Comparative study of plant protein extracts as wall materials for the improvement of the oxidative stability of sunflower oil by microencapsulation

Recent progress in plant-based proteins: From extraction and modification methods to applications in the food industry

Plant proteins can meet consumers' demand for healthy and sustainable alternatives to animal proteins. It has been reported to possess numerous health benefits and is widely used in the food industry. However, conventional extraction methods are time-consuming, energy-intensive, as well as environmentally unfriendly. Plant proteins are also limited in application due to off-flavors, allergies, and anti-nutritional factors. Therefore, this paper discusses the challenges and limitations of conventional extraction processes. The current advances in green extraction technologies are also summarized. In addition, methods to improve the nutritional value, bioactivity, functional and organoleptic properties of plant proteins, and strategies to reduce their allergenicity are mentioned. Finally, examples of applications of plant proteins in the food industry are presented. This review aims to stimulate thinking and generate new ideas for future research. It will also provide new ideas and broad perspectives for the application of plant proteins in the food industry.

Influence of emulsifier on lipid oxidation in spray-dried microencapsulated O/W emulsions

Lipid oxidation limits the shelf-life of dried microencapsulated oils (DMOs), such as infant formula. However, it is poorly understood how lipid oxidation is affected by different types of emulsifiers. To improve our understanding, we prepared DMOs with different emulsifiers (whey protein isolate (WPI), pea protein isolate (PPI), and non-proteinaceous CITREM) and studied lipid oxidation in both the free and encapsulated fat. Only a small difference in oxidation rate was observed between these fat fractions for all formulations. We ascribed this to a non-discrete distribution of the fractions and the subsequent low fractionation selectivity as shown by Raman microscopy. The DMO with PPI showed hardly any oxidation during a 7-week incubation at 40 °C, whereas the DMOs with WPI and CITREM both reached significantly higher contents of oxidation products (lipid hydroperoxides, aldehydes, and epoxides). The enhanced stability of DMO-PPI could not be ascribed to the presence of phytic acid. In conclusion, we demonstrate the potential of using PPI to produce oxidatively stable DMOs.

Plant and animal protein mixed systems as wall material for microencapsulation of Mānuka essential Oil: Characterization and in vitro release kinetics

Combination of plant and animal protein diet is becoming a valuable source of nutrition in the modern diet due to the synergistic functional properties inherent in these protein complexes. Moreover, the synergy between animal and plant proteins can contribute to the high stability and improved solubility of the encapsulated bioactive ingredients (e.g., essential oils). Therefore, the study was designed to evaluate the plant (pea protein (PP) and lupine protein (LP)) and animal protein (whey protein, WP) mixed systems as a wall material for microencapsulation of mānuka essential oil, as an example of bioactive compound. Moreover, physicochemical properties and in vitro release profile of encapsulated mānuka essential oil were studied. Mānuka essential oil microcapsules exhibited low moisture content (5.3-7.1 %) and low water activity (0.33-0.37) with a solubility of 53.7-68.1 %. Change in wall material ratio significantly affected the color of microcapsules, while microcapsules prepared with 1:1 protein/oil ratio demonstrated a high encapsulation efficiency (90.4 % and 89.4 %) for protein mixed systems (PP + WP and LP + WP), respectively. Microcapsules further showed low values for lipid oxidation with a high oxidative stability and antioxidant activity (62.1-87.0 %). The zero order and Korsmeyer-Peppas models clearly explained the release mechanism of encapsulated oil, which was dependent on the type and concentration of the protein mixed used. The findings demonstrated that the protein mixed systems successfully encapsulated the mānuka essential oil with controlled release and high oxidative stability, indicating the suitability of the protein mixed systems as a carrier in encapsulation and application potential in development of encapsulated functional foods.

