Encapsulation of Hydrophobic Apigenin into Small Unilamellar Liposomes Coated with Chitosan Through Ethanol Injection and Spray Drying.

Despite the multiple health benefits, natural flavonoid apigenin has poor aqueous solubility that restricts its delivery in foods. This study investigated the potential of spray-dried chitosan-coated liposomes prepared from scalable methods for the food industry as the delivery carriers for apigenin. Apigenin-loaded small unilamellar liposomes produced from ethanol injection had an encapsulation efficiency of 74.88 ± 5.31%. They were electrostatically stabilised via chitosan coating (0.25% w/v) and spray-dried. Spray-dried chitosan-coated apigenin liposomes (SCAL) exhibited the following powder characteristics: yield 66.62 ± 3.08%, moisture content 4.33 ± 0.56%, water activity 0.2242 ± 0.0548, particle size 10.97 ± 1.55 µm, nearly spherical morphology with wrinkles and dents under microscopic observation. Compared with the unencapsulated apigenin, SCAL demonstrated improved aqueous solubility (10.22 ± 0.18 mg/L), higher antioxidant capacity, and stability against simulated gastrointestinal digestion. The chitosan coating gave a slower in-vitro release of apigenin in SCAL (77.0 ± 6.2%) than that of uncoated apigenin liposomes (94.0 ± 5.3%) at 12 h. The apigenin release kinetics from SCAL could be represented by the Korsmeyer-Peppas model (R2 = 0.971). These findings suggest that SCAL could be a promising delivery system of apigenin for functional food applications.

A review on application of ultrasound and ultrasound assisted technology for seed oil extraction.

Oil has extensively been extracted from oil-bearing crops and traded globally as a major food commodity. There is always a huge demand from the fats and oils industries to increase oil yield because of profitability benefits. If extraction is conducted under mild operating conditions to preserve and improve the oil quality, then it would be an added value. Ultrasound that works on the cavitational action helps to fulfil the gap. Ultrasound is gaining tremendous interest as an alternative to replace the current conventional extractions approach because of its multiple benefits. Cavitation generated by ultrasound eases the release of oil from cell matrices, thereby allowing the extraction to be carried out under mild processing conditions. The effect enhances the oil yield whilst preserving the quality of the oil. In ultrasound, green solvents can be used to replace toxic organic solvents. Recent up-to-date approaches utilised a combination of ultrasound with enzyme, microwave and supercritical technology to further enhance the oil extraction. This review highlights a comprehensive work of the impact of ultrasound and ultrasound in combination with other technologies on oil extraction, which emphasises the extraction yield and physicochemical properties of the oil, such as fatty acid composition, oxidative stability with the retention of the lipophilic phytochemicals and iodine, saponification values and colour parameters. Understanding of ultrasonication techniques for oil extraction served to be essential and useful information for the fats and oils scientists from academia and industries to explore the possibility of employing a sustainable and mild approaches for extracting oil from various crops.

Physicochemical and antioxidative properties of ultrasound-assisted extraction of mahua (Madhuca longifolia) seed oil in comparison with conventional Soxhlet and mechanical extractions.

Ultrasound-assisted solvent extraction (UAE) was applied to extract underutilized Madhuca longifolia seed oil. The effect of extraction time, temperature, solvent type, solvent/sample ratio, and amplitude on the oil yield and recovery were investigated. Approximately 56.97% of oil yield and 99.54% of oil recovery were attained using mild conditions of 35 min, 35 °C, 40% amplitude, isopropanol to acetone (1:1), and solvent to sample (20 mL/g). UAE oil yield and recovery were comparable with Soxhlet extraction (SXE) whilst mechanical pressing (ME) yielded < 50% of UAE recovery. UAE does not affect the fatty acids composition (46% C18:1; 22% C16:0; 21% C18:0, 10% C18:2), and triacylglycerol profile (23% POO, 17% POS, 16% SOO, and 14% POP). Interestingly, UAE extracted oil conferred remarkably (P < 0.05) higher antioxidant capacity (IC50 of DPPH 106.60 mg/mL and ABTS 39.80 mg/mL) than SXE (IC50 of DPPH 810.40 mg/mL and ABTS 757.43 mg/mL) or ME (IC50 of DPPH 622.38 mg/mL and ABTS 392.87 mg/mL).

