrichment of GS with AV and SF along with optimal drying protocols could provide a quality fortified DGSAVSF through an energy-proficient sustainable process. The highly nutritious product with suitable colour, microbial stability and rehydration ratio also satisfied a 9-point hedonic scale, thus confirming consumer acceptability. © 2020 Society of Chemical Industry.

Effects of tri-frequency ultrasound-ethanol pretreatment combined with infrared convection drying on the quality properties and drying characteristics of scallion stalk.

BACKGROUND: Having short drying time and attractive product quality are important in fruit and vegetable dehydration processing. In this work, tri-frequency (20, 40 and 60 kHz) ultrasound-ethanol pretreatment, ultrasound-water pretreatment and ethanol pretreatment were employed before infrared convection drying (ICD) of scallion stalks, which was aimed at improving the drying process and quality of the end products. The mass transfer, drying characteristics (moisture ratio and drying rate and quality properties of scallion (rehydration, color, flavor, optical microscope image, moisture distribution and microbiological quality) were analyzed. RESULTS: All pretreatments have decreased the drying time by 33.34-83.34% compared to the control, while ultrasound-ethanol pretreatment provided the highest time reduction (83.34%). The reason is that the volatility of ethanol have replaced air in the tissue, which produced a better osmotic dehydration effect and the cavitation effect of ultrasound changed the cell function of the material, so that the food tissue was rapidly compressed and expanded, resulting in damage to the cell structure. Ultrasonic-ethanol pretreatment has greatly reduced the water loss and dry matter of fresh scallion, improved the rehydration effect of dried scallion, better retained the color and flavor of scallion and effectively reduced the microbiological quality of the scallion. CONCLUSION: The tri-frequency ultrasound-ethanol pretreatment has effectively improved the drying process and quality characteristics of the dried scallion. Therefore, this research has a great contribution to the drying technology, as evident in the remarkable reduction in drying time and the improvement in the quality of the end product. © 2020 Society of Chemical Industry.

Synthesis, drying process and medical application of polysaccharide-based aerogels.

Aerogels are promisingly intended for the use in describing lighter solid materials with huge porous structures. The outcome of aerogels is of potential interest in biomedical purposes owing to many features such as high surface area, low density and porous structure, and so forth. There are numerous inorganic and organic materials employed in the preparation of aerogels. Many drying techniques are a fundamental part of their preparation such as supercritical, freeze-drying, vacuum, ambient pressure and microwave which have been utilized for drying the wet-gel via substitute the liquid inside the wet-gel pores with air. Three common lighter solid materials (i.e. aerogel, cryogel and xerogel) could be synthesized depending on the drying technique applied. This review focuses on aerogel definition, the steps for the preparation of aerogel, techniques used for drying the wet-gel platforms. Further it highlights the pros and cons of each drying technique for synthesizing a demanded material's properties. As polysaccharide considered as one of the most prominent biocompatible and environmentally friendly polymers used for their preparation, thus we will present some examples (e.g.; cellulose, chitosan, starch, alginate, carrageenan and curdlan) and finally the potential biomedical applications of polysaccharides-based aerogel are briefly emphasized.

Ultrasound assisted low-temperature drying of kiwifruit: Effects on drying kinetics, bioactive compounds and antioxidant activity.

BACKGROUND: Low-temperature drying is considered to be a promising technique for food processing. It preserves thermolabile compounds and might be intensified by acoustic assistance. The effect of acoustic assistance (20.5 kW m-3 ) during low-temperature drying of kiwifruit (at 5, 10 and 15 °C, and 1 m s-1 ) on drying kinetics, bioactive compounds (such as ascorbic acid, vitamin E, and total polyphenols), and antioxidant activity was studied. RESULTS: Drying time was shortened by 55-65% when using power ultrasound. A diffusion model was used to evaluate the drying kinetics. The effective diffusion coefficient increased by 154 ± 30% and the external mass transfer coefficient increased by 158 ± 66% when ultrasound was applied during drying, compared with drying without ultrasound application. With regard to bioactive compounds and antioxidant activity, although samples dried at 15 °C presented significantly higher (P < 0.05) losses (39-54% and 57-69%, respectively) than samples dried at 5 °C (14-43% and 23-50%, respectively) when ultrasound was not applied, the application of ultrasound during drying at 15 °C significantly reduced (P < 0.05) those losses in all quality parameters (15-47% and 47-58%, respectively). CONCLUSION: Overall, low-temperature drying of kiwifruit was enhanced by acoustic assistance preserving bioactive compounds and antioxidant activity, especially at 15 °C. © 2018 Society of Chemical Industry.

