Effect of amylose and amylopectin content on the colloidal behaviour of emulsions stabilised by OSA-Modified starch

Spatially selective catalysis of OSA starch for preparation of Pickering emulsions with high emulsification properties

The traditional strategies of chemical catalysis and biocatalysis for producing octenyl succinic anhydride modified starch can only randomly graft hydrophobic groups on the surface of starch, resulting in unsatisfactory emulsification performance. In this work, a lipase-inorganic hybrid catalytic system with multi-scale flower like structure is designed and applied to spatially selective catalytic preparation of ocenyl succinic anhydride modified starch. With the appropriate floral morphology and petal density, lipases distributed in the "flower center" can selectively catalyze the grafting of hydrophobic groups in a spatial manner, the hydrophobic groups are concentrated on one side of starch particles. The obtaining OSA starch exhibits excellent emulsifying property, and the pickering emulsion has good protective effect on the embedded curcumin. This work provides a direction for the development of high-performance starch-based emulsifiers for the food and pharmaceutical industries, which is of great significance for improving the preparation and emulsification theory research of modified starch.

Physicochemical and functional properties of short-chain fatty acid starch modified with different acyl groups and levels of modification

Rice and quinoa starches are modified with short-chain fatty acids (SCFA) with different SCFA acyl chain lengths and levels of modification. This work is aimed to investigate the impact of modifying rice and quinoa starches with short-chain fatty acids (SCFAs) on various physicochemical properties, including particle size, protein and amylose content, thermal behavior, pasting characteristics, and in vitro digestibility. Both native and SCFA-starches showed comparable particle sizes, with rice starches ranging from 1.58 to 2.22 μm and quinoa starches from 5.18 to 5.72 μm. SCFA modification led to lower protein content in both rice (0.218-0.255 %) and quinoa starches (0.537-0.619 %) compared to their native counterparts. Esterification led to the reduction of gelatinization and pasting temperatures as well as the hardness of the paste of SCFA-starches were reduced while paste clarity increased. The highest level of modification in SCFA-starch was associated with the highest amount of resistant starch fraction. Principal component analysis revealed that modification levels exerted a greater influence on starch properties than the types of SCFA used (acetyl, propionyl, and butyryl). These findings is importance in considering the degree of substitution or level of modification when tailoring starch properties through SCFA modification, with implications for various applications in food applications.

Effect of ultrasonic power on delivery of quercetin in emulsions stabilized using octenyl succinic anhydride (OSA) modified broken japonica rice starch

In this study, emulsions stabilized by octenyl succinic anhydride-modified broken japonica rice starch (OSA-BJRS) were prepared at different ultrasonic power intensities for the delivery, controlled release, and improved bioavailability of quercetin. The OSA-BJRS emulsions ultrasonicated at 400 W exhibited the highest encapsulation efficiency (89.37 %) and loading efficiency (58.34 %) of quercetin, the smallest volume-average droplet diameter (0.51 μm) and polydispersity index (0.19), the highest absolute value of the ζ-potential (26.73 mV), and the highest apparent viscosity and viscoelasticity. The oxidation stability, storage stability, thermal stability, and salt ion stability of the emulsions were also notably improved by the ultrasonication treatment. In addition, the results of the simulated in vitro digestion demonstrated that the ultrasonicated OSA-BJRS emulsions had an enhanced quercetin delivery performance and could stably transport quercetin to the small intestine for digestion. The OSA-BJRS emulsion ultrasonicated at 400 W exhibited the highest cumulative release rate (95.91 %) and the highest bioavailability (30.48 %) of quercetin. This suggests that OSA-BJRS emulsions prepared by ultrasonication can be considered effective delivery systems for hydrophobic functional components.

Differences in the structural properties of three OSA starches and their effects on the performance of high internal phase Pickering emulsions

The emulsifying properties of emulsions are significantly influenced by the structural properties of octenyl succinic anhydride (OSA) starch. The purpose of this work was to elucidate the effect of the structure of OSA starch on its performance as an emulsifier to stabilize Pickering high-internal-phase emulsions (HIPEs). The degrees of substitution (DS) of the three OSA starches were 0.0137, 0.0177 and 0.0236, and their degrees of branching (DB) were 13.96 %, 14.20 % and 14.32 % measured by 1H NMR, which were sequentially labeled as OSA1, OSA2, and OSA3. The OSA3 starch with higher DS and DB had a lower critical micelle concentration (CMC) (0.11 mg/mL). Its emulsification activity (EAI) and emulsion stability (ES) were 61.8 m2/g and 72.5 min, respectively, which were higher than OSA1 and OSA2 starches. The contact angle of the three OSA starches increased from 45.35° to 80.03° with increasing DS and DB. Therefore, it is hypothesized that OSA3 starches have better emulsification properties. The results of physical stability of HIPEs confirmed the above results. These results indicated that DS and DB have a synergistic effect on emulsion properties, and OSA starch with higher DS and DB values were more conducive to the construction of stable HIPEs systems.