Effect of drying methods on yield, physicochemical properties, and total polyphenol content of chamomile extract powder.

Chamomile (Matricaria chamomilla L.) is a traditional medicinal plant used to treat hay fever, inflammation, muscle spasms, menstrual disorders, insomnia ulcers, wounds, gastrointestinal disorders, rheumatic pain, and hemorrhoids. Dried chamomile flowers have a longer shelf life and the dried extract in form of powder offers much flexibility for new therapeutic formulations as it could be used as a replacement for liquid extract and serve as a shelf-stable ingredient in new applications. This study aims to determine the effect of drying methods, i.e., convection oven-drying at 45 °C, freeze-drying at -50°C, and spray-drying at 140°C at 10.5 and 12 ml/min, respectively) on powder yield, physicochemical properties (moisture content, water activity, and color attributes), and total polyphenol content of chamomile extract powder. Our findings showed that spray-drying conducted at 140°C, 12 ml/min resulted in the lowest yield of powder (16.67%) compared to convection oven-drying (90.17%) and freeze-drying (83.24%). Decreasing the feed flow rate to 10.5 ml/min during spraying caused an increase in powder yield to 26.99%. The moisture content of spray-dried chamomile extract powder obtained at 140°C, 10.5 ml/min was higher (11.00%) compared to that of convection oven-dried (8.50%) and freeze-dried (7.50%). Both convection oven-dried and freeze-dried chamomile extract powder displayed no significant difference (p > 0.05) in moisture content. The higher feed flow rate (12 ml/min) in spray-drying also led to an increase in the moisture content of chamomile extract powder to 12.00%. The higher residual moisture found in the spray-dried samples resulted in partial agglomeration of particles. In terms of water activity, freeze-dried chamomile extract powder was found to have the highest water activity (0.63) compared to that of convection oven-dried (0.52), spray-dried at 140°C, 10.5 ml/min (0.57), and spray-dried at 140°C, 12 ml/min (0.58). Spray-dried and freeze-dried chamomile extract powder with high moisture content and water activity could be highly susceptible to microbial growth. In terms of color attributes, higher drying temperature in spray-drying led to darker, redder, and more yellowish chamomile extract powder that could be caused by heat-induced Maillard reaction and caramelization. Since lower drying temperature was used in both convection oven-drying and freeze-drying, both convection oven-dried (56.94 mg GAE/g powder) and freeze-dried chamomile extract powder (55.98 mg GAE/g powder) were found to have higher total polyphenol content compared to those of spray-dried (42.79-46.79 mg GAE/g powder). The present findings allow us to understand the effect of drying methods on the properties of chamomile extract powder and provide a better drying option to dry chamomile extract. Due to higher powder yield with ideal powder properties such as low moisture content and water activity, desirable color, and high total polyphenol content obtained from convection oven-drying, convection oven-drying was a better option than freeze-drying and spray-drying for drying chamomile extract.

Volatile organic compounds and sensory profile of dark chocolates made with cocoa beans fermented with Pichia kudriavzevii and Hanseniaspora thailandica.

Volatile organic compounds (VOCs) are important to determine the aroma and sensory perception of cocoa. Starter cultures can modulate the volatile profile of cocoa beans during fermentation. This study aimed to determine the VOCs and sensory of chocolates produced using cocoa beans fermented with yeast starters (Pichia kudriavzevii (MH979681), Hanseniaspora thailandica (MH979675) and the mixture of the two yeasts (Mix)). The VOCs of chocolates were determined by Head-Space Solid Phase Microextraction followed by Gas Chromatography-Mass Spectrophotometry. Sensory analysis was determined by using trained panels. VOCs profiles of chocolates produced using beans fermented with HT, PK or Mix were noticeably different from Ghana and control chocolates (no starter). The addition of yeast starters during cocoa fermentation produced chocolates that were preferred by trained panels. Bitterness and astringency were the more intense flavour attributes in chocolates produced using cocoa beans added with yeast starters. The chocolate produced using cocoa beans fermented with PK was the most acidic; whereas chocolate produced using beans fermented with Mix had the sweetest taste. The addition of PK or HT is helpful in producing chocolate with a distinct flavour.