Effects of dehydration methods on quality characteristics of yellow passion fruit co-products.

BACKGROUND: The production and processing of fruits generate a large amount of residues, which are usually disposed of or under-used, representing losses of raw material and energy. The present paper investigates the effect of four dehydration techniques (convective, infrared, microwave and freeze-drying) on yellow passion fruit (Passiflora edulis f. flavicarpa) co-products and the influence of the main variables on moisture removal and bioactive compounds. The compounds analyzed were total phenolics, total flavonoids, ascorbic acid and pectin. RESULTS: The content of phenolics and flavonoids increased after dehydration in all techniques investigated and the process temperatures directly affected the ascorbic acid content. Microwave dehydration showed the best results for most bioactive compounds analyzed, if performed in suitable process conditions. However, the highest levels of pectin content were obtained by freeze-drying and convective dehydration. CONCLUSION: This study reinforces the importance of the adequate use of passion fruit co-products due to the high levels of bioactive compounds in this material. Microwave dehydration presented the best results, which indicates the potential use of this technique for a better exploitation of fruit co-products. Larger quantities of pectin were extracted from samples dehydrated through methodologies with long-time process and low temperatures, such as convective drying and freeze-drying. © 2017 Society of Chemical Industry.

Preparation of Diacylglycerol-enriched Rice Bran Oil by Lipase-catalyzed Deacidification in Packed-bed Reactors by Continuous Dehydration.

Diacylglycerol-enriched rice bran oil (RBO-DAG) was produced by deacidification of high-acid rice bran oil (RBO) with glycerol (Gly) using Lipozyme RM IM by continuous dehydration by combination of two enzyme columns (column 1 and 3, used for deacidification) with one molecular sieves column (column 2, used for dehydration). The conditions for three columns were respectively optimized. Response surface methodology (RSM) was used to optimize the conditions of column 1. The content of DAG and conversion of free fatty acid (FFA) were used as indicators and the effects of the enzyme load (8-12 g), flow rate (0.3-0.6 mL/min), substrate molar ratio (4-6) and reaction temperature (55-75°C) were investigated. The content of DAG and conversion of FFA were significantly correlated to the flow rate and substrate molar ratio. Most desirable conditions of the reaction with respect to the maximal DAG content and FFA conversion was attained under the residence time of 40 min, substrate molar ratio of 5.52 (Gly: RBO) and temperature of 66°C. The conditions for column 2 were investigated by varying molecular sieves load and flow rate, and the maximal dehydration rate of 85.22% was obtained under the optimal conditions. For column 3, the optimum conditions were obtained as: flow rate, 0.2mL/min; temperature, 65°C, and the content of DAG and FFA were 38.99% and 3.04%, respectively under these conditions. The catalytic activity of the lipase was stable in twelve continuous operations with 83.22% of its original ability, demonstrating its potential in the continuous packed-bed reactors (PBRs) system. These results showed that packed-bed reactors combined with continuous deacidification and dehydration in one system had great value in industrial production for high-acid RBO with the improved conversion rate.

[Development of rapid setting-drying device for herbarium specimens and its application in survey of Chinese materia medica resources in Anhui].

Herbarium specimens are the basis for the plant classification and indispensable media in teaching, scientific research and resources investigation. They have also played an important role in identifying and producing traditional Chinese medicine. High-quality herbarium specimens shall meet high requirements for integrity, smoothness, color and fabricating efficiency. Therefore, we designed a rapid setting and drying device for herbarium specimens, which could make the herbarium specimens smooth, colorful and not easy to mildew. In this paper, we pointed out the deficiency of traditional methods in making herbarium specimens, and introduced the structure and working principle of the device. Besides, we also discussed the effect of the device in setting and drying herbarium specimens and its application in the fourth national survey of the Chinese material medica resources (CMMR) in Anhui province. As a result, the device provides new ideas for producing herbarium specimens, with a reasonable design, good uniformity, high efficiency, safety and portability, and so is worthy of promotion and application in the national survey of CMMR.