New perspective on protein-based microcapsules as delivery vehicles for sensitive substances: A review

Sensitive substances have attracted wide attention due to their rich functional activities, such as antibiosis activities, antioxidant activities and prevent disease, etc. However, the low stability of sensitive substances limits their bioavailability and functional activities. Protein-based microcapsules can encapsulate sensitive substances to improve their adverse properties due to their good stability, strong emulsifying ability and wide source. Therefore, it is necessary to fully elaborate and summarize protein-based microcapsules to maximize their potential benefits in nutritional interventions. The focus of this review is to highlight the classification of protein-based microcapsules. In addition, the principles, advantages and disadvantages of preparation methods for protein-based microcapsules are summarized. Some novel preparation methods for protein-based microcapsules are also emphasized. Moreover, the mechanism of protein-based microcapsules that release sensitive substances in vitro is elucidated and summarized. Furthermore, the applications of protein-based microcapsules are outlined. Protein-based microcapsules can effectively encapsulate sensitive substances, which improve their bioavailability, and provide protective effects during storage and gastrointestinal digestion. In addition, microcapsules can improve the sensory quality of food and enhance its stability. The performance of protein-based microcapsules for delivering sensitive substances is influenced by factors such as protein type, the ratio between protein ratio and the other wall material, the preparation process, etc. Future research should focus on the new composite protein-based microcapsule delivery system, which can be applied to in vivo research and have synergistic effects and precise nutritional functions. In summary, protein-based microcapsules have broader research prospects in the functional foods and nutrition field.

Technological advances in protein extraction, structure improvement and assembly, digestibility and bioavailability of plant-based foods

Plant-based foods are being considered seriously to replace traditional animal-origin foods for various reasons. It is well known that animals release large amounts of greenhouse gases into the environment during feeding, and eating animal-origin foods may also cause some health problems. Moreover, animal resources will likely be in short supply as the world population grows. It is highly likely that serious health problems ascribed to insufficient protein intake in some areas of the world will occur. Studies have shown that environmentally friendly, abundant, and customizable plant-based foods can be an effective alternative to animal-based foods. However, currently, available plant-based foods lack nutrients unique to animal-based foods. Innovative processing technologies are needed to improve the nutritional value and functionality of plant-based foods and make them acceptable to a wider range of consumers. Therefore, protein extraction technologies (e.g., high-pressure extraction, ultrasound extraction, enzyme extraction, etc.), structure improvement and assembly technologies (3D printing, micro-encapsulation, etc.), and technologies to improve digestibility and utilization of bioactive substances (microbial fermentation, physical, etc.) in the field of plant-based foods processing are reviewed. The challenges of plant-based food processing technologies are summarized. The advanced technologies aim to help the food industry solve production problems using efficient, environmentally friendly, and economical processing technologies and to guide the development of plant-based foods in the future.

Valorization of Bioactive Compounds from Two Underutilized Wild Fruits by Microencapsulation in Order to Formulate Value-Added Food Products

Currently, microencapsulation has become a viable method of nutrient delivery for the food industry. This work microencapsulated the bioactive compounds extracted from two neglected species (Balanites aegyptiaca and Ziziphus mauritiana) by freeze-drying. A combination of wall materials (whey protein and pectin; soy protein and maltodextrin) was chosen to prepare the microcapsules. The phytochemical and physicochemical characterization of the microcapsules was then carried out. The encapsulation yield ranged from 82.77% to 96.05% for Balanites and Ziziphus, respectively, whereas the efficiency was 76.18 ± 1.39% and 80.93 ± 1.71%. The stimulated in vitro gastrointestinal test showed that encapsulation increased the bioavailability of the bioactive compounds. The total carotenoids were the most bioavailable compounds with 85.89 ± 0.06% for Ziziphus and 70.46 ± 1.10% for Balanites, followed by total flavonoids for Zizyphus with 63.27 ± 1.56%. Furthermore, regardless of species or wavelengths, the HPLC analysis resulted in the identification of 17 bioactive metabolites. The predominant one was epicatechin, whose level ranged from 231.52 ± 5.06 to 250.99 ± 3.72 mg/100 g DW in Ziziphus and 91.80 ± 3.85 to 116.40 ± 4.09 mg/100 g DW in Balanites. In estimating the enzyme inhibition and antioxidant power, both studied fruits showed antidiabetic, inflammatory, and antioxidant effects. These findings suggest that natural bioactive compounds are abundant in the fruits of Z. mauritiana and B. aegyptiaca and could be a valuable source for the food and pharmaceutical industries.

