Encapsulation of Citrus By-Product Extracts by Spray-Drying and Freeze-Drying Using Combinations of Maltodextrin with Soybean Protein and ι-Carrageenan

Optimization Model of Phenolics Encapsulation Conditions for Biofortification in Fatty Acids of Animal Food Products

The nutritional quality of animal products is strongly related to their fatty acid content and composition. Nowadays, attention is paid to the possibility of producing healthier foods of animal origin by intervening in animal feed. In this field, the use of condensed tannins as dietary supplements in animal nutrition is becoming popular due to their wide range of biological effects related, among others, to their ability to modulate the rumen biohydrogenation and biofortify, through the improvement of the fatty acids profile, the derivate food products. Unfortunately, tannins are characterized by strong astringency and low bioavailability. These disadvantages could be overcome through the microencapsulation in protective matrices. With this in mind, the optimal conditions for microencapsulation of a polyphenolic extract rich in condensed tannins by spray drying using a blend of maltodextrin (MD) and gum Arabic (GA) as shell material were investigated. For this purpose, after the extract characterization, through spectrophotometer assays and ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, a central composite design (CCD) was employed to investigate the combined effects of core:shell and MD:GA ratio on the microencapsulation process. The results obtained were used to develop second-order polynomial regression models on different responses, namely encapsulation yield, encapsulation efficiency, loading capacity, and tannin content. The formulation characterized by a core:shell ratio of 1.5:5 and MD:GA ratio of 4:6 was selected as the optimized one with a loading capacity of 17.67%, encapsulation efficiency of 76.58%, encapsulation yield of 35.69%, and tannin concentration of 14.46 g/100 g. Moreover, in vitro release under varying pH of the optimized formulation was carried out with results that could improve the use of microencapsulated condensed tannins in animal nutrition for the biofortification of derivates.

Functionalization of whey protein isolate fortified with blackcurrant concentrate by spray-drying and freeze-drying strategies

A solution of whey protein isolate was combined with blackcurrant concentrate via spray-drying and freeze-drying techniques separately to develop novel protein ingredients, (SWB and FWB). Chemical compositions, colour profiles, total anthocyanin content and encapsulation efficacy of the protein ingredients were evaluated. An in vitro digestion process was employed to observe the changes in total phenolic content, antioxidant activity, and predictive in vitro glycaemic response of the protein ingredients. The half maximal inhibitory concentration (IC₅₀) towards α-Amylase, and a molecular docking study on the interactions of α-Amylase with anthocyanins, were both performed to investigate the potential mechanisms of hypoglycaemic properties of these protein ingredients. The protein contents of SWB and FWB were 67.94 ± 0.47% and 68.16 ± 0.77%, respectively. Blackcurrant concentrate significantly (p < 0.001) changed the colour profiles of whey protein isolate. SWB obtained a higher total phenol content (3711.28 ± 4.36 μg/g), total anthocyanin content (85390.80 ± 162.81 μg/100 g), and greater encapsulation efficacy (99.64 ± 0.16%) than those of FWB (3413.03 ± 20.60 μg/g, 64230.24 ± 441.08 μg/100 g, and 95.43 ± 0.14%, respectively). Total phenolic content and antioxidant activities of SWB and FWB decreased after the in vitro digestion. The reducing sugar released during the in vitro digestion from SWB and FWB decreased compared with their corresponding controls (SWC and FWC). FWB (IC₅₀ = 73.46 μg/mL) exhibited stronger α-Amylase inhibitory activity than SWB (IC₅₀ = 81.46 μg/mL). Different anthocyanins differed from binding affinities to bind with the active sites of α-Amylase via formation of hydrogen bonds. This study suggested whey protein encapsulated-blackcurrant concentrate might be an innovative food product with improved nutritional profiles. Both spray- and freeze-drying are potential options to this encapsulation.

