Influence of inlet air temperature and carrier material on the production of instant soluble sage (Salvia fruticosa Miller) by spray drying

Beyond Traditional Methods: Deep-Learning Machines Empower Fingerroot (Boesenbergia rotunda)-Extract Production with Superior Antioxidant Activity

This study investigated the impact of drying parameters on the quality of fingerroot (Boesenbergia rotunda) extract, focusing on phenolic compounds, flavonoids, and antioxidant activity. A Box-Behngen design was employed to evaluate the effects of maltodextrin concentration, inlet temperature, and outlet temperature on the extract's properties. The highest total phenolic content (18.96 µg of GAE/mg extract) and total flavonoid content (33.52 µg of GE/mg extract) were achieved using 20% maltodextrin, a 160 °C inlet temperature, and an 80 °C outlet temperature. Antioxidant activity, measured by DPPH and FRAP assays, was also influenced by drying parameters. Stepwise regression analysis revealed that maltodextrin concentration significantly affected all responses, while the inlet temperature had no significant effect. The outlet temperature significantly influenced FRAP activity. The developed mathematical models accurately predicted experimental values, validating the effectiveness of the RSM and Deep-Learning Machine. Optimal drying conditions for maximizing phenolic compounds were determined to be 20% maltodextrin, a 150 °C inlet temperature, and a 70 °C outlet temperature, resulting in TPC 15.33 µg of GAE/mg extract, TF 28.75 µg of GE/mg extract, IC50 value of 3.99 µg/mL, FRAP value at 4.44 µmoL Fe2+/mg extract of phenolic content, and 18.96 µg of the GAE/mg extract. Similar conditions were found to be optimal for maximizing flavonoid content. These findings provide valuable insights for optimizing the drying process of fingerroot extract to preserve its bioactive compounds and enhance its potential applications.

Development of Cyclodextrin-Based Mono and Dual Encapsulated Powders by Spray Drying for Successful Preservation of Everlasting Flower Extract

The study aimed to develop encapsulation systems to maintain the preservation of everlasting (Helichrysum plicatum) flower extract polyphenols. Spray-dried encapsulates were formulated using β-cyclodextrin (BCD) and 2-hydroxypropyl-β-cyclodextrin (HPBCD) as supramolecular hosts, and their macromolecule mixtures with the conventional carriers, maltodextrin (MD) and whey protein (WP). The obtained microparticles were comparatively assessed regarding technological, physicochemical, and phytochemical properties. The highest yields were achieved by combining cyclodextrins with whey protein (73.96% for WP+BCD and 75.50% for WP+HPBCD compared to 62.48% of pure extract). The extract-carrier interactions and thermal stability were evaluated by FTIR and DSC analysis, suggesting successful entrapment within the carriers. Carriers reduced the particle diameter (3.99 to 4.86 μm compared to 6.49 μm of pure extract), classifying all encapsulates as microsystems. Carrier blends made the particle size distribution uniform, while SEM analysis revealed the production of more spherical and less aggregated particles. The HPBCD provided the highest encapsulation efficiency, with the highest content of detected aglycones and slightly lower values of their glycosylated forms. An analysis of the dual macromolecule encapsulation systems revealed the highest bioactive preservation potential for SHE+MD+BCD and SHE+WP+HPBCD. Overall, macromolecule combinations of cyclodextrins and conventional biopolymers in the spray-drying process can enhance the functional properties of H. plicatum extract.

Physicochemical and biological properties of encapsulated Boesenbergia rotunda extract with different wall materials in enhancing antioxidant, mineralogenic and osteogenic activities of MC3T3-E1 cells

Boesenbergia rotunda (L.) comprises bioactive compounds with biological and pharmacological properties, especially flavonoid compounds with osteoblastogenesis-stimulating potential. However, the application of B. rotunda in the food and pharmaceutical industry is restricted by its low solubility and stability. Encapsulation becomes an alternative to overcome these restrictions. The purpose study was to encapsulate B. rotunda extract by freeze-drying and to investigate the effects of different wall materials (maltodextrin (MD), gum arabic (GA), and their combination (MDGA)) and extract contents on the physicochemical, bioactive properties and in vitro enhancement of osteogenesis of MC3T3-E1 cells of the obtained encapsulates. The results revealed that encapsulated B. rotunda can reduce cytotoxicity, enhance biological activity, and maintain the stability of bioactive compounds. The MD was a good wall material for yield percentage. However, the values of moisture content Aw, and solubility among all the encapsulated powders were no significant differences, with all encapsulated powders having similar structures based on scanning electron microscopy. Fourier transform infrared spectroscopy confirmed the extract was encapsulated by the selected wall materials. Combining the MD and GA encapsulation agents afforded the best protection of the bioactive compounds, increasing EE (MDGA-7 > MDGA-5), pinostrobin content, TPC, and antioxidant activities (MDGA-5 > MDGA-7). The MDGA-5 and MDGA-7 at 10-50 μg/mL were not toxic to cells and promoted MC3T3-E1 cell viability, while also enhancing the Alkaline phosphatase activity, and promoting matrix mineralization of pre-osteoblast MC3T3-E1 cells after 21 and 28 days. This result showed that MDGA was a suitable wall material for B. rotunda encapsulations and a potential source of bioactive ingredients that could applied in food or pharmaceutical products for osteoporosis prevention.