Investigation into Lewis and Brønsted acid interactions between metal chloride and aqueous choline chloride-oxalic acid for enhanced furfural production from lignocellulosic biomass.

Furfural has been identified as a valuable biobased platform chemical that can be further converted into bioenergy and biochemicals. Furfural is derived from lignocellulosic biomass and can also be regarded as a sustainable alternative to petrochemical products. Herein, the performance of trivalent metal chlorides (FeCl3, AlCl3) and tetravalent metal chlorides (SnCl4, TeCl4) as Lewis acidic cocatalysts was investigated in an aqueous choline chloride-oxalic acid (16.4 wt% H2O) deep eutectic solvent (DES) system for producing furfural from oil palm fronds (OPFs). The metal chlorides with greater electrical field gradients were stronger Lewis acids that enhanced both furfural production and degradation reactions. The main degradation product in this reaction system was humin, and this result was confirmed by FTIR analysis. By subjecting OPFs to an aqueous DES reaction (120 °C, 45 min) with SnCl4 (2.50 wt%), a furfural yield of 59.4% was obtained; without incorporated metal chlorides, the furfural yield was 46.1%. Characterization studies showed synergistic Lewis and Brønsted acid interactions between metal chlorides and DES components. Overall, the residual OPFs showed high glucan content, which led to the production of glucose (71.4%) as a byproduct via enzymatic hydrolysis. Additionally, the aqueous DES system was recycled and reused for several additional runs. The proposed aqueous DES system presents a promising biorefinery approach for the conversion of OPFs to biochemicals.

Palm Olein Organogelation Using Mixtures of Soy Lecithin and Glyceryl Monostearate.

The present work investigated the interaction between soy lecithin (SL), glyceryl monostearate (GMS), and water in structuring palm olein (PO) to create an organogel having similar mechanical properties to commercial spread. Extreme vertices mixture design was used to optimize the composition of PO-based organogel. The resulting model showed a good fit to the predicted data with R2 ≥ 0.89. The optimum composition was 8% SL, 22% GMS, 28% water, and 42% PO (w/w) to produce a mean firmness of 1.91 N, spreadability of 15.28 N s-1, and oil binding capacity (OBC) of 83.83%. The OBC of optimized organogel was 10% higher than commercial spread product, and no significant difference was observed in the mechanical properties (p > 0.05). The microstructure, as well as the rheological and thermal properties of the optimized organogel were characterized. Fourier transform infrared analysis indicated that hydrogen bonding and van der Waals interactions were the key driving forces for organogelation. The mixture of SL and GMS favored the formation of ß' + ß form crystals with a predominance of the ß' form. These results have important implications for the development of PO-based organogel as a potential fat replacer in the production of low-fat spread.

Effects of convection-, vacuum-and freeze-drying on antioxidant, physicochemical properties, functional properties and storage stability of stink bean (Parkia speciosa) powder.

This study aims to investigate the antioxidant, physicochemical and functional properties of convection-, vacuum-and freeze-dried stink bean (Parkia speciosa) powder upon storage at various relative humidity (RH) at room temperature, 25 °C. Both convection- and vacuum-dried samples exhibited stronger DPPH free radical scavenging activity (7.62 ± 1.77 and 10.38 ± 0.63 mg AA/g·db respectively) and ferric ion-chelating (FIC) ability (16.55 ± 1.29 and 18.88 ± 2.36 mg/mL·db respectively) compared to the fresh and freeze-dried samples. Stink bean powder had low water solubility index, water holding capacity and oil holding capacity but it had the potential as emulsifier in food systems. Apparent formation of clumps were observed after 25-day storage of powder at RH of 43%, 54% or 75% due to absorption of moisture from surroundings. Generally, the antioxidant properties and colour of the powders deteriorated after storage especially at higher RH. Vacuum drying would be the most suitable drying method to produce stink bean powder because of its enhanced antioxidant capacities, light colour and relatively more stable after storage.

