Optimization of Drum Drying Parameters for Low Amylose Rice (KDML105) Starch and Flour

An attempt was made to study and model the effects of drum drying process variables on the physico-chemical properties of low amylose rice (KDML105) flour and starch. Drum surface temperature, holding time and solid content of the slurry were varied at three levels: 115-135°C, 14-84 s and 20-40%, w/w, respectively. The dependent variables were moisture content (MC), degree of gelatinization (DG), water absorption index (WAI), water solubility index (WSI) and pasting property. High solid content led to a decrease in DG, WAI and initial peak viscosity (IPV) and increase in WSI of dried samples. Longer holding time resulted in increased DG while surface temperature had no significant effect on all characteristics. Predictive correlations were developed using stepwise multiple linear regression to predict MC, DG, WAI, WSI, and IPV of dried products from drum drying variables.     

Optimization of Drum Drying Parameters for Low Amylose Rice (KDML105) Starch and Flour

Abstract

An attempt was made to study and model the effects of drum drying process variables on the physico–chemical properties of low amylose rice (KDML105) flour and starch. Drum surface temperature, holding time and solid content of the slurry were varied at three levels: 115–135°C, 14–84 s and 20–40%, w/w, respectively. The dependent variables were moisture content (MC), degree of gelatinization (DG), water absorption index (WAI), water solubility index (WSI) and pasting property. High solid content led to a decrease in DG, WAI and initial peak viscosity (IPV) and increase in WSI of dried samples. Longer holding time resulted in increased DG while surface temperature had no significant effect on all characteristics. Predictive correlations were developed using stepwise multiple linear regression to predict MC, DG, WAI, WSI, and IPV of dried products from drum drying variables.     

Effects of the Addition of Spray‐Dried Whey on the Stability of Fat‐Reduced Mayonnaise‐Type Emulsions During Storage

The applicability of the spray‐dried whey for the production of reduced‐calorie mayonnaise‐type emulsions was studied. Whey was used as a stabilizing/emulsifying agent and as a fat‐replacement component. Whey powder was spray‐dried at 130, 140, and 180 °C. As control sample, 80% w/w standard fat emulsion was prepared. Mayonnaise‐like fat‐reduced emulsions contained 65% w/w of fat and 15% w/w of three distinct types of whey. The destabilization of the emulsions was investigated within 7 days of storage by scanning the samples with laser light. Backscattering, Turbiscan stability index, elasticity index, and macroscopic viscosity index were determined. The most stable emulsion contained whey powder spray‐dried at 180 °C. The emulsion made with whey powder spray‐dried at 130 °C was less stable than that with 180 °C spray‐dried whey, but it was more stable than the control and the one with whey spray‐dried at 140 °C.     

Composition optimization of poly(vinyl alcohol)‐/cornstarch‐blended biodegradable composite using response surface methodology

Response surface methodology was used to analyze the effect of amylase level (X₁) and glycerol level (X₂) on the objective [water solubility index (WSI), water absorption index (WAI), and Max. loading] attributes of a poly(vinyl alcohol)‐/cornstarch‐blended composite. A rotable central‐composite design (CCD) was used to develop models for the objective responses. The experiments were run at die temperature 100°C with a feed rate of 25 g/min and a screw speed of 35 rpm. Responses were most affected by changes in the amylase level (X₁) and to a lesser extent by glycerol level (X₂). Individual contour plots of the different responses were overlaid, and regions meeting the optimum WSI of 3.03 (%), WAI of 5.08 (g gel/g dry wt), and Max. loading of 29.36 (N) were identified at the amylase level of 2.8 (mL) and the glycerol level of 92.2 (mL), respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of glycerol and ethylene–acrylic acid on composition optimization of PVOH/starch‐blended biodegradable resin using response surface methodology

Response surface methodology was used to analyze the effect of glycerol (X₁) and ethylene–acrylic acid (EAA) level (X₂) on the objective (water solubility index (WSI), water absorption index (WAI), and tensile strength) attributes of a poly(vinyl alcohol) (PVOH)/starch‐blended plastic resin. A rotable central composite design was used to develop models for the objective responses. The experiments were run with different barrel temperatures, such as zone 1: 100°C, zone 2: 100°C, zone 3: 105°C, and zone 4: 105°C, respectively, with a feed rate of 20 g/min and screw speed of 25 rpm. Responses were most affected by changes in glycerol level (X₁) and to a lesser extent by EAA level (X₂). Individual contour plots of the different responses were overlaid, and regions meeting the optimum WSI of 6.10%, WAI of 5.57 g gel/g dry wt, and tensile strength of 62.14 MPa were identified at the glycerol level of 72.41 mL and the EAA level of 36.03 g, respectively. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effects of α‐amylase and glycerol levels on the composition optimization of poly(β‐hydroxybutyrate‐co‐valerate)/starch blended biodegradable resin analyzed with response surface methodology