Widely targeted metabolomics reveals the effect of different raw materials and drying methods on the quality of instant tea

Introduction

Instant teas are particularly rich in tea polyphenols and caffeine and have great potential as food ingredients or additives to improve the quality of food and enhance their nutritional and commercial value.

Methods

To determine the relationships between raw material, drying method, and sensory and other quality attributes, instant teas were prepared from three tea varieties, namely black, green and jasmine tea, using two drying methods, namely spray-drying (SD) and freeze-drying (FD).

Results

Both the raw tea material and drying method influenced the quality of the finished instant teas. Black tea was quality stable under two drying, while green tea taste deteriorated much after SD. Jasmine tea must be produced from FD due to huge aroma deterioration after SD. FD produced instant tea with higher sensory quality, which was attributed to the lower processing temperature. Chemical compositional analysis and widely targeted metabolomics revealed that SD caused greater degradation of tea biochemical components. The flavonoids content changed markedly after drying, and metabolomics, combined with OPLS-DA, was able to differentiate the three varieties of tea. Instant tea preparations via SD often lost a large proportion of the original tea aroma compounds, but FD minimized the loss of floral and fruity aroma compounds. Changes in the tea flavonoids composition, especially during drying, contributed to the flavor development of instant tea.

Discussion

These results will provide an practicle method for high-quality instant tea production through choosing proper raw tea material and lowering down drying temperature with non-thermal technologies like FD.

Spray dried date fruit extract with a maltodextrin/gum arabic binary blend carrier agent system: Process optimization and product quality

Bioactive compounds can be protected from degradation through encapsulation, increasing their bioavailability and shelf life. Spray drying is an advanced encapsulation technique mainly used for the processing of food-based bioactives. In this study, Box-Behnken design (BBD)-based response surface methodology (RSM) was used to study the effects of combined polysaccharide carrier agents and other spray drying parameters on encapsulating date fruit sugars obtained from a supercritical assisted aqueous extraction. The spray drying parameters were set at various levels: Air inlet temperature (150-170 °C), feed flow rate (3-5 mL/min), and carrier agent concentration (30-50 %). Under the optimized conditions (inlet temperature of 170 °C, the feed flow rate of 3 mL/min, and carrier agent concentration of 44 %), a maximum sugar powder yield of 38.62 % with 3.5 % moisture, 18.2 % hygroscopicity and 91.3 % solubility was obtained. The tapped density and particle density of the dried date sugar were estimated as 0.575 g cm-3 and 1.81 g cm-3, respectively, showing its potential for easy storage. In addition, scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis revealed better microstructural stability of the fruit sugar product, which is essential for commercial applications. Thus, the hybrid carrier agent system (maltodextrin and gum arabic) can be considered a potential carrier agent for producing stable date sugar powder with longer shelf-life and desirable characteristics in the food industry.

Physicochemical and Biological Characterization of Encapsulated Olive Leaf Extracts for Food Preservation

Phenolic compounds in olive leaves have an excellent antioxidant activity and good antimicrobial properties. These bioactive molecules have beneficial properties for health, arousing great scientific and commercial interest. This study reports lyophilized olive leaf extracts (OLE) encapsulated by spray-drying using maltodextrins, maltodextrins-pectin and maltodextrins-gum Arabic as encapsulating agents. Lyophilized OLE were collected from two varieties cultivated in a harsh pedo-climatic conditions of the arid region of Tunisia. The effects of the genetic factor and the different encapsulating agents on the physicochemical properties of microcapsules and their behavior during storage, as well as their antimicrobial activities, were studied. Microcapsules successfully passed heat treatment and storage conditions and their antimicrobial activities were preserved. The encapsulating agent combination improved the encapsulation efficiency and the product yield in Zarrazi variety compared to Dhokar one. In addition, Dhokar variety microparticles showed the best heat stability at 4 and 25 °C after 90 days of storage and the higher inhibition percent against bacteria. The results of the present study evidenced that the best conditions for OLE encapsulation were obtained when the maltodextrins-pectin and maltodextrins-gum Arabic were combined to form a hybrid coating material.