Characterising absorption and health-related properties of phytochemicals extracted from Malaysian palm fruit biomass after oil extraction.

After oil extraction, palm fruit biomass contains abundant water-soluble phytochemicals (PCs) with proven bioactivity in regulating oxidative stress and inflammation (OSI). For optimal bioefficacy following oral consumption, the pharmacokinetic plasma peak (Tmax) should be bio-matched with the onset of OSI, which can be predicted from the Phytochemical Absorption Prediction (PCAP) model and methodology. Predicted absorption and potential for regulation of OSI by measures of total phenolic content, antioxidant capacity and hydrogen peroxide production capacity, were applied to characterise eight extracts from mesocarp fibre and kernel shells of oil-depleted palm fruits. Results indicated post-consumption absorption Tmax ranges of 0.5-12 h and 2-6 h for intake in liquid and solid forms, respectively, and generally high antioxidant activity of the extracts. The research supports that PC extracts of palm fruit biomass have broad potential uses for human health as dietary antioxidants in foods, supplements or functional beverages.

Stability and recovery of cyclodextrin encapsulated catechin in various food matrices.

Catechin is astringent in taste, sparingly soluble in water and sensitive to oxygen, light and pH. These properties restrict its application in food products. The present study investigated the stability of inclusion complex (IC) and catechin in various food matrices and investigated in vitro recovery profile of catechin and IC in liquid, semi-solid and solid food matrices. Besides, the sensory profile of IC added yogurt was also determined. Results showed that IC and catechin was more stable in solid matrix compared to semi-solid and liquid matrices. IC added in milk and yogurt show the highest percentage recovery of catechin compared to IC added in cheese and catechin added in all the matrices in in vitro digestive system. Through IC, ß-CD masked the bitterness of catechin. These results suggest that protection of antioxidant such as catechin by ß-CD inclusion complex may have applications in functional foods and health supplements.

One-pot furfural production using choline chloride-dicarboxylic acid based deep eutectic solvents under mild conditions.

The performances of various anhydrous and aqueous choline chloride-dicarboxylic acid based deep eutectic solvents (DESs) were evaluated for furfural production from oil palm fronds without any additional catalyst. The effects of different carbon chain length dicarboxylic acids and water content in each DES on furfural production were investigated. Oil palm fronds, DES and water (0-5 ml) were mixed and reacted in an oil bath (60-300 min). Reacted oil palm fronds had the potential to be reused as cellulose-rich-valuable by-products. At 100 °C, aqueous choline chloride-oxalic acid (16.4 wt% H2O) produced the highest furfural yield of 26.34% and cellulose composition up to 72.79% in the reacted oil palm fronds. Despite operating at suitable reaction duration for dicarboxylic acid with longer carbon chain length, aqueous choline chloride-malonic acid and aqueous choline chloride-succinic acid performed poorly with furfural yield of less than 1%.

Deep eutectic solvent and inorganic salt pretreatment of lignocellulosic biomass for improving xylose recovery.

