Effects of the spray-drying temperatures on the physiochemical properties of an encapsulated bitter melon aqueous extract powder

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.

Microencapsulation of Hibiscus sabdariffa L. extract using porous starch and gum Arabic: Optimized process, characterization, stability, and simulated gastrointestinal conditions

Hibiscus extract exhibits considerable antioxidant activity and a high anthocyanin content, which suggesting potential health benefits. However, these compounds are highly susceptible to environmental factors. The aim of this study was to establish the optimal conditions for the encapsulation of Hibiscus sabdariffa extract (HSE) using mixed porous maize starch-gum Arabic to enhance the stability of bioactive compounds under accelerated aging conditions. Response surface methodology (RSM) was used to optimize microencapsulation conditions through spray drying. The optimal conditions for microencapsulation of HSE by RSM were determined to be 126 °C at the inlet temperature (IT) and 8.5 % at the total solid content (TSC). Using these conditions, the amount of bioactive compounds in optimized microcapsules (OMs) was 2368 mg GAE/100 g, 694 mg QE/100 g, and 930 mg EC3G/100 g, of phenolic compounds, flavonoids, and anthocyanin, respectively. The release rate of anthocyanins during in vitro digestion was more effectively regulated in the OM sample, which retained up to 40 % of anthocyanins compared with 10 % in the HSE. The experimental values in this study exhibit high assertiveness, which renders the optimization model technologically and financially viable for the encapsulation of bioactive compounds with potential use in the food and pharmaceutical industries.

Effects of wall materials on the physicochemical properties of spray-dried bitter gourd (Momordica charantia L.) powders

Bitter gourd has numerous health-promoting effects on the human body. However, its use has been greatly limited due to its poor acceptance by consumers, resulting from its strong bitterness. This study investigated the effects of five wall materials, namely, soybean protein isolate, gum arabic, maltodextrin, resistant starch, and a soybean lecithin calcium caseinate mixture, on the physicochemical properties of spray-dried bitter gourd powders. The results showed that all five wall materials reduced the moisture content, water activity, browning degree, agglomeration, and bitterness of the spray-dried bitter gourd powder. Maltodextrin was found to be the most effective at reducing water activity, while soybean protein isolate was best at protecting the colour, and the soybean lecithin calcium caseinate mixture was best at reducing hygroscopicity and masking bitterness. Additionally, all five wall materials improved the preservation of flavonoids, saponins, and vitamin C, with soybean protein isolate being the most effective in improving the total flavonoid retention ratio and the soybean lecithin calcium caseinate mixture being the best in improving the retention ratios of total saponins and vitamin C. The spray-dried bitter gourd powder prepared with soybean protein isolate had the highest antioxidant activity and α-glucosidase inhibitory activity. These results are significant for understanding the relationship between wall materials and the physicochemical properties of spray-dried powder. Additionally, these materials provide bitter gourd product manufacturers with useful guidance for producing high-quality products. Furthermore, the results could provide useful insights for processing fruits with similar product characteristics, thus contributing to the enrichment of food processing knowledge.

Characterization of microencapsulated powders rich in saponins from cocoa pod husk (Theobroma cacao L.) and medicinal plant an xoa (Helicteres hirsuta Lour.)

Cocoa pod husk (CPH) is a major residue of cocoa processing industry, while medicinal plant H. hirsuta is used for treatment of malaria and diabetes mellitus in folk medicine. This study aimed to produce microencapsulated powders from saponin-enriched CPH and H. hirsuta extracts and assess their physicochemical, phytochemical, antioxidant, and α-glucosidase inhibition properties. The findings show that the microencapsulated powders were achieved diserable physicochemical properties (moisture of 3.22-4.76 %, water activity of 0.43-0.46, water solubility index of 74.18-88.77 %, particle size of 254.2-719.7 nm, and zeta potential from -6.97 to -15.1 mV). The phytochemical content of microencapsulated CPH powders gained at high levels (total saponin content of 151.87-193.46 mg EE/g DS, total flavonoid content of 33.80-46.05 mg CE/g DS), total alkaloid content of 15.20-24.23 mg AA/g DS, and total phenolic content of 5.41-6.49 mg GAE/g DS). The antioxidant potential of microencapsulated CPH powders using ARSC and FRAP assays was 15.51-18.20 and 9.61-11.89 mg TE/g DS, respectively, while their α-glucosidase inhibition capacity at 100 μg/mL was found at 51.74-52.16 %. The phytochemical content (except total alkaloid content), antioxidant, and α-glucosidase inhibitory potential of microencapsulated CPH powders were smaller than those of microencapsulated H. hirsuta and combined powders. This study reveals that the microencapsulated CPH and H. hirsuta powders were prospective in reducing hyperglycemia activity. Therefore, this study provided an evidence for further application of CPH and H. hirsuta plant for functional food development.