Microencapsulates of Blue Maize Polyphenolics as a Promising Ingredient in the Food and Pharmaceutical Industry: Characterization, Antioxidant Properties, and In Vitro-Simulated Digestion

An anthocyanin-rich blue maize waste product was used for anthocyanin extraction. To preserve bioactive phenolic compounds, a spray-drying technique was employed using conventional wall material maltodextrin (MD), with novel one, hydroxypropyl-β-cyclodextrin (HPBCD). The obtained spray-dried maize extract (SME) and microencapsulates were analyzed based on physicochemical powder properties, chemical analysis, antioxidant activity, and digestibility. The examined microencapsulates demonstrated good powder properties, exhibited a high powder yield (up to 83%), and had a low moisture content (less than 5%). HPBCD and MD + HPBCD combinations demonstrated superior powder properties in the terms of decreasing the time necessary for rehydration (133.25 and 153.8 s, respectively). The mean average particle diameter ranged from 4.72 to 21.33 µm. DSC analyses signified high powder thermal stability, around 200 °C, related to the increasing preservation with biopolymer addition. The total phenolic and anthocyanin compounds ranged from 30,622 to 32,211 mg CE/kg (CE-catechin equivalents) and from 9642 to 12,182 mg CGE/kg (CGE-cyanidin 3-glucoside equivalents), respectively, associated with good bioactive compound protection. Microencapsulates with both carriers (15% MD and 15% HPBCD) had the highest digestibility (73.63%). Our results indicated that the microencapsulates created with the active ingredient and the wall materials (MD and HPBCD) could protect phenolic compounds/anthocyanins against ABTS radicals (63.53 and 62.47 mmol Trolox Eq/kg, respectively).

Preservation of active components in olive leaf extract by spray drying method in biodegradable polymers: Optimization, in vitro gastrointestinal digestion and application

INTRODUCTION

Encapsulation of the bioactive ingredients in biodegradable and edible polymers is an alternative novel application method to keep these kind of natural products stable.

OBJECTIVE

The purpose is to optimize the encapsulation system of olive leaf extract by spray drying method, and to apply the products into a model food.

METHODS

Olive leaf extract was encapsulated in arabic gum/maltodextrin blend by spray drying method. Combined design approach under I-optimal design type was used to optimize the system. Characterisation studies under moisture content, water activity, solubility, bulk density, tapped density, Carr index, particle size distribution, powder morphology and glass transition temperature were applied to the microparticles obtained under optimum conditions. The bioavailability of the encapsulated active material was tested by in vitro gastrointestinal digestion. Furthermore, microparticles produced under optimum conditions were also evaluated for a potential functional food application.

RESULTS

The optimum conditions were achieved by arabic gum/maltodextrin (3.7:6.3) with 10% (w/v) in the mixture of wall material and active material under 165.5°C to achieve maximum encapsulation efficiency (86.92%), encapsulation yield (71.32%) and antioxidant activity (5.74 mg Trolox equivalent antioxidant capacity/g dry microparticle).

CONCLUSIONS

Olive leaf extract encapsulated in arabic gum/maltodextrin may be a good alternative additive to prevent the lipid oxidation in fat-containing food products as well as improvement of the product quality by functional properties.

Design of encapsulation method for chlorogenic acid and caffeine in coffee waste by-product

INTRODUCTION

Coffee silver skin (CSS) is a thin covering over green coffee seeds inside coffee cherry. It is a good source of bioactive compounds like chlorogenic acid and caffeine. It is produced as a by-product of the roasting process.

OBJECTIVE

The goal of this study is to apply spray drying method to encapsulate 5-O-caffeoylquinic acid (chlorogenic acid) and caffeine extracted from CSS.

METHODS

The main-plots for optimisation were feed solid concentration (2.5, 5, 10°Bx), and the sub-plots of the whole-plot were carrier material type (maltodextrin, modified starch, arabic gum) and inlet air temperature (130, 160, 190°C). Responses included were drying yield, chlorogenic acid concentration, caffeine content, Carr index, and solubility values.

RESULTS

Suitable conditions were spray drying inlet temperature of 190°C, extract concentration of 10°Bx, and wall material composition [modified starch/arabic gum (MS:AG)] 10.5:9.5. As the feeding CSS extract concentration increased, the amount of chlorogenic acid and caffeine in the final powder increased, while the powder's flow characteristics improved.

