Foam Mat Drying Research Articles

Drying of Onion Paste to Develop Powders by Foam-Mat Drying Process using Egg Albumin as Foaming Agent

Drying of Onion Paste to Develop Powders by Foam-Mat Drying Process using Egg Albumin as Foaming Agent

Effects of drying methods on color retention and chlorophyll of celery (ApiumgraveolensL.), spinach (Spinacia oleraceaL.), Malabar spinach (Basella albaL.)

Dried vegetables are considered convenient for storage, transportation and preservation. The different drying techniques could influence the quality of resulting products. This study aimed to evaluate the effects of three distinguish drying methods as hot-air drying, foam-mat drying and microwave drying on the color retention and chlorophyll of green vegetables powder. Fresh spinach(Spinacia oleraceaL.), celery (Apium graveolensL.), Malabar spinach (Basella albaL.) were dried by different methods: hot air at 60oC, foam-mat at 60oC and microwave at 270 W until the samples reached approximately 9% of moisture content (wb). The drying time of the dried samples by microwave, foam-mat and hot-air method were 60, 210 and 240 min, respectively. Foam-mat dried vegetables were found to have the best quality in terms of color and the residual chlorophyll content. The findings suggest that foam-mat drying is promising in dried vegetable processing

PHYTOCHEMICAL CONTENT, PHYSICOCHEMICAL AND MICROSTRUCTURAL PROPERTIES OF APPLE POWDER AS AFFECTED BY DRYING METHOD

Apple in forms of slice and juice dried through methods of freeze drying (FZD), microwave drying (MWD), oven drying (OVN), spray drying (SPD) and foam mat drying (FMD) and the resulted powders were characterized in terms of water activity, vitamin C (Vc), phenolic compounds (TP), anthocyanin (TA), density, porosity, color, glass transition temperature and microstructure. The nutritional quality of apple powders expressed by the amount of Vc, TP and TA was found to be in the highest level in samples obtained after FZD followed by SPD. The minimum shift of color indexes from fresh apple observed for FZD followed by MWD. The highest and lowest bulk and true density were noted after OVD and FMD, and FZD and SPD, respectively. DSC analysis showed the powders obtained from apple slice through FZD, MWD and OVD have significantly lower Tg than those of produced from apple juice, by SPD and FMD. Scanning electron micrograph confirmed the porous structure of FMD and FZD and the dense structure of OVD.

Foam-mat drying of bacaba (Oenocarpus bacaba): Process characterization, physicochemical properties, and antioxidant activity

This work studied the foam-mat drying (FMD) of bacaba pulp, evaluating the parameters of foam-forming and the effects of thickness layer (5–15 mm) and temperature (50–70 °C) during the drying process. The results showed the need for an emulsifier, in addition to the foaming agent, to obtain a low density and stable foam. The powder showed high content of proteins (15.9 ± 0.6 %), fibers (49.6 ± 0.4 %), and lipids (35.6 ± 0.2 %). The combination of the lowest drying temperature and thickness resulted in a final product with good solubility (37.5 ± 1.2 %) and a high antioxidant capacity (525 ± 13 μmol TE g−1), which suggests a great potential for use in the development of functional products.

Effect of gum Arabic concentrations on foam properties, drying kinetics and physicochemical properties of foam mat drying of cantaloupe

The effect of gum arabic (GA) concentrations (0, 5, 10, and 15%) on the foam properties, drying kinetic, and effective moisture diffusivity of foam mat drying of cantaloupe (Cucumis melo) were analysed. Results showed that foam mat drying of cantaloupe puree with 10% GA has better foam density, foam expansion, and foam stability. The Page model fits the foam mat drying behavior of cantaloupe foam with different concentrations of GA at a constant temperature of 55 °C. The moisture content of foam mat dried cantaloupe powder was ranged from 3.29 to 4.64%. The powder flowability was significantly affected by the GA concentration. The powder produced at higher GA concentration showed good powder flowability and lower cohesiveness. Fresh cantaloupe fruit can be preserved into foam mat dried cantaloupe powder and used as a food ingredient in a variety of food products. Applications of foam mat dried cantaloupe powder in cake icing gave a natural colorant with antioxidants and no significant changes on flow behavior index of the icing viscosity.

