Hydrogels containing spray-dried avobenzone and resveratrol-loaded nanocapsules using titanium dioxide and microalgae as drying adjuvants: An innovative formulation for photoprotection

Effects of maltodextrin (MD) and four types of proteins, viz., whey protein isolate, egg albumin, soy protein isolate and pea protein on the physicochemical and antioxidant properties of spray-dried black mulberry juice powders were investigated. Generally, animal proteins were more effective than the plant ones in powder recoveries. Differential scanning calorimeter analysis revealed better compatibility of the mulberry juice-MD than that of juice-protein matrix. When the juice total soluble solid was replaced by protein at the same ratio, the spray-dried powders with animal protein involvements resulted in smaller particle size, lower moisture content, bulk density, total phenolic content, DPPH scavenging capacity but higher water solubility index (WSI) and total color difference (ΔE) as compared with the plant proteins. In addition, the spray-dried powders with MD as carrier showed lower hygroscopicity, ΔE and higher WSI as compared with the proteins. This work provided some fundamental knowledge and practical guidance in improving the powder recovery of spray drying of fruit juice.

This study was designed to compare the quality characteristics of spray-dried (SD) and freeze-dried (FD) Pueraria thunbergiana extracts powder hot water extracts. Quality characteristics of the SD and FD powder including moisture content, color value, water absorption index, water solubility index, dynamic angle and antioxidant activities were evaluated. The moisture content of SD powder (1.50%) was lower than that of FD powder (2.92%). L* and b* values of SD powder was lower than of FD powder. The water absorption index was higher in FD powder (1.40) and water solubility index in SD powder (94.10%) was higher than that FD powder (90.69%). Dynamic angle of SD powder (36.46°) was higher than that of FD powder (33.30°). The DPPH radical scavenging activities of 5 mg/mL solution of SD powder and FD powder were 85.38 mg/mL, 59.38 mg/mL, respectively. And, the same trend was observed for the ABTS radical scavenging activities of the drying powder as that observed for their DPPH radical scavenging activities. There were relatively higher contents of phenolic compounds in SD powders than in FD powders. In conclusion, spray-dried Pueraria thunbergiana extracts showed the high WSI, polyphenol, DPPH and ABTS radical scavenging activities and low moisture content and dynamic angle than freeze dried powder.

BACKGROUND ‘Kedondong’ fruit is regarded as an exotic fruit that is gaining popularity due to its deliciousness and pleasant flavour. However, this fruit has a short shelf life, leading to problems with postharvest loss. In order to prevent losses, the fruit could be produced as a value-added product. In this study, the ‘kedondong’ fruit was preserved by drying into powder using different drying methods. METHODS The kedondong powder was dried using five methods: convection oven drying, vacuum drying, spray drying, drum drying and freeze drying. The physical properties, flowability and DPPH radical scavenging ability of dried kedondong powder were examined. RESULTS Spray-dried powder provided the significantly (p ≤ 0.05) highest process yield, which was 54.93%. All the powder produced had a low moisture content (3.03 to 5.66%) and water activity (0.19–0.37). Visually, whitish and fine powders were observed on spray-dried and freeze-dried samples, while convection oven-dried and vacuum-dried powder appeared yellowish and coarse. The pH of the reconstituted powders varied from 2.71 to 2.83, where drum-dried powder was the most acidic. Spray-dried powder showed the highest wettability and shortest dissolution time, which was 172.65 s and 10.55 s, respectively. With the exception of drum-dried powder, all the dried powders were classified as non-caking powders. The bulk and tapped density of the powders ranged from 0.32 to 0.70 g/mL and 0.38 to 0.86 g/mL, respectively. Vacuum-dried powder had very good flowability, convection oven-dried and drum-dried powder had good flowability, while spray-dried and drum-dried powder had fair flowability. Antioxidant assay showed that freeze-dried powder exhibited the highest free radical scavenging activity (IC50 = 701.29 μg/mL). CONCLUSIONS This study indicates that spray-dried kedondong powder has great potential in the food industry due to its high process yield and better powder quality. Meanwhile, freeze drying best preserved the antioxidant properties of the powder, which could potentially be used as a functional ingredient as a result. This study is important for the fruit processing industry as it offers an alternative for the farmer to produce kedondong fruit powder because the fruit has a short shelf life. Converting the fruit into powder can diversify the resulting produce into different applications, such as fruit juice, beverages, jam and other food products.