Deep eutectic solvents (DESs) have received considerable attention in recent years due to their low cost, low toxicity, and biodegradable properties. In this study, a sequential pretreatment comprising of a DES (choline chloride:urea in a ratio of 1:2) and divalent inorganic salt (CuCl2) was evaluated, with the aim of recovering xylose from oil palm fronds (OPF). At a solid-to-liquid ratio of 1:10 (w/v), DES alone was ineffective in promoting xylose extraction from OPF. However, a combination of DES (120°C, 4h) and 0.4mol/L of CuCl2 (120°C, 30min) resulted in a pretreatment hydrolysate containing 14.76g/L of xylose, remarkably yielding 25% more xylose than the CuCl2-only pretreatment (11.87g/L). Characterization studies such as FE-SEM, BET, XRD, and FTIR confirmed the delignification of OPF when DES was implemented. Thus, the use of this integrated pretreatment system enabled xylose recoveries which were comparable with other traditional pretreatments.

Recent Advances in the Application of Inorganic Salt Pretreatment for Transforming Lignocellulosic Biomass into Reducing Sugars.

Currently, the transformation of lignocellulosic biomass into value-added products such as reducing sugars is garnering attention worldwide. However, efficient hydrolysis is usually hindered by the recalcitrant structure of the biomass. Many pretreatment technologies have been developed to overcome the recalcitrance of lignocellulose such that the components can be reutilized more effectively to enhance sugar recovery. Among all of the utilized pretreatment methods, inorganic salt pretreatment represents a more novel method and offers comparable sugar recovery with the potential for reducing costs. The use of inorganic salt also shows improved performance when it is integrated with other pretreatment technologies. Hence, this paper is aimed to provide a detailed overview of the current situation for lignocellulosic biomass and its physicochemical characteristics. Furthermore, this review discusses some recent studies using inorganic salt for pretreating biomass and the mechanisms involved during the process. Finally, some prospects and challenges using inorganic salt are highlighted.

Effects of heat, pH, antioxidant, agitation and light on betacyanin stability using red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate as models.

Red-fleshed dragon fruit (Hylocereus polyrhizus) is rich in antioxidants. The aim of this study was to determine the effects of heat pasteurization, pH adjustment, ascorbic acid addition as well as storage under agitation and light or dark condition on betacyanin content in red-fleshed dragon fruit (Hylocereus polyrhizus) juice and concentrate. The concentrate was produced by concentrating clarified red-fleshed dragon fruit juice in a rotary evaporator at 40 °C. UV-Visible spectrophotometer was used for analyzing betacyanin content. Addition of 0.25 % ascorbic acid, pH 4.0, and pasteurization at 65 °C for 30 min were selected as the best processing conditions to retain betacyanin content in red-fleshed dragon fruit juice. Storage at the agitation speed of 220 rpm showed that the concentrated samples had higher betacyanin stability compared to juice, while both juice and concentrate had almost similar betacyanin stability when tested for storage in the presence of light. In summary, ascorbic acid stabilized betacyanin in both juice and concentrate at agitated or non-agitated conditions. In contrast, light degraded betacyanin in both juice and concentrate models.

Enhanced xylose recovery from oil palm empty fruit bunch by efficient acid hydrolysis.

Oil palm empty fruit bunch (EFB) is abundantly available in Malaysia and it is a potential source of xylose for the production of high-value added products. This study aimed to optimize the hydrolysis of EFB using dilute sulfuric acid (H2SO4) and phosphoric acid (H3PO4) via response surface methodology for maximum xylose recovery. Hydrolysis was carried out in an autoclave. An optimum xylose yield of 91.2 % was obtained at 116 °C using 2.0 % (v/v) H2SO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. A lower optimum xylose yield of 24.0 % was observed for dilute H3PO4 hydrolysis at 116 °C using 2.4 % (v/v) H3PO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. The optimized hydrolysis conditions suggested that EFB hydrolysis by H2SO4 resulted in a higher xylose yield at a lower acid concentration as compared to H3PO4.

Cryo-responses of two types of large unilamellar vesicles in the presence of non-permeable or permeable cryoprotecting agents.