CONCLUSIONS

The concentration stage might be used to produce free-flowing powdered particles with good bioactive retention for use in the food processing industry.

Impact of hydrocolloid and foaming agent on the physicochemical, microstructural and bioactive characteristics of foam-mat freeze-dried tapai (fermented black glutinous rice) powder

The aim of this study was to obtain fermented black glutinous rice (FBGR) powder using the foam-mat freeze-drying method and to evaluate the physicochemical, microstructural, and bioactive characteristics of FBGR powder. To obtain FBGR foams, maltodextrin (MD; 0%-40% w/w) and whey protein isolate (WPI; 7.5% w/w) were used. The results showed that MD concentration had a significant effect (p ≤ .05) on powder recovery and bulk density which increased from 68.9% to 80.5% and 0.46% to 0.63 g/ml, respectively. The lowest moisture content (2.17%) and water activity (0.48) were found in powders produced with 20% MD. The solubility of FBGR powders ranged from 74% to 75% and increasing MD concentration gave higher lightness (L*) and yellowness (b*) readings in color properties of powders. Although the addition of the carrier agent caused reductions in total phenolic content and anthocyanins, the retention of these bioactive compounds rose with increasing MD content from 67% to 76% and 78% to 84%, respectively. FBGR produced with 40% MD had the most superior physical and technological properties, and foam-mat freeze-drying is a promising technology for retaining the bioactive compounds in FBGR.

Garden cress gum and maltodextrin as microencapsulation coats for entrapment of garden cress phenolic-rich extract: improved thermal stability, storage stability, antioxidant and antibacterial activities

The obtained garden cress 6-day sprouts phenolic-rich extract (GCSP) contained efficient health-promoting antioxidant-phenolic compounds. To improve the stability, bioavailability, and functional properties of these valuable phenolic compounds, GCSP was encapsulated by freeze-drying technique using different ratios of garden cress gum (GG) and maltodextrin (M) in the absence and presence of sonication (S). The prepared S/GG-microcapsule retained the highest phenolic content (95%), antioxidant activity (141.6%), and encapsulation efficiency (98.2%). It displayed the highest bio-accessibility of GCSP-phenolic compounds in simulated intestine fluid (87%) and demonstrated the greatest storage-stability at 40 °C for 60 days. S/GG-microcapsule possessed better physical properties including moisture, solubility, swelling, and morphological structures using SEM. The main spectral features, crosslinking, and improved thermal stability were demonstrated for S/GG-microcapsule using FTIR and thermogravimetric analyses. S/GG-microcapsule demonstrated much greater antibacterial activity than GCSP against pathogenic bacteria. S/GG-microcapsule can be added to different food products to improve their antioxidant and antibacterial properties.

Study on production conditions, volatile composition, and chemical characteristics of herbal tea using Arapgir purple basil (Ocimum basilicum L.)

In this work, production of purple basil (Ocimum basilicum L.) herbal tea was studied. Purple basil is a medicinal and aromatic herb with many health benefits; it is commonly used for seasoning foods. Semi-shade and tray drying methods were used for drying purple basil for tea production. Physical, chemical, and sensory characteristics of samples were evaluated. Total polyphenol contents of samples increased with drying processes and were between 9.55 and 14.18 mg GAE/g. Colour values decreased with drying. Volatile composition of samples was determined using the SPME/GC-MS system. 2-Propenoic acid, 1,8-cineole (eucalyptol), and eugenol were the predominant volatile compounds in all samples. In sensory evaluation, samples produced by tray drying with added citric acid had the highest general acceptance. In conclusion, purple basil was evaluated as a suitable plant for herbal tea production due to its easy preparation, pleasant flavour and colour.

Effect of Spray Drying Encapsulation on Nettle Leaf Extract Powder Properties, Polyphenols and Their Bioavailability

Nettle (Urtica dioica L.) is a plant rich in a health-promoting compounds such as polyphenols, which are sensitive and unstable compounds with low bioavailability, that need to be stabilized and protected from external influences. Therefore, the aim of this study was to examine how the temperature, type of carrier and sample to carrier ratio influence the physicochemical properties and encapsulation and loading capacity of the nettle leaf extract powder and examine the effect of encapsulation on the antioxidant capacity and bioavailability of polyphenols. The process yield ranged from 64.63–87.23%, moisture content from 1.4–7.29%, solubility from 94.76–98.53% and hygroscopicity from 13.35–32.92 g 100 g⁻¹. The highest encapsulation (98.67%) and loading (20.28%) capacities were achieved at 160 °C, β-CD:GA (3:1) and sample:carrier ratio of 1:3. Extracts encapsulated at selected conditions showed high antioxidant capacity and distinct polyphenolic profile comprised of 40 different compounds among which cinnamic acids were the most abundant. Moreover, the encapsulation increased the bioavailability of nettle leaf polyphenols, with the highest amount released in the intestinal phase. Thus, the obtained encapsulated extract represents a valuable source of polyphenols and may therefore be an excellent material for application in value-added and health-promoting products.

