Wall Material Research Articles

Initial design concepts for solid boron injection in ITER

As part of ITER’s consideration to change its first wall material from beryllium to tungsten, the ITER Organization has proposed studying the feasibility of real-time solid boron injection (SBI) into the plasma to coat the walls and divertor to supplement glow discharge boronization (GDB) [1]. Boron deposits getter oxygen and reduce sputtering of tungsten from plasma facing components (PFCs). Particularly in areas with significant plasma wall interactions, boron coatings are expected to be short-lived under high performance plasma conditions. The proposed SBI system aims to maintain boron layers in these areas to avoid excessive radiation from tungsten in the plasma as a risk mitigation to ensure ITER will be able to reach and sustain Q = 10 conditions. The system will be used sparingly, as redeposition of boron can lead to significant tritium retention, which must be minimized in ITER to comply with nuclear safety concerns. SBI is proposed to limit and precisely control the amount of boron injected in real-time during plasma operation. Here, some of the design requirements and initial concepts for an SBI system in ITER are presented based on previous results carried out with SBI systems on a number of tokamaks and stellarators around the world [2–18].Previous results using SBI systems installed by PPPL have injected boron particles from 5 µm–2 mm diameter at calibrated rates of 2–200 mg/s in real-time during plasma operation on AUG [4], DIII-D [5], EAST [6], KSTAR [7], LHD [8], TFTR [9], WEST [10], and W7-X [11,12], leading to improved wall conditions with reduced plasma impurity concentrations and radiated power and improved plasma performance. The boron is ionized in the plasma edge and then deposited on plasma-wetted surfaces. On AUG [4], EAST [6] and WEST [10] reduced tungsten sputtering sources were observed following several discharges with SBI. Extrapolation of these SBI results are presented to estimate the amount of boron needed for wall conditioning in ITER. Real-time SBI control requirements and plasma operation scenarios for ITER are also described.

Preparation, characterization, stability, and antioxidant of quercetin-loaded hyaluronic acid complexes via pH-induced co-assembly

The purpose of this study was to investigate the feasibility of constructing an oral delivery system for quercetin (QUT) using hyaluronic acid (HA) as the wall material. The findings revealed that when the mass ratio of QUT to HA was 1:10, the prepared QUT-HA complexes exhibited excellent stability (particle size of 802 nm, zeta potential of -36 mV) and QUT loading capacity (encapsulation efficiency of 79.77%, loading capacity of 89.65 mg/g). The characterization of QUT-HA complex confirmed the formation of hydrogen bond between QUT and HA, resulting in a homogeneously dispersed coral-like complex and leading to the transformation of QUT's crystal structure into an amorphous state. Environmental stability analysis demonstrated that the QUT-HA complex maintains good stability within an ionic concentration range of 0-500 mM, a pH range of 3-8, and at temperatures of 50-90°C. In vitro simulations of gastrointestinal digestion indicated that the QUT-HA complex aggregates during simulated gastric fluid digestion and dissociates following simulated intestinal fluid digestion, effectively enhancing the bioaccessibility of QUT. Antioxidant assays showed that the scavenging ability of QUT against DPPH and ABTS radicals was significantly improved by complex loading. Therefore, the QUT-HA complex developed in this study possesses a high QUT loading capacity, excellent processing and digestive stability, and can effectively enhance the bioaccessibility and antioxidant activity of QUT, making it a promising candidate for use as an oral nutritional supplement in the field of functional foods.

Long-term storage of pink pepper essential oil microencapsulated by chickpea protein/pectin complexes: volatile release, antioxidant and antimicrobial activities.