[Optimization of vacuum belt drying process of Gardeniae Fructus in Reduning injection by Box-Behnken design-response surface methodology].

To optimize the belt drying process conditions optimization of Gardeniae Fructus extract from Reduning injection by Box-Behnken design-response surface methodology, on the basis of single factor experiment, a three-factor and three-level Box-Behnken experimental design was employed to optimize the drying technology of Gardeniae Fructus extract from Reduning injection. With drying temperature, drying time, feeding speed as independent variables and the content of geniposide as dependent variable, the experimental data were fitted to a second order polynomial equation, establishing the mathematical relationship between the content of geniposide and respective variables. With the experimental data analyzed by Design-Expert 8. 0. 6, the optimal drying parameter was as follows: the drying temperature was 98.5 degrees C , the drying time was 89 min, the feeding speed was 99.8 r x min(-1). Three verification experiments were taked under this technology and the measured average content of geniposide was 564. 108 mg x g(-1), which was close to the model prediction: 563. 307 mg x g(-1). According to the verification test, the Gardeniae Fructus belt drying process is steady and feasible. So single factor experiments combined with response surface method (RSM) could be used to optimize the drying technology of Reduning injection Gardenia extract.

[Optimization for vacuum belt drying process of Qibai Pingfei granule through response surface methodology].

Based on single factor tests,the optimum vacuum belt drying conditions of Qibai Pingfei granule were obtained through Box-Benhnken central combination design and RSM. In this study, drying time, drying temperature and extract density were chosen as independent variables, while transferring rate ginsenoside Rg1, Re, Rb1and astragaloside IV were taken as dependent variables. The optimum parameters are as follows: drying time of 112 min, drying temperature of 87 °C and extract density of 1.30 g · mL⁻¹. At the optimum condition, transferring rate ginsenoside Rg1+ Re, Rb1and astragaloside IV were 88.01%, 87.31%, 84. 34%. Above all, the optimum processing parameters of vacuum belt drying of Qibai Pingfei granule is reasonable and feasible, which can provide reliable basis for production.

Drying effects on the antioxidant properties of tomatoes and ginger.

In this study, the effects of four different drying processes, sun drying (SD), oven drying (OD), vacuum oven drying (VOD) and freeze drying (FD) for tomatoes (Solanum lycopersicum) and ginger (Zingiber officinale) in terms of thiolic and phenolic contents have been studied. Thiol content, total phenolic content (TPC), ascorbic acid (AA) content, and cupric ion reducing antioxidant capacity (CUPRAC) were determined in fresh and dried samples. Glutathione (GSH) and cysteine (Cys) were determined as the thiol contents of tomatoes and ginger. Significant losses were observed in the contents of TPC, AA, GSH and Cys and CUPRAC values in all samples that were dried using the thermal method. There was a statistically significant difference in the losses of the TPC, AA, and thiol contents between the use of thermal drying and freeze drying (except Cys in tomatoes) methods. Freeze dried tomato and ginger samples have been found to have better antioxidant properties.

Product characteristics and quality of bovine blood-enriched dried vegetable paste.

BACKGROUND: The aim of this study was to evaluate a preparation of vegetable paste with bovine blood in order to maximize the protein content using linear programming, and to analyze the product characteristics and quality of bovine blood-enriched vegetable paste dried in a spouted bed. The drying experiments were performed by evaluating the effects of inlet air temperature, paste flow rate and paste solids concentration on the dried product characteristics and quality (functional and nutritional properties). RESULTS: The vegetable paste enriched with bovine blood was a good source of protein (∼0.20 g g(-1) , dry basis), and the linear programming was adequate to select the constituents (carrot, onion, potato, kale, tomato, soybean oil and bovine blood) and optimize their quantities. The drying conditions of bovine blood-enriched vegetable paste in the spouted bed that gave the best product characteristics were an air temperature of 110 °C and a paste flow rate of 600 mL h(-1) with 0.07 g g(-1) solids concentration. CONCLUSION: The addition of bovine blood to vegetable paste by linear programming increased the protein content of the paste and improved its functional properties and digestibility. The powder obtained from the spouted bed drier showed suitable functional and nutritional properties and was also a good source of antioxidant compounds.