Comparison of Antioxidant and Alpha-Glucosidase Inhibitory Properties of Moringa peregrina and Ferulago carduchorum Leaf Extracts and Microencapsulation of Superior Plant

Today, medicinal plants have a crucial role in treating diseases such as diabetes and cancer. These plants do not impose any side effects owing to their bioactive compounds in comparison with chemical drugs. Several studies have demonstrated antioxidant capacity and α-glucosidase inhibitory effects of bioactive compounds from medicinal plants. According to previous studies, Moringa peregrina (MP) and Ferulago carduchorum (FC) are two promising plants in terms of antioxidant capacity and α-glucosidase inhibitory effects. This research followed a three-stage study. In the first stage, the antioxidant and α-glucosidase inhibitory properties of MP and FC ethanolic extracts, native to Iran, were compared using spectrophotometric methods. The results showed that the ABTS•+ radical scavenging and α-glucosidase enzyme inhibitory activities of both plants were dependent on extract concentration. MP exhibited lower IC50 values in both tests, 1.01 and 4.96 mg·mL−1, respectively. Accordingly, the extract of MP was selected for further experiments. In the second stage, total phenolic content (TPC) and GC-MS analysis were conducted on MP extract to investigate the reason behind its antioxidant capacity and α-glucosidase inhibitory properties. Results of assessing total phenolic content (TPC) using the Folin-Ciocalteu method revealed a strong positive correlation between TPC with antioxidant activity (r = 0.94, $p<0.05$ ). GC-MS was used to identify phytoconstituents of the extract, leading to the determination of 35 components whose major one was vitamin E (10.2%). To ensure its suitability for food fortification, in the third stage, encapsulation of the MP extract was followed. Microencapsulation was performed using three polymer coatings, and the effects of carriers were investigated on moisture content, solubility, bulk density, microencapsulation yield, particle size, antioxidant activity, and TPC. According to the experiments, antioxidant activity and TPC were retained well in all carriers. Moreover, SEM, DSC, and FTIR analyses confirmed that the extract was well-coated and no surface fractures were observed. The results indicated that MP can be a promising plant for food fortification as a natural antioxidant and antidiabetic source.

Spray-Dried Nipa Palm Vinegar Powder: Production and Evaluation of Physicochemical, Nutritional, Sensory, and Storage Aspects

Nipa palm vinegar (NPV) is a naturally fermented vinegar derived from the nipa palm (Nypa fruticans Wurmb) sap. This work optimized production of spray-dried nipa palm vinegar powder. The influence of the various drier air inlet temperatures (150, 170, and 190 °C) and maltodextrin DE10 carrier concentrations (15 and 20% w/v) in the feed, on the characteristics of the product powder was investigated. Nipa palm vinegar powder (NPVp) was evaluated in terms of the following responses: physicochemical and nutritional properties, sensory acceptability, and storage stability. All processing variables affected the responses. Based on product desirability as the optimization criterion, spray-drying with a hot air inlet temperature of 170 °C with a 15% w/v maltodextrin DE10 in the feed was optimal. The nutritional characteristics of the product made under the above identified optimal conditions were (per 100 g dry product): a calorific value of 366.2 kcal; 1.3 g protein; 88.1 g carbohydrate; 0.96 g fat; 883.9 mg potassium; 12.7 mg vitamin C; and 105 mg gallic acid equivalent (GAE) phenolics content. The product, vacuum-packed and heat-sealed in aluminum laminated polyethylene bags, could be stored at 25 °C for at least 180 days without noticeable loss in quality.

Bioactive Components and Anticancer Activities of Spray-Dried New Zealand Tamarillo Powder

Tamarillo fruit contains many phytochemicals that have beneficial therapeutic and nutritional properties. Spray-drying is widely used to preserve fruit puree in powder form. However, to obtain high-quality fruit powder, the optimisation of spray-drying conditions is necessary, as a high drying temperature can damage sensitive bioactive compounds. This study investigated the effects of spray-drying on the microstructure, polyphenolics, total flavonoids, total carotenoids, antioxidant activity, and anticancer capacity of tamarillo powder. Response surface methodology (RSM) was used to optimise the spray-drying process to produce tamarillo powder. The independent variables were inlet drying temperature (120-160 °C), flow rate (1-5 g/mL), and maltodextrin concentration (0-10%). These variables influenced the microstructural attributes, bioactive components, and cytotoxicity of the spray-dried tamarillo powder. The increase in polyphenols and antioxidant activities were favoured under high-temperature spray drying conditions and a low carrier concentration. The optimised spray-drying conditions for producing tamarillo powder with high antioxidant and anticancer activities, high yield, and stable bioactive compounds were found to be at 146.8 °C inlet temperature, and a flow rate of 1.76 g/mL.

