Spray drying conditions for orange juice incorporated with lactic acid bacteria

This work aimed to develop an orange juice powder by spray drying with lactic acid bacteria (Lactobacillus plantarum 299v and Pediococcus acidilactici HA‐6111‐2), testing their survival both during drying and storage (room temperature and 4 °C). Initially, the best conditions for spray drying were chosen to allow the best survival of each LAB: (i) inlet air temperature of 120 °C and (ii) 0.5:2 ratio of the orange juice soluble solids and drying agent added (prebiotics: 10 DE maltodextrin or gum Arabic). Survival of LAB was not affected by drying process, and it was higher when cultures were stored at 4 °C. A slightly higher protection was conferred by 10 DE maltodextrin, in the case of L. plantarum and at 4 °C. Pediococcus acidilactici was more resistant during storage at 4 °C, with logarithmic reductions lower than 1 log‐unit. It was demonstrated that it is possible to produce a functional nondairy product, orange juice powder supplemented with prebiotic compounds, containing viable LAB for at least 7 months, when stored at 4 °C.     

A Feasibility Study on the Drying of Lime Juice: The Relationship between the Key Operating Parameters of a Small Laboratory Spray Dryer and Product Quality

Concentrated lime juice with 20% total soluble solids was dried using three levels of maltodextrin (40%, 50%, and 60% solid base) and a BüCHI B-190 spray dryer. The drying air temperature and flow rate were 140 °C, 155 °C, and 170 °C and 47.1, 53.5, and 57.8 m³/h, respectively. A total of 27 experiments were conducted (in triplicate) with the feed rate, temperature, and compressed air flow for the atomizer kept constant. Analysis of the data revealed that product recovery increased when the maltodextrin in the feed and drying air flow rate were increased, but the inlet air temperature had no significant (P < 0.05) effect on powder recovery. The moisture content of the powder varied with the maltodextrin level, inlet air temperature, and air flow rate. Using scanning electron microscope images, larger particle size was observed with the increase of maltodextrin concentration. Powder bulk density also increased from 0.41 to 0.68 g/cm³, depending on the level of maltodextrin, whereas the drying air temperature and flow rate were not as effective. The results of this study are beneficial for scaling up the spray drying of lime juice to the food industry.     

Degradation Kinetics and Storage Stability of Vacuum Spray-Dried Micro Wet-Milled Orange Juice (<Emphasis Type="Italic">Citrus unshiu</Emphasis>) Powder

The aim of this work was to evaluate the degradation kinetics and stability of micro wet milled orange juice powders obtained by vacuum spray drying, using maltodextrin as a carrier agent. Powders were produced with four combinations of orange juice solids/maltodextrin solids 60:40, 50:50, 40:60, and 30:70 by weight. Ascorbic acid degradation, color, and antioxidant activity of powders were evaluated throughout 90 days. Powders were stored at 10, 25, and 35 °C and relative humidity of 33%. Temperature and storage time negatively influenced the stability of ascorbic acid and color, whereas antioxidant activity increased at the beginning of storage at a higher temperature then decreased slightly after 60 days. For stability study, powders were stored at different water activities (0.11 to 0.84) in order to determine the plasticizing effects of water on glass transition temperature. Both water activity and glass transition temperature were used to predict the critical conditions for storage. Vacuum spray dried powder produced with a ratio of 30:70 (orange juice solids/maltodextrin solids) was considered as the most stable, since it showed highest critical water activity (a_w?=?0.61) and lowest moisture content (0.11 g water/g of dry solid) among the four powders. Vacuum spray drying using superheated steam as the heating medium was proven to be an effective way of producing orange juice powders with minimum loss of nutrients.     

Glass Transition Behavior of Spray Dried Orange Juice Powder Measured by Differential Scanning Calorimetry (DSC) and Thermal Mechanical Compression Test (TMCT)

Spray drying behavior of orange juice concentrate with various levels of maltodextrin (DE 6) was studied. Five combinations of orange juice concentrate and maltodextrin (25:75, 30:70, 35:65, 40:60, and 50:50) were spray dried at 160 and 65°C inlet and outlet temperatures, respectively. The product recovered with 50% maltodextrin concentration was sticky and only 20% powder was recovered. The recovery of orange juice powder increased as the amount of maltodextrin in powders increased. The particle size and bulk density remained almost the same in all except in 50% maltodextrin powder which was slightly larger and more dense. The moisture content of spray dried powders was high and desiccated before measuring glass transition temperature. The anhydrous spray dried powders showed increased T_g values with increasing maltodextrin concentration, from 66°C in 50% maltodextrin to 97°C in 75% maltodextrin containing powders. The glass rubber transition (T_g-r) values of all the products measured using novel Thermal Mechanical Compression Test (TMCT) were higher than T_g values measured by DSC; the difference in values increased with increase in maltodextrin concentration.     