Caracterização físico-química e análises por espectrofotometria e cromatografia de Peperomia pellucida L. (H. B. K. ) / Physical chemical characterization and spectrophotometric analysis and chromatography (TLC) of the Peperomia pellucida L. (H. B. K. )

O objetivo deste trabalho foi realizar a caracterização físico-química do pó e da tintura, e análise por espectrofotometria e cromatografia do extrato seco de Peperomia pellucida L. (H. B. K.). As metodologias seguiram a Farmacopéia Brasileira IV ed., com exceção da prospecção química, da espectrofotometria, da obtenção do perfil cromatográfico do extrato seco, e determinação do resíduo seco. A prospecção química revelou a presença de saponinas espumídicas; açúcares redutores; proteínas e aminoácidos; fenóis; taninos; flavonóides; esteróides e triterpenóides. Na análise por CCD, o melhor perfil da fração flavonoídica foi obtido com MeOH/CHOOH (90:10). Foi confirmada, através de CLAE, a presença de 3',4',7-tri-O-metoxiflavona no extrato seco deste material vegetal. Os resultados obtidos contribuem para a determinação de especificações de uma futura monografia em Farmacopéias da Peperomia pellucida L. (H.B.K.).

The aim of this study was the physical chemical characterization of the powder and the tincture, and the chromatographic and spectrophotometric analysis of the Peperomiapellucida L. (H. B. K.) dry extract. The methodology followed the Farmacopeia Brasileira IV ed., except for the chemical prospection, the chromatographic profile obtained and the spectrophotometry of the dry extract, and determination of dried residues. The chemical prospection revealed the presence of foaming saponins; reducing sugars; proteins and amino acids; phenols; tannins; flavonoids; steroids and triterpenoids; depsideos and depsidones. The best profile from TLC for flavonoidic fraction was obtained with methanol/formic acid (90:10 v/v). HPLC confirmed the presence of 3 ',4',7-tri-methoxyflavone in the dry extract of the plant material. The results obtained in this work should contribute for the determination of specifications for a future monograph on Peperomia pellucida L. (H.B.K.).

Effects of spray drying on antioxidant capacity and anthocyanidin content of blueberry by-products.

UNLABELLED: The effect of spray drying on degradation of nutraceutical components in cull blueberry extract was investigated. Samples collected before and after spray drying were tested for antioxidant capacity using oxygen radical absorbance capacity (ORAC(FL) ) and total phenolics; and for individual anthocyanidins. In Study 1, four different levels of maltodextrin (blueberry solids to maltodextrin ratios of 5: 95, 10: 90, 30: 70, and 50: 50) were spray dried a pilot-scale spray dryer. There was significantly higher retention of nutraceutical components with increased levels of maltodextrin indicating a protective effect of maltodextrin on the nutraceutical components during spray drying. In Study 2, the air inlet temperature of the spray dryer was kept constant for all runs at 150 °C, with 2 different outlet temperatures of 80 and 90 °C. The degradation of nutraceutical components was not significantly different at the 2 selected outlet temperatures. ORAC(FL) reduction for blueberry samples after spray drying was 66.3% to 69.6%. After spray drying, total phenolics reduction for blueberry was 8.2% to 17.5%. Individual anthocyanidin reduction for blueberry was 50% to 70%. The experimental spray dried powders compared favorably to commercial blueberry powders. Results of the study show that use of blueberry by-products is feasible to make a value-added powder. PRACTICAL APPLICATION: Results can be used by producers to estimate final nutraceutical content of spray-dried blueberry by-products.

Improving thermal dewatering characteristics of mechanically dewatered sludge: response surface analysis of combined lime-heat treatment.

