Nutritional and rheological characterization of spray dried sweetpotato powder

Spray drying feasibility of sweetpotato puree is enhanced using alpha-amylase treatment to reduce puree viscosity and maltodextrin (MD) addition to facilitate drying. To better determine potential applications of powders produced with various levels of amylase and MD, nutrient composition and rheological properties of the hydrated spray dried sweetpotato powders were examined and compared with sweetpotato puree. Proximate composition, beta-carotene, vitamin C, and mineral analyses were performed. Steady shear rheology of reconstituted powder solutions was also evaluated at different temperatures and shear rates. Spray drying significantly reduced the β-carotene and ascorbic acid contents. Additionally, the all-trans form of beta-carotene was further transformed to the cis-isomers during dehydration. The viscosity of the reconstituted solutions was much lower than that of the puree at the same solid concentration. Rheologically, the reconstituted sweetpotato slurries behaved similarly to pregelatinized starch solutions. Thus, spray dried sweetpotato powders have a potential to enhance food systems as a thickener despite the need for increased nutrient retention.     

The use of spray drying to microencapsulate 2-acetyl-1-pyrroline, a major flavour component of aromatic rice

Summary Different ratios of gum acacia and maltodextrins were used to investigate the appropriate wall materials for encapsulation, by spray drying, of 2‐acetyl‐1‐pyrroline (ACPY). This compound, which is the major flavour component of aromatic rice, was extracted from pandan (Pandanus amaryllifolius) leaves by steam distillation. The amounts of ACPY before and after spray drying encapsulation were not significantly different (P < 0.05). Better retention of ACPY was obtained by encapsulation. In its liquid form ACPY degraded quickly as 63% reduction occurred in a basic solution after 7 days; however, only 30% reduction was found in acidic solution after 35 days of storage. After 72 days of storage, the amount of ACPY in encapsulated powders made with differing amounts of gum acacia and maltodextrin decayed as follows: ratios of gum acacia:maltodextrin of 70:30, 60:40, 50:50, 40:60, 30:70 and 0:100 gave the following amounts of degradation of 27.7, 33.4, 43.2, 35.7, 30.6 and 32.6% respectively. Encapsulation in 70:30 gum acacia:maltodextrin gave the best retention of ACPY.     

Characteristics of soy sauce powders spray-dried using dairy whey proteins and maltodextrins as drying aids

This study investigated the effect of adding whey protein isolate (WPI) as a complementary drying aid of maltodextrin (MD) on spray drying of soy sauce powders. Soy sauce powders were prepared by spray drying soy sauce liquid adding 5%, 10% and 15% of WPI respectively together with MD as the drying aids. Tests were conducted to evaluate the powder properties relevant to the caking issue of the soy sauce powders. Results showed that addition of just 5% WPI could significantly increase the product yield for the spray drying process. At the same time, the caking strength of the spray dried soy sauce powders were significantly reduced during storage with WPI addition. XPS results indicated that WPI have preferential migration to the surface of the soy sauce powder. The over-expression of WPI on powder surface after spray drying might explain the improved stability for soy sauce powders during the caking test.     

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.     

Microencapsulation of Corn Wastewater (Nejayote) Phytochemicals by Spray Drying and Their Release Under Simulated Gastrointestinal Digestion

Corn lime cooking generates a large amount of wastewater known as nejayote that is composed of suspended solids and solubilized phytochemicals. Spray drying can be an alternative to recover bioactive molecules, such as ferulic acid, from nejayote. Besides the yield, the physicochemical properties (solubility, water activity, pH, moisture, hygroscopicity, total phenolic content, and distribution of free and bound hydroxycinnamic acids) of spray‐dried nejayote powders were analyzed. The powders were obtained at 200 °C/100 °C or 150 °C/75 °C (inlet/outlet) air temperatures with the addition of maltodextrin (MD) or 2‐hydroxypropyl‐beta‐cyclodextrin (HBCD) as encapsulating agents. Even when no carrier agent was used, a spray‐dried nejayote powder was produced. The use of MD or HBCD as carrier increased the yield from 60.26% to 68.09% or 71.83%, respectively. As expected, a high inlet temperature (200 °C) allowed a satisfactory yield (>70%) and a low powder moisture (2.5%) desired by the industry. Water activity was reduced from 0.586 to 0.307 when HBCD was used in combination with a drying inlet temperature of 150 °C; and from 0.488 to 0.280 when the inlet temperature was set at 200 °C. Around 100% bioaccessibility of the compounds was observed after in vitro digestion. The addition of HBCD increased the release time (P < 0.05). Under simulated physiological conditions, there was no reduction of total phenolics, suggesting a good stability. This paper showed the feasibility to engage the spray drying technology to the corn industry to minimize their residues and reuse their by‐products.     