Banana Powder Production via Foam Mat Drying

Banana puree is one of the main commercial banana products available in the market worldwide. However, like other purees, banana puree deteriorates quite rapidly and gets a chilling injury when refrigerated. Therefore, this study focused on the dehydration of banana puree using a foam mat drying (FMD) technique to prolong its shelf life. It involved whipping the banana puree to form foams with the help of whey protein concentrate (WPC) and carboxymethyl cellulose (CMC) as the foaming agent and foam stabilizer, respectively. The study evaluated the effect of different foaming agent percentages (5, 7.5, 10, 12.5 and 15%) and drying temperatures (50, 60, 70 and 80°C) on the production of the foam mat dried banana powder. Besides that, the drying curves of banana puree using FMD and oven drying methods were compared. The banana powders produced were also analyzed in terms of the foam density, moisture content, solubility, color (browning index) and flowability (caking strength). Based on the findings, the FMD technique has proven to produce a good quality banana powder better than the control sample especially at a higher foaming agent concentration (15%) and drying temperature (80°C). By using the FMD technique, the banana puree has the capacity to be dried three times faster compared to the conventional oven drying method to form a more stable banana powder.

Comparison of bioactive compounds and nutrient contents in whey protein concentrate admixture of turmeric extract produced by spray drying and foam mat drying

We developed a whey protein admixture of turmeric extract by spray drying (TWPC-SD) and by foam mat drying (TWPC-FMD) and compared its bioactive compounds and nutrients contents. TWPC samples were evaluated for preference and acceptability. Vitamins and carotenoids were determined by high-performance liquid chromatography. Total phenolics, curcumin and antioxidant capacity were determined by spectrophotometry. Centesimal composition was performed according to the Association of Official Analytical Chemists. Chemical elements were determined by inductively coupled plasma optical emission spectrometry. TWPC containing 3.6 mg of curcumin showed good acceptability. Carotenoids and riboflavin were not detected in either TWPC. Vitamin C content was maintained, and antioxidant capacity was increased in both products (p < 0.05). TWPC-SD showed higher total phenolic and curcumin contents compared to TWPC-FMD (p < 0.05). Thus, the TWPC-SD is a good alternative for human consumption since it showed good sensory acceptability and its nutrients and bioactive compounds can contribute to human health.

Prototype continuous microwave foam-mat dryer: design and fabrication.

A prototype microwave foam mat dryer with continuous operation was fabricated for tomato and guava. Results of preliminary studies on microwave foam mat drying of tomato and guava were used to design the prototype. The continuous foaming operation was achieved with the help of a submersible pump controlled by a time switch which ensured the delivery of pulp into foaming container and streamlined the delivery of foam on the drying surface (belt). The drying section presented a combination of hot air and microwaves, which resulted in accelerated heating and subsequently drying of the foam. Dried flakes were collected at the exit with the scrapper blade, which ensured appreciable recovery. The quality evaluation of guava pulp and tomato pulp dried at different microwave powers and inlet air temperatures revealed that the products dried at 1000W microwave power and 50°C exhibited excellent physicochemical properties in both the cases. Performance evaluation study depicted that the capacity of the dryer for guava drying was 4.84l/h, the final moisture retention in the dried powder was 0.059g H2O/g d.m, recovery was 98.34% and energy consumption was 1.32kWh/l. Similarly, for tomato drying the capacity, final moisture content, recovery and energy consumption were 4.03l/h, 0.062g H2O/g d.m, 91.29% and 1.49kWh/l respectively.

MİKRODALGA KOŞULLARINDA MUZUN KÖPÜK KURUTMA ÖZELLİKLERİNİN MODELLENMESİ

In this study, it was aimed to dry banana using microwave-assisted foam-mat drying and to identify the drying behavior. Foam-mat drying of banana foam was made using a microwave oven at output power of 100, 180, 300, 450 and 600 W. Effective moisture diffusivities were obtained in the range of 5.9536 x 10-9 and 3.5692 x 10-8 m2 s-1. Activation energy was determined as 10.80 W g-1 of microwave dried banana foam. Besides, to find the best model to experimental moisture ratio values, thin layer models of Page, Wang and Singh, Midilli and others, Silva and others, two-term and Peleg were applied. As a result, Midilli and others’ model gave a better fit than others with highest value of R2, lowest values of RMSE, RSS and χ2.

