Effect of the degree of substitution of octenyl succinic anhydride-banana starch on emulsion stability

The structural, antioxidant and emulsifying properties of cellulose nanofiber-dihydromyricetin mixtures: Effects of composite ratio

In this work, effects of cellulose nanofiber/dihydromyricetin (CNF/DMY) ratio on the structural, antioxidant and emulsifying properties of the CNF/DMY mixtures were investigated. CNF integrated with DMY via hydrogen bonding and the antioxidant capacity of mixtures increased with decreasing CNF/DMY ratio (k). The oxidative stability of emulsions enhanced as the DMY content increased. Emulsions formed at Φ = 0.5 displayed larger size (about 25 μm), better viscoelasticity and centrifugal stability than those at Φ = 0.3 (about 23 μm). The emulsions at k = 17:3 and Φ = 0.5 exhibited the most excellent viscoelasticity. In conclusion, the DMY content in mixtures and the oil phase fraction exhibited distinct synergistic effects on the formation and characteristics of emulsions, and the emulsions could demonstrate superior oxidative and storage stability. These findings could provide a novel strategy to extend the shelf life of cellulose-based emulsions and related products.

Stabilization of oil-in-water high internal phase emulsions with octenyl succinic acid starch and beeswax oleogel

High internal phase emulsions (HIPEs) based on beeswax (BW) oleogels and octenyl succinic acid starch (OSA starch) were prepared by a facile one-step method. Effects of the oleogelation of internal phase on the formation, stability and functionality of the HIPEs were investigated. OSA starch absorbed at the interface allowed high surface charge (|ζ| > 25 mV) of the droplets, and small droplet size (d ≈ 5 m). Microstructural observation suggested that the HIPEs were of O/W type with droplets packed tightly. With the increase in BW content (0-4 %), the particle size (4-7 μm) and ζ-potential (-25 ~ -30 mV) of the HIPEs were first decreased and then increased. Stability analysis revealed that the addition of BW effectively improved emulsion stability against centrifugation, freeze-thawing, changes in pH and ionic strength, and the HIPE with 2 % BW presented the best stability. Rheological tests indicated that the HIPEs with higher content of BW exhibited higher storage modulus, solid-like properties, and shear thinning behaviors. Creep-recovery results implied that the oleogelation enhanced the structure of HIPEs and improved the deformation resistance of the systems. When subjected to light and heat, oleogel-in-water HIPEs showed advantages in protecting β-carotene from degradation, and β-carotene in the HIPEs with 2 % BW had the lowest degradation rate. These findings suggested that gelation of oil phase could improve the stability of HIPEs and the encapsulation capability, which would be meaningful for the development of novel healthy food.

Structure and surface properties of ozone-conjugated octenyl succinic anhydride modified waxy rice starch: Towards high-stable Pickering emulsion

In the present work, a dual-modified waxy rice starch (OOWRS) fabricated with OSA and ozone was successfully used to stabilize the O/W Pickering emulsion. The molecular structure, surface properties, and underlying stabilizing mechanism were systematically investigated. The results showed that oxidation occurring on the surface of OSA-modified waxy rice starch (OSAWRS) resulted in the presence of indentations and cracks. The relative crystallinity of starch was generally decreased with increasing degree of oxidation. Due to the introduction of carbonyl and the variation in surface structure, the hydrophobicity and acidity of OSAWRS were significantly enhanced after the ozone treatment. Remarkably, OOWRS stabilized Pickering emulsion exhibited a feature of typical O/W emulsion, and the 0.5 h and 1 h OOWRS emulsion exhibited a more uniform droplet size as well as a higher surface potential. We also noted that a weak-gel network was formed within the OOWRS emulsion system as the hydrophilic starch chains played a bridging role. Two reasons for the improved stability of the emulsion were the special gel structure and the enhanced electrical repulsion among the droplets. This research provides that ozone-conjugated OSA modification is a promising strategy for improving the emulsion ability of starch-based Pickering emulsions.