Optimization of Hypericum Perforatum Microencapsulation Process by Spray Drying Method

Hypericum perforatum (HP) contains valuable and beneficial bioactive compounds that have been used to treat or prevent several illnesses. Encapsulation technology offers protection of the active compounds and facilitates to expose of the biologically active compounds in a controlled mechanism. Microcapsulation of the hydroalcoholic gum arabic and maltodextrin have hot been used as wall materials in the encapsulation of HP extract. Therefore, the optimum microencapsulation parameters of Hypericum perforatum (HP) hydroalcoholic extract were determined using response surface methodology (RSM) for the evaluation of HP extract. Three levels of three independent variables were screened using the one-way ANOVA. Five responses were monitored, including total phenolic content (TPC), 2,2-Diphenyl-1-picrylhydrazyl (DPPH), carr index (CI), hausner ratio (HR), and solubility. Optimum drying conditions for Hypericum perforatum microcapsules (HPMs) were determined: 180 °C for inlet air temperature, 1.04/1 for ratio of maltodextrin to gum arabic (w/w), and 1.98/1 for coating to core material ratio (w/w). TPC, antioxidant activity, CI, HR, and solubility values were specified as 316.531 (mg/g GAE), 81.912%, 6.074, 1.066, and 35.017%, respectively, under the optimized conditions. The major compounds of Hypericum perforatum (hypericin and pseudohypericin) extract were determined as 4.19 μg/g microcapsule and 15.09 μg/g microcapsule, respectively. Scanning electron microscope (SEM) analysis revealed that the mean particle diameter of the HPMs was 20.36 µm. Based on these results, microencapsulation of HPMs by spray drying is a viable technique which protects the bioactive compounds of HP leaves, facilitating its application in the pharmaceutical, cosmetic, and food industries.

Effects of cluster dextrin encapsulation on the properties and antioxidant stability of fractionated Riceberry protein hydrolysate powder prepared by bromelain

In this work, the biological properties of fractionated Riceberry bran protein hydrolysate obtained by ultrafiltration (URBPH) were evaluated and the possibility of using cluster dextrin to produce hydrolysate powder by spray-drying was investigated. Fractionation into peptides < 3 kDa was observed to improve antioxidant activity. URBPH < 3 kDa was then freeze-dried (FD-URBPH) and spray-dried (SD-URBPH) at different inlet air temperatures of 100-160 °C. The water solubility and antioxidant activity of FD-URBPH were higher than those of SD-URBPH. Nevertheless, encapsulation of hydrolysate with 10% cluster dextrin and an inlet temperature of 120 °C was also successful in maintaining protein qualities, which showed high 2,2'-azino-bis 3-ethylbenzthiazoline-6-sulfonic (ABTS•+) scavenging activity (89.14%) and water solubility index (92.49%) and low water activity (aw = 0.53). Moreover, encapsulation preserved the antioxidant activity of peptides during gastrointestinal digestion better than the free form. URBPH and its spray-dried microcapsules could be used as bioactive ingredients in functional drinks or foods.