Impact of Wall Materials on Physicochemical Properties of Microencapsulated Fish Oil by Spray Drying

The aim of the present study was to investigate the effect of wall materials composition on physicochemical characteristics of fish oil microcapsules produced by spray drying (180 °C). Four different combination of coating materials (fish gelatin, chitosan, combination of gelatin and chitosan, and a mixture of microbial transglutaminase (MTGase) with maltodextrin) were applied to two different fish oils to produce 40 % solid emulsions. Scanning electron microscopy and extraction of surface and encapsulated oils revealed that fish gelatin provided the highest preserving effect on the covering fish oil. Meantime, addition of MTGase to gelatin could also increase this ability and reveled less surface oil than chitosan treatment (2.63 and 2.80 % versus 4.66 and 5.23 %, respectively; P?<?0.05). Mixture of gelatin and maltodextrin with MTGase as wall material led to the highest encapsulation efficiency, being selected as the best microencapsulation condition; meantime, application of chitosan with maltodextrin provided the worse encapsulation efficiency (P?<?0.05). All indices of powders (encapsulation efficiency, surface morphology, and particle size) showed that powders prepared from gelatin and gelatin with MTGase increased the encapsulation efficiency and would increase the stability of microcapsule powders.     

A new technique for spray drying orange juice concentrate

A new technique for spray drying concentrated orange juice using dehumidified air as drying medium and maltodextrin as drying agent was developed. A pilot-scale spray dryer was employed for the spray drying process. The modification made to the original design consisted in connecting the dryer inlet air intake to an absorption air dryer. 21 DE, 12 DE, and 6 DE maltodextrins were used as drying agents. Concentrated orange juice was spray dried at inlet air temperatures of 110, 120, 130, and 140 °C and (concentrated orange juice solids)/(maltodextrin solids) ratios of 4, 2, 1, and 0.25. Data for the residue remaining on the walls were gathered and the powders were analyzed for moisture content, bulk density, rehydration, hygroscopicity, and degree of caking. The combination of maltodextrin addition and use of dehumidified air was proved to be an effective way of reducing residue formation.Industrial relevanceOrange juice powder has many benefits and economic potentials over its liquid counterparts and provides a stable, natural, easily dosable ingredient, which generally finds usage in many foods and pharmaceutical products such as flavoring and coloring agents. However, the dehydration of orange juice is not a simple task. Thus, the objective of this study was to develop a new technique for spray drying orange juice using dehumidified air as drying medium and maltodextrin as drying agent.     

Improving the emulsifying property of potato protein by hydrolysis: an application as encapsulating agent with maltodextrin

Potato protein concentrate (PPC) is a by-product from starch industry and traditionally used as a low-value ingredient. Depending on its recovery/drying methods, protein functionality and technological applications can be compromised. Hydrolysis offers an alternative to this challenge by modifying protein structure, opening a prospect to find value-added opportunities for this residue. Hence, this study aimed to evaluate the impact of enzymatic hydrolysis on the emulsifying property of PPC. More importantly, we investigated the application of PPC with maltodextrin (proportion of 30:70) as wall material in the microencapsulation of a lipophilic ingredient by spray drying. When PPC was submitted to a 2% degree of hydrolysis, its emulsifying capacity significantly increased from 359 to 416 g oil/g protein. Spray drying microencapsulation using potato protein concentrate/hydrolysate and maltodextrin as wall materials were effective in entrapping flaxseed oil. Additionally, high encapsulation efficiency was observed (92– 96%). Overall, the application of potato protein combined with maltodextrin as wall material was successful for spray drying microencapsulation.     

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.     

Spray-dried conjugated linoleic acid encapsulated with Maillard reaction products of whey proteins and maltodextrin

Encapsulation performance of Maillard reaction products (MRPs) produced by whey proteins and maltodextrin were examined for microencapsulation of conjugated linoleic acid (CLA) using spray-drying. CLA was encapsulated using 3 different wall materials containing a single constituent such as whey protein concentrate (WPC), whey protein isolate (WPI), and maltodextrin (MD), and 4 different MRPs. For the development of MRPs, ratios of WPC to MD were 1:2 and 1:3, whereas those of WPI to MD were 1:5 and 1:10. CLA and wall material were mixed and homogenized, and then spraydried. The physical properties of encapsulated CLA powders were characterized by particle size and morphology, ζ-potential, flowability, solubility, and dispersibility. The CLA powders coated with WPI-based MRPs have better encapsulation efficiency, water solubility, and smaller particle size than those coated with WPI, WPC, or MD alone. These encapsulated CLA powders have a number of possible utilities as ingredients in a variety of foods.     