Pink pepper essential oil was microencapsulated with chickpea protein (CP) and chickpea protein/pectin (CP-HMP) by spray drying. The reconstitution and storage properties of the powders were evaluated after drying. The impact of microencapsulation in the volatiles release, antioxidant and antimicrobial activity of oil was evaluated during 135days of storage. CP resulted in more soluble powders (93.52%), CP/HMP resulted in denser powders (0.39g/mL) while wall material did not influence the wettability. Free pink pepper essential oil (FEO) showed a slight loss of the predominant terpenes (α-pinene, β-pinene, β-mircene, δ-3-carene and D-limonene) after encapsulation. In general, all samples showed an increase in the volatiles release during storage. The evaluation of mass loss showed that FEO had a high release of volatiles, followed by CP and CP-HMP. The antioxidant activity of the FEO decreased (10.8μg Trolox/mg of oil) after 135days of storage, whereas the antioxidant activity of CP (14.9) and CP-HMP (14) increased. Both microcapsules presented antimicrobial activity against Bacillus subtilis and Staphylococcus aureus during storage. CP microcapsules had a strong inhibitory effect against the strains tested, and this advantage was even more evident in long-term storage.

Microencapsulation of Hibiscus sabdariffa extract in taro starch: Determination of optimal conditions of bioactive compound retention using response surface methodology

Hibiscus sabdariffa (HS) extract contains a large amount of bioactive compounds with antioxidant, anticarcinogenic, and antihypertensive effects. The extraction of total phenols, flavonoids, and anthocyanins is more efficient at boiling temperature (~91 °C) than that performed at room temperature (~27 °C). In this study, a central composite rotatable design (CCRD) was used to optimize the inlet temperature conditions of a spray dryer and the concentration of taro starch solids to obtain microcapsules with the highest retention of bioactive compounds in hibiscus extracts. Optimized microcapsules (OM) were obtained at an inlet temperature of 118 °C and solid concentration of 26.5 %. Low moisture content (4.54 %) and water activity (0.2) and high content of total phenols (3374.91 mg GAE/100 g), flavonoids (372.81 mg QE/100 g), monomeric anthocyanins (36.74 mg C-3-GE/100 g), and angiotensin-converting enzyme inhibitory activity (80.01 %), were determined in OM using response surface methodology. OM showed a range of spherical agglomerate sizes (10––32 μm). These results indicate that CCRD is a good tool for establishing the optimal conditions for solid concentration and drying temperature to maximize the protection of bioactive compounds using taro starch as the wall material.

Starch-based encapsulation to enhance probiotic viability in simulated digestion conditions

This research aims to meet the demand for efficient delivery systems in the food, nutraceutical, and pharmaceutical industries. The study involved the synthesis of starch-based nanoparticles for potential application in the encapsulation of Lactobacillus rhamnosus. Various techniques such as zeta sizer, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were used to characterize the encapsulated probiotics in microbeads. The results showed 85.00 % encapsulation efficiency of beads. Microscopic analysis revealed that the probiotics accumulated within the wall material and formed small, smooth polygonal granules on the capsule surface. XRD analysis confirmed the presence of amorphous humps and some crystallinity of nanoparticles in the capsules. Moreover, encapsulation significantly improved probiotic viability under simulated gastrointestinal conditions. This study highlights the potential of starch-based nanoparticles to enhance the stability and viability of probiotics, demonstrating their potential applications across various industrial sectors. Further research should focus on investigating the long-term stability and functional efficacy of encapsulated probiotics in microbeads for real-world applications.

Calcium alginate-encapsulated propolis microcapsules: Optimization, characterization, and preservation effects on postharvest sweet cherry