Effect of starch-based emulsion with different amylose content on the gel properties of Nemipterus virgatus surimi

The emulsion was prepared with peanut oil and corn starch with different amylose content using high-speed homogenization assisted high-pressure homogenization, and the effect of starch-based emulsion on the gel properties, whiteness, microstructure, protein secondary structure, chemical forces, texture and sensory properties of Nemipterus virgatus surimi was investigated. The results showed that high amylose corn starch was more beneficial to the stability of emulsion than normal and waxy starch. The gel strength, water holding capacity and texture properties of surimi were significantly improved by adding 10 % waxy corn starch-based emulsion or 15 % high amylose or normal corn starch-based emulsion. Moreover, the whiteness of surimi gel containing starch-based emulsion was higher, and the microstructure was more compact and delicate than that of surimi without emulsion. The addition of starch-based emulsion could increase the hydrophobic interaction and disulfide bond content, and promote the transformation of protein secondary structure to irregular direction. The sensory properties such as color, texture, taste and overall acceptability could be improved to varying degrees. Therefore, starch-based emulsion could be used to enhance the gel properties and nutritional value of surimi products.

Comparative study on the in vitro digestion of different lipids in starch-based Pickering emulsions

Starch-based Pickering stabilizer has attracted more attentions due to its health-friendly attribute. Lipid digestion in Pickering emulsion is the key to its delivery ability for active substances. Herein, in vitro oral-gastric-intestinal digestions of Pickering emulsions stabilized by starch particles with different oil phases (e.g., coconut, corn, olive, and sunflower oils) were investigated. The highest rate of lipid digestion was coconut oil (25.71 %), followed by olive (12.64 %), corn (11.16 %), and sunflower (8.99 %) oils. The lipid digestibility was influenced by saturation of fatty acids: coconut (91.41 %)>olive (16.58 %)>corn (14.63 %)>sunflower (10.85 %) oils. The increase of starch concentration (0.5 % - 4.0 %, w/w) had positive effects, while the increase of oil fraction (25 % - 70 %, v/v) had negative impacts on free fatty acid release due to the formation of different initial droplet sizes. The microstructures observed using confocal laser scanning microscope indicated that starch-based Pickering emulsion possessed super stability against oral and gastric digestions, which made it a superior delivery system for lipophilic active substances under severe gastric environment. These results may promote the design of functional food emulsions stabilized by starch particles which can regulate digestion of triglycerides.

Foaming with Starch: Exploring Faba Bean Aquafaba as a Green Alternative

The demand for sustainable and functional plant-based products is on the rise. Plant proteins and polysaccharides often provide emulsification and stabilization properties to food and food ingredients. Recently, chickpea cooking water, also known as aquafaba, has gained popularity as a substitute for egg whites in sauces, food foams, and baked goods due to its foaming and emulsifying capacities. This study presents a modified eco-friendly process to obtain process water from faba beans and isolate and characterize the foam-inducing components. The isolated material exhibits similar functional properties, such as foaming capacity, to aquafaba obtained by cooking pulses. To isolate the foam-inducing component, the faba bean process water was mixed with anhydrous ethanol, and a precipitated fraction was obtained. The precipitate was easily dissolved, and solutions prepared with the alcohol precipitate retained the foaming capacity of the original extract. Enzymatic treatment with α-amylase or protease resulted in reduced foaming capacity, indicating that both protein and carbohydrates contribute to the foaming capacity. The dried precipitate was found to be 23% protein (consisting of vicilin, α-legumin, and β-legumin) and 77% carbohydrate (amylose). Future investigations into the chemical structure of this foam-inducing agent can inform the development of foaming agents through synthetic or enzymatic routes. Overall, this study provides a potential alternative to aquafaba and highlights the importance of exploring plant-based sources for functional ingredients in the food industry.

Application of Pickering emulsions stabilized by corn, potato and pea starch nanoparticles: Effect of environmental conditions and approach for curcumin release

To apply octenyl succinic anhydride (OSA)-modified corn, potato and pea starch nanoparticles (OCSNPs, OPtSNPs and OPSNPs, respectively) as Pickering emulsion stabilizers, effect of environmental conditions such as 30 days of storage period, pH of 1-11, ionic strength of 0.1-0.9 mol/L and heat of 30-90 °C on the stability of the emulsions was evaluated. Compared with emulsions stabilized by starch nanoparticles (SNPs), the emulsions stabilized by OSA-modified SNPs (OSNPs) kept stable against different environmental stresses (pH, ionic strength and heat) as well as for a storage period of 30 days, especially for OPtSNPs. Additionally, oiling-off was not observed in OSNPs emulsions over the storage time. OSNPs emulsions also showed improved protection on curcumin during storage and controlled release during in vitro digestion. These findings enlarged the application of OCSNPs, OPtSNPs and OPSNPs stabilized-Pickering emulsion in food systems and deliver system.

Effect of polymer architecture on the adsorption behaviour of amphiphilic copolymers: A theoretical study

HYPOTHESIS

Polymer architecture is known to have significant impact on its adsorption behaviour. Most studies have been concerned with the more concentrated, "close to surface saturation" regime of the isotherm, where complications such as lateral interactions and crowding also additionally affect the adsorption. We compare a variety of amphiphilic polymer architectures by determining their Henry's adsorption constant (k_H), which, as with other surface active molecules, is the proportionality constant between surface coverage and bulk polymer concentration in a sufficiently dilute regime. It is speculated that not only the number of arms or branches, but also the position of adsorbing hydrophobes influence the adsorption, and that by controlling the latter the two can counteract each other.