Response surface methodology was used to analyze the effects of the enzyme level (X₂) and glycerol level (X₁) on objective attributes [water solubility index (WSI), water absorption index (WAI), and maximum loading (Y₃)] of a cornstarch/poly(β‐hydroxybutyrate‐co‐valerate) blended composite. A rotatable central composite design was used to develop models for the objective responses. The experiments were run at barrel temperatures of 160, 160, 165, and 165°C, with a screw speed of 40 rpm and complete feeding (filling ratio = 1). Responses were most affected by changes in X₂ and to a lesser extent by X₁. Individual contour plots of the different responses were overlaid, and regions meeting the optimal WSI of 8.73%, WAI of 3.94 g of gel/g of dry weight, and Y₃ of 304.17 N were established at an X₂ of 5.43 g and an X₁ of 120.79 mL. These predicted values for the optimal process conditions were in good agreement with the experimental data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effect of maltodextrin concentration and inlet temperature during spray drying on physicochemical and antioxidant properties of amla (Emblica officinalis) juice powder

The effects of inlet temperatures of 125, 150, 175 and 200 °C and maltodextrin levels at 3, 5, 7 and 9% on the physicochemical properties, total phenolic content (TPC) and 2,2-diphenyl picryl hydrazile (DPPH) scavenging activity of spray dried amla juice powder were studied. Moisture content and hygroscopicity of powder were significantly affected by inlet temperature and maltodextrin level. However, an increase in the level of maltodextrin did not significantly affect the bulk density and water solubility index (WSI). An increase in drying temperature and maltodextrin concentration decreased the free radical scavenging activity of the powder. Morphological study revealed that at higher inlet temperatures the spray dried powder had small sized particles that were densely packed. Spray dried amla juice powder made with 7% maltodextrin and processed at 175 °C inlet temperature had less hygroscopicity, acceptable color and potent free radical scavenging activity.     

Nixtamalization cooking characteristics of 11 maize varieties

In the present study, 11 maize varieties were analyzed for their nixtamalization cooking quality. The 11 varieties were grown in the same locality and in the same year. The samples were evaluated for their physical characteristics, such as moisture content averaging 13.3%, average 1000 kernel weight (312.5 g), grain hardness through density (1.28 g/ml) and percent floaters (9.5%). These data indicated that all maize varieties had a hard endosperm which is recommended for the nixtamalization cooking process. The 11 varieties were formed on the average by 5.7% seed coat, 11.5% germ and 82.8% endosperm. The low seed coat content suggest a low solids loss during processing. Cooking quality evaluation was done by applying a standard lime cooking procedure to all varieties. An average solid loss of 3.2% was measured, with 0.8% of seed coat still attached to the endosperm. Water absorption at the end of cooking was 40.8% without soaking and 46.9% at the end of soaking. Nixtamal moisture was 47.9% after soaking and only 41.5% at the end of cooking. Cooking time with soaking for 50% moisture in the grain varied from 69 to 122 minutes at 1500 meters over sea level. The cooked grain was dried with hot air and ground however, the particle size obtained was not as that in commercial nixtamalized maize flour. However, the cooking quality parameters to make dough and tortillas were acceptable, with a penetration index of hydrated flour of 178.6 mm, pH 7.97, water absorption index (WAI) of 3.23 g gel/g flour and 4.11% water solubility index (WSI). All flours from the 11 varieties of maize gave acceptable tortillas as evaluated by physical characteristics and sensory quality. However of the 11 varieties 7 including the control were superior for nixtamalization cooking quality.     

Characteristics and gel properties of gelatin from goat skin as affected by spray drying

Gelatin powder from goat skin prepared by spray drying at various inlet temperatures (160–200°C) was characterized. Predominant particle sizes were in the range of 4.65–5.14?µm. Gelatin powder was mostly concave in shape with varying sizes, depending on inlet temperatures used. All gelatin powders were creamy whitish. Powder generally became more yellowish as the inlet temperature of spray drying increased (p?p?p?p?>?0.05). Goat skin gelatin spray dried with inlet temperatures of 160 or 180°C had higher gel strength than commercial bovine gelatin (p?相似文献   