The role and mechanism of electron beam irradiation in glutaric anhydride esterified proso millet starch: Multi-scale structure and physicochemical properties

To investigate the effect of electron beam irradiation (EBI) pretreatment on the multiscale structure and physicochemical properties of esterified starch, this study used EBI pretreatment to prepare glutaric anhydride (GA) esterified proso millet starch. GA starch did not show the corresponding distinct thermodynamics peaks. However, it had a high pasting viscosity and transparency (57.46-74.25 %). EBI pretreatment increased the degree of glutaric acid esterification (0.0284-0.0560) and changed its structure and physicochemical properties. EBI pretreatment disrupted its short-range ordering structure, reducing the crystallinity, molecular weight and pasting viscosity of glutaric acid esterified starch. Moreover, it produced more short chains and increased the transparency (84.28-93.11 %) of glutaric acid esterified starch. This study could offer a rationale for using EBI pretreatment technology to maximize the functional properties of GA modified starch and enlarge its implementation in modified starch.

Influence of fatty acid-esterified waxy maize starch type and concentration on stability and properties of oil-in-water emulsions

In the current study, native and different fatty acid-esterified waxy maize starches (octanoate, myristoate, and stearoate), followed by an OSA-potato starch (as an industrial emulsifier) were used to prepare sunflower oil-in-water (O/W) emulsion. The effect of emulsifier type and concentration were evaluated on properties of emulsions in terms of mean droplet size, droplet size distribution, and creaming index. To prepare the emulsion, the emulsifier to oil ratios of 1.25 and 0.5 for octanoate and industrial emulsifier (control) were considered as the selected formulations based on the lowest creaming index (2.63 and 0 %, respectively). The influence of various pHs and ionic strengths on droplet size, span and zeta potential value was similar for both produced emulsions. Therefore, the fatty acid-esterified starch could be suggested as a promising environmentally friendly alternative to industrial emulsifiers for fabrication of emulsions with similar stability.

Effects of octenyl succinylation on the properties of starches with distinct crystalline types and their Pickering emulsions

Effects of octenylsuccinic anhydride (OSA) esterification on the morphology, crystalline structure, and emulsifying properties of three representative starches with different crystalline types, namely waxy corn starch (A-type), potato starch (B-type), and pea starch (C-type) were investigated. XRD patterns testified OSA substitution occurred principally in the amorphous region without affecting the crystalline patterns, whereas SEM verified esterification was mainly a surface phenomenon. However, OSA esterification caused a decrease in the peak intensity and area of small-angle X-ray scattering profiles, indicating the semi-crystalline lamellae ordering was impeded to a certain extent. Compared with A- and C-type starches, B-type starch had a stronger affinity for OSA, as manifested by its higher degree of substitution (DS), graver surface detriment, and depressed order of semi-crystalline lamellae. The emulsifying properties of all starches were pronouncedly improved by OSA modification, especially for A-type starch even with comparatively lower DS. Pickering emulsion stabilized by OSA-modified A-type starch (A-OSAS) with smaller droplet size and more uniform droplet size distribution exhibited more splendiferous stability relative to the other two modified starches. Moreover, rheological tests revealed A-OSAS possessed the highest apparent viscosity and storage modulus (G'), insinuating strong intermolecular interactions between starch granules at the interface and/or in the continuous phase.

The Properties, Modification, and Application of Banana Starch

Banana is a tropical fruit crop that is consumed at large, not only because of the quantity produced but also because it serves the calorific needs of millions of people. Banana is a potential source of high starch content (more than 60%). The application of starch for various purposes is dependent upon its structural, physicochemical, and functional properties. A native starch does not possess all required properties for specific use in the food product. To improve its application, starch can be modified physically, chemically, and enzymatically. Each of these modification methods provides different characteristics to the modified starch. This review aims to examine the chemical composition, granule morphology, crystallinity, pasting, thermal properties, and digestibility of banana starch, and discusses the various modifications and potential applications of banana starch in the food industry.