Preparation and Characterization of a New Polymeric Multi-Layered Material Based K-Carrageenan and Alginate for Efficient Bio-Sorption of Methylene Blue Dye

The current study highlights a novel bio-sorbent design based on polyelectrolyte multi-layers (PEM) biopolymeric material. First layer was composed of sodium alginate and the second was constituted of citric acid and k-carrageenan. The PEM system was crosslinked to non-woven cellulosic textile material. Resulting materials were characterized using FT-IR, SEM, and thermal analysis (TGA and DTA). FT-IR analysis confirmed chemical interconnection of PEM bio-sorbent system. SEM features indicated that the microspaces between fibers were filled with layers of functionalizing polymers. PEM exhibited higher surface roughness compared to virgin sample. This modification of the surface morphology confirmed the stability and the effectiveness of the grafting method. Virgin cellulosic sample decomposed at 370 °C. However, PEM samples decomposed at 250 °C and 370 °C, which were attributed to the thermal decomposition of crosslinked sodium alginate and k-carrageenan and cellulose, respectively. The bio-sorbent performances were evaluated under different experimental conditions including pH, time, temperature, and initial dye concentration. The maximum adsorbed amounts of methylene blue are 124.4 mg/g and 522.4 mg/g for the untreated and grafted materials, respectively. The improvement in dye sorption evidenced the grafting of carboxylate and sulfonate groups onto cellulose surface. Adsorption process complied well with pseudo-first-order and Langmuir equations.

Antimicrobial, Shelf-Life Stability, and Effect of Maltodextrin and Gum Arabic on the Encapsulation Efficiency of Sugarcane Bagasse Bioactive Compounds

This study shows the effects of maltodextrins and gum arabic as microencapsulation agents on the stability of sugarcane bagasse extracts and the potential use of the extracts as antimicrobial agents. The bioactive compounds in sugarcane bagasse (SCB) were extracted using 90% methanol and an orbital shaker at a fixed temperature of 50 °C, thereby obtaining a yield of the total phenolic content of 5.91 mg GAE/g. The bioactive compounds identified in the by-product were flavonoids, alkaloids, and lignan (-) Podophyllotoxin. The total phenolic content (TPC), antioxidant activity, and shelf-life stability of fresh and microencapsulated TPC were analyzed. This experiment's optimal microencapsulation can be obtained with a ratio of 0.6% maltodextrin (MD)/9.423% gum arabic (GA). Sugarcane bagasse showed high antioxidant activities, which remained stable after 30 days of storage and antimicrobial properties against E. coli, B. cereus, S. aureus, and the modified yeast SGS1. The TPC of the microencapsulated SCB extracts was not affected (p > 0.05) by time or storage temperature due to the combination of MD and GA as encapsulating agents. The antioxidant and antimicrobial capacities of sugarcane bagasse extracts showed their potential use as a source of bioactive compounds for further use as a food additive or nutraceutical. The results are a first step in encapsulating phenolic compounds from SCB as a promising source of antioxidant agents and ultimately a novel resource for functional foods.

Enhanced Microencapsulation of C-Phycocyanin from Arthrospira by Freeze-Drying with Different Wall Materials

RESEARCH BACKGROUND

C-phycocyanin (C-PC), a water-soluble blue pigment, was extracted from microalgae Arthrospira sp. C-PC could be a good substitute for synthetic pigments with high antioxidant activity. However, C-PC is unstable due to sensitivity to temperature, light, pH and oxygen; therefore, applications of C-PC in food and other products are limited. Microencapsulation of C-PC using freeze-drying is a solution to this problem and is considered a suitable method for drying the heat-sensitive pigment.

EXPERIMENTAL APPROACH

C-phycocyanin was extracted from Arthrospira platensis. C-PC microcapsules were modified by freeze-drying, with maltodextrin and gum Arabic used as microencapsulation wall materials at different fractions from 0 to 100%. The physical properties including moisture content and water activity, solubility, hygroscopicity, bulk density, colour appearance, particle morphology and size distribution of the produced powders were evaluated. Thermal stability and antioxidant activity of freeze-dried microencapsulated C-PC powders were also assessed.