COMPARISON OF GLASS TRANSITION TEMPERATURE AND STICKY POINT TEMPERATURE FOR SKIM MILK POWDER

Wall deposition of particles in spray dryers is a key processing problem, and information about the glass transition temperature of the amorphous material that arises from spray drying can be used to guide the selection of operating conditions that may minimise wall deposition. The glass transition temperatures for skim milk powder with various moisture contents were determined using Differential Scanning Calorimetry (DSC), and a repeatable glass transition temperature diagram was established from these results. The glass transition temperature decreased as the moisture content increased, as expected (low moisture content 1.65 g/100 g of dry powder, glass transition temperature 87.7°C; high moisture content 4.52 g/100 g of dry powder, glass transition temperature 46.7°C). The glass transition temperature was found to be virtually the same as the sticky-point temperature measured using a thermo-mechanical test. The difference is essentially due to the difference between doing a mechanical test for viscosity (sticky-point) and a phase transition measurement (DSC).     

Pro-oxidative effects of spray drying orange oil in a bench top dryer

The influence of potential heat exposure during spray drying on the oxidative stability of spray dried orange oil was studied. The design of some of the table top spray driers expose dried product to dryer exit air temperatures in the powder collection chamber or on the walls of the dryer if there is an accumulation of material on the drying chamber walls. This heat exposure may accelerate oxidation of the product in subsequent storage. To determine the potential for heat damage to affect oxidation of the powders produced, an orange oil infeed emulsion (carrier material - modified starch) was prepared and spray dried using the sample collection chamber supplied by the manufacturer as standard equipment. The spray dryer was then modified to extend the collection chamber inlet such that the product remained cooler than in the standard collection chamber. In this study, the spray dryer was operated for 1?h (inlet air temperature; 180°C and an exit air temperature; 100°C). Thus, the spray dry product could have been exposed to as much as 1?h of heating in the collection chamber (potentially at temperatures as high as the exit air temperature). In the case of spray drying with a collection chamber extension, the collected product was maintained at ca. room temperature. This would approximately mimic the heat exposure powders receive in an industrial spray dryer. Powders produced using both equipment designs were taken from both the collection and drying chambers, adjusted in water activity (0.33) under a nitrogen environment, and then put into storage in an incubator maintained at 35°C for 4 weeks (exposed to air). The ratio of limonene oxide to limonene was used to monitor oxidation using gas chromatography. This study showed a substantial increase in rate of oxidation of the spray dried powder from the table top spray dryer with the standard commercial collection chamber and much less in case of an extended collection chamber. The powder from the respective drying chamber also showed a higher rate of oxidation in comparison to its collection chamber. Thus, we urge researchers studying heat damage (e.g., oxidation) of powders produced on the table top dryers to be conscious of overestimating heat damage during drying.     

Applying Spray Drying to Customized Powder Manufacture

Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition, dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper r     

用喷雾干燥方法制造具有指定特性的颗粒

Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition,dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper reviews the aspects of spray dryer design and operation for consideration when customized powder manufacture is involved.     

Production of Microencapsulated Crawfish (Procambarus clarkii) Astaxanthin in Oil by Spray Drying Technology

In this study, an emulsion prepared with flaxseed oil containing crawfish astaxanthin, sodium caseinate, lactose, and water was spray dried to produce microencapsulated flaxseed oil containing crawfish astaxanthin powder (MCA). Production rate and energy used to produce MCA were estimated. Physicochemical properties and storage stability of MCA were determined. The energy required to spray dry the microencapsulated flaxseed oil containing astaxanthin was 2.36 × 10⁴ kJ/kg of emulsion. The microencapsulation efficiency for MCA was 86.06%, which indicated that more oil was encapsulated than on the particles’ surfaces. The particle size of MCA ranged from 6 to 100 µm. The astaxanthin concentration in MCA was 13.76 μg/g powder and alpha-linolenic acid (ALA) was the predominant fatty acid (53%) in MCA. Degradation of astaxanthin in MCA followed first-order reaction kinetics and could be well described by the Arrhenius equation. The astaxanthin in MCA was more stable when the powder was stored at 5°C than at 25 or 40°C.     

Microencapsulation of Flaxseed Oil by Spray Drying: Effect of Oil Load and Type of Wall Material

The objective of this work was to evaluate the effect of the type of wall material and the oil load on the microencapsulation of flaxseed oil by spray drying. Gum arabic, whey protein concentrate, and a modified starch were used to produce the microcapsules, each with four oil concentrations (10, 20, 30, and 40% oil, w/w, with respect to total solids), for a total of 12 tests. Initially, the feed emulsions were characterized for stability, viscosity, and droplet size. Then they were dried in a laboratory-scale spray dryer and the resulting particles were analyzed for encapsulation efficiency, lipid oxidation, moisture content, and bulk density. The increase in oil concentration led to the production of emulsions with larger droplets and lower viscosity, which directly affected powder properties, resulting in lower encapsulation efficiency and higher lipid oxidation. Among the three wall materials evaluated, the modified starch showed the best performance, with the highest encapsulation efficiency and lowest peroxide values.     