The increasing consumption of fresh fruits and vegetables has led to the development of eco-friendly and active preservation materials which have slow-release effect of antioxidant/antifungal agents. The propolis microcapsules (PM), utilizing calcium alginate as the wall material, incorporating ethanolic extract of propolis (EEP) as the core material, were prepared by ionic gelation method and conducted a investigation of its characteristics After optimization by single factor experiment and theoretical response models, PM which was prepared by dropping 9.3 g L−1 100 mL sodium alginate solution containing 9.8 mL EEP into 0.22 mol L−1 calcium chloride solution showed an encapsulation efficiency of 69.29±1.12 %. Prepared microcapsules were spherical with a dense surface which protected propolis well from the environment, retained a large number of bio-active compounds and improve thermal stability of propolis. Moreover, the microcapsules exhibited good slow-release effect and good inhibitory influence on the development of Alternaria Alternata growth which the colony diameter of the control was 41.38 % higher than the treatment at day six. With 5.0 g PM placed in the small non-woven bag in the application on sweet cherries with non-direct contact method, the decay rate and weight loss of fruits were reduced by 47.5 % and 17.6 %, concurrently the PM also effectively maintain the good appearance, hardness, antioxidant capacity by slowing the reduction in the content of total phenols, flavonoids and enzymatic activities. Therefore, the PM with superior antioxidant and antifungal capacity have the great potential to design as a practical active materials for fruits preservation.

Experimental and numerical investigations on the impact of openings on the stiffness of CLT shear walls

Cross-laminated timber (CLT) exhibits high in-plane strength and stiffness, positioning it as a viable material for shear walls in seismic regions. However, the influence of openings on the in-plane stiffness of CLT shear walls remains inadequately studied. In this study, 43 CLT shear walls with different opening sizes were tested under in-plane loading. The stiffness reduction was less than 29% for openings 800×800mm (53% of panel width), but exceeded 60% for openings 1200×1200mm (80% of panel width). When assessed with identical opening sizes, 139mm and 175mm thick CLT shear walls displayed consistent stiffness reductions. Panels with an aspect ratio of 3:1 exhibited a more pronounced drop than 2:1 aspect ratio panels. A validated 3D finite element model was used to investigate the influence of panel layup and opening shape and location on the in-plane stiffness reduction. For a distance between the opening and panel edge exceeding 300mm, the shape and location of openings exerted negligible effects. Finally, the Dujič’s model was shown to be a suitable predictor to evaluate the in-plane stiffness reduction of CLT shear walls with openings.

Encapsulation of Antarctic krill peptide by polysaccharide-based nanoparticles: Preparation, characterization, evaluation of stability and hypoglycemic activity

The aim of this study was to construct a chitosan quaternary ammonium salt (HTCC)/sodium alginate (SA) nanoparticle delivery system for the encapsulation of Antarctic krill peptide (AKP), with the goal of enhancing its stability and post-digestive hypoglycemic activity. Additionally, the effect of the content and encapsulation sequence of HTCC/SA on the structure and properties of AKP-loaded nanoparticles (AKP-loaded NPs) was investigated. As the content of the outermost wall material (HTCC) increased, the particle size of nanoparticles initially increased and then decreased. Concurrently, the zeta potential showed a trend of increase, ranging from -38.77 to 46.07 mV. When SA was used as the outermost wall material, the nanoparticles exhibited a smaller particle size (240.1 nm) and better dispersibility. Electrostatic interaction and hydrogen bonding were the major forces involved in the formation of AKP-loaded NPs. X-ray diffraction revealed that AKP was successfully encapsulated in an amorphous state. Scanning electron microscopy showed that AKP-loaded NPs had an elliptical or blocky appearance. Moreover, AKP-loaded NPs demonstrated good storage and temperature stability, while nanoparticles with HTCC in the outermost layer (HTCC:SA=2:1) showed good pH and ionic stability. During simulated digestion, AKP-loaded NPs inhibited the release of AKP in gastric fluid. Consequently, the hypoglycemic activity of digested AKP-loaded NPs was remarkably higher than unencapsulated AKP. Notably, the nanoparticles with HTCC in the outermost layer provided superior hypoglycemic activity. In summary, the polysaccharide-based delivery system exhibited great potential to improve the stability and post-digestive hypoglycemic activity of AKP, broadening its applications in the food and pharmaceutical industries.