Water removal during drying process consumes energy and lead to high production cost. Hence, enzymatic mash treatment was proposed to reduce the usage of water to produce feed concentration that is suitable for drying. In this study, papaya powder was prepared from papaya puree treated with 1.0% v/w of Pectinex® Ultra SP-L, a pectinase enzyme, with incubation under 50 °C up to 2 hours. The liquefied papaya puree was spray-dried at selected maltodextrin concentrations (10% to 50% w/w of papaya puree) and inlet temperatures (140 °C to 180 °C). The physico-chemical properties of papaya puree, spray-dried powder, and reconstituted powder were assessed. Results showed that an increase in maltodextrin concentration led to lower process yield, lower moisture content and hygroscopicity, and better solubility. The powder produced was brighter in colour (L*) and less yellowish (b*). The papaya puree added with 20% maltodextrin achieved the highest process yield (74.91% ± 9.15%) and better solubility (69.60 ± 0.48 s/g) with optimal moisture content (5.21% ± 0.15% dry basis) and hygroscopicity (24.79% ± 0.58%) which was selected as optimal concentration. Meanwhile, increasing spray drying inlet temperatures led to a reduction in moisture content (26%) but did not significantly affect (p > 0.05) water activity, hygroscopicity, bulk density and colour of spray-dried papaya powders. The inlet temperature of 150 °C achieved the highest solubility (48.17 ± 4.51 s/g) with moderate process yield (74.01% ± 7.69%) and moisture content (5.91% ± 0.70% dry basis) which was considered as optimal drying temperature. The reconstituted powder showed no significant effect in viscosity, pH, and colour regardless of the different maltodextrin concentrations and inlet temperatures used. The optimized spray powder showed no significant difference with initial spray drying feed in total soluble solids, pH, and b* value.

Investigation into the production process and storage stability of spray-dried whole bitter almond powder.

Perilla oil is vulnerable to lipid oxidation owing to its high linolenic acid content. Microencapsulation using freeze- and spray-drying methods was applied to enhance the oxidative stability and change the physicochemical properties of perilla oil. Freeze-dried powder (FDP) possessed 11.77 to 38.48% oil content, whereas spray-dried powder (SDP) had 8.90-27.83% oil content. Encapsulation efficiency ranged from 51.22 to 85.71% by freeze-drying and from 77.38 to 90.74% by spray-drying. The oxidative stability of powders depends on the oil content and production methods. Generally, FDP had higher oxidative stability and water solubility, and lower moisture content and water activity than SDP. The particle size of FDP (154.00-192.00μm) in volume-weight mean diameter was 2.56-24.49 times larger than that of SDP (7.84-72.03μm). SDP had a lower volatile content at the initial time of storage than FDP, while more volatiles were observed in SDP as storage time increased. The microencapsulation method should be selected appropriately depending on the target property or usage in food applications.

Patterned and self-assembled ferroelectric nano-structures obtained by epitaxial growth and e-beam lithography