Microencapsulation of Carvacrol by Complex Coacervation of Walnut Meal Protein Isolate and Gum Arabic: Preparation, Characterization and Bio-Functional Activity

As a natural phenolic compound, carvacrol has attracted much attention due to its excellent antibacterial and antioxidant activities. However, its application is limited due to its instability, such as easy volatilization, easy oxidation, etc. Protein-polysaccharide interactions provide strategies for improving their stability issues. In this study, the plant-based carvacrol microcapsules via complex coacervation between walnut meal protein isolate (WMPI) and gum Arabic (GA) has been fabricated and characterized. The formation conditions of WMPI-GA coacervates were determined by some parameters, such as pH, zeta-potential, and turbidity. The optimum preparation conditions were achieved at pH 4.0 with a WMPI-to-GA ratio of 6:1 (w/w). The mean particle size, loading capacity (LC), and encapsulation efficiency (EE) of the microcapsules were 43.21 μm, 26.37%, and 89.87%, respectively. Fourier transform infrared spectroscopy (FT-IR) and fluorescence microscopy further confirmed the successful microencapsulation of carvacrol. The microencapsulation of carvacrol improved the thermal stability of the free carvacrol. The swelling capacity results indicated that it could resist gastric acid, and facilitate its intestinal absorption. Meanwhile, the carvacrol molecules trapped within the microcapsules could be continuously released in a concentration-dependent manner. Furthermore, the microcapsules presented good antioxidant activity and antibacterial activity against the Gram-negative (E. coli) and the Gram-positive (S. aureus) bacteria. These results indicated that the obtained carvacrol microcapsules have a potential application value as a food preservative in the food industry.

Impact of Freeze- and Spray-Drying Microencapsulation Techniques on β-Glucan Powder Biological Activity: A Comparative Study

The study compares the impact of freeze- and spray-drying (FD, SD) microencapsulation methods on the content of β-glucan, total polyphenols (TP), total flavonoids (TF), phenolic acids (PA), and antioxidant activity (AA) in commercially β-glucan powder (Pleurotus ostreatus) using maltodextrin as a carrier. Morphology (scanning electron microscopy- SEM), yield, moisture content (MC), and water activity (aw) were also evaluated in the samples. Our examinations revealed significant structural differences between powders microencapsulated by the drying methods. As compared to non-encapsulated powder, the SD powder with yield of 44.38 ± 0.55% exhibited more reduced (p < 0.05) values for aw (0.456 ± 0.001) and MC (8.90 ± 0.44%) than the FD one (yield: 27.97 ± 0.33%; aw: 0.506 ± 0.002; MC: 11.30 ± 0.28%). In addition, the highest values for β-glucan content (72.39 ± 0.38%), TPC (3.40 ± 0.17 mg GAE/g), and TFC (3.07 ± 0.29 mg QE/g) have been detected in the SD powder. Our results allow for the conclusion that the SD microencapsulation method using maltodextrin seems to be more powerful in terms of the β-glucan powder yield and its contents of β-glucan, TP, and TF as compared to the FD technique.

Production of rice bran oil (Oryza sativa L.) microparticles by spray drying taking advantage of the technological properties of cereal co-products

AIM

To evaluate the effects of the use of rice co-products (flour and protein) on the encapsulation process and on the stability of rice bran oil.

METHODS

The stability of the emulsions was evaluated by dynamic turbidimetry, zeta potential, and creaming index. Efficiency parameters, particle size, and densities were investigated in the particles. The study of oxidative stability was carried out by the determination of peroxides and volatiles (60 °C for 8 weeks).

RESULTS

Rice bran oil presented 1.75% ɣ-oryzanol. AG/RP (10% of rice protein): no phase separation after 24 h, higher zeta potential (- 29.09 mV ±0.67), encapsulation efficiency (73.90% ± 0.22) and real density (1.27 g/cm^-3), and smaller particle size (8.27 µm ± 0.13). Lower peroxide (AG/RF/RP) and hexanal (AG/RF) levels were associated with the use of rice flour.

CONCLUSION

The co-products improve the emulsion characteristics, particle properties and stability of the encapsulated oil.