Phytochemical Compounds, and Antioxidant, Anti-Hyperglycemic, and Anti-Inflammatory Activity of Microencapsulated Garambullo (Myrtillocactus geometrizans) Extract During In Vitro Digestion and Storage

Garambullo fruit (Myrtillocactus geometrizans) is a rich source of phytochemical compounds that exhibit antioxidant, anti-hyperglycemic, and anti-inflammatory activities, helping to prevent diseases associated with oxidative stress. The objective of this study was to evaluate phenolic compound (PC), betalain (BL), betaxanthin (BX), and betacyanin (BC) contents, and in vitro biological activities (antioxidant, anti-hyperglycemic, and anti-inflammatory) in microencapsulated garambullo extract during in vitro gastrointestinal digestion and storage. Microencapsulation was performed using spray drying. Arabic Gum (GA, 10% in feed solution) and soy protein isolate (SPI, 7% in feed solution) were used as wall materials. After in vitro digestion, the microcapsules (GA, SPI) exhibited higher bioaccessibility (p ≤ 0.05) of PC, BL, BX, and BC, and higher antioxidant activity (AA), compared to the non-encapsulated extract. Both microcapsules showed bioaccessibility in anti-hyperglycemic activity: α-amylase (GA: 90.58%, SPI: 84.73%), α-glucosidase (GA: 76.93%, SPI: 68.17%), and Dipeptidyl peptidase-4 (DPP-4) (GA: 52.81%, SPI: 53.03%); and in anti-inflammatory activity: cyclooxygenase-1 (COX-1) (GA: 78.14%, SPI: 77.90%) and cyclooxygenase-2 (COX-2) (GA: 82.77%, SPI: 84.99%). During storage, both microcapsules showed a similar trend with a significant decrease (p ≤ 0.05) in PC (GA: 39.29%, SPI: 39.34%), BL (GA: 21.17%, SPI: 21.62%), BX (GA: 23.89%, SPI: 23.45%), BC (GA: 19.55%, SPI: 19.84%), and AA (GA: 41.59%, SPI: 42.51%) after 60 days at 30 °C. Both microcapsules retained anti-hyperglycemic activity evaluated by the inhibitory activity of α-amylase (GA: 68.84%, SPI: 70.18%), α-glucosidase (GA: 59.93%, SPI: 58.69%), and DPP-4 (GA: 52.81%, SPI: 53.01%), and anti-inflammatory activity evaluated by the inhibitory activity of COX-1 (GA: 82.18%, SPI: 82.81%) and COX-2 (GA: 81.11%, SPI: 81.08%). Microencapsulation protected the phytochemical compounds and in vitro biological activities by allowing controlled release during in vitro digestion compared to the non-encapsulated extract. However, after 60 days storage at 30 °C, 60% of PC and AA, 80% of BL, BX, and BC, and 20–45% of the anti-hyperglycemic and anti-inflammatory activity were lost.

Microencapsulation of Lactobacillus reuteri by Emulsion Technique and Evaluation of Microparticle Properties and Bacterial Viability Under Storage, Processing, and Digestive System Conditions

ABSTRACTIn this research, the emulsification method was used to encapsulate Lactobacillus reuteri in microparticles of whey protein concentrate (WPC) at different levels (1%, 2%, and 4%) and gum Arabic (GA) at three levels (0/5%, 1%, and 1/5%) and a constant level of sunflower oil (5%). The results showed that emulsions with higher quantities of wall materials exhibited better encapsulation efficiency (67%/57%) and preservation ability at different temperatures, different pH, and presence of 1% bile salt. During the storage time, the droplet size of the emulsion increased more than two times (from 2.2 to 4.6 μm) and the absolute zeta potential of the optimal emulsion decreased (from −19/63 to −16/76 mV). Encapsulating Lactobacillus reuteri in the stabilized emulsion with the highest concentration of wall material improved the cells' protection during storage. The study also observed a decline in the number of primary encapsulated live cells in the gastrointestinal tract (from 4/32 to 3/58 Log CFU/mL) after 90 days of storage. In the case of the nonencapsulated sample, the initial live population decreased from 2.8 to 1 Log CFU/mL after 90 days of storage. The electron microscope images showed that the emulsions became unstable after 30, 60, and 90 days of storage, but the microbial cells were still visible in the continuous phase. Overall, encapsulating Lactobacillus reuteri using emulsification technique can preserve the probiotics during storage and “in vitro” gastrointestinal digestion.