Optimization of the Spray-Drying Encapsulation of Sea Buckthorn Berry Oil

The aim of this study was to evaluate the effect of spray-drying parameters on the physicochemical properties of encapsulated sea buckthorn berry oil. Different carriers (gum arabic, β-cyclodextrin, and their mixture (1:1, w/w)), inlet air temperatures (120, 150, and 180 °C), and carrier-to-oil ratios (2, 3, and 4, w/w) were evaluated. The obtained powders were characterized in terms of the product yield (36.79-64.60%), encapsulation efficiency (73.08-93.18%), moisture content (0.23-3.70%), hygroscopicity (1.5-7.06 g/100 g), solubility (19.55-74.70%), bulk density (0.25-0.44 g/L), total carotenoid content (mg/100 g dm), and antioxidant capacity (871.83-1454.39 μmol TE/100 g dm). All physicochemical properties were significantly affected by the carrier-to-oil ratio and inlet air temperature. Higher carrier-to-oil ratios increased the product yield, encapsulation efficiency, solubility, and bulk density and decreased the powder hygroscopicity. Elevating the drying temperatures during spray drying also increased the product yield, encapsulation efficiency, and solubility, while it decreased the powder moisture content, total carotenoid content, and antioxidant capacity. Based on the physicochemical properties, the use of β-cyclodextrin as a carrier, a drying temperature of 120 °C, and a carrier-to-oil ratio of 4 were selected as optimal conditions for the production of sea buckthorn berry oil powder. The obtained powder is a valuable material for a wide range of applications in the food and nutraceutical industries.

A New Functional Food Ingredient Obtained from Aloe ferox by Spray Drying

Aloe mucilages of Aloe ferox (A. ferox) and Aloe vera (A. vera) were spray-dried (SD) at 150, 160 and 170 °C. Polysaccharide composition, total phenolic compounds (TPC), antioxidant capacity and functional properties (FP) were determined. A. ferox polysaccharides were comprised mainly of mannose, accounting for >70% of SD aloe mucilages; similar results were observed for A. vera. Further, an acetylated mannan with a degree of acetylation >90% was detected in A. ferox by ¹H NMR and FTIR. SD increased the TPC as well as the antioxidant capacity of A. ferox measured by both ABTS and DPPH methods, in particular by ~30%, ~28% and ~35%, respectively, whereas in A. vera, the antioxidant capacity measured by ABTS was reduced (>20%) as a consequence of SD. Further, FP, such as swelling, increased around 25% when A. ferox was spray-dried at 160 °C, while water retention and fat adsorption capacities exhibited lower values when the drying temperature increased. The occurrence of an acetylated mannan with a high degree of acetylation, together with the enhanced antioxidant capacity, suggests that SD A. ferox could be a valuable alternative raw material for the development of new functional food ingredients based on Aloe plants.

Optimization of spray drying process parameters for the food bioactive ingredients

Spray drying (SD) is one of the most important thermal processes used to produce different powders and encapsulated materials. During this process, quality degradation might happen. The main objective of applying optimization methods in SD processes is maximizing the final nutritional quality of the product besides sensory attributes. Optimization regarding economic issues might be also performed. Applying optimization approaches in line with mathematical models to predict product changes during thermal processes such as SD can be a promising method to enhance the quality of final products. In this review, the application of the response surface methodology (RSM), as the most widely used approach, is introduced along with other optimization techniques such as factorial, Taguchi, and some artificial intelligence-based methods like artificial neural networks (ANN), genetic algorithms (GA), Fuzzy logic, and adaptive neuro-fuzzy inference system (ANFIS). Also, probabilistic methods such as Monte Carlo are briefly introduced. Some recent case studies regarding the implementation of these methods in SD processes are also exemplified and discussed.

Microencapsulation of steroidal saponins from agave sap concentrate using different carriers in spray drying

Concentrated agave sap is a product with in vivo proven hypocholesterolemic and hypoglycemic activities, as well as in vitro anticancer potential. In the present work, a factorial design was used to determine the suitable drying conditions of concentrated agave by studying the effect of inlet temperature (150 °C, 180 °C and 210 °C) and the type of carrier agent (maltodextrin, hydroxypropyl methylcellulose, guar gum and xanthan gum). The response variables for each treatment were the product recovery and microencapsulated saponins. Further characterization of concentrated agave powders was performed: solubility in water, hygroscopicity, moisture content, tap density, bulk density, Carr's index followability and morphology by scanning electron microscopy analysis. The hydroxypropyl methylcellulose proved to improve physicochemical properties and enhance product yield, using 210 °C inlet temperature and a mix of carrier agents of maltodextrin/hydroxypropyl methylcellulose/xanthan gum at 50/48.5/1.5 (w/w/w) proportion exhibited the highest saponin recovery of 53.81%. Moreover, different carrier agents in powders revealed two shapes, regular spherical shape with smooth surface and collapsed shapes. The use of polymers excipients helped to decrease the stickiness of the desired product and enhanced the powder stability and microencapsulation of the steroidal saponins.

