Influence of process conditions on the physicochemical properties of açai ( Euterpe oleraceae Mart.) powder produced by spray drying

The objective of this work was to study the influence of inlet air temperature and maltodextrin concentration on the physicochemical properties of acai juice powder produced by spray drying. The process was carried out in a mini spray dryer and the maltodextrin 10DE was used as carrier agent. Inlet air temperature varied from 138 to 202 °C and maltodextrin concentration varied from 10 to 30%. The characteristics analyzed were: moisture content, hygroscopicity, anthocyanin retention, color, particle size distribution, and morphology. The increase in the temperature resulted in particles with larger size, less moisture content, more hygroscopy and with lower anthocyanin retention, besides promoting a reduction in the color parameter L* and in the hue angle H*. The increase of maltodextrin concentration resulted in less hygroscopy, particles with larger size, , with higher luminosity (L*), lower C* values and higher H* values. With respect to morphology, the increase in the temperature led to the formation of a great number of particles with smooth surface, which is due to the higher heat transfer and, consequently, to the faster formation of a membrane around the atomized drop.

Influence of process conditions on the physicochemical characteristics of cumaru (Amburana cearensis) powder produced by spray drying

The purpose of this work was to study the effects of spray-drying conditions on the physicochemical characteristics of blackberry powder using a central composite rotatable design. Inlet air temperature (140–180°C) and maltodextrin concentration (5–25%) were employed as independent variables. Moisture content, hygroscopicity, anthocyanin retention, color, powder morphology, and particle size were analyzed. A higher inlet air temperature significantly increased the hygroscopicity of the powder, decreased its moisture content, and led to the formation of larger particles with smooth surfaces. Powders produced with higher maltodextrin concentrations were less hygroscopic, slightly lighter and less red, and had a lower moisture content. Anthocyanin retention was mainly affected by drying temperature due to the heat sensitivity of the pigment. The optimal processing conditions were an inlet air temperature of 140–150°C and maltodextrin concentration of 5–7%. Overall, these results indicate that good quality powders can be obtained by spray drying, with potential applications for the food industry.

Optimization of spray drying parameters for encapsulation of Nettle (Urtica dioica L.) extract

Based on a full factorial experimental design, the effects of the feed ratio, atomizer speed, and inlet air temperature on properties of spray-dried orange juice powders were investigated. The results indicate that increasing inlet air temperature increases the particle size, average time of wettablity, and insoluble solids and decreases the bulk density and moisture content of the powder. Increasing atomizer speed results in increasing the bulk density and average time of wettablity of powder and decreases the particle size, moisture content, and insoluble solids of powder. Increase in feed flow rate increases the bulk density, particle size, and moisture content of the powder and decreases the average time of wettablity and insoluble solids of powder. With multivariable regression analysis the relationships between physical properties of orange juice powder and operating parameters with high coefficient were obtained.

Response surface methodology was used to optimize the spray-drying process for the development of stingless bee honey powder. The independent variables were: inlet air temperature (110–150 oC) and maltodextrin 10DE content (50–70 % wb). The responses were powder yield, moisture, volatiles retention, solubility time, hygroscopicity, bulk loose, and hydroxymethylfurfural content. Powder moisture content, solubility time, hygroscopicity and loose bulk density were negatively affected by inlet air temperature, while powder yield, volatiles retention and hydroxymethylfurfural content were directly related. Powder yield, volatiles retention and solubility time increased with the rise in maltodextrin content, while moisture content, hygroscopicity, loose bulk density and hydroxymethylfurfural content were negatively affected by maltodextrin content. Multiple response optimization indicated that an inlet air temperature of 150 oC and maltodextrin content of 61 % wb were predicted to provide 40 % powder yield, 4.9 % wb moisture content, 71 % volatiles retention, 242 s solubility time and 232 mg/kg hydroxymethylfurfural content.

‘Cempedak’ (Artocarpus integer) is an aromatic fruit that looks similar to jackfruit. Response surface methodology was used to optimize the spray-drying process to produce ‘cempedak’ fruit powder, with inlet air temperature (140–180 °C) and maltodextrin (DE 10) concentrations (5–15% w/w) as independent variables. Statistical analysis revealed that these variables significantly affected process yield, moisture content, water activity, hygroscopicity, L* value of powder and carotenoid content. Inlet air temperature had a negative correlation with all significant variables. At the same time, maltodextrin concentration was found to be positively correlated with all significant powder variables except process yield and moisture content. The recommended optimum spray-drying conditions for drying ‘cempedak’ juice were inlet air temperature and maltodextrin concentration of 160 °C and 15% (w/w), respectively. Under optimized spray-drying conditions, the yield of ‘cempedak’ powder was 60.5%, with moisture content, water activity, hygroscopicity and carotenoid content of 6.07%, 0.22, 25.8 g/100 g and 1.00 mg/g, respectively.