Characterization of Plant based spray dried powders using oil seed proteins and chokeberry extract from wine byproduct

Spray drying is a standard method for preserving bioactive ingredients and enhancing their storage stability. This study aimed to produce entirely plant-based spray-dried powders by using hemp, canola, and flax seed proteins, combined with maltodextrin, as wall material, while chokeberry extract from wine waste served as core material. We conducted a thorough analysis of the oil-seed proteins, examining their nitrogen solubility index, emulsification, and foaming capacities. The encapsulation process was evaluated based on its yield and efficiency. The spray-dried powders were further assessed through colour analysis, particle morphology and size distribution, hygroscopicity, and storage stability measurements. The encapsulation yield with oil-seed proteins ranged from 75.0 ± 6.2 to 78.5 ± 1.3%, and the efficiency from 58.4 ± 0.8 to 77.5 ± 1.9%. These plant-based spray-dried powders exhibited similar colour parameters, morphology, and stability to those of whey protein powders. The study highlights the significant potential of oil-seed proteins in producing plant-based spray-dried powders.

Extrusion and Co-extrusion: A Technology in Probiotic Encapsulation with Alternative Materials.

Encapsulation, in particular extrusion and co-extrusion, is a common practice to protect probiotics from the harsh conditions of the digestive tract as well as processing. Hydrocolloids, including proteins and carbohydrates, natural or modified, are a group of ingredients used as the wall material in extrusion. Hydrocolloids, due to their specific properties, can significantly improve the probiotic survivability of the final powder during the microencapsulation process and storage. The present article will discuss the different kinds of hydrocolloids used for microencapsulation of probiotics by extrusion and co-extrusion, along with new sources of novel gums and their potential as wall material.

Evaluation of the phytochemical, bioactive compounds and descriptive sensory of encapsulated Lingzhi (Ganoderma lucidum) extracts with combined wall materials for masking effect on the perception of off-flavour and bitterness.

Lingzhi mushroom (Ganoderma lucidum) is known as a medicinal mushroom that can be utilized in various functional foods available in the market, including powders, dietary supplements, and tea. However, its use is limited due to factors such as bitterness, flavour, and astringency. The objective of this study is to characterize and quantify the sensory profile of Lingzhi mushroom samples (fresh, dried and Lingzhi extracts) using quantitative descriptive analysis and investigate the physicochemical and sensory properties of encapsulated Lingzhi extracts using different ratios of wall material (maltodextrin, gum Arabic and modified starch from rice flour). The optimal ratio for encapsulation involved 32.75% maltodextrin, 42.25% gum Arabic, and 25% modified starch w/w. Three parallel experiments were performed under practical conditions, resulting in average encapsulation efficiencies of 88.39±0.09% for flavonoids 89.53±0.06% for polysaccharides and 0.31± 0.01 of water activity. The sensory descriptive analysis indicated the following ratings: brown sugar aroma (4.36±0.17), earthy aroma (22.04±0.12), nutty aroma (2.00±0.01), fresh mushroom aroma (11.18±0.19), dried Lingzhi aroma (3.08±0.13), black tea aroma (4.50±0.19), salty taste (1.00±0.01), earthy flavour (23.14±0.22) and Mushroomy (after taste) (2.06±0.09), respectively. The flavour identified of Lingzhi extracts and encapsulated by gas chromatography electronic nose (GC-E-Nose). The result showed ten flavour compounds (Acetaldehyde, Methanethiol, Propanal, propane-2-one, Methyl acetate, 2-methyl propanal, Ethyl Acetate, Heptane, 1-Butanamine, 2-methyl butanal, Thiophene). Optimizing the encapsulation conditions has a significant impact on reducing off-flavours and bitterness. Comparing the flavour profiles of Lingzhi extracts with encapsulated Lingzhi extracts using gas chromatography electronic nose (GC-E-Nose). Encapsulation technology represents a burgeoning field that holds immense potential in ensuring the stability of functional ingredients and facilitating their incorporation into instant beverage products.