Optimization of process parameters for foam mat drying of black rice bran anthocyanin and comparison with spray- and freeze-dried powders

The foaming conditions and air-drying temperature for producing instant powder from black rice bran anthocyanin extracts were studied. The conditions required for forming a foam to possess the maximum overrun, foam density, and foam stability, which contributed to boost the efficiency of drying foams using a hot-air dryer, were optimized using response surface methodology (RSM). Two independent variables were studied: the foaming agent concentrations (0.02–0.10%, w/w) and the whipping times (7.93–22.1 min). The optimal foaming conditions from RSM were 0.06% (w/w) foaming agent and 16.1 min whipping time, providing foams with the highest overrun (218%), foam density (0.31 g/mL), and foam stability (79.3%). The foams were dried at different temperatures (60, 70, and 80 °C). The best qualities of foam mat-dried powders were observed at 80 °C. Compared to spray- and freeze-dried anthocyanin powders, the total anthocyanin content and encapsulation efficiency of the foam mat-dried powders were comparable and higher to those of the spray- and freeze-dried powders, respectively. However, the solubility and dispersibility of the foam mat-dried powders were lower. The morphology of the foam mat-dried powder showed a smooth, flat shape, with a larger size than the spray- and freeze-dried powders.

Usability of soapwort and horse chestnut saponin extracts as foaming agents in foam mat drying of pomegranate juice.

This study evaluated the usability of saponin-rich extracts (soapwort and horse chestnut) as a foaming agent for foam mat drying of pomegranate juice. According to the foaming and stabilization studies, the optimum conditions were determined as 0.4% of soapwort extract, 0.03% of carboxymethyl cellulose as a stabilizer, and 3 min of whipping time. The foams produced using these conditions were dried at different spreading thicknesses and drying temperatures. The results showed that the thicker spreading thicknesses provided a higher antioxidant activity. On the other hand, drying temperature had a significant effect on all measured parameters except moisture content and water activity. The higher drying temperature caused a greater colour change and a lower content of total phenolics, total monomeric anthocyanins, cyanidin-3-glucoside, and delphinidin-3-glucoside. On the other hand, a higher content of ascorbic acid and better antioxidant activity was determined in the samples dried at 70 °C. According to the results obtained, spreading thickness of 2 mm and drying temperature of 70 °C were suggested for pomegranate juice powder production by foam mat drying. Overall, it was demonstrated that saponin-rich extracts are a good foaming agent alternative that provides foaming at very low concentrations and a product with high quality. © 2020 Society of Chemical Industry.

Foam mat drying of taro (Colocasia esculenta): The effect of ultrasonic pretreatment and drying techniques on the drying behavior, flow, and reconstitution properties of taro flour

AbstractIn this study, the effect of ultrasound pretreatment (UP) and drying methods (convective hot air [CHAD] and microwave oven [MOD]‐assisted foam mat drying [FMD]) on the drying time, behavior and rate, diffusion coefficient, moisture content, color, bulk and tapped densities, flow properties, and reconstitution behavior of taro (Colocasia esculenta) flour were assessed. For this purpose, the taro foams with and without ultrasonic pretreatment (35 kHz, 80°C for 25 min) were dried in a convective oven (70°C, 20% ventilation rate) and microwave oven (460 W). The UP resulted in a higher drying rate, diffusion coefficient, moisture content, Hausner ratio (HR), and wettability time, and a lower drying time compared to the nontreated samples. Combined CHAD and MOD‐assisted FMD improved the disadvantages of the CHAD method for example: long drying time (decreased around 63.33% for CHAD and 59.16% for UP + CHAD), low drying and diffusion rates, high moisture content, low brightness (L*) values, high Carr index (CI), HR, and times of wettability and solubility. Additionally, the CI and HR of the taro flours ranged between 4.29–13.96 and 1.04–1.16 which can also be classified as very good and low levels, respectively.Practical ApplicationsTaro flour is an important alternative flour source in baby food, cake, chips, noodle, and so forth due to its pasting, functional, and nutritional properties. In order to obtain taro flour, the taro corm (root) is washed, peeled, and sliced then generally blanched with distilled water, dried, and ground. The quality of taro flour depends on the preparation method such as the drying method and conditions. Foam mat drying (FMD) is an alternative technique and it has several advantages like low drying time and energy consumption, a high drying rate, increased drying surface area, porous structure, and the desired instant properties of the obtained powders. Ultrasound pretreatment (UP) has also some advantages such as increasing the mass transfer rate, reducing drying time, and energy consumption. In this study, the advantages of these techniques (FMD and UP) were combined and the effects on the drying behavior, time, effective moisture diffusivity, and the physical and powder properties were observed.