Fruit Juice Industry Wastes as a Source of Bioactives

Food processing sustainability, as well as waste minimization, are key concerns for the modern food industry. A significant amount of waste is generated by the fruit juice industry each year. In addition to the economic losses caused by the removal of these wastes, its impact on the environment is undeniable. Therefore, researchers have focused on recovering the bioactive components from fruit juice processing, in which a great number of phytochemicals still exist in the agro-industrial wastes, to help minimize the waste burden as well as provide new sources of bioactive compounds, which are believed to be protective agents against certain diseases such as cardiovascular diseases, cancer, and diabetes. Although these wastes contain non-negligible amounts of bioactive compounds, information on the utilization of these byproducts in functional ingredient/food production and their impact on the sensory quality of food products is still scarce. In this regard, this review summarizes the most recent literature on bioactive compounds present in the wastes of apple, citrus fruits, berries, stoned fruits, melons, and tropical fruit juices, together with their extraction techniques and valorization approaches. Besides, on the one hand, examples of different current food applications with the use of these wastes are provided. On the other hand, the challenges with respect to economic, sensory, and safety issues are also discussed.

A comprehensive review on bitter gourd (Momordica charantia L.) as a gold mine of functional bioactive components for therapeutic foods

Bitter gourd is a tropical wine grown mainly in India, China and South East Asia. The plant is cultivated mainly for its fruit part which is edible. Bitter gourd is unaccepted widely due to its bitter taste. Nevertheless, the fruit is a source of several key nutrients. The plant, as a whole contains, more than 60 phyto-medicines that are active against more than 30 diseases, including cancer and diabetes. Currently, the incorporation of the bioactive compounds isolated from bitter gourd into functional foods and beverages finds a new horizon. Nanoencapsulation and novel green extraction methods can be employed to improve the yield and quality of extracted compounds and their stability while incorporation into food products. The present review is an attempt to throw light to nutritional aspects, various bioactive compounds present and important nutraceutical properties of the bitter gourd plant in detail.

Graphical Abstract

Hot Air-Assisted Radio Frequency (HARF) Drying on Wild Bitter Gourd Extract

Wild bitter gourd (Momordica charantia L. var. abbreviata S.) is a kind of Chinese herbal medicine and is also a vegetable and fruit that people eat daily. Wild bitter gourd has many bioactive components, such as saponin, polysaccharide, and protein, and the extract is used to adjust blood sugar in patients with diabetes. The objective of this study was to investigate simultaneous hot air-assisted radio frequency (HARF) drying and pasteurization for bitter gourd extract, and then to evaluate its effects on blood sugar of type II diabetic mice. The results showed that the solid–liquid ratio of the wild bitter gourd powder to water was 1:10 and it was extracted using focused ultrasonic extraction (FUE) for only 10 min with 70 °C water. Then, 1 kg of concentrated bitter gourd extract was mixed with soybean fiber powder at a ratio of 2:1.1. It was dried by HARF, and the temperature of the sample could reach above 80 °C in only 12 min to simultaneously reduce moisture content (wet basis) from 58% to 15% and achieve a pasteurization effect to significantly reduce the total bacterial and mold counts. Type II diabetic mice induced by nicotinamide and streptozocin (STZ) for two weeks and then were fed four-week feeds containing 5% RF-dried wild gourd extract did not raise fasting blood glucose. Therefore, the dried powder of wild bitter gourd extracts by HARF drying had a hypoglycemic effect.

Optimization of spray drying process parameters for production of Japanese apricot (Prunus mume Sieb. et Zucc.) juice powder

Optimization of spray drying conditions namely inlet air temperature (IAT) and maltodextrin (MD) concentration was utilized by response surface methodology for Japanese apricot (Prunus mume Sieb. et Zucc.) juice powder (JAJP) manufacture. Drying yield, moisture content, water solubility index (WSI), bulk density, color, pH, total phenol content (TPC), total flavonoid content (TFC), vitamin C content, and DPPH radical-scavenging activity of juice powder were measured. Moisture content, vitamin C content, color, DPPH radical-scavenging activity, pH, and bulk density were greatly influenced by IAT, but drying yield, WSI, TPC, and TFC were only significantly affected by MD concentration. The spray drying condition was optimum at 10% MD concentration and 165.8 °C IAT. The properties of juice powder were 37.50% drying yield, 4.81% moisture content, 134.25 mg/g vitamin C content, 27.52% DPPH radical-scavenging activity, 2.78 pH, 89.15% WSI, 232.856 μg GAE/100 g TPC, 404.66 μg CE/100 g TFC, and 0.49 bulk density.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-00950-8.