Cryo-responses of two types of large unilamellar vesicles (LUV) that were made from either egg yolk L-alpha-phosphatidylcholine (EPC) or 1,2-dipalmitoyl-rac-glycero-3-phosphocholine (DPPC), in the presence of non-permeable or permeable cryoprotective agents (CPA) was investigated. Partial ternary phase diagrams of CPA-salt-water with specific CPA to salt ratio (R), were constructed to estimate the phase volume of ice and unfrozen matrix of the LUV dispersion, which could aid in understanding the mechanistic actions of CPA. Leakage of both EPC and DPPC LUV was reduced if the sugar concentrations are above 10% (w/w) for disaccharides and 5% (w/w) for monosaccharides. Above these sugar concentrations, non-permeable CPA were more effective in preventing leakage of DPPC LUV than in EPC LUV. Below these sugar concentrations, EPC and DPPC LUV with limited mobility in the remaining unfrozen matrix were more likely to approach and interact with one and another, which were not anticipated when the LUV were completely embedded in the ice matrix. In the presence of Me(2)SO or EG, EPC LUV that had been subjected to freezing and thawing processes were protected from leakage. At room temperature, Me(2)SO and EG were detrimental to the DPPC LUV. This study suggests that the choice of CPA for cell cryopreservation depends on the type of phospholipids in plasma membranes, which vary in their acyl chain length and gel-liquid crystal phase transition temperature.

Characterizing the freezing behavior of liposomes as a tool to understand the cryopreservation procedures.

Freezing behaviors of egg yolk l-alpha-phosphatidylcholine (EPC) and 1,2-dipalmitoyl-rac-glycero-3-phosphocholine (DPPC) large unilamellar vesicles (LUV) were quantitatively characterized in relation to freezing temperatures, cooling rates, holding time, presence of sodium chloride and phospholipid phase transition temperature. Cooling of the EPC LUV showed an abrupt increase in leakage of the encapsulated carboxyfluorescein (CF) between -5 degrees C and -10 degrees C, which corresponded with the temperatures of the extraliposomal ice formation at around -7 degrees C. For the DPPC LUV, CF leakage started at -10 degrees C, close to the temperature of the extraliposomal ice formation; followed by a subsequent rapid increase in leakage between -10 degrees C and -25 degrees C. Scanning electron microscopy showed that both of these LUV were freeze-concentrated and aggregated at sub-freezing temperatures. We suggest that the formation of the extraliposomal ice and the decrease of the unfrozen fraction causes freeze-injury and leakage of the CF. The degree of leakage, however, differs between EPC LUV and DPPC LUV that inherently vary in their phospholipid phase transition temperatures. With increasing holding time, the EPC LUV were observed to have higher leakage when they were held at -15 degrees C compared to at -30 degrees C whilst leakage of the DPPC LUV was higher when holding at -40 degrees C than at -15 degrees C and -50 degrees C. At slow cooling rates, osmotic pressure across the bilayers may cause an additional stress to the EPC LUV. The present work elucidates freeze-injury mechanisms of the phospholipid bilayers through the liposomal model membranes.

Effect of intra- and extra-liposomal distribution of sodium chloride on the stability of large unilamellar vesicles.

Three groups of 1,2-dipalmitoyl-rac-glycero-3-phosphocholine (DPPC) large unilamellar vesicle (LUV) dispersions were studied: LUV (A) dispersions with only extraliposomal sodium chloride (NaCl), LUV (B) dispersions with intra- and extraliposomal NaCl, and LUV (C) dispersions with only intraliposomal NaCl. The NaCl concentrations ranged from 0 to 150 mM. An abrupt increase in leakage was observed around -10 degree C for all the three groups of LUV, which coincided with the temperature of extraliposomal ice formation. Within the three groups, leakage of LUV (C) was significantly higher than the other groups. Extraliposomal ice formation and the resulting freeze-concentration of LUV may be the major cause of the leakage. Intraliposomal ice formation observed at -43 degree C seemed to stop leakage of LUV when LUV were frozen below -43 degree C. An exotherm of eutectic crystallization of NaCl was occasionally observed at -37 degree C, with a higher probability of formation at 150 mM extraliposomal NaCl than at 50 mM. The eutectic crystals were thought to cause additional leakage from the LUV (B).