Effect of cold plasma pretreated hot-air drying on the physicochemical characteristics, nutritional values and antioxidant activity of shiitake mushroom

BACKGROUND

Shiitake mushroom is one of the most popular delicious vegetables, although fresh shiitake mushroom has short shelf life as a result of biochemical degradation. Drying can prolong the shelf life of mushroom. Additionally, application of cold plasma pretreatments (CPT) before drying can preserve the product quality, processing costs and nutritional values. Therefore, we aimed to explore the effect of cold plasma pretreated hot-air drying at 50, 60 and 70 °C on the physicochemical characteristics, nutritional values and antioxidant activity of shiitake mushroom.

RESULTS

Scanning electron microscopy micrographs showed that CPT induced the surface modification of fresh shiitake (such as cellular disarrangement, cellular shrinkages, disruption or break down of cell walls, and intracellular spaces and cavities) and facilitate the rapid drying than control samples. Furthermore, CPT improved the powder qualities (bulk density, water retention and swelling index) and preserved higher nutritional attributes (sugars, vitamins, phenolic acids contents and antioxidant activity) compared to the control groups.

CONCLUSION

Conclusively, CPT could be a suitable alternative technique for improving drying characteristics and preserving nutritional attributes of agro-based products. © 2021 Society of Chemical Industry.

Physicochemical, reconstitution, and morphological properties of red pepper juice (Capsicum annuum L.) powder

ABSTRACT

The aim of this study is to investigate the influence of the encapsulating agents (maltodextrin (MD), whey protein isolate (WP), and gum arabic (GA)) and their blends (MD + WP, MD + GA, WP + GA, and MD + WP + GA) on the powder yield, drying ratio, productivity, drying rate, physicochemical, bulk, reconstitution, and morphological properties of the red pepper juice powders (RPJP) and to calculate the energy efficiency of the spray dryer. A pilot-scale spray dryer (180/80 °C inlet/outlet air temperature, 392 kPa atomization pressure, 1.54 m³/min air flow rate, and a 12.0 ± 0.2°Bx feeding concentration) was used for the drying experiments. The acceptable powder yield (52.48-94.25%) and specific energy consumption values (7.39-9.72 MJ/kg H₂O) were obtained. The RPJP presented moisture content and water activity values lower than 10% and 0.367. The red pepper juice powders were found to be highly dispersible (88.34-95.18%), soluble (solubility time and index are 9.75-77.25 s and around 99%), and easly wetted (9.75-122.00 s). The average particle sizes of the RPJPs were 14.92 μm, 19.68 μm, 19.36 μm, 17.58 μm, 19.96 μm, 19.41 μm, and 18.72 μm for RPJP + MD, RPJP + WP, RPJP + GA, RPJP + MD + WP, RPJP + MD + GA, RPJP + WP + GA, and RPJP + MD + WP + GA respectively. Despite the low powder yield and high water activity value, RPJP + MD exhibited superior (bulk density, flowability, cohesiveness, wettability and solubility times) or statistically similar (productivity, moisture content, browning index, porosity, dispersibility, and hygroscopicity) properties compared to other powders.

GRAPHIC ABSTRACT

Microencapsulation of probiotics in finger millet milk complex to improve encapsulation efficiency and viability

This study aimed to assess the effectiveness of finger millet milk complex (almond gum with maltodextrin) to encapsulate the isolated Lactobacillus strains. The wall materials were optimized based on its encapsulation efficiency, antioxidant activity, total phenol content and encapsulation yield. The strains were spray-dried at the optimized condition: 120 °C inlet temperature, maltodextrin 30% and almond gum 1.5%. Survival count of microencapsulated Lactobacillus plantarum RS09 and RS23 strains were 7.91 and 7.83 CFU/g respectively. Viability of microencapsulated strains and free cells under low pH, bile salt, simulated gastric juice and intestinal juice were assessed. Strain RS09 exhibited the highest viable count. Addition of almond gum and finger millet milk increased the phenolic content and offered a protective effect to the strains during spray drying. Results also showed that the powders were amorphous with partial irregularities and a smooth surface with less dents. Hence, they could be used as potential encapsulating agents during spray drying.