Spray‐drying encapsulation of citral in sucrose or trehalose matrices: physicochemical and sensory characteristics

The potential of the disaccharide trehalose as carrier for producing spray‐dried citral was examined. Some physical and sensory characteristics of citral encapsulated in matrices containing either trehalose or sucrose and maltodextrin (MD) were analysed. They included water sorption, glass transition temperatures (T_g), nuclear magnetic resonance (NMR) relaxation and citral retention during spray‐drying. The glassy state at room temperature (25 °C) was maintained as far as 33% relative humidities (RH) for the spray‐dried trehalose formulation and 43% RH for trehalose–MD; however, for sucrose–MD and for sucrose formulations, the glassy state was limited to RHs lower than 33% and 22%, respectively. Sensory evaluation and gas chromatographic analysis indicated that citral retention after spray‐drying was similar for matrices containing either trehalose or sucrose. However, trehalose formulations had improved physical stability as compared to sucrose.     

Encapsulation of mangosteen pericarp anthocyanin-rich extract by spray drying

Mangosteen pericarp anthocyanin-rich extract (MPA) was encapsulated by maltodextrin dextrose equivalent 20 (MD20) combined with gum arabic (GA), inulin (IN) or pectin (PEC) using spray drying. The highest encapsulation efficiency and anthocyanin content exhibited MD20:PEC and MD20:IN combinations. The MPA-encapsulated powders had a crystalline-mixed amorphous structure. Scanning electron microscopy (SEM) analysis showed smooth, round, fine particles. Fourier transform infrared spectroscopy (FTIR) analysis confirmed entrapment of anthocyanins by carrier agents. Thermogravimetric analysis (TGA) revealed a high thermal stability of encapsulated powders at temperatures <200°C and found that encapsulation reduced thermal degradation of anthocyanins. Incorporation of MPA-encapsulated powders into natural yoghurt produced shelf-stable naturally coloured product but slightly suppressed the multiplication of Lactobacillus bulgaricus. Encapsulation of anthocyanin-rich mangosteen pericarp extract using spray drying presents a viable opportunity for food technologists to utilise this source in the development of functional food products.     

微胶囊粉末猪油膜结构影响因素的研究

采用乳化喷雾干燥法制备粉末猪油,考察了蛋白质与麦芽糊精的比例、麦芽糊精ＤＥ值以及喷雾干燥条件对胶囊膜结构的影响。     

Dispersion in the Presence of Acetic Acid or Ammonia Confers Gliadin‐Like Characteristics to the Glutenin in Wheat Gluten

Spray‐dried gluten has unique properties and is commercially available in the food industry worldwide. In this study, we examined the viscoelastic properties of gluten powder prepared by dispersion in the presence of acetic acid or an ammonia solvent and then followed by lyophilization instead of a spray drying. Mixograph measurements showed that the acid‐ and ammonia‐treated gluten powders had marked decreases in the time to peak dough resistance when compared with the control gluten powder. The integrals of the dough resistance and bandwidth for 3 min after peak dough resistance decreased in both treated gluten powders. Similar phenomena were observed when gliadin was supplemented to gluten powders. Basic and acidic conditions were applied to the acid‐ and ammonia‐treated gluten powders, respectively, and the viscoelastic behaviors were found to depend on the pH in the gluten dispersion just before lyophilization. These behaviors suggest that gluten may assume a reversible change in viscoelasticity by a fluctuation in pH during gluten dispersion. SDS‐PAGE showed that the extractable proteins substantially increased in some polymeric glutenins including the low molecular weight‐glutenin subunit (LMW‐GS) when the ammonia‐treated gluten powder was extracted with 70% ethanol. In contrast, the extractable proteins markedly increased in many polymeric glutenins including the high molecular weight‐glutenin subunit and/or the LMW‐GS when the acid‐treated gluten powder was extracted with 70% ethanol. It thus follows that the extractability of polymeric glutenin to ethanol increases similarly to gliadin when gluten is exposed to an acidic or a basic pH condition; therefore, glutenin adopts gliadin‐like characteristics.     

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.     