This study was conducted to investigate the effects of three variables namely cellulase (Celluclast, Novozymes, Denmark) concentration (0–1%, v/w (x1)), maltodextrin (MD) concentration (15–30%, w/w (x2)), and spray-dryer air inlet temperature (150–190 °C (x3)) on pumpkin powder characteristics using enzymatically macerated pumpkin with Pectinex® Ultra SP-L (2.5%, v/w). The powder characteristics considered as response variables in response surface methodology were process yield, moisture content, stickiness, water activity, and hygroscopicity. Results indicated that the response surface models were significantly (p ≤ 0.05) fitted for all response variables in the studied independent variables range. The concentration of Celluclast and MD should be considered as critical factors which may increase process yield of pumpkin powder. The effect of Celluclast concentration on pumpkin powder characteristics especially for process yield and stickiness was noticeable. The main effect of MD and quadratic term of Celluclast had the most significant effect on stickiness. Negative interaction value of MD with Celluclast indicated that stickiness decreased when mixture of MD and Celluclast was used and also Celluclast reduced the impact of air inlet temperature on stickiness. The overall optimum region resulted in a desirable powder characteristics was predicted to be obtained by combined level of air inlet temperature 180 °C, Celluclast 0.7% (v/w), and MD 23% (w/w). The theoretical and experimental validation ensuring the adequacy of the response surface models described the changes in physical properties of powder as a function of Celluclast, MD, and air inlet temperature.

Honey is a natural product commonly used in milk powder for flavoring purposes. Currently, honey flavor is added to milk powder in powder form. This study aimed to investigate the effect of spray drying operating conditions on the quantity and quality parameters of the honey powder recovered. The influence of inlet air temperatures, feed flow rates, and type of microencapsulating agents upon the properties of obtained powders was examined. Spray drying of honey with the addition of maltodextrin DE 18 and 12 was carried out at inlet air temperatures of 150, 170, 190℃ and feed flow rates of 330 and 660 mL/h. The properties of the powders obtained were quantified in terms of moisture content (MC), hygroscopicity (HG) and color. Results of experiments showed higher inlet air temperature and lower feed flow rate led to a significant increase (p<0.05) in powder recovery. The total powder recoveries found in this study were between 39.42±2.35% to 71.92±4.17%, which indicates that this process has the potential to be applied on an industrial scale. The decrease in DE of maltodextrin promoted a higher powder recovery. Furthermore, it was found that the browning index increased with the decreasing inlet air temperature and increasing feed flow rate.

The influence of spray-drying conditions on some physicochemical properties of palm-sugar powder ( Arenga pinnata ) was studied. Twenty tests were carried out according to a central composite design. Independent variables were: inlet temperature (150–190°C), feed flow rate (9–21 g/min), and maltodextrin concentration (14–25%). Process yield, hygroscopicity, and outlet temperature were analyzed as responses. Results revealed that increasing inlet temperature resulted in higher process yield and outlet temperature and a lower hygroscopicity. Similarly, higher inlet temperature led to lower moisture content, dissolution rate, and total phenolic content of the powder. Conversely, the feed flow rate negatively influenced process yield and hygroscopicity, and positively influenced moisture content. Moreover, maltodextrin exhibited negative influence on process yield and hygroscopicity, respectively. Moreover, storage (30°C, six months) led to noticeable losses in flowability and wettability. Powder morphology was also influenced by the inlet temperature. Lower inlet temperature resulted in particles with shrivelled surfaces while higher temperature produced a greater number of larger particles with smooth surfaces.

O objetivo deste trabalho foi avaliar a influência da temperatura do ar de secagem (160 ou 180 ºC) e da concentração de maltodextrina (5, 15 ou 25%) sobre as características físico-químicas do suco de amora-preta em pó, produzido por spray drying. O produto final foi analisado quanto ao teor de umidade e de antocianinas, higroscopicidade, atividade de água, cor, distribuição do tamanho das partículas e microestrutura. Temperaturas de secagem mais altas resultaram na redução da umidade, da atividade de água e do conteúdo de antocianinas dos pós, além da formação de partículas maiores e mais higroscópicas. A temperatura teve um efeito significativo na diminuição dos valores dos parâmetros de cor L* e C* somente nos ensaios realizados com 25% de maltodextrina. Em relação à microestrutura, as partículas produzidas à temperatura de 180 ºC apresentaram superfície lisa e uma maior uniformidade em relação às amostras secas a 160 ºC. O aumento da concentração de maltodextrina resultou na formação de partículas com menor umidade e higroscopicidade. Além disso, esses pós apresentaram menor teor de antocianinas, em função da diluição dos pigmentos da fruta, o que levou ao aumento da luminosidade e à redução do croma e do ângulo de tom das amostras. O ensaio realizado à temperatura de 160 ºC com 5% de maltodextrina foi o mais efetivo na manutenção do teor de antocianinas dos pós, visto que a retenção desses pigmentos foi em torno de 80%.