METHODOLOGY

The Self-consistent field calculation of Scheutjens and Fleer was implemented to calculate the adsorbed amount of polymer for many different polymer architectures including linear, star and dendritic. Using the adsorption isotherms at very low bulk concentrations, we determined the value of k_H for these.

FINDINGS

It is found that the branched structures (star polymers and dendrimers) can be viewed as analogues of linear block polymers based on the location of their adsorbing units. Polymers containing consecutive trains of adsorbing hydrophobes in all cases showed higher level of adsorption compared to their counterparts, where the hydrophobes were more uniformly distributed on the chains. While increasing the number of branches (or arms for star polymers) also confirmed the known result that the adsorption decreased with the number of arms, this trend can be partially offset by the appropriate choice of the location of anchoring groups.

Octenyl succinic anhydride modified starch with excellent emulsifying properties prepared by selective hydrolysis of supramolecular immobilized enzyme

Octenyl succinic anhydride modified starch is a common green and safe emulsifier. Although the conventional pretreatment method of free enzyme hydrolysis increases the hydroxyl content on the starch surface, thus improving the grafting degree of octenyl succinic anhydride and the amphiphilicity of the modified starch, the amylose and amylopectin structures are indiscriminately hydrolyzed, reducing the emulsion stability of modified starch. In this work, α-amylase organic-inorganic hybrid nanoflower biocatalyst is designed and synthesized for pretreatment of synthetic octenyl succinic anhydride modified starch. The α-amylase organic-inorganic hybrid nanoflower biocatalyst with a unique micro-nano spatial structure can selectively hydrolyze the amylopectin and protect the amylose of starch. The amylose ratio of starch pretreated by nanoflower biocatalyst is about twice that of starch pretreated by free enzyme, reaching 22.62 %. Meanwhile, the granular structure of starch is not damaged. The obtained octenyl succinic anhydride modified starch exhibits a high degree of substitution, up to 0.0213. The emulsion prepared with this modified starch maintains excellent emulsifying properties and stability. This study provides a novel strategy for the preparation of octenyl succinic anhydride modified starch with excellent emulsifying properties, which promote the application of octenyl succinic anhydride modified starch in food, pharmaceutical and cosmetic industries.

Lipase-polydopamine magnetic hydrogel microspheres for the synthesis of octenyl succinic anhydride starch

Octenyl succinic anhydride (OSA) starch is an important edible additive in the food field, and its synthesis method has attracted much attention. Lipase as a biocatalyst can improve the synthesis efficiency of OSA starch, and significantly inhibit the occurrence of side reactions. However, free lipase has not been widely applied in the synthesis of OSA starch due to the difficulty of separation from starch and poor reusability. In this work, a promising strategy for the synthesis of OSA starch catalyzed by lipase immobilized on polydopamine magnetic hydrogel microspheres (PMHM) is reported. The prepared lipase-polydopamine magnetic hydrogel microspheres (L-PMHM) can be uniformly dispersed in starch slurry, which is conducive to the full contact between lipase and starch. L-PMHM (Km =2.6276 μmol/mL) exhibits better affinity to the substrate than free lipase (Km = 3.4301 μmol/mL). Compared with the OSA starch catalyzed by free lipase (DS = 0.0176), the degree of substitution of OSA starch catalyzed by L-PMHM is up to 0.0277 in a short reaction time. In cyclic catalysis, L-PHMM can remain about 48 % of their original activity after 20 reuses and can be quickly separated from the product. These results suggest that L-PMHM has great potential as a biocatalyst for the efficient synthesis of OSA starch.

Enhanced oral oil release and mouthfeel perception of starch emulsion gels

Reducing oil/fat content without compromising the structural and sensory quality of food is a great technical challenge to the food industry. The present work aims to investigate the possibility of a novel emulsion design that gives an enhanced oral release of oil/fat from an emulsion gel and therefore an enhanced mouthfeel of oiliness. Hence, alpha-amylase sensitive emulsifier such as starch was used for this purpose. On the other hand, whey protein isolate (WPI) i.e. α-amylase insensitive emulsifier was used as a reference. The gellan gum was selected as a gelling agent to prepare emulsion gels. The mastication and size reduction of the emulsion gels were examined through in-vitro and in-vivo studies. The amount of oil released as indicated by the β-carotene analysis was monitored and various influencing factors (pH, time, compositions, etc.) were also investigated. Using sensory panelists, oral processing of emulsion gels was examined in terms of both mastication parameters and perceptions of oiliness and thickness. The obtained results showed that the use of a starch emulsifier gives a higher oil release and an enhanced oral sensation of oiliness mouthfeel. Therefore, starch emulsion could provide a novel solution in the design of fat-reduced food products with no effect on the mastication parameter, sensation and perception of fat-related attributes.