Development of water spinach powder and its characterization

The study was performed on water spinach (Ipomea aquatica), a hidden gem with lots of nutritional attributes and medicinal properties. To check its feasibility as an ingredient in other food products and to know its nutritional attributes, powders were made by drying the leaves and stems of the plant using different drying techniques such as sun drying, freeze-drying, and tray drying. The physicochemical analysis of powder was done to get a comparative result, in which the freeze-dried powder showed the most significant result. The physicochemical analysis revealed that lyophilized water spinach powder has a good amount of carbohydrates (58.15%), ash (12.39%), protein (4.01%), and fat (4.46%) content. The powder also possessed a high antioxidant property of 77.25% and a total phenolic content of 32 µg/ ml. SEM and XRD results showed that the water spinach powder was amorphous in nature.

Effect of drying methods and storage with agro-ecological conditions on phytochemicals and antioxidant activity of fruits: a review

Choice of drying methods significantly impacts the nutritive and non-nutritive compounds in fruits and vegetables. Phytochemicals such as total phenolics and total flavonoids are non-nutritive bioactive compounds and are found in plants which are of important value due to their antioxidant properties in minimizing the oxidation reaction. However, drying and storage conditions and duration significantly affect these important quality attributes. There is currently no review article on the impact of the drying and storage conditions on these quality attributes. Therefore, the aim of this review paper is to investigate the impact of drying methods on these important phytochemicals and their antioxidant activity on dried products during the storage period. Different drying methods cause desirable and undesirable changes to dried products both physically and chemically. It is found that during the drying process at various temperature ranges from 40 to 80 °C, chemical changes occurs which affects the phenolic and the flavonoid content of dried products to increase or decrease. The increase in antioxidant activity after drying is also due to oxidized polyphenols and Maillard reaction products. This results to changes in the antioxidant potential of the dried food product and its impact on the shelf life.

Process for production of ready to drink iced teas from sage (Salvia officinalis L.) and linden (Tilia cordata): pressurized hot water extraction and spray drying

The aim of this study was to produce ready to drink (RTD) iced teas from sage and linden. For this purpose, phenolics of sage and linden were extracted by pressurized hot water extraction (PHWE) and then the extracts obtained were spray dried by the addition of maltodextrin. The powders produced by spray drying were processed into RTD sage and linden iced teas by adding sucrose and citric acid. The optimum conditions of PHWE of sage and linden were at 160 °C and for 10 min and 5 min, respectively. The solubility and microencapsulation efficiency of spray dried powders were found to be greater than 97%. In addition, total phenolic content and antioxidant activity of RTD iced teas are parallel with those of microencapsulated sage and linden powders after pasteurization at 80 °C for 5 min. The sensory analysis of RTD iced teas showed that products were well-accepted by the panelists.

Effects of Spray-Drying Temperatures and Carriers on Physical and Antioxidant Properties of Lemongrass Leaf Extract Powder

This research was conducted to identify influences of spray-drying temperatures and carriers on physical and antioxidant properties of lemongrass leaf extract powder. Two variables including: inlet temperatures (110 °C, 120 °C, 130 °C, 140 °C and 150 °C) and carriers (Gum Arabic, Maltodextrin and Gum Arabic: Maltodextrin mixture) were studied. Loose density, moisture content, solubility, total phenolic content (TPC), total flavonoid content (TFC) and antioxidant capacity of the obtained powder were analyzed. Overall, moisture content, TPC and TFC were reduced; however, loose density, solubility and antioxidant capacity were enhanced when temperature increased. Among all powder samples, the one produced at 110 °C had the highest TPC (3.02 mg GAE/100 g DW) and TFC (541.82 mg CE/100 g DW) compared to the others. However, due to high moisture content, which is not suitable for the shelf life of powder product, this condition cannot be recommended as a favorable condition for lemongrass powder manufacturing. The powder samples produced by mixing with Maltodextrin at 130 °C retained the high levels of antioxidant capacity, TFC, TPC and had the highest water-soluble ability and lowest moisture content as compared to the others, matching well with quality requirements for an instant powder product.