Optimisation of pomegranate (Punica Granatum L.) juice spray‐drying as affected by temperature and maltodextrin content

Pomegranate juice powder is easier to handle and has more potential applications than the concentrate. In this study, the response surface, 3‐level factorial design was used to evaluate the influence of spray‐drying conditions on the physicochemical properties of a powdered product obtained by drying pomegranate juice concentrate (PJC). It was spray‐dried with a lab‐scale spray‐dryer using 18 and 7 dextrose equivalent (DE) maltodextrins (MD) as drying‐aid agents. Adding MD significantly reduced the hygroscopicity and stickiness of the pomegranate juice powder, and thus yielded higher recovery. The maximum achieved ratio of PJC/MD was 1/1, and it was obtained with the use of DE7 MD. However, graphical optimisation studies resulted in 125–145 °C and 0.6–0.8 PJC/MD ratio as optimum variables to produce acceptable dried powder. The results indicated that increasing inlet air temperature increases solubility time and loss of anthocyanins and decreases bulk density and moisture content of the powder.     

CFD Modeling and Simulation of Maltodextrin Solutions Spray Drying to Control Stickiness

Particle stickiness during spray drying can lead to operational problems or be used to perform agglomeration inside the chamber. A simplified computational fluid dynamics approach is proposed to simulate the spray drying of 40% w/w aqueous solutions of maltodextrin DE12 and DE21 in a pilot cocurrent spray dryer equipped with rotary atomizer. Drying was simulated at steady state considering the geometry of the equipment (drying chamber, air inlet, atomizer) and the close relation between drying air and product properties. To take into account the lower drying rate of liquid solutions compared to pure water, the water vapor pressure of the drying particles was decreased with a coefficient determined from experimental data on air temperatures and humidities measured in the chamber. The evolution of particle temperature and water content was simulated. From these values and glass transition temperatures of the considered materials, it was possible to determine zones and operating conditions for which particles could be sticky inside the chamber. Maltodextrin DE12 was quickly dried close to the atomizer reaching a stable nonsticky state below glass transition temperatures Tg, while maltodextrin DE21 with lower Tg could exhibit a sticky behavior in a wider part of the chamber, depending on the liquid flow rate. This approach provides a methodology to evaluate possible stickiness to avoid fouling of the plant or to optimize powder insertion position for agglomeration.     

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 spray drying conditions on the physicochemical properties of açai powder. The process was carried out on a mini spray dryer and maltodextrin 10DE was used as carrier agent. Seventeen tests were made, according to a central composite design. Independent variables were: inlet air temperature (138–202 °C), feed flow rate (5–25 g/min) and maltodextrin concentration (10–30%). Moisture content, hygroscopicity, process yield and anthocyanin retention were analysed as responses. Powder moisture content and process yield were positively affected by inlet air temperature and negatively affected by feed flow rate, which are directly related to heat and mass transfer. Process yield was also negatively influenced by maltodextrin concentration, due to the increase on mixture viscosity. Powders hygroscopicity decreased with increasing maltodextrin concentration, decreasing temperature and increasing feed flow rate. Powders with lower moisture content were more hygroscopic, which is related to the greater water concentration gradient between the product and the surrounding air. Anthocyanin retention was only affected by temperature, due to its high sensitivity. In respect to morphology, the particles produced at higher temperature were larger and a great number of them showed smooth surface.     

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

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.     

Physical and Structural Properties of Spray Dried Tamarind (Tamarindus indica L.) Pulp Extract Powder with Encapsulating Hydrocolloids

This work investigated the effect of different carriers on the powder properties during spray drying of tamarind pulp extract. A pilot-scale spray dryer was used for the spray drying process. Maltodextrin 21DE, gum acacia, and a combination of both maltodextrin/gum acacia were used as drying agents. Tamarind pulp extract was spray dried at different conditions with inlet temperatures of 150–180°C, outlet temperature of 80–110°C and 11–14°Brix. Optimization for different carriers was initially done based on the yield of spray dried powder. The three best tamarind pulp extract powders were chosen from three different carriers. Physical and structural parameters were analyzed for the three best powders. The results revealed that the best powder on the basis of physical and structural properties was obtained at the 155°C inlet temperature, 100°C outlet temperature, 12°Brix, and tamarind pulp extract-maltodextrin ratio 70:30.     