Optimization of Process Parameters for Foam-Mat Drying of Peaches

ABSTRACT Peach (Prunus persica) is a highly perishable fruit with short shelf-life and susceptible to mechanical damage during harvest and post-harvest operations such as sorting, processing, packaging, and transport. Therefore, converting peaches into dehydrated products will not only reduce their post-harvest losses but also retain their nutritional and sensory qualities. The current study aimed at the optimization of process parameters of foam-mat drying for the production of peach powder from the peaches grown in Ontario, Canada. The operating parameters of foam-mat dryer such as temperatures (65°C, 70°C, and 75°C), foam thickness (3, 5, and 7 mm) and the concentration of foaming agents (soy and pea protein isolates (0.5% w/w, 1% w/w, and 1.5% w/w), were optimized using response surface methodology. The resulting peach powder obtained after drying was assessed for moisture, color, total phenols, antioxidant activity, microstructure, and thermal properties. It was observed that drying time increased with an increase in foam thickness and decreased with an increase in temperature and foaming agent concentrations. The optimum drying rate obtained for both proteins based foams was observed at 65°C. Physico-chemical analysis of peach powder showed significantly higher retention of bioactive components such as total phenols and antioxidants in foam mat dried peach powder containing PPI as the foaming agent. The differential scanning calorimetry thermogram for both protein isolates suggested a denaturation temperature of proteins was around 85°C. No significant difference was observed in the morphological structure of powders obtained by using both protein isolates as foaming agents.

Foaming process optimization, drying kinetics and quality of foam mat dried papaya pulp.

This study was performed to optimize the papaya pulp foaming process and determine the effect of drying conditions on the drying kinetics and the quality of the obtained powder. Thus, the one- factor-at-a-time experimental method, followed by 2k full factorial design was implemented to determine the optimal conditions of the foaming process. The factors studied were egg white percentage (EW%), xanthan gum percentage (XG%), and whipping time (WT) which varied between 5-20%, 0-0.5%, and 5-20min, respectively. The optimum conditions (EW% of 15%, XG% of 0.3% and WT of 15min) for papaya foam expansion percentage (FE%) resulted in a foam with the highest FE% (275.64%) and desirability of 0.916. Foamed and non-foamed papaya pulp in thickness layers of 2-, 4- and 6-mm were dried at 60° and 80° C. Foaming papaya pulp reduced drying time at various layer thicknesses from 140-400min to 60-160min, and from 70-160min to 30-100min at 60° and 80° C, respectively. Foamed powder samples had the lowest dissolution times and hygroscopicity values; in addition, reconstituted solutions were lighter than non-foamed solutions. Ascorbic acid retention and total phenolic compound content was adversely affected by increased drying time. The obtained papaya powder was classified into six groups based on its quality parameters via hierarchical cluster analysis. In general, foam mat drying is a promising method for producing papaya pulp powder due to its high drying rates and better-quality product.

Cheese powder production and characterization: A foam-mat drying approach

Herein, white cheese powder was produced using a foam mat drying method. Foaming conditions namely amount of white cheese (40, 50 and 60% w/w), whey protein concentrate (WPC) (1, 3 and 5% w/w) and foaming temperature (30, 55 and 80 °C) were investigated on the foam density (FD), drainage volume (DV) and surface tension. Surface tension generally decreased with increasing of WPC content and temperature. The best conditions to produce ideal white cheese foam were WPC 3% (w/w), white cheese 60% (w/w) and whipping temperature 55 °C. Ideal foam dried at temperatures of 50, 65 and 80 °C on 1, 3 and 5 mm thicknesses. The effective moisture diffusivity varied from 0.906 × 10−8 to 1.771 × 10−8 m2/s, and from 3.398 × 10−8 to 7.066 × 10−8 m2/s, and from 43.626 × 10−8 to 282.185 × 10−8 m2/s with activation energy values of 21.351, 23.358 and 58.811 kJ/mol for 1, 3 and 5 mm thicknesses, respectively. The analysis of powders showed that the temperature increase and thickness reduction, significantly reduced moisture content and water activity, but no significant difference was found between the powders’ hygroscopicity. The powders produced at 65 °C resulted higher L* and a*. Protein and fat contents of powder in ideal drying conditions (3 mm–65 °C) were 46.59 and 37.25% respectively, that is a rich source of protein and fat to use in ready-to-eat and/or ready-to-cook meals.