In this study, disintegration of dewatered sludge (dry solids content [DS%] = 23 +/- 2) was studied to assess the possibility of enhancing the overall performance of a thermal dewatering processes. Powdered lime was used as an alkaline disintegrator. The combined effects of drying temperature, powdered lime dosage, and organic content on the thermal drying rate of dewatered sludge were investigated in a full-scale wastewater treatment plant. Effects of selected design parameters on the sludge drying rate were modeled using a response surface method. In addition, the possible interaction between lost on ignition and total organic carbon parameters also was investigated statistically. Specific resistance to filtration and free water contents of raw and disintegrated mixed sludge (DS% = 1.0 to 1.8) samples were compared statistically. The obtained results indicated that all of the selected design parameters have a significant effect on thermal dewatering characteristics, and the alkaline disintegration technique could remarkably improve thermal evaporation rate of dewatered sludge. These results are important because they could help to establish a sustainable sludge management model, which is critical in reducing environmental health risks.

Improvement of water transport mechanisms during potato drying by applying ultrasound.

BACKGROUND: The drying rate of vegetables is limited by internal moisture diffusion and convective transport mechanisms. The increase of drying air temperature leads to faster water mobility; however, it provokes quality loss in the product and presents a higher energy demand. Therefore, the search for new strategies to improve water mobility during convective drying constitutes a topic of relevant research. The aim of this work was to evaluate the use of power ultrasound to improve convective drying of potato and quantify the influence of the applied power in the water transport mechanisms. RESULTS: Drying kinetics of potato cubes were increased by the ultrasonic application. The influence of power ultrasound was dependent on the ultrasonic power (from 0 to 37 kW m(-3) ), the higher the applied power, the faster the drying kinetic. The diffusion model considering external resistance to mass transfer provided a good fit of drying kinetics. From modelling, it was observed a proportional and significant (P < 0.05) influence of the applied ultrasonic power on the identified kinetic parameters: effective moisture diffusivity and mass transfer coefficient. CONCLUSIONS: The ultrasonic application during drying represents an interesting alternative to traditional convective drying by shortening drying time, which may involve an energy saving concerning industrial applications. In addition, the ultrasonic effect in the water transport is based on mechanical phenomena with a low heating capacity, which is highly relevant for drying heat sensitive materials and also for obtaining high-quality dry products.

Spray drying technique: II. Current applications in pharmaceutical technology.

This review presents current applications of spray drying in pharmaceutical technology. The topics discussed include the obtention of excipients and cospray dried composites, methods for increasing the aqueous solubility and bioavailability of active substances, and modified release profiles from spray-dried particles. This review also describes the use of the spray drying technique in the context of biological therapies, such as the spray drying of proteins, inhalable powders, and viable organisms, and the modification of the physical properties of dry plant extracts.

[Optimization for vacuum belt drying process of Panax notoginseng extract].

OBJECTIVE: To optimize the conditions of the vacuum belt drying process (VBD) for drying Panax notoginseng extract and compare with methods of vacuum freezing drying and spray drying. METHOD: The optimum conditions of VBD were obtained by orthogonal design and validated by determinations of moisture content of the dried product and recovery of active ingredients. Experiments on different drying methods were also conducted. RESULT AND CONCLUSION: The optimum conditions are as follows, the feeding speed was 15 mL x min(-1), the belt speed was 4 mm x min(-1), and the heating temperature was (105, 100 degrees C). Comparing with the drying methods of vacuum freezing drying and spray drying, vacuum belt drying possesses some advantages, such as higher recovery of active ingredients, less moisture content of dried product and better overall yield.

Fluid bed drying of guarana (Paullinia cupana HBK) extract: effect of process factors on caffeine content.

The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate, and air inlet temperature, on the quality of the dry extract was determined using the caffeine and moisture content for the process evaluation. The caffeine content in the alcoholic and dried extracts was determined by capillary gas chromatography. The experiments were performed following a 3(3) factorial design and the data analyzed by response surface. The analysis of dry extract showed that the air and extract feed rates did not significantly affect (25% level) the caffeine content, but that drying temperature is a major factor to consider when the extract is submitted to fluid bed drying. Caffeine losses were significant (1% level) for drying temperatures above 120 degrees C, while moisture content was lower than 3% for temperatures above 120 degrees C. The data showed that there is an optimum temperature for the drying of guarana extracts in spouted beds, and under the conditions used in this study it was 120 degrees C.