Fabrication and optimization of ultra-long stable microencapsulated chlorophyll using combinations of wall material via response surface methodology

Nowadays, the need to use natural pigments instead of artificial colorants in food has increased due to health risks. Chlorophyll is a natural colorant with antioxidant properties. Chlorophyll is a natural pigment with superior antioxidant properties. However, this pigment is unstable in the different conditions of food processing. To increase the stability of chlorophyll extracted from Ulva intestinalis algae, encapsulation of chlorophyll with maltodextrin (MD) and whey protein isolate (WPI) carriers by two drying methods including spray drying and freeze drying was achieved. The optimum combination of wall and core materials to achieve the highest response including encapsulation efficiency (EE) and chlorophyll content (CC) was obtained by response surface methodology and central composite design. The optimal chlorophyll microcapsule (Chl-M) obtained was chosen for subsequent tests containing solubility, moisture content, and antioxidant properties. The results showed that the highest EE and CC were 90.27 ± 0.21%, 55.36 ± 0.36 μg/mL, and 90.46 ± 0.62%, 85.85 ± 0.43 μg/mL, respectively in SD and FD. The microcapsules produced by the freeze dryer (FD) had higher antioxidant activity (79.1 ± 0.24) than the microcapsules produced by the spray dryer (SD) (67.5 ± 0.16). The highest solubility (95.32%) and the lowest moisture content (3.7 ± 0.05) were related to the SD. Freeze drying method (FDM) had the highest EE (91.2%), CC (89.67 μg/mL), and antioxidant properties (79.1%). It is hoped that the encapsulated chlorophyll can be used as a health-promoting food color additive in the food industry.

Dairy and nondairy proteins as nano-architecture structures for delivering phenolic compounds: Unraveling their molecular interactions to maximize health benefits.

Phenolic compounds are recognized for their benefits against degenerative diseases. Clinical and nutritional applications are limited by their low solubility, stability, and bioavailability, compromising their efficacy. Natural macromolecules, such as lipids, polysaccharides, and proteins, employed as delivery systems can efficiently overcome these limitations. In this sense, proteins are attractive due to their biocompatibility and dynamic structure properties, functional adaptability and self-assembly capabilities, offering stability, efficient encapsulation, and controlled release. This review explores the potential use of dairy proteins, caseins, and whey proteins, and, alternatively, nondairy proteins, gelatin, human serum albumin, maize zein, and soybean proteins, in building wall materials for the delivery of phenolic compounds. To optimize performance, aspects, such as protein-phenolic affinity and complex stability/activity, should be considered when designing particle nano-architecture. Molecular interactions between protein-phenolic compound complexes are, thus, further discussed, as well as the effects of temperature and pH and strategies to stabilize and preserve nano-architecture and retain phenolic compound activity. All proteins harbor one or more putative binding sites, shared or not, depending on the phenolic compound. Preservation techniques are still a case-to-case study, as no behavior patterns among different complexes are noted. Safety aspects necessary for the marketing of nanoproducts, such as characterization, toxicity assessments, and post-market monitoring as defined by the European Food Safety Authority and the Food and Drug Administration, are discussed, evidencing the need for a unified regulation. This review broadens our understanding and opens new opportunities for the development of novel protein-based nanocarriers to obtain more effective and stable products, enhancing phenolic compound delivery and health benefits.

