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Vitamin D3 was encapsulated in 10% wt soybean oil-in-water (O/W) Pickering emulsions stabilized by either nanofibrillated cellulose (NFC) or whey protein isolate (WPI) at 0.3%, 0.5%, and 0.7% w/w. The vitamin D3 -enriched emulsions were tested for their stability against temperature (30 °C to 90 °C), pH (2 to 8), and ionic strength (0 to 500 mM NaCl). The mean particle diameter (d32 ), ζ-potential, and creaming stability of the oil droplets in the emulsions were measured, as well as their vitamin D3 encapsulation efficiency (EE). After preparation, the oil droplet size (d32 ) of the emulsions stabilized by NFC increased with increasing emulsifier concentration, whereas the droplet size of emulsions stabilized by WPI decreased. NFC provided good stability to the emulsions through a combination of steric and electrostatic repulsion. The EE of vitamin D3 increased with increasing emulsifier concentration. Heating or ionic strength did not significantly (P < 0.05) affect the emulsions properties and EE. On the other hand, the NFC-stabilized emulsions were sensitive to highly acidic conditions (pH 2), with an increase in particle size and decrease in EE. The WPI-stabilized emulsions aggregated around the isoelectric point of the adsorbed proteins (pI ≈ 4.8). Increasing NFC or WPI concentration improved the stability and EE of the emulsions against environmental stresses. NFC-stabilized emulsions had good long-term stability. The results show that NFC can be used as an effective emulsifier for creating vitamin-enriched emulsions with good stability. PRACTICAL APPLICATION: This study can be used to develop more effective encapsulation technologies for fat-soluble vitamins in emulsion-based food products. Encapsulation using nanofibrillated cellulose effectively protected the encapsulated vitamins against environmental stresses which occur in industrial food production (such as pH changes, salt addition, and thermal processing). Moreover, nanofibrillated cellulose extracted from mangosteen rind is a nature-derived emulsifier that is environmental friendly.

The aim of this research was to investigate the extraction yield and physicochemical properties of sago starch extracted after enzymatic pretreatment. Sago pith was enzymatic-pretreated by varying enzyme (cellulase enzyme complex) concentration, pretreatment time, and sago pith slurry concentration. The extracted sago starch was analyzed for its properties, e.g., extraction yield, pasting and thermal properties, and in vitro starch digestibility. Sago pith contained 82% (db) starch. The extraction yield and reducing sugar released increased with enzyme concentration and pretreatment time. The optimum enzymatic pretreatment conditions were 10% (w/w) sago pith slurry, enzyme concentration of 0.25 mL (618 carboxymethylcellulose unit and 139 p-nitrophenyl-β-d-glucopyranoside unit)/g substrate, and 24 h pretreatment time, providing the highest extraction yield of 71.36% (w/w sago pith, db), while control method, without enzymatic pretreatment, provided 61.01% extraction yield. Results from pasting and thermal properties confirmed that the granular stability, resistance to shear, and crystalline perfection of sago starch were improved due to hydrothermal effect of annealing during enzymatic pretreatment. The enzymatic-pretreated sago starch also had lower retrogradation but higher starch digestibility than the control sago starch. The enzymatic pretreatment enhanced the extraction yield of sago starch and also improved its quality by the effect of annealing.

The purpose of this study was to produce and characterize core-shell biopolymer particles based on electrostatic deposition of an anionic polysaccharide (beet pectin) onto amphoteric protein aggregates (heat-denatured beta-lactoglobulin [beta-lg]). Initially, the optimum conditions for forming stable protein particles were established by thermal treatment (80 degrees C for 15 min) of 0.5 wt% beta-lg solutions at different pH values (3 to 7). After heating, stable submicron-sized (d=100 to 300 nm) protein aggregates could be formed in the pH range from 5.6 to 6. Core-shell biopolymer particles were formed by mixing a suspension of protein aggregates (formed by heating at pH 5.8) with a beet pectin solution at pH 7 and then adjusting the pH to values where the beet pectin is adsorbed (< pH 6). The impact of pH (3 to 7) and salt concentration (0 to 250 mM NaCl) on the properties of the core-shell biopolymer particles formed was then established. The biopolymer particles were stable to aggregation from pH 4 to 6, but aggregated at lower pH values because they had a relatively small -potential. The biopolymer particles remained intact and stable to aggregation up to 250 mM NaCl at pH 4, indicating that they had good salt stability. The core-shell biopolymer particles prepared in this study may be useful for encapsulation and delivery of bioactive food components or as substitutes for lipid droplets.

A preparation of β-glucan, obtained from spent brewer's yeast, was evaluated for potential food applications. This material was autolysed and the cell walls that were obtained were homogenized, extracted firstly with alkali, then with acid, and then spray dried. Effects of the homogenization on the chemical composition, rheological properties and functional properties of β-glucan were investigated. Homogenized cell walls exhibited higher β-glucan content and apparent viscosity than those which had not been homogenized because of fragmentation of the cell walls. When compared with commercial β-glucan from baker's yeast, it was found that the β-glucan obtained from this study had higher apparent viscosity, water-holding capacity and emulsion stabilizing capacity, but very similar oil-binding capacity. These findings suggest that β-glucan obtained from brewer's yeast can be used in food products as a thickening, water-holding, or oil-binding agent and emulsifying stabilizer.

Sago starch extracted from the pith of sago palm using a traditional method has a low extraction yield. In this study, an effective extraction method for sago starch production with high extraction yield and acceptable starch quality was investigated using various pretreatment techniques, that is, ultrasonic, microwave, and enzymatic pretreatments, as well as combined pretreatment methods. The sago pith slurry was pretreated before subjecting to the normal process of sago starch extraction. The extracted sago starch was analyzed for extraction yield and physicochemical properties. Sago pith had high starch content of 82.0% (db). The highest extraction yields obtained using ultrasonic, microwave, enzymatic, and combined ultrasonic–enzymatic pretreatment methods were 71.5, 63.7, 71.4, and 72.5%, respectively, while the control method (without pretreatment) provided 61.0% extraction yield. The peak viscosity and color L* value of all extracted sago starches met the requirements of edible sago starch. Concerning the effective pretreatment method in terms of reduced time and energy consumption, while providing high extraction yield and acceptable starch quality, the ultrasonic pretreatment was recommended. The highest yielding ultrasonic pretreatment conditions were found to be 10% w/w sago pith slurry, 160 W power input, and 7 min pretreatment time.