ABSTRACTIn this work, anthocyanin of rose residue was microencapsulated, using spray-drying (1:1 (w/w) of GA to MD, the inlet air temperature was170°C, the drying airflow rate was 5.0 m3/min, feed rate was 0.36 L/h) and freeze-drying (processing 48 h at −52°C, vacuum degree was 0.45 mbar) with gum arabic and maltodextrin as external materials. The total phenolic content (TPC), anthocyanin content (ACN), antioxidant activity, moisture content, water activity (Aw), solubility, hygroscopicity, colorimetric property, particle micromorphology and size distribution of the microencapsulated anthocyanin were measured. Thermal degradation kinetic and thermodynamic parameters of ACN extracts and microcapsules in the accelerated model were determined. The spray-dried powder (SDP) presented a spherical shape while the freeze-dried powders (FDP) were in indefinite and laminated structures with more homogeneous distribution. After microencapsulation, the retention rate of TPC and ACN was 86.00% and 75.85% for SDP, 91.44% and 95.12% for FDP, respectively. Both of spray-dried and freeze-dried strategy provided efficient preservation for rose residues, enabling them to have lower moisture content, water activity, significantly higher solubility (P < .05) compared with the rose anthocyanin extracts (RAE), and have high-fidelity color that was similar to RAE. Meanwhile, the antioxidant activity of the microcapsules decreased with the deteriorating of bioactive compounds. In the degradation kinetic study of anthocyanin at the temperature 70, 80, 90°C, both FDP and SDP had longer half-life duration, lower absolute value of activation entropy, and better effect of freeze-drying embedding method compared to RAE. Therefore, microencapsulation, especially by freeze-drying method, could efficiently enhance the stability of anthocyanin in rose residue during thermal processing and storage, and thus greatly facilitate the utilization of by-product of rose essential oil.Abbreviations: RAE: rose anthocyanin extracts; GA: gum arabic; MD: maltodextrin; SDP: spray-dried powders; FDP: freeze-dried powders; TPC: total phenolic content; ACN: anthocyanin content

Red fruit oil is a potential coloring agent with high carotenoid content. Oil encapsulation could be done to improve its applicability to food products. This study evaluated the effect of different ratios of maltodextrin and whey protein during the encapsulation process of red fruit oil using spray and freeze drying. The powders were analyzed in terms of total carotenoid content, physicochemical properties, and stability. Spray drying resulted in powders with lower moisture content. Freeze drying resulted in powders with high carotenoid content in most samples. All powders showed low hygroscopicity and low crystallinity, but also low flowability. Spray-dried powders were spherical and wrinkled, while freeze-dried powders were irregular and rough. Sample with 1:1 ratio of maltodextrin and whey protein showed generally better properties in both spray and freeze drying. Freeze-dried powder showed better carotenoid stability than spray dried powder throughout the 4 weeks storage period.

Photocatalytic activity of titanium dioxide prepared by a gamma-ray irradiation

Photocatalytic reduction of CO2 to valuable fuels by novel nanostructured titania materials

Two plant-based emulsifiers, soybean lecithin and pea protein isolate, were studied for their emulsifying and encapsulating capacities of an antimicrobial molecule, trans-cinnamaldehyde (TC), at two different pH values, three and seven, and after drying with two different techniques, spray-drying and freeze-drying. To characterize the obtained capsules, various physicochemical tests were conducted to examine particle size, encapsulation efficiency, thermal and moisture stability, and powder morphology. The spray-dried (SD) and freeze-dried (FD) powders had an average particle size of 8.35 µm and 144.49 µm, respectively. The SD powders showed similar encapsulation efficiency (EE) for soybean lecithin and pea protein isolate with an average value of 95.69%. On the other hand, the FD powders had lower EE compared to SD powders, with an average of 58.01% for lecithin-containing powders and 83.93% for pea-protein-containing powders. However, the water content of FD powders (2.83%) was lower than that of SD powders (4.72%). The powders prepared at pH 3 showed better thermal stability. Morphological analysis showed spherical particles for SD powders and irregular shapes for FD powders. Nanoemulsions as well as dried powders showed interesting antimicrobial activities against Escherichia coli and Listeria innocua, confirming their potential use as natural preservatives in foods.