The apoptosis mechanisms of HepG2 cells induced by bitter melon seed

Liver cancer is one of the leading causes of cancer-related deaths in the world. Bitter melon seed (BMS) is well known for anti-inflammatory and anticancer properties. MicroRNA-421 (miR-421) is considered as a regulator of cancer initiation, tumor metastasis, and progression, interfering with transcription of the mRNAs responsible for the cancer pathogenesis. HepG2 cells were treated with BMS water extract (BMSW) for 24 hr, and the IC₅₀ was 586.27 ± 0.07 µg/ml. The ROS, mitochondrial membrane potential, the protein expression, and the nuclear fragmentation after the treatment of BMSW were respectively detected. The increase of ROS resulted in the decrease of mitochondrial membrane potential, which induced the apoptosis of cells subsequently. BMSW inhibited the proliferation of HepG2 cells by blocking cell cycle in the S phase and influenced the nuclei and the expression of protein, leading to cellular laxity and apoptosis. The expression level of miR-421 in HepG2 was distinctly down-regulated by 13.74 fold with 600 µg/ml of BMSW. Comprehensive microarray and RT-PCR analysis identified six putative target genes of miR-421 (GADD45B, DUSP6, DUSP3, DUSP10, CASP3, and CAPN2). The relationships of DUSP6, CASP3, and miR-421 were further confirmed by miR-421 mimics/inhibitor transfection by RT-PCR and western blot. The CASP3 was identified as target gene of miR-421. BMSW induced the apoptosis of HepG2 cell by regulating miR-421 and CASP3. PRACTICAL APPLICATIONS: Hepatocellular carcinoma (HCC) is a malignant tumour with the fourth highest mortality rate in the world. Bitter melon seed (BMS) as edible and medical food has significant anticancer activity. Our study indicated the anticancer mechanisms of BMS and provided the scientific basis for the application of BMS in healthy or novel functional foods. BMS can be used as dietary supplements or nutritional fortifiers to improve the survival status of patients with liver cancer due to safety and effectiveness.

Laboratory-Scale Preparation and Characterization of Dried Extract of Muirapuama (Ptychopetalumolacoides Benth) by Green Analytical Techniques

This work reports on the preparation of a drying process from the ethanolic extract of Muirapuama and its characterization through green analytical techniques. The spray-drying processes were performed by using ethanolic extract in a ratio of 1:1 extract/excipient and 3² factorial design. The properties of dried powder were investigated in terms of total flavonoid content, moisture content, powder yield, and particle size distribution. An analytical eco-scale was applied to assess the greenness of the developed protocol. Ultra-high performance liquid chromatography (UHPLC)with reduced solvent consumption in the analysis was compared to the conventional HPLC method. A Fourier transform near-infrared (FT-NIR) spectroscopic method was applied based on the principal component scores for the prediction of extract/excipient mixtures and partial least squares regression model for quantitative analysis. NIR spectroscopy is an economic, powerful, and fast methodology for the detection of excipient in muirapuama dried extracts, generating no residue in the analysis. Scanning electron microscopy (SEM) images showed samples with a higher concentration of excipient, presenting better morphological characteristics and a lower moisture absorption rate. An eco-scale score value of 85 was achieved for UHPLC and 100 was achieved for NIR (excellent green analysis). Above all, these methods are rapid and green for the routine analysis of herbal medicines based on dried extracts.