RESULTS AND CONCLUSIONS

Freeze-dried microencapsulated C-PC powders with maltodextrin and gum Arabic as wall materials gave high encapsulation efficiency of around 99%. At higher gum Arabic mass fraction, moisture content decreased and water activity improved. Maltodextrin gave higher solubility of C-PC powders whereas gum Arabic led to a similar colour of C-PC to those without microencapsulation. Freeze-dried microencapsulated C-PC powders were composed of different sized microparticles regardless of the combination of wall materials with amorphous glassy shapes. Thermal stability of encapsulated C-PC increased and also showed high antioxidant properties.

NOVELTY AND SCIENTIFIC CONTRIBUTION

This study demonstrates that the freeze-dried microencapsulated C-PC powders have pigment stability with antioxidant properties and are resistant to high temperatures. Therefore, they may have a potential for the development of microencapsulated C-PC as a functional ingredient with improved colour and bioactive properties. Such a product can be applied in food, cosmetic, biotechnology and nutraceutical industries.

Encapsulation and Degradation Kinetics of Bioactive Compounds from Sweet Potato Peel During Storage

Research background

The aim of this work is to evaluate utilization of sweet potato peel as a source of bioactive compounds. The effect of solvents (acetone and acetone/ethanol mixture) on the extraction efficiency of total carotenoids and phenolics from sweet potato tuber, flesh and peel, and antioxidant activity were investigated. Sweet potato peel extract stood out in terms of antioxidant activity and was chosen for encapsulation by spray and freeze-drying.

Experimental approach

Encapsulation is an effective method to improve phytochemical stability by entrapping the core material with a coating agent. In this study, spray and freeze-drying techniques were applied for improving the stability of bioactive compounds (carotenoids and phenolics) using whey protein as a coating material. The main advantages of the applied techniques over the other encapsulation techniques are simplicity, continuity, effectiveness, availability and applicability.

Results and conclusions

Physicochemical characteristics revealed that spray drying resulted in the formation of lower size particles, better flow properties and encapsulation efficiency of carotenoids. The retention of encapsulated and non-encapsulated bioactive compounds was monitored during storage in daylight and dark conditions. Storage conditions affected the carotenoid retention, whereas higher degradation rate of all samples was observable in daylight. Phenolic compounds exhibited higher retention in all investigated samples. Degradation kinetic parameters suggest the longer shelf life of spray dried encapsulated extract and potent method for stabilization of bioactive ingredients.

Novelty and scientific contribution

This study demonstrates that the spray drying technique and utilization of sweet potato peel have a big potential for the development of functional additives with improved nutritional, colour and bioactive properties.

Freeze-Drying Technique for Microencapsulation of Elsholtzia ciliata Ethanolic Extract Using Different Coating Materials

The present study reports on the encapsulation of Elsholtzia ciliata ethanolic extract by freeze-drying method using skim milk, sodium caseinate, gum Arabic, maltodextrin, beta-maltodextrin, and resistant-maltodextrin alone or in mixtures of two or four encapsulants. The encapsulation ability of the final mixtures was evaluated based on their microencapsulating efficiency (EE) of total phenolic compounds (TPC) and the physicochemical properties of freeze-dried powders. Results showed that the freeze-dried powders produced using two encapsulants have a lower moisture content, but higher solubility, Carr index, and Hausner ratio than freeze-dried powders produced using only one encapsulant in the formulation. The microencapsulating efficiency of TPC also varied depending on encapsulants used. The lowest EE% of TPC was determined with maltodextrin (21.17%), and the highest with sodium caseinate (83.02%). Scanning electron microscopy revealed that freeze-drying resulted in the formation of different size, irregular shape glassy particles. This study demonstrated good mucoadhesive properties of freeze-dried powders, which could be incorporated in buccal or oral delivery dosage forms. In conclusion, the microencapsulation of E. ciliata ethanolic extract by freeze-drying is an effective method to produce new value-added pharmaceutical or food formulations with polyphenols.