紫玉米花色苷微胶囊化工艺和性能研究

采用响应面分析法优化紫玉米花色苷微胶囊化的配方及工艺,并对其微观特性进行表征。结果显示：喷雾干燥入口温度是影响紫玉米花色苷包埋率最主要因素;紫玉米花色苷最佳工艺为紫玉米花色苷占总固形物质量分数15%、麦芽糊精占总固形物质量分数45%、总固形物质量分数为25%和喷雾干燥入口温度140℃,在最佳工艺条件下,紫玉米花色苷包埋率为95.2%;扫描电镜和激光粒度仪分析进一步验证当喷雾干燥入口温度为140℃时,微胶囊化紫玉米花色苷的表面无明显裂痕和孔洞,粒径分布均比较集中(2～30μm),峰值出现在7.13μm。     

An integrated process for utilization of pomegranate wastes — Seeds

In this work, a new method for pomegranate seeds application was developed based on the ultrasound-assisted extraction of seed oil and its subsequent encapsulation by spray drying. Extraction temperature, solvent/solid ratio, amplitude level, and pulse duration/pulse interval ratio were the factors investigated with respect to extraction yield. Ultrasound was sound to increase extraction yield, but mainly to shorten the treatment time by over 12 times. Different materials were used as encapsulating agents. Ratio of core to wall material, inlet air temperature, drying air flow rate, and feed solids concentration were the factors investigated with respect to encapsulation efficiency. The resulting microcapsules were evaluated in terms of moisture content, bulk density, and rehydration ability. The optimum operating conditions were found to be: wall material, maltodextrin/Tween 80; ratio of core to wall material, 0.23; inlet air temperature, 150 °C; drying air flow rate, 22.8 m³/h; feed solids concentration, 30% (w/w).Industrial relevancePomegranate seeds, a by-product of pomegranate juice and concentrate industries, present a wide range of pharmaceutical and nutraceutical properties. Therefore, the seeds could have more beneficial applications in food industries instead of being used as animal feed or in commercial cosmetic products. In this work, a new method for pomegranate seeds application was developed based on the ultrasound-assisted extraction of seed oil and its subsequent encapsulation by spray drying.     

速溶枸杞粉的加工工艺研究

以枸杞浓缩浆为原料,异VC-Na、柠檬酸为护色剂,麦芽糊精和β-环状糊精为助干剂,CMC-Na为稳定剂,白砂糖为甜味剂,柠檬酸为酸味剂,蔗糖脂肪酸酯和单甘酯为乳化剂,使用喷雾干燥法生产速溶枸杞粉。采用正交试验确定最佳的枸杞粉加工工艺。     

Spray Drying of Fruit and Vegetable Juices—A Review

The main cause of spray drying is to increase the shelf life and easy handling of juices. In the present paper, the studies carried out so far on spray drying of various fruits and vegetables are reported. The major fruit juices dried are mango, banana, orange, guava, bayberry, watermelon, pineapple, etc. However, study on vegetable juices is limited. In spray drying, the major optimized parameters are inlet air temperature, relative humidity of air, outlet air temperature, and atomizer speed that are given for a particular study. The juices in spray drying require addition of drying agents that include matlodextrin, liquid glucose, etc. The drying agents are added to increase the glass transition temperature. Different approaches for spray dryer design have also been discussed in the present work.     

响应面优化刺梨清汁喷雾干燥制粉工艺

本研究以刺梨清汁、麦芽糊精为主要原料，通过喷雾干燥技术制备刺梨粉；以刺梨粉中维生素C含量、黄酮含量、多酚含量及感官评价综合评分为指标，通过刺梨清汁喷雾干燥单因素实验和响应面优化试验，研究刺梨清汁喷雾干燥制粉最佳工艺条件。单因素实验结果表明：麦芽糊精最适添加量为15%、最适进风温度为165℃、最适进料流量为1.5 L/h。响应面试验结果表明：麦芽糊精最适添加量为15%、最适进风温度为160℃、最适进料流量为1.5 L/h，在此条件下制备的刺梨粉品质最佳，其刺梨粉维生素C含量为6722.02 mg/100 g，黄酮含量为1904.02 mg/100 g，多酚含量为8122.43 mg/100 g，感官综合评判总分达到83.22分，刺梨粉组织状态均匀、具有明显的刺梨香气。本研究所制备的刺梨粉成本较低，营养价值较高，且制备方法简单，适合于工业化生产。     

Production of a red–purple food colorant from Opuntia stricta fruits by spray drying and its application in food model systems