Microencapsulation of cocoa liquor nanoemulsion with whey protein using spray drying to protection of volatile compounds and antioxidant capacity

The aim of this study was microencapsulated a nanoemulsion of cocoa liquor with whey protein by spray drying, and evaluate the effect of different inlet drying temperatures on the properties of microcapsules. The nanoemulsion showed a particle size of 202.13 nm, PdI of 0.424, and ζ-potential of -25.20 mV. The inlet drying temperature showed differences in physicochemical properties of microcapsules. Microcapsules presented good thermal stability and protection against the melting of cocoa liquor. Microcapsules obtained showed excellent yields of polyphenolic compounds (78-93%), and high retention of volatile compounds, especially of pyrazines. Greater microencapsulation yield of bioactive compounds and retention of volatile compounds was obtained at higher drying temperature (180 °C). Excellent stability of polyphenols content, antioxidant capacity, and volatile compounds of cocoa liquor were observed during storage of the microcapsules at different temperature conditions, indicating the feasibility of this powder for its incorporation into functional foods.

Optimized aqueous extracts of maqui (Aristotelia chilensis) suitable for powder production

The aim of this work was to obtain powders rich in bioactive compounds from maqui berry aqueous extracts by spray drying. First, the process parameters of the maqui aqueous extraction were optimized. The optimal operating conditions were found using an experimental Box-Behnken design with three factors: solvent/fruit ratio (2:1, 3.5:1 and 5:1), extraction temperature (25, 50 and 75 °C) and extraction time (30, 75 and 120 min). Soluble solids content, monomeric anthocyanin content (ACY), total polyphenol content (TPC) and antioxidant capacity in the liquid extracts were analyzed as key responses to find the optimal extraction conditions. Secondly, the best aqueous extract (solvent/fruit ratio = 2:1; extraction temperature = 75 °C and extraction time = 75 min) was subjected to spray drying. The effects of different drying adjuvants (maltodextrin, colloidal silicon dioxide, arabic gum, and microcrystalline cellulose) on the powders flow properties, the process yield (PY), the bioactive compounds content and the superficial color were studied. The product based on colloidal silicon dioxide presented the best powder properties: excellent flowability (α: 30.4 ± 0.7°, CI: 8.0 ± 1.7%), adequate moisture content (4.9 ± 0.3%), very good PY (70 ± 1%), high ACY (1528 ± 41 mg cy-3glu/100 g of powder) and TPC (3936 ± 132 mg GAE/100 g of powder), and a purple hue. This maqui powder offers valuable properties that allow its use, among other applications, as a functional ingredient, natural colorant and nutraceutical product.

Optimised Extraction of Trypsin Inhibitors from Defatted Gac (Momordica cochinchinensis Spreng) Seeds for Production of a Trypsin Inhibitor‐Enriched Freeze Dried Powder

The seeds of the Gac fruit, Momordica cochinchinensis Spreng, are rich in trypsin inhibitors (TIs) but their optimal extraction and the effects of freeze drying are not established. This study aims to (1) compare aqueous solvents (DI water, 0.1 M NaCl, 0.02 M NaOH and ACN)/water/FA, 25:24:1) for extracting TIs from defatted Gac seed kernel powder, (2) to optimise the extraction in terms of solvent, time and material to solvent ratio and (3) to produce a TI-enriched freeze-dried powder (FD-TIP) with good characteristics. Based on the specific TI activity (TIA), the optimal extraction was 1 h using a ratio of 2.0 g of defatted powder in 30 mL of 0.05 M NaCl. The optimisation improved the TIA and specific TIA by 8% and 13%, respectively. The FD-TIP had a high specific TIA (1.57 ± 0.17 mg trypsin/mg protein), although it also contained saponins (43.6 ± 2.3 mg AE/g) and phenolics (10.5 ± 0.3 mg GAE/g). The FD-TIP was likely stable during storage due to its very low moisture content (0.43 ± 0.08%) and water activity (0.18 ± 0.07) and its ability to be easily reconstituted in water due to its high solubility index (92.4 ± 1.5%). Therefore, the optimal conditions for the extraction of TIs from defatted Gac seed kernel powder followed by freeze drying gave a high quality powder in terms of its highly specific TIA and physical properties.

Advances in Spray-Drying Encapsulation of Food Bioactive Ingredients: From Microcapsules to Nanocapsules

Many natural food bioactive ingredients are sensitive to processing and environmental conditions and thus it is necessary to improve their stability to create products with long shelf lives. Encapsulation by spray drying is a widely used economical strategy to tackle this issue, and many scientists and manufacturers are using it in their research, development, and production activities. In this review, the spray-drying process is described, as are recent trends in the encapsulation of fish oils, essential fatty acids, probiotics, phenolic compounds, and natural food colorants. The formulation and process conditions used in previous research and the results obtained are tabulated. Also, new innovations in bioactive encapsulation using nano-spray drying are described.