Encapsulation of phenolic-rich extract from banana (Musa cavendish) peel

Banana peel, a by-product rich in phenolics and other bioactive compounds, has great potentials as a natural preservative or healthy food ingredient. However, the instability of bioactive compounds derived from banana peel limits their applications, and as such encapsulation is necessary to improve their stability and widen their applications. This study investigated the impact of spray drying conditions and coating materials on the physical, phytochemical, and antioxidant properties of the peel extract to identify the most suitable encapsulation process. The results showed that inlet temperature (ranging from 140 to 180 °C) and feeding rate (3-15 mL/min) did not significantly affect the total phenolic content (TPC) and antioxidant capacity but influenced the moisture content and recovery yield of the powder. The ratio of dry matter in fresh extract-to-coating material (DM-to-CM) (1:1-1:7 (w/w)) did not affect the moisture content. However, it affected the TPC, antioxidant properties, and recovery yield of the powder. Finally, the type of coating materials did not significantly affect TPC and antioxidant properties, but other physical properties, dopamine levels and recovery yield. The most suitable encapsulation conditions were identified as an inlet drying temperature of 150 °C, a feeding rate of 9 mL/min, a ratio of DM-to-CM of 1:1 (w/w), and coating with a combination of maltodextrin M100 and gum acacia. Powder prepared under the most suitable conditions had a spherical shape with a rough surface and had stable TPC under storage conditions of 40 °C for 4 weeks. It also has ideal physical, phytochemical and antioxidant properties and is suitable for further applications.

Antioxidants of Natural Plant Origins: From Sources to Food Industry Applications

In recent years, great interest has been focused on using natural antioxidants in food products, due to studies indicating possible adverse effects that may be related to the consumption of synthetic antioxidants. A variety of plant materials are known to be natural sources of antioxidants, such as herbs, spices, seeds, fruits and vegetables. The interest in these natural components is not only due to their biological value, but also to their economic impact, as most of them may be extracted from food by-products and under-exploited plant species. This article provides an overview of current knowledge on natural antioxidants: their sources, extraction methods and stabilization processes. In addition, recent studies on their applications in the food industry are also addressed; namely, as preservatives in different food products and in active films for packaging purposes and edible coatings.

Application of encapsulated natural bioactive compounds from red pepper waste in yogurt

Aim: The aim of this study was to encapsulate red pepper waste (RPW) bioactives and monitor their stability in yogurt.Methods: RPW extract was encapsulated in whey protein using spray and freeze-drying techniques. Physicochemical characteristics of encapsulates were evaluated, and better encapsulates were used to develop functional yogurt. Retention of bioactives was followed over 21 days of storage, and sensory analyses were assessed.Results: Freeze-dried encapsulates (FDE) showed better characteristics like water activity, moisture content, solubility, flowing and colour properties, and, therefore, incorporated in yogurt. Yogurt with FDE successfully retained carotenoids (71.43%) and caused increasing of polyphenol retention (up to 123.73%). This yogurt exhibited higher sensory and general acceptability scores compared to control sample. The fortification of yogurts had a positive influence on maintaining the initial number of lactic acid bacteria during storage.Conclusion: Freeze drying and utilisation of pepper waste are efficient for functional food development, with improved nutritional, colour and bioactive properties.

Functional Ingredients based on Nutritional Phenolics. A Case Study against Inflammation: Lippia Genus

Epidemiological studies have reported convincing evidence that natural dietary compounds may modify inflammation, it being an important event described in the pathophysiology of age-related infirmity. Among different dietary components, nutritional phenolics have demonstrated links to a lower risk of inflammation in the most common degenerative and chronic diseases. In this way, the healthy potential of phenolics against inflammation and the emergence of new functional ingredients have caused an enhancement of nutraceutical and functional food formulation. The present review focuses on: (a) nutritional phenolics and their effects on inflammation and (b) functional ingredients based on phenolic compounds with anti-inflammatory properties. Furthermore, the emerging interest in health-promoting products by consumers has caused an increase in the demand for functional products and nutraceuticals. Additionally, this review includes a case study of the Lippia genus, which has shown anti-inflammatory effects claiming to be a natural alternative for the management of this physiological disorder. This report is a practical tool for healthcare providers.