Effect of spray drying on the physicochemical properties and color stability of the powdered pigment obtained from vinification byproducts of the Bordo grape (Vitis labrusca)

The aim of this research was to study the effect of spray drying condition on quality of kantan (Etlingera elatior) powder and their characteristics. Effects of Hanjeli Flour and Modified Cassava Flour (MOCAF) concentration at 5 % (wt/v) and Maltodextrin concentrations at 5 %, 10 %, 15 %, 20 % and 2 5% (w/v), on physical properties and antioxidant properties of spray dried kantan powder were investigated. Agridon mini spray dryer, model AG-1-06, was used in this research which an inlet and outlet air temperature, feed flow rate and air spray pressure control range was standardize at 180°C, 80°C, 3.0 Lh−1 and 0.7-1.4 kgcm−2, respectively. The result of this study resulted 5 % MOCAF were showed the higher in physical and antioxidant properties such as process yield (31.82 %), flowability (30°) and ABTS (50.50%) of spray-dried kantan powder compared to 5 % Hanjeli flour and 5 % maltodextrin. Next, increased maltodextrin concentrations resulted in increased process yield (31.04 %-36.03 %), bulk density (0.33 g/ml-0.48 g/ml) and flowability (37°-57°), while the solubility (50.50-133.30 sec), wettability (14.90-45.20 sec), moisture content (5.24 %-5.83 %) and absorbance (2.44-0.99) decreased. However, there were no significant changes in the water activity (0.22-0.37) and soluble solid (15.16 %-16.80 %) of the kantan powder at all maltodextrin concentrations. The degradation percentage of antioxidant contents ranged in 36 %-66 % in DPPH, ABTS, TPC and TFC after spray drying process at higher temperature. The results from this study can be used to develop instant beverages, cube production as a ready-cook product and several food formulations such as ice-cream, desserts, bakery products.

This paper investigated the influence of operating parameters such as inlet air temperature, compressed air flow rate, concentration of carrier agent and type of carrier on the physicochemical properties of fruit juice powders produced by spray drying.The results indicated that increasing inlet air temperature resulted in the larger size particles with smoothly spherical appearance, and to lower bulk density and moisture content. The bulk density of powders also decreased with increasing carrier agent concentration, decreasing compressed air flow rate. The higher feed flow rate negatively affected process yield and positively influenced moisture content, and occurring the wall deposition easily. Additionally, the anthocyanin retention mainly depends on the inlet air temperature and type of carrier. Moreover, the novel methods and ideas to this problem in the next studies were presented.

Physical and morphological characteristics of powdered acai juice were evaluated in this work. Powders produced by spray drying at different temperatures (140, 170 and 200C) using different carrier agents (maltodextrin 10DE, maltodextrin 20DE and gum Arabic) were evaluated for moisture content, water activity, hygroscopicity, bulk density, particle size distribution and morphology. Sorption isotherms were also constructed. The samples produced with maltodextrin 10DE showed the highest moisture content, water activity and mean diameter and were the less hygroscopic. The increase in drying temperature resulted in particles with lower moisture content, water activity and bulk density. Moreover, powders produced at higher temperatures were more hygroscopic and exhibited a greater number of particles with smooth surface. Sorption isotherms were of type III and showed a better fit to Guggenheim-Anderson-de Boe and Brunauer-Emmett-Teller models. PRACTICAL APPLICATIONS The present study provides useful information about the production of powdered acai juice by spray drying. In this process, the addition of a carrier agent is normally necessary in order to avoid problems like stickiness on the dryer wall, which would be negative to process yield and product quality. Moreover, among the process variables related to spray drying, the inlet air temperature can be considered very important, since it is directly related with powder quality, as well as with energy saving/wasting. Thus, in this work, the effect of three different types of carrier agents and three inlet air temperatures on the physicochemical properties of spray-dried acai juice was evaluated. The results can be useful for food and cosmetic companies looking for novel and inexpensive sources of natural pigments, to be used as colorants and flavorings.