Development of Health Products from Natural Sources

BioActive Compounds (BACs) recovered from food or food by-product matrices are useful in maintaining well being, enhancing human health, and modulating immune function to prevent or to treat chronic diseases. They are also generally seen by final consumers as safe, non-toxic and environment-friendly. Despite the complex process of production, chemical characterization, and assessment of health effects, BACs must also be manufactured in stable and bioactive ingredients to be used in pharmaceutical, food and nutraceutical industry. Generally, vegetable derivatives occur as sticky raw materials with pervasive smell and displeasing flavor. Also, they show critical water solubility and dramatic stability behavior over time, involving practical difficulties for industrial use. Therefore, the development of novel functional health products from natural sources requires the design of a suitable formulation to delivery BACs at the site of action, preserve stability during processing and storage, slow down the degradation processes, mask lousy tasting or smell, and increase the bioavailability, while maintaining the BACs functionality. The present review focuses on human health benefits, BACs composition, and innovative technologies or formulation approaches of natural ingredients from some selected foods and by-products from industrial food transformations.

Microencapsulated betacyanin from colored organic quinoa (Chenopodium quinoa Willd.): optimization, physicochemical characterization and accelerated storage stability

BACKGROUND

Betalains are presently gaining popularity as pigments for use as natural colorants and/or bioactive compounds in functional foods. Quinoa (Chenopodium quinoa Willd.) has been recognized as an extremely nutritious grain and has recently been found to be a novel and good betalain source. Microencapsulation has been studied as a protected-delivery procedure to stabilize betalains. There are no studies about microencapsulation of betacyanins extracted from quinoa using spray-drying technology.

RESULTS

Optimal microencapsulation was obtained at a drying temperature of 165 °C, a rotameter air flow rate of 47 mm (940 L h^-1 ) and 10% w/w maltodextrin, which produced good encapsulation yield (58.1%) and efficiency (100%). Optimized maltodextrin-betacyanin microcapsules (diameter 4.4 μm) have low moisture (1.64 ± 0.08%) and water activity (0.127 ± 0.006), a betacyanin content of 0.1995 ± 0.0017 g kg^-1 and saponin content <0.080 mg kg^-1 . The oxygen consumption rate by betacyanin was -4.373 × 10^-5 bar min^-1 at 80 °C and -6.67 × 10^-5 bar min^-1 at 90 °C, which was accompanied by fading of the color.

CONCLUSION

Microencapsulated betacyanin was optimized by response surface methodology, and its stability was measured under accelerated conditions by oxygen consumption. Microencapsulations contain betacyanin and low saponin concentration, which might confer unique health-promoting properties. © 2018 Society of Chemical Industry.

Bioactive Composition, Antioxidant Activity, and Anticancer Potential of Freeze-Dried Extracts from Defatted Gac (Momordica cochinchinensis Spreng) Seeds

Background: Gac (Momordica cochinchinensis Spreng) seeds have long been used in traditional medicine as a remedy for numerous conditions due to a range of bioactive compounds. This study investigated the solvent extraction of compounds that could be responsible for antioxidant activity and anticancer potential. Methods: Defatted Gac seed kernel powder was extracted with different solvents: 100% water, 50% methanol:water, 70% ethanol:water, water saturated butanol, 100% methanol, and 100% ethanol. Trypsin inhibitors, saponins, phenolics, and antioxidant activity using the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the ferric reducing antioxidant power (FRAP) assays; and anticancer potential against two melanoma cancer cell lines (MM418C1 and D24) were analysed to determine the best extraction solvents. Results: Water was best for extracting trypsin inhibitors (581.4 ± 18.5 mg trypsin/mg) and reducing the viability of MM418C1 and D24 melanoma cells (75.5 ± 1.3 and 66.9 ± 2.2%, respectively); the anticancer potential against the MM418C1 cells was highly correlated with trypsin inhibitors (r = 0.92, p < 0.05), but there was no correlation between anticancer potential and antioxidant activity. The water saturated butanol had the highest saponins (71.8 ± 4.31 mg aescin equivalents/g), phenolic compounds (20.4 ± 0.86 mg gallic acid equivalents/g), and antioxidant activity, but these measures were not related to anticancer potential. Conclusions: Water yielded a Gac seed extract, rich in trypsin inhibitors, which had high anticancer potential against two melanoma cell lines.