The Impact of Drying Techniques on Stabilizing Microencapsulated Astaxanthin From Shrimp Shells: A Comparative Study of Spray Drying Versus Freeze Drying

ABSTRACTThe research aimed to study how different drying methods (spray and freeze drying) affect the release kinetics of microencapsulated astaxanthin in various environmental conditions. Shrimp shell extract containing astaxanthin was encapsulated using different wall components (maltodextrin with different dextrose equivalents and modified starch) via a simplex lattice mixture design. The encapsulated extract was then subjected to storage at different temperatures (25°C ± 2°C and 2°C ± 4°C) and humidity conditions (52% ± 2% and 75% ± 2%), as well as exposure to UV light (four 15 W lamps, 254 nm, for 10 h). The release kinetics of astaxanthin were analyzed using various models (page, Newton Korsmeyer–Peppas model, Modified Henderson and Pabis, Diffusion approach, and Two‐term exponential). The evaluation results of correlation coefficient (R2), root mean square deviation (RMSE), and mean absolute percentage error (MAPE) values of different models showed that the astaxanthin degradation followed a two‐term exponential kinetics in both types of microcapsules. Astaxanthin degradation increased with higher temperatures, humidity, and UV light exposure. However, microcapsules with equal wall compound ratios exhibited better preservation of astaxanthin. The study also emphasized the significance of optimizing storage conditions and wall materials for microencapsulated astaxanthin, as well as the utility of the two‐term exponential model in enhancing stability and shelf life.

Elucidation of pineapple softening based on cell wall polysaccharides degradation during storage

The degradation of cell wall polysaccharides in pineapple fruit during softening was investigated in the present study. Two pectin fractions and two hemicellulose fractions were extracted from the cell wall materials of ‘Comte de Paris’ pineapple fruit at five softening stages, and their compositional changes were subsequently analyzed. The process of softening of the fruit corresponded to an increase in the water-soluble pectin (WSP) and 1 M KOH-soluble hemicellulose (HC1) fractions, and a decrease in the acid-soluble pectin (ASP) fraction, which suggested the solubilization and conversion of cellular wall components. However, the content of 4 M KOH-soluble hemicellulose (HC2) decreased and then returned to the initial level. Furthermore, WSP, ASP, and HC1 showed an increment in the content of low molecular weight polymers while a decline in the high molecular weight polymers throughout softening, and not significant change in the contents of different molecular polymers of HC2 was observed. Moreover, the galacturonic acid (GalA) content in the main chain of WSP was maintained at a relatively constant level, but the major branch monosaccharide galactose (Gal) in WSP decreased. Different from WSP, the molar percentages of Gal and GalA in ASP decreased. The Gal or Arabinose (Ara) in HC1 exhibited a gradual decline while the molar percentages of xylose (Xyl) and glucose (Glu) in the main chain increased. These suggested that the main chain of ASP degraded while the branched chains of ASP, WSP and HC1 depolymerized during pineapple softening. Overall, fruit softening of ‘Comte de Paris’ pineapple was found to be the result of differential modification of pectin and hemicellulose.

Preparation and characterization of Pummelo essential oil microcapsules and their application to preservation of <i>Agricus bisporus</i> (white mushrooms)

Pummelo essential oil is a natural plant oil with antioxidant and antibacterial properties; however, it is poorly stabilized and volatile, which limits its application in food preservation research. In the present work, pummelo essential oil microcapsules were prepared using the complex coalescence method, with pummelo essential oil as the core material and glutenin as the wall material. Pummelo essential oil was successfully encapsulated by glutenin, forming a stable microcapsule structure with enhanced thermal stability. Microcapsules (GH-4) with the addition of 4 mL of pummelo essential oil exhibited the best embedding effect, achieving an encapsulation efficiency of 91%. Compared with GH-0, white mushrooms preserved with GH-4 effectively maintained the hardness of the fruiting body (about 7.5 N), delayed browning (the L* value was about 80), inhibited respiration (about 18×103 mL kg-1 h-1), and slowed the quality deterioration of the white mushrooms. In conclusion, GH-4 microcapsules can be used not only for the preservation of fruits and vegetables but also provide a theoretical basis for sustainable food preservation.