The influence of plasticizer on extruded thermoplastic starch

This paper describes the use of an extruder for the plastification process of potato starch with glycerol and water as plasticizers. The influence of both plasticizers is expressed in the water absorption index (WAI) and water solubility index (WSI). The amount of water added prior to extrusion is a tool to protect the starch polymers from degradation and to improve the extruder performance.     

A nonconventional method for drying of Pseudomonas aeruginosa and its comparison with conventional methods

In this study, preparation of dried cultures of Pseudomonas aeruginosa using nonconventional drying method, namely, low-temperature low-humidity (LTLH) drying was investigated. The effect of carrier materials (whey protein, corn starch, and trehalose) was examined one at a time and also in combinations (to explore the synergistic effect). The results were compared with those obtained using spray drying and freeze drying in terms of cell survival and dry cell powder yield. The powder samples were analyzed also for morphology, flowability, particle size, and moisture content. In LTLH drying, good cell survival was observed along with high powder yield when compared with that in spray drying. Corn starch showed the highest cell survival (91%) and powder yield (94%, w/w) among the carrier materials employed besides resulting in good cell survival (65%) even after a storage period of 6 months.     

Influence of Carrier Agents on the Physicochemical Properties of Mussel Protein Hydrolysate Powder

The objective of this work was to evaluate the influence of carrier agents, maltodextrin 10 dextrose equivalent (DE) and gum arabic, on the physicochemical properties of mussel meat protein hydrolysate powder produced by spray drying. Hydrolysate was obtained by enzymatic hydrolysis using Protamex (Novozymes, Bagsvaerd, Denmark) and was carried out at 51°C, 4.5 g enzyme/100 g protein, and pH 6.85. The hydrolysate, without and with 15 and 30% of carrier agent, was spray dried at 180°C inlet air temperature and 0.8 L/h feed flow rate. Moisture content, hygroscopicity, particle size, glass transition temperature, morphology, antioxidant capacity, and volatile loss of powders were evaluated. Powder moisture content decreased with the increase in carrier agent concentration. Glass transition temperature increased with carrier agent addition and consequently powder hygroscopicity was reduced, increasing its physical stability. Higher feed solution viscosity was obtained for 30% of maltodextrin and 15 and 30% of gum arabic. The particles obtained from these solution presented a greater number of dents and larger particle size. The use of carrier agents reduced volatile loss and preserved the powder's antioxidant capacity.     

Synthesis of colloidal nanosilica from waste glass powder as a low cost precursor

Waste glass powder was used as a low cost precursor for production of colloidal nanosilica for the first time. The process includes production of wet silica gel and thermal peptization of the wet gel. Purification of the glass powder and wet gel production were initiated by acid washing. The obtained powder was reacted with sodium hydroxide to produce wet silica gel. Type of the applied acid was examined in one factor at a time route. Temperature of the alkaline step and concentrations of the applied acid and base were investigated using Taguchi design of experiments. After finding the best combination of the investigated factor levels in production of the wet gel, time of the stabilization in thermal peptization was studied. Characterizations of the wet gel and colloidal silica were performed by XRF, DLS, FESEM, TEM, FTIR and N₂ sorption evaluation. Accordingly pure and stable colloidal nanosilica (98.50%) with average particle size of 21.9?nm was produced from the glass powder successfully. Specific surface area of the dried porous optimum sample was 83.63?m²/g.     

Spray Drying of Green Corn Pulp

Maize (Zea mays) is a cereal grown in Brazil, and its availability is limited to the harvest season. An alternative processing route is based on the production of green corn powder, which has a longer shelf-life and increased versatility. This study aimed to evaluate the influence of drying conditions on the physical characteristics, size, and morphology of green corn powder. Drying experiments were performed on a spray dryer according to a central composite rotational design to evaluate inlet air temperature, feed flow rate, and pulp concentration. The yield of dried pulp corn had an average value of 36.19%. The following mean values for the physical properties of the powder were measured: solubility of 94.37 g/100 g, wettability of 128.05 seconds, moisture content of 1.97%, water activity of 0.13, density of 0.79 g/mL, and a particle diameter of 31.02 µm. The powder was also yellow with less intensity, and the particle surface was smooth at higher temperatures and had a tendency to form agglomerates. The estimated optimal conditions for spray drying were 48% (w/w) pulp concentration, 172°C inlet air temperature, and feed flow rate of 0.56 L/h.