Characterization of starch and gum arabic-maltodextrin microparticles encapsulating acacia tannin extract and evaluation of their potential use in ruminant nutrition

OBJECTIVE

The use of tannin extract and other phytochemicals as dietary additives in ruminants is becoming more popular due to their wide biological actions such as in methane mitigation, bypass of dietary protein, intestinal nematode control, among other uses. Unfortunately, some have strong astringency, low stability and bioavailability, and negatively affecting dry matter intake and digestibility. To circumvent these drawbacks, an effective delivery system may offer a promising approach to administer these extracts to the site where they are required. The objectives of this study were to encapsulate acacia tannin extract (ATE) with native starch and maltodextrin-gum arabic and to test the effect of encapsulation parameters on encapsulation efficiency, yield and morphology of the microparticles obtained as well as the effect on rumen in vitro gas production.

METHODS

The ATE was encapsulated with the wall materials, and the morphological features of freeze-dried microparticles were evaluated by scanning electron microscopy. The in vitro release pattern of microparticles in acetate buffer, simulating the rumen, and its effect on in vitro gas production was evaluated.

RESULTS

The morphological features revealed that maltodextrin/gum-arabic microparticles were irregular shaped, glossy and smaller, compared with those encapsulated with native starch, which were bigger, and more homogenous. Maltodextrin-gum arabic could be used up to 30% loading concentration compared with starch, which could not hold the core material beyond 15% loading capacity. Encapsulation efficiency ranged from 27.7%±6.4% to 48.8%±5.5% in starch and 56.1%±4.9% to 64.8%±2.8% in maltodextrin-gum arabic microparticles. Only a slight reduction in methane emission was recorded in encapsulated microparticles when compared with the samples containing only wall materials.

CONCLUSION

Both encapsulated products exhibited the burst release pattern under the pH conditions and methane reduction associated with tannin was marginal. This is attributable to small loading percentages and therefore, other wall materials or encapsulation methods should be investigated.

Interactions of flavonoids from yellow onion skins with whey proteins: Mechanisms of binding and microencapsulation with different combinations of polymers

The interaction of flavonoids extracted from yellow onion skins with whey proteins isolate was studied using fluorescence spectroscopy and simulation methods from the perspectives of microencapsulation. The fluorescence spectroscopy revealed a static quenching mechanism and the involvement of van der Waals and H bonding in complexes formation. The in silico methods suggested that the heat treatment of the major whey proteins affected the binding pockets and therefore the affinity for the main flavonoids. The interaction surface decreased and the interaction energy increased, suggesting lower binding strength. Further, the yellow onion skins extract was successfully encapsulated in whey proteins isolate and different combinations of polymers, including chitosan, maltodextrin and pectin by freeze drying. The resulted powder showed a total flavonoid content of 5.84 ± 0.23 mg quercetin equivalents/g DW in whey protein-chitosan combination and 104.97 ± 5.02 mg quercetin equivalents/g DW in whey protein-maltodextrin-pectin combinations, with antioxidant activity of 175.93 ± 1.50 mM mM Trolox/g DW and 269.20 ± 3.59 mM Trolox/g DW, respectively. The confocal microscopy indicated that the flavonoids aggregated inside the matrix formed between the whey proteins and various polymers and irregular and compact clusters. Therefore, a comprehensive approach involving the extraction of flavonoids from underutilized food by-products, such as yellow onion skins, evaluation of binding mechanisms with whey proteins, whereas tailoring their functional benefit through microencapsulation in order to obtain active ingredients are reported.