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.

Effect of Solvents and Extraction Methods on Recovery of Bioactive Compounds from Defatted Gac (Momordica cochinchinensis Spreng.) Seeds

Gac (Momordica cochinchinensis Spreng.) seeds contain bioactive compounds with medicinal properties. This study aimed to determine a suitable solvent and extraction technique for recovery of important compounds, namely, trypsin inhibitors, saponins, and phenolics. The antioxidant capacity and total solids of derived extracts were also measured. Water with conventional extraction method gave the highest value of trypsin inhibitor activity (118.45 ± 4.90 mg trypsin g−1) while water-saturated n-butanol and methanol extracts were characterized by their highest content of saponins (40.75 ± 0.31 and 38.80 ± 2.82 mg AE g−1, respectively). Aqueous extract with microwave assistance achieved the highest phenolics (3.18 ± 0.04 mg GAE g−1). As a measure of antioxidant capacity, the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay gave highest value to the aqueous microwave extract (23.56 ± 0.82 μmol TE g−1) while the ferric reducing antioxidant power (FRAP) assay gave highest values to water-saturated n-butanol and 70% ethanol extracts (5.25 ± 0.04 and 4.71 ± 0.39 μmol TE g−1, respectively). The total solids value was highest using water with microwave assistance (141.5 g kg−1) while ultrasound treatment did not improve any extractions. Therefore, trypsin inhibitors are suitably recovered using water while water-saturated n-butanol or methanol is for saponins, both using a conventional method. Microwave extraction is suitable for phenolics recovery. These conditions are recommended for an efficient recovery of bioactive compounds from defatted Gac seeds.

Effect of drying procedures on the physicochemical properties and antioxidant activities of polysaccharides from Crassostrea gigas

Crassostrea gigas polysaccharides (CGP) were obtained by different drying methods: freeze-drying (FD), spray-drying (SD) or rotary evaporation-drying (RED). The physicochemical properties of CGP were evaluated on the basis of polysaccharide content, protein content, color characteristics, FT-IR spectroscopy, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Antioxidant activities were researched three different free radicals, including DPPH free radicals, ABTS free radicals and reducing power. The results demonstrated that FDCGP, SDCGP and REDCGP have different physicochemical properties and antioxidant activities. Contrasted with FDCGP and REDCGP, SDCGP exhibited stronger antioxidant abilities. Therefore, considering the polysaccharides appearances and antioxidant activities, the spray drying method is a decent selection for the preparation of such polysaccharides, and it should be selected for application in the food industry.

Melatonin-loaded chitosan/Pluronic® F127 microspheres as in situ forming hydrogel: An innovative antimicrobial wound dressing

The aim of this study was to develop melatonin-loaded chitosan based microspheres as dry powder formulation suitable for wound dressing, rapidly forming hydrogel in contact with wound exudate. Microspheres were produced by spray-drying method. Fractional factorial design was employed to elucidate the effect of formulation and process parameters (feed flow rate, inlet air temperature, chitosan concentration, chitosan/melatonin ratio and chitosan/Pluronic® F127 ratio) on the product characteristics related to process applicability (production yield, entrapment efficiency and product moisture content) and microsphere performance in biological environment (microsphere mean diameter and surface charge). Appropriate formulation and process parameters for the establishment of efficient drying process resulting in fine-tuned chitosan and chitosan/Pluronic® F127 microspheres (efficient melatonin encapsulation, small diameter positive surface charge and low moisture content) were identified. Microspheres were characterized by appropriate flowability and high rate and extent of fluid uptake. Incorporation of Pluronic® F127 in microsphere matrix resulted in high melatonin amorphization and consequent higher melatonin release rate. Entrapment of melatonin in chitosan/Pluronic® F127 microspheres has potentiated chitosan antimicrobial activity against Staphylococcus aureus and five clinical isolates S. aureus MRSA strains. Microspheres were shown to be biocompatible with skin keratinocytes and fibroblasts at concentrations relevant for antimicrobial activity against planktonic bacteria.