Encapsulation of ɣ-Aminobutyric Acid Compounds Extracted from Germinated Brown Rice by Freeze-Drying Technique.

Gamma-aminobutyric acid (GABA) from plants has several bioactivities, such as neurotransmission, anti-cancer cell proliferation, and blood pressure control. Its bioactivities vary when exposed to pH, heat, and ultraviolet. This study analyzed the protective effect of the GABA encapsulation technique using gum arabic (GA) and maltodextrin (MD) and the freeze-drying method. The impact of different ratios of the wall material GA and MD on morphology, GABA content, antioxidant activity, encapsulation efficiency, process yield, and physical properties were analyzed. Results showed that the structure of encapsulated GABA powder was similar to broken glass pieces of various sizes and irregular shapes. The highest GABA content and encapsulation efficiency were, respectively, 90.77 mg/g and 84.36% when using the wall material GA:MD ratio of 2:2. The encapsulated powder's antioxidant activity was 1.09-1.80 g of encapsulation powder for each formula, which showed no significant difference. GA and MD as the wall material in a 2:2 (w/w) ratio showed the lowest bulk density. The high amount of MD showed the highest Hausner ratio (HR), and Carr's index (CI) showed high encapsulation efficiency and process yield. The stability of encapsulated GABA powder can be kept in clear glass with a screw cap at 35 °C for 42 days compared to the non-encapsulated one, which can be preserved for only 18 days under the same condition. In conclusion, this study demonstrated that the freeze-drying process for GABA encapsulation preserved GABA component extracts from brown rice while increasing its potential beneficial properties. Using a wall material GA:MD ratio of 2:2 resulted in the maximum GABA content, solubility, and encapsulation efficiency while having the lowest bulk density.

Fish oil-containing edible films with active film incorporated with extract of Psidium guajava leaves: preparation and characterization of double-layered edible film.

The utilization of zein and gum arabic has grown in an attempt to formulate wall materials based on protein-polysaccharide complexes. This mixture provides a versatile delivery system for hydrophilic (guava leaf extract, GLE) or lipophilic (fish oil, FO) bioactive compounds, and it can be used as an edible film-forming polymer. This study was undertaken to characterize FO-containing edible films that were double-layered with a film containing GLE. Modified zein and gum arabic solutions (MG complex) were mixed at a ratio of 1:1.5 (v/v), adjusted to pH 5, added with glycerol (20% of the complex) and FO (5% of the complex), and finally adjusted to pH 5. This was prepared as the bottom/lower layer. The upper/active layer was prepared by mixing MG complex, glycerol, and GLE (1, 3, and 5% w/v of the complex). The total phenolic and flavonoid contents in GLE were 15.81 mg GAE/g extract and 6.99 mg QE/g extract, respectively. The IC50 of the DPPH radical scavenging activity of GLE was 26.86 ppm with antibacterial activity against Bacillus subtilis and Escherichia coli of 9.83 and 12.55 mm. The total plate counts of double-layered films containing GLE were retained below 3 log CFU/g during 28-day storage. The peroxide values of these films were dimmed for no more than 9.08 meq/kg sample on day 28 of storage. Thickness (872.00-971.67 μm), water vapor transmission rate (12.99-17.04 g/m 2/day), tensile strength (1.56-2.02 kPa), elongation at break (61.53-75.41%), glass transition (52.74-57.50°C), melting peak (131.59-142.35°C), inhibition against B. subtilis (33.67-40.58 mm), and inhibition against E. coli (2.05-9.04 mm) were obtained by double-layered films. GLE can be successfully incorporated into the active layer of a double-layer film to improve its characteristics while significantly slowing down the microbial contamination and oxidation rate. MG complex and FO can also contribute to the performance of the edible film.