月见草油微胶囊的制备及微观结构分析

采用4 种不同的配方通过喷雾干燥技术制备月见草油微胶囊,并对4 种配方制备的月见草油微胶囊的表面油含量、包埋率、粒径及表面结构进行分析。结果表明：以变性淀粉和麦芽糊精为壁材制备的月见草油微胶囊表面油含量低,包埋率好,粒径小,颗粒圆,微胶囊表面平整光滑。选用以变性淀粉和麦芽糊精为壁材制备的月见草油微胶囊进行脂肪酸组分及含量的测定,发现微胶囊化对月见草油的主要功能性成分亚油酸和γ-亚麻油酸的含量基本没有影响。用N-甲基靛红酸酐标记此配方中的麦芽糊精,通过激光共聚焦扫描显微镜进行断层扫描观察微胶囊的内部结构,发现微胶囊呈球形,单核结构,麦芽糊精在微胶囊壁中均匀分布。     

Moisture sorption characteristics and glass transition temperature of apple puree powder

The aim of this study was to characterise the influence of different foam‐mat‐drying methods on the moisture sorption characteristics and glass transition temperatures of apple puree powder. Apple puree was foamed with the addition of 2.5% egg albumin and 0.5% methylcellulose. Convective air‐drying and microwave‐drying techniques were used. Also foamed puree with and without maltodextrin (6% or 15% w/w) was freeze‐dried. Moisture equilibrium data of powders were determined by using a static desiccator method in a water activity range of 0.0–0.903. Modulated differential scanning calorimetry (MDSC) was used to obtain the glass transition temperature. No effect of drying method on sorption properties and glass transition temperatures of apple puree powders was observed. The addition of maltodextrin to the apple puree caused an increase in T_g by 10–30 °C depending on the amount of incorporated additive. Addition of maltodextrin significantly reduced the hygroscopicity of apple puree powders.     

复合壁材共轭亚油酸微胶囊的制备及表征

以乳清浓缩蛋白(WPC-80)、辛烯基琥珀酸酯化淀粉(CAPSUL)及麦芽糊精(MD,DE17)为复合壁材组分,喷雾干燥制备了共轭亚油酸(CLA)微胶囊。比较了不同壁材组分微胶囊的包埋效果、色泽变化及氧化稳定性,利用场发射扫描电镜对微胶囊的微观形貌进行了表征。结果表明,麦芽糊精(MD,DE17)分别和乳清浓缩蛋白(WPC-80)、辛烯基琥珀酸酯化淀粉(CAPSUL)复合作为壁材,可改善微胶囊的氧化稳定性。大部分微胶囊直径1～5μm,内部呈空腔状,CLA油滴(50～200 nm)包埋于囊壁中。增加复合壁材中麦芽糊精(MD,DE17)的比例,微胶囊收缩加剧。     

Impact of chitosan and oregano extract on the physicochemical properties of microencapsulated fish oil stored at different temperature

Fish oil is an excellent source of omega-3 fatty acids and is easily susceptible to oxidation. Microencapsulation is a commonly employed technique to protect fish oil against oxidation. In the present study, the potential of chitosan in combination with bovine gelatin and maltodextrin as wall material for microencapsulation of fish oil by spray drying was evaluated. To improve the oxidative stability of the fish oil microencapsulates, oregano (Origanum vulgare L) extract was added at 0.50 g/100 g of emulsion. The spray-dried powder showed a moisture content of 2.8 – 3.2 g/100 g of spray-dried powder. The powder contained spherical microparticles with different sizes as indicated by scanning electron microscope images. Encapsulation efficiency of microencapsulates ranged between 68.94% and 81.88%. Differential scanning calorimetry and Fourier-transformed infrared spectroscopy analysis of microencapsulates revealed the possible structural stabilization of core and wall material. The oxidative stability of fish oil microencapsulates were monitored under three different temperature (60°C, 28 ± 2°C, and 4°C). Incorporation of oregano extract minimized the generation of secondary and tertiary oxidation products as indicated by lower peroxide value and thiobarbituric acid reactive substance values compared to control. Overall, the results suggested that combination of chitosan along with bovine gelatin and maltodextrin as wall material improved the surface morphology of the microparticle and encapsulation efficiency, whereas incorporation of oregano extract in fish oil before spray drying enhanced the oxidative stability during storage.     

Encapsulation of polyphenols and anthocyanins from pomegranate (Punica granatum) by spray drying

Pomegranate (Punica granatum) bioactive compounds (polyphenols and anthocyanins) of juice (PJ) and ethanolic extracts (PE) were encapsulated with maltodextrin (MD) or soybean protein isolates (SPI) by spray drying using a 2² statistical factorial design for each systems studied (PJ–MD, PJ–SPI, PE–MD and PE–SPI) considering the proportion of coating material and the inlet temperature as independent variables. The stability of the bioactive compounds microcapsules powders obtained under optimal conditions for each system was studied at 60 °C in oven for 56 days. The polyphenols encapsulating efficiency was significantly better in SPI matrix whereas for anthocyanins was in MD matrix. By the other hand, during the storage, the MD microcapsules provided a significant greater protective effect on the polyphenols and anthocyanins than SPI, as was shown by the lower degradation rate constants. When the microcapsules were added to yogurt the stability of the bioactive compounds followed a similar behaviour to those without encapsulation, except for PE–MD.