Comparison of freeze drying and foam mat drying effects on characteristics of inulin from gembili (dioscorea esculenta)

Gembili (Dioscorea esculenta) is of Dioscorea spp. which contains high inulin. Several factors can affect the physico-chemical characteristics of inulin, one of which is drying method. The purpose of this study was to compare the freeze drying and foam mat drying methods in producing of inulin from gembili (Dioscorea esculenta) based on physicochemical characteristics. Based on the analysis of inulin content of day the best gembili obtained, the samples dried using foam mat drying contained about 9,38% inulin while those dried using freeze contained about 8,66%inulin. The colors of dried samples were relatinglight as indicated by high L values 95.9% for freeze drying and 91,3% for foam mat drying.

EVALUATION OF FOAM-MAT DRYING BEHAVIOUR OF CRAB APPLE (MALUS FLORIBUNDA) FRUIT JUICE AND POWDER QUALITY

Malus floribunda (MF) is an ornamental plant and the fruits with its red flesh have potential to be used as natural food colorant. In this study, the effects of faba bean protein concentrate (FB) and maltodextrin (MD) levels on MF juice foam stability was evaluated. In addition, the effects of drying conditions (temperature/power) on drying kinetics and powder quality (powder flow properties, colour, and anthocyanin content) were determined. The foam stability was significantly dependent on the FB level (P &amp;lt;0.05), but MD addition didn’t have any significant effect (P &amp;gt;0.05). Drying period was reduced with foam-mat drying compared to control, and the average Carr index values were found between 17.3-26.0%, while the Hausner ratios were between 1.21-1.35. The redness and lightness values of foam-mat dried powders were comparably higher than the control and MD-added sample at every drying condition (P &amp;lt;0.05), although the anthocyanin content decreased with increasing drying temperatures.

Foam mat drying of banana juice: varieties of ripe banana analysis and egg albumen foam

Abstract Drying technologies for ripen bananas is needed. Ripe bananas contains more antioxidant levels, anti-cancerous properties, easier to digest and useful for anxiety and depression. Considering nutrition compositional changes and the effect of external factors during processing ripe banana as a flour, foam mat drying with egg albumen foam was chosen. This research aim to provide an overview of banana juice foam mats from three different varieties bananas at level 5 up to 7 of maturity and mixed into different proportion using egg albumen as foaming agent and dried at temperatures from 60 °C to 80 °C in a cabinet dryer to a brittle and porous solid which able to grind. The study revealed that there is a significant difference in combination of banana varieties to rendement, the solubility of the powder and moisture content. The combination of various varieties of bananas is considered better to produce quality of ripen banana flour.

INFLUENCE OF ALBUMIN ON GUAVA PULP POWDER OBTAINED BY FOAM-MAT DRYING

ABSTRACT Guava is a fruit that stands out for its aroma, intense flavor, vitamins, and minerals. Its availability as a powdered food enhances its commercial applications. This study aimed to evaluate mathematical models for adsorption isotherms and determine the properties and flowability of guava pulp powder obtained by foam-mat drying. The models of GAB, BET, Henderson and Oswin were fitted to determine the isotherms of powders with 4 and 8% albumin, at temperatures of 35°C and 45°C. The powders were evaluated by wall friction angle, flow index, apparent density, and particle microstructure analysis. The best fit to the isotherms was obtained by the GAB model. Wall friction angle ranged from 15.7 to 21.9° and from 13.6 to 20.4° for samples containing 4 and 8% albumin, respectively. Higher densities were observed in the powder containing 8% albumin. The powders were classified as easy flowing when the flow index was between 8.00 and 8.68. The presence of albumin in powders resulted in particles with less rough surfaces, less hygroscopicity, and improved flowability.

Analysis of the Anthocyanin Degradation in Blue Honeysuckle Berry under Microwave Assisted Foam-Mat Drying.

Changes in nutrient content and bioactivity are important indicators to evaluate the quality of products. Berries are rich in antioxidant anthocyanins, which are prone to degradation during drying. The effects of different variables on the stability of anthocyanins in berry puree during microwave assisted foam-mat drying (MFD) was investigated by path analysis and degradation kinetics analysis. The experimental results showed that the degradation of anthocyanins mainly occurred in the last drying stage. The temperature and the moisture content have both direct and indirect effects on the anthocyanin stability. The direct path coefficient of the moisture content on anthocyanins was 0.985, and the direct path coefficient of temperature on anthocyanins was −0.933. The moisture content to temperature ratio (M/T) was first put forward to estimate the anthocyanin degradation. The results of the regression analysis confirmed that the anthocyanins were stable at M/T of 0.96–3.60. A finite element simulation model was established to predict the anthocyanin degradation rate and content. These research results could provide a theoretical reference for use in optimizing the MFD processing technologies.