A Review on Influence of Spray Drying Process Parameters on the Production of Medicinal Plant Powders

Medicinal plants are used by 80% of the world population as primary health care and the phytomedicine market is growing exponentially. Currently, the production of phytopharmaceuticals with proper efficacy, safety and consistent quality constitutes a relevant challenge. The dried dosage forms of medicinal plants are preferred than liquid presentations because of their higher stability. The spray drying technology is the most employed process to produce dried extracts from medicinal plant liquid extracts. These powders need to meet certain physicochemical (e.g., moisture content, hygroscopicity, particle size, density, the concentration of active ingredients) and mechanical (e.g., flowability and compressibility) properties to be used in a solid pharmaceutical form. In addition, high process yields and good powder quality can be obtained by selecting suitable process parameters: spray drying operating conditions and type/concentration of carriers (drying coadjuvants). The optimal process parameters are strongly affected by the chemical nature of the medicinal plant extract. This review aims to give a general guide to understand the effect of the process parameters on the product properties and process yield. This guideline could help practitioners and researchers to initially select the levels of the process variables to decrease the time and cost of the development stage of medicinal plants powders.

Microencapsulation of Theobroma cacao L. waste extract: optimization using response surface methodology

The cocoa extract (Theobroma cacao L.) has a significant amount of polyphenols (TP) with potent antioxidant activity (AA). This study aims to optimise microencapsulation of the extract of cocoa waste using chitosan and maltodextrin. Microencapsulation tests were performed according to a Box-Behnken factorial design, and the results were evaluated by response surface methodology with temperature, maltodextrin concentration (MD) and extract flowrate (EF) as independent variables, and the fraction of encapsulated TP, TP encapsulation yield, AA, yield of drying and solubility index as responses. The optimum conditions were: inlet temperature of 170 °C, MD of 5% and EF of 2.5 mL/min. HPLC analysis identified epicatechin as the major component of both the extract and microparticles. TP release was faster at pH 3.5 than in water. These results as a whole suggest that microencapsulation was successful and the final product can be used as a nutrient source for aquatic animal feed. Highlights Microencapsulation is optimised according to a factorial design of the Box-Behnken type. Epicatechin is the major component of both the extract and microcapsules. The release of polyphenols from microcapsules is faster at pH 3.5 than in water.

Optimization of a method for preparing solid complexes of essential clove oil with β-cyclodextrins

BACKGROUND

Clove oil (CO) is an aromatic oily liquid used in the food, cosmetics and pharmaceutical industries for its functional properties. However, its disadvantages of pungent taste, volatility, light sensitivity and poor water solubility can be solved by applying microencapsulation or complexation techniques.

RESULTS

Essential CO was successfully solubilized in aqueous solution by forming inclusion complexes with β-cyclodextrins (β-CDs). Moreover, phase solubility studies demonstrated that essential CO also forms insoluble complexes with β-CDs. Based on these results, essential CO-β-CD solid complexes were prepared by the novel approach of microwave irradiation (MWI), followed by three different drying methods: vacuum oven drying (VO), freeze-drying (FD) or spray-drying (SD). FD was the best option for drying the CO-β-CD solid complexes, followed by VO and SD.

CONCLUSION

MWI can be used efficiently to prepare essential CO-β-CD complexes with good yield on an industrial scale. © 2016 Society of Chemical Industry.

Green Tea Leaves Extract: Microencapsulation, Physicochemical and Storage Stability Study

Green tea polyphenols have been reported to possess many biological properties. Despite the many potential benefits of green tea extracts, their sensitivity to high temperature, pH and oxygen is a major disadvantage hindering their effective utilization in the food industry. Green tea leaves from the Cameron Highlands Malaysia were extracted using supercritical fluid extraction (SFE). To improve the stability, green tea extracts were encapsulated by spray-drying using different carrier materials including maltodextrin (MD), gum arabic (GA) and chitosan (CTS) and their combinations at different ratios. Encapsulation efficiency, total phenolic content and antioxidant capacity were determined and were found to be in the range of 71.41%–88.04%, 19.32–24.90 (g GAE/100 g), and 29.52%–38.05% respectively. Further analysis of moisture content, water activity, hygroscopicity, bulk density and mean particles size distribution of the microparticles were carried out and the results ranged from; 2.31%–5.11%, 0.28–0.36, 3.22%–4.71%, 0.22–0.28 g/cm³ and 40.43–225.64 µm respectively. The ability of the microparticles to swell in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) was determined as 142.00%–188.63% and 207.55%–231.77%, respectively. Release of catechin polyphenol from microparticles in SIF was higher comparable to that of SGF. Storage stability of encapsulated catechin extracts under different temperature conditions was remarkably improved compared to non-encapsulated extract powder. This study showed that total catechin, total phenolic content (TPC) and antioxidant activity did not decrease significantly (p ≥ 0.05) under 4 °C storage conditions. The half-life study results were in the range of 35–60, 34–65 and 231–288 weeks at storage temperatures of 40 °C, 25 °C and 4 °C respectively, therefore, for improved shelf-life stability we recommend that microparticles should be stored at temperatures below 25 °C.