Opuntia stricta fruit juice is a potential source of betacyanin pigments which can be used as a natural red-purple food colorant. In this work a powder food colorant was obtained by co-current spray drying of O. stricta fruit juices with a bench-scale two fluid nozzle spray dryer. Glucose syrup (DE 29) was used as drying aid. Optimum conditions for spray drying were as follow: juice content (20% v/v; 1.2 °Brix), glucose syrup content (10% w/v), liquid feed rate (0.72 l/h), spray air flow-rate (0.47 m³/h), drying air flow-rate (36 m³/h), and inlet drying air temperature 160 °C. Color was retained during the drying process (>98%) and drying yield was high (58%). The powder colorant showed high color strength (4.0), being this color strength stable when stored at room temperature for one month. This colorant was successfully applied in two food model systems: a yogurt and a soft-drink. Food presented a vivid red-purple tonality very attractive for consumers that was maintained after one month under refrigeration (4 °C) (ΔE < 5).     

喷雾干燥制备枸杞粉工艺研究

以枸杞酱为原料,通过喷雾干燥制备枸杞粉,采用单因素和正交试验相结合确定最佳工艺。试验结果表明,当麦芽糊精添加量为50％、固形物浓度为8％、进风温度为180℃、出风温度为80℃时,喷雾干燥效果最好,在此条件下喷雾制备枸杞粉的出粉率为29．1％。     

葛根核桃肽复合饮料喷雾干燥工艺研究

为了改善葛根核桃肽复合饮料的喷雾干燥效果,优化喷雾干燥工艺,该研究考察了进口温度、进料流量、物料质量分数以及助干剂的种类和添加量的变化对葛根核桃肽复合饮料喷雾干燥效果的影响,并采用正交设计法优化喷雾干燥条件。结果显示,喷雾干燥最佳工艺条件为进口温度170 ℃,进料流量1.96 mL/min,物料质量分数15%,麦芽糊精添加量为总固形物含量的80%,β-环糊精添加量为总固形物含量的15%,在此条件下,所得产品的感官评分为95分,水分含量为3.98%。     

Addition of cashew tree gum to maltodextrin-based carriers for spray drying of cashew apple juice

This study involved an attempt to totally or partially replace maltodextrin DE10 (MD10) by cashew tree gum (CTG) as a drying aid agent in spray drying of cashew apple juice. The objective was to evaluate the impact of drying aid/cashew apple juice dry weight ratio (D/C, ranging from 3 to 5) and degree of replacement of MD10 with CTG (CTG_R, ranging from 0% to 100%) on ascorbic acid retention (AAR), hygroscopicity, flowability and water solubility of spray dried cashew apple juice powder. AAR was increased from 72.90% to 95.46% by increasing D/C from 3 to 5. CTG was shown as a promising maltodextrin replacer, being more effective than the latter to decrease powder hygroscopicity. The most adequate drying conditions (D/C = 5, CTG_R≥50%) resulted in more than 90% of AAR, and produced a powder with good flowing properties and water solubility.     

Effects of the spray drying conditions of chokeberry (Aronia melanocarpa L.) juice concentrate on the physicochemical properties of powders

A semi‐industrial spray drying process of chokeberry juice concentrate using maltodextrin was analysed. The influence of the content and dextrose equivalent (DE) of maltodextrin, inlet air temperature and rotary disc atomiser speed was studied on the physicochemical properties of the obtained powders. The size and structure of the powder particles, bulk density, moisture content, flowability, yield and total polyphenol content were analysed. An increase in carrier content from 50% to 70% caused a 4.9% increase in total polyphenol retention, better flowability (Hausner ratio decrease of 0.17) and greater yield of the powder (60%). An increase in the drying temperature (150–170 °C) caused larger particle size and improved powder flowability but also resulted in greater loss of total polyphenols. A decrease in rotary atomiser speed (11 000–15 000 rpm) had a moderate influence on particle size and improvement in flowability but had no effect on polyphenol retention. Changes in the DE (8–22) of maltodextrin as a carrier indicated a moderate growing dependence on particle size and worse flowability.     

Microencapsulation by Spray Drying Ethyl Caprylate in Whey Protein and Carbohydrate Wall Systems

Ethyl caprylate was microencapsulated by spray drying in wall systems consisting of whey protein in combination with maltodextrin (DE 5–15) or corn syrup solids (DE 24). Ester particle-size distribution in the infeed emulsion was adversely affected by high proportions of low DE maltodextrin. Ester retention during drying was affected (P < 0.05) by type of carbohydrate used and its proportion and ranged from 70 to 91%. The proportion of solvent extractable core was reduced with increasing DE value of carbohydrate. Combinations of whey proteins and high DE mal-todextrins or corn syrup solids are effective wall systems for microencapsulation of volatiles.