Microcapsules with slow-release characteristics prepared by soluble small molecular starch fractions through the spray drying method

The utilization of starch in the food and medical industry can be facilitated by using new non-chemical methods to make starch the only wall material to encapsulate microcapsules. In this study, soluble small molecular fraction obtained from corn starch by gelatinization and centrifugation methods and commercial soluble starch were used independently to encapsulate oil under the condition that wall material and core material were 2:1. Molecular weight of these starch fractions was measured firstly. The peak molecular weight of the soluble small molecular fraction of corn starch and commercial soluble starch was 3.537 × 105 Da and 2.720 × 104 Da, respectively. Basic physicochemical characteristics and application characteristics of the microcapsules were then characterized and compared. The soluble small molecular fraction of corn starch encapsulated microcapsule and the commercial soluble starch encapsulated microcapsule had high encapsulation efficiency (higher than 88%), high boiling water solubility (higher than 74%), high rehydration stability (higher than 2 h). Most importantly, the encapsulated oil of these microcapsules could be slowly released under the action of α-amylase and amyloglucosidase. Overall, both the soluble small molecular fraction of corn starch and commercial soluble starch could be used as microcapsule wall materials and might have great application potential in food and medicine.

Potato protein: current review of structure, technological properties, and potential application on spray drying microencapsulation

Studies regarding spray drying microencapsulation are aplenty available; especially focusing on processing parameters, microparticle characteristics and encapsulation efficiency. Hence, there is a rising interest in tailoring wall materials aiming to improve the process's effectiveness. Reflecting a market trend in the food industry, plant-based proteins are emerging as alternative protein sources, and their application adaptability is an increasing research of interest related to consumers' demand for healthy food, product innovation, and sustainability. This review presents a perspective on the investigation of potato protein as a technological ingredient, considering it a nonconventional source obtained as by-product from starch industry. Furthermore, this piece emphasizes the potential application of potato protein as wall material in spray drying encapsulation, considering that this purpose is still limited for this ingredient. The literature reports that vegetal-based proteins might present compromised functionality due to processing conditions, impairing its technological application. Structural modification can offer a potential approach to modify potato protein configuration aiming to improve its utilization. Studies reported that modified proteins can perform as better emulsifiers and antioxidant agents compared to intact proteins. Hence, it is expected that their use in microencapsulation would improve process efficiency and protection of the core material, consequently delivering superior encapsulation performance.

Whole Wheat Crackers Fortified with Mixed Shrimp Oil and Tea Seed Oil Microcapsules Prepared from Mung Bean Protein Isolate and Sodium Alginate

Shrimp oil (SO) rich in n-3 fatty acids and astaxanthin, mixed with antioxidant-rich tea seed oil (TSO), was microencapsulated using mung bean protein isolate and sodium alginate and fortified into whole wheat crackers. SO and TSO mixed in equal proportions were emulsified in a solution containing mung bean protein isolate (MBPI) and sodium alginate (SA) at varied ratios. The emulsions were spray-dried to entrap SO-TSO in MBPI-SA microcapsules. MBPI-SA microcapsules loaded with SO-TSO showed low to moderately high encapsulation efficiencies (EE) of 32.26–72.09% and had a fair flowability index. Two selected microcapsules with high EE possessed the particle sizes of 1.592 and 1.796 µm with moderate PDI of 0.372 and 0.403, respectively. Zeta potential values were −54.81 mV and −53.41 mV. Scanning electron microscopic (SEM) images indicated that microcapsules were spherical in shape with some shrinkage on the surface and aggregation took place to some extent. Fourier transform infrared (FTIR) and differential scanning calorimetry (DSC) analyses of samples empirically validated the presence of SO-TSO in the microcapsules. Encapsulated SO-TSO showed superior oxidative stability and retention of polyunsaturated fatty acids (PUFAs) to unencapsulated counterparts during storage of 6 weeks. When SO-TSO microcapsules were fortified in whole wheat crackers at varying levels (0–10%), the crackers showed sensorial acceptability with no perceivable fishy odor. Thus, microencapsulation of SO-TSO using MBPI-SA as wall materials could be used as an alternative carrier system, in which microcapsules loaded with PUFAs could be fortified in a wide range of foods.

Effect of crosslinking and drying method on the oxidative stability of lipid microcapsules obtained by complex coacervation

The crosslinking and drying method of microcapsules prepared by complex coacervation has been investigated in order to reach a better control of the oxidative stability of final powder product. Methyl...