In soils, colloidal transport has been identified as the most important pathway for strong adsorbing, environmental contaminants like pesticides, heavy metals, and phosphorus. We conducted a comparative dye tracer experiment using a Brilliant Blue (BB) solution and a Titanium(IV) oxide (TiO) colloid suspension (average particle size 0.3 μm), aiming to visualize and quantify colloid pathways in soils. Both dye tracers showed comparable general flow patterns with preferred transport over the deepest part of the soil profile, independent of clay content. The stained area was generally smaller for TiO than for BB by a factor of ten, however, and there was no TiO to be found at all in the low clay content soil. The travel distance was almost identical for the solution and the suspension (0.7 m) giving evidence that environmentally critical compounds bound to microparticles may be vertically transported over longer distances in soils, even within single rainfall events. The spatial variability of the dye patterns was large on a small scale with a range of 0.35 m for TiO in the horizontal plane, which was taken as a general proof for a pronounced preferential transport situation. The study indicates that TiO is transported exclusively through singular macropores of biogenetic nature, while BB passes also through the soil matrix of coarse-bedded soils, the secondary pore system or interaggregate pore space. The results emphasize the general suitability of TiO for the visualization of colloid transport pathways in soils, opening up new research opportunities for contaminant transport in soils.

The physicochemical properties and the survival of Lactiplantibacillus plantarum mixed with blend of fruit juice powders dried by spray and freeze drying methods were investigated. A formula containing maltodextrin 14% and malt extract 6% as a carrier and juices of red grape 20.4%, mulberry 75.6%, and strawberry 4.0% along with the bacterium (Lpb. plantarum) with 3 × 10 9 CFU/mL were dried by spray drying and freeze drying methods, separately. The physicochemical properties including color attribute, nutritional properties of the powders such as antioxidant, and phenolic content were measured. Drying efficiency of freeze-dried was 80.48%, which was higher than the spray-dried powders (50.84%). The higher antioxidant (87.95) and total phenolic content (3032.6 mg GAE/L) was achieved by freeze drying technique; however, lower moisture content and flowability as well as higher solubility and bulk density were obtained for spray-dried powders. The survival of probiotics in freeze-dried powders was higher than the spray-dried powders which can be related to mild conditions. The study indicated that the juice powders are suitable carriers for Lpb. plantarum and constitute good alternatives to highly acidic fruit juices.

&lsquo;Kedondong&rsquo; fruit is regarded as an exotic fruit that is gaining popularity due to its deliciousness and pleasant flavour. However, this fruit has a short shelf life, leading to problems with postharvest loss. In order to prevent losses, the fruit could be produced as a value-added product. In this study, the &lsquo;kedondong&rsquo; fruit was preserved by drying into powder using different drying methods. The kedondong powder was dried using five methods: convection oven drying, vacuum drying, spray drying, drum drying and freeze drying. The physical properties, flowability and DPPH radical scavenging ability of dried kedondong powder were examined. Spray-dried powder provided the significantly (p &le; 0.05) highest process yield, which was 54.93%. All the powder produced had a low moisture content (3.03 to 5.66%) and water activity (0.19&ndash;0.37). Visually, whitish and fine powders were observed on spray-dried and freeze-dried samples, while convection oven-dried and vacuum-dried powder appeared yellowish and coarse. The pH of the reconstituted powders varied from 2.71 to 2.83, where drum-dried powder was the most acidic. Spray-dried powder showed the highest wettability and shortest dissolution time, which was 172.65 s and 10.55 s, respectively. With the exception of drum-dried powder, all the dried powders were classified as non-caking powders. The bulk and tapped density of the powders ranged from 0.32 to 0.70 g/mL and 0.38 to 0.86 g/mL, respectively. Vacuum-dried powder had very good flowability, convection oven-dried and drum-dried powder had good flowability, while spray-dried and drum-dried powder had fair flowability. Antioxidant assay showed that freeze-dried powder exhibited the highest free radical scavenging activity (IC50 = 701.29 &mu;g/mL). This study indicates that spray-dried kedondong powder has great potential in the food industry due to its high process yield and better powder quality. Meanwhile, freeze drying best preserved the antioxidant properties of the powder, which could potentially be used as a functional ingredient as a result. This study is important for the fruit processing industry as it offers an alternative for the farmer to produce kedondong fruit powder because the fruit has a short shelf life. Converting the fruit into powder can diversify the resulting produce into different applications, such as fruit juice, beverages, jam and other food products.