Physicochemical properties, microstructure, and storage stability of Pulicaria jaubertii extract microencapsulated with different protein biopolymers and gum arabic as wall materials

This study aimed to evaluate the possibility of using gum arabic (GA) with different protein materials namely whey protein isolate (WP), sodium caseinate (SC), and soybean protein (SP) as wall materials to encapsulate Pulicaria jaubertii extract (PJ) using freeze-drying. Four formulations of microencapsulation of Pulicaria jaubertii extract (MPJE) were produced, including WPGA-MPJE, SCGA-MPJE, SPGA-MPJE, and GA-MPJE. The formulations were stored at 4 °C and 25 °C for 28 days to assess the storage stability. The results indicated that mixtures of proteins with GA improved the physicochemical properties and bioactive content of the MPJE compared to GA-MPJE. The SCGA-MPJE formula showed optimal values of particle size (450.13 nm), polydispersity index (0.33), zeta potential (74.63 mV), encapsulation efficiency (91.07%), total phenolic content (25.51 g GAE g^-1 capsules), and antioxidants compounds, as well as presented a lower release of bioactive composites with high oxidative stability during storage at 4 °C and 25 °C. The microstructure of MPJE formulations showed a flat surface without any visible cracking on surfaces. The microcapsules prepared from protein mixtures with GA, especially the SCGA-MPJE formula, are the most efficient in encapsulating the plant extract derived from the PJ, which could be useful for application in various industrial fields.

Preparation and Characterization of Microcapsules Containing Antioxidant Fish Protein Hydrolysates: a New Use of Bycatch in Brazil

In this study, we evaluated the effect of complexation and microencapsulation with pea protein on the antioxidant activity of protein hydrolysates from bycatch in Brazil. The zeta potential values of complexes changed from negative to positive with the increase of pea protein as a result of positively charged complexes formation. The increase in the ratio of pea protein/hydrolysates also resulted in increased turbidity in all samples. Particle size measurements indicated that the complexes tended to form larger aggregates (ranged from 61.5 ± 1.7 μm to 183 ± 2.8 μm). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the pea protein/fish protein hydrolysate complexes was higher than that of the protein hydrolysates alone. Moreover, increasing levels of pea protein did not affect the antioxidant activity of fish protein hydrolysates. The complexes of the Paralonchurus brasiliensis were chosen for the microencapsulation process by spray-drying. The results revealed that spray-drying did not have a significant effect (P > 0.05) on the protein hydrolysate antioxidant activity when they were complexed with pea protein. Thus, this work suggests that the complexation with pea protein and subsequent microencapsulation by spray-drying is an efficient way to protect the biological activity of protein hydrolysates obtained from bycatch. This study provides evidence for the potential use of bycatch from shrimp fisheries as functional ingredients or nutraceuticals.

A review on protein extracts from sunflower cake: techno-functional properties and promising modification methods

De-oiled sunflower cake is a sustainable and promising protein source with high phenolic and fiber contents. The cake, which is an industrial by-product has been the subject of many studies investigating various aspects such as protein extraction, functional properties, interaction with other ingredients, and its performance in a wide range of food products. Innovative and conventional techniques of protein extraction from sunflower cake have been investigated to increase extraction yield and improve desired functional characteristics. Modulation of structure of plant-based proteins helps to control their techno-functional properties and widen their applications. Structure modification of proteins by physical methods including ultrasound treatment and gamma irradiation as well as enzymatic and chemical methods has been used to improve the functional properties of sunflower protein. This review collects and critically discusses the available information on techno-functional properties of protein extracts from sunflower cake and how its techno-functional properties can be tailored using various structure modification methods.

Potential use of vegetable proteins to reduce Brazil nut oil oxidation in microparticle systems

Brazil nut oil is mostly composed of unsaturated fatty acids, some of which are associated with decreased incidence of cardiovascular diseases. Vegetable proteins have been increasingly used as wall material for partial replacement of carbohydrates and whey proteins. In order to create an oil preservation method, Brazil nut oil was encapsulated with three different types of vegetable protein concentrates and gum arabic (GA): rice (RPC + GA); pea (PPC + GA); and soy (SPC + GA) .For this purpose, vegetable protein concentrates were characterized, and after the drying process the physicochemical characteristics of the microparticles were evaluated. The most stable emulsion, after seven days of evaluation, was composed of RPC + GA. RPC + GA. This treatment was also more stable based on the shelf life assessments. We concluded that RCP microparticles were the best option for encapsulating Brazil nut oil in comparison with the other particles evaluated. In addition, the product obtained is potentially capable of being included in various processed foods.