Supramolecular structure of quinoa starch affected by nonenyl succinic anhydride (NSA) substitution

Quinoa starch granular structure as affected by nonenyl succinic anhydride (NSA) substitution was investigated by multiple approaches, including scattering, spectroscopic, and microscopic techniques. The modification had little impact on the morphology of starch granules. The NSA substitution was found mainly in the amorphous lamellae and amorphous growth rings. The NSA modification increased the thickness of the amorphous lamellae. The homogeneity of the ordered structure in the granules was improved, probably because the NSA modification reduced the amount of defects in the semi-crystalline growth ring. Compared to other chemical modifications such as acylation, succinylation was more effective in modifying the starch lamellar structure. A possible reaction pattern of NSA modification on quinoa starch is proposed, in which the NSA modification may follow the sequence of amorphous growth rings, the amorphous matrices among blocklets, amorphous and crystalline lamellae in semi-crystalline growth rings. This study provides new insights on the structural changes of starch granules induced by succinylation on the supramolecular level.

Octenyl succinic anhydride modification alters blending effects of waxy potato and waxy rice starches

This study compared blending effects of native and octenyl succinic anhydride (OSA) modified blends (waxy rice and waxy potato starch). OSA groups were observed to be present primarily in the outer layer of waxy potato starch granule, but throughout the whole waxy rice granule. A high linear correlation with blending ratio was observed for trough viscosity and final viscosity of native blends, but for peak viscosity (PV) and breakdown viscosity (BD) of esterified blends. PV and BD of esterified blends showed weaker non-additive effects than those of native blends. Consistency coefficient in downward curve, flow behavior index in downward curve, and loss tangent mainly showed non-additive effects in native blends, but additive effects in esterified blends. OSA modification affects interaction between molecules on the outer surfaces of two starch granules by altering molecular structures on the outer surfaces, resulting in different blending effects between native and esterified waxy starch blends.

A Comparison of Microfluidic-Jet Spray Drying, Two-Fluid Nozzle Spray Drying, and Freeze-Drying for Co-Encapsulating β-Carotene, Lutein, Zeaxanthin, and Fish Oil

Various microencapsulation techniques can result in significant differences in the properties of dried microcapsules. Microencapsulation is an effective approach to improve fish oil properties, including oxidisability and unpleasant flavour. In this study, β-carotene, lutein, zeaxanthin, and fish oil were co-encapsulated by microfluidic-jet spray drying (MFJSD), two-fluid nozzle spray drying (SD), and freeze-drying (FD), respectively. The aim of the current study is to understand the effect of different drying techniques on microcapsule properties. Whey protein isolate (WPI) and octenylsuccinic anhydride (OSA) modified starch were used as wall matrices in this study for encapsulating carotenoids and fish oil due to their strong emulsifying properties. Results showed the MFJSD microcapsules presented uniform particle size and regular morphological characteristics, while the SD and FD microcapsules presented a large distribution of particle size and irregular morphological characteristics. Compared to the SD and FD microcapsules, the MFJSD microcapsules possessed higher microencapsulation efficiency (94.0–95.1%), higher tapped density (0.373–0.652 g/cm³), and higher flowability (the Carr index of 16.0–30.0%). After a 4-week storage, the SD microcapsules showed the lower retention of carotenoids, as well as ω-3 LC-PUFAs than the FD and MFJSD microcapsules. After in vitro digestion trial, the differences in the digestion behaviours of the microcapsules mainly resulted from the different wall materials, but independent of drying methods. This study has provided an alternative way of delivering visual-beneficial compounds via a novel drying method, which is fundamentally essential in both areas of microencapsulation application and functional food development.

Recent advances in polysaccharides stabilized emulsions for encapsulation and delivery of bioactive food ingredients: A review

Many bioactive food ingredients were encapsulated in different forms to improve their stability and bioavailability. Emulsions have showed excellent properties in encapsulation, controlled release, and targeted delivery of bioactives. Polysaccharides are widely available and have different structures with different advantages including non-toxic, easily digested, biocompatible and can keep stable over a wide range of pH and temperatures. In this review, the most common polysaccharides and polysaccharide based complexes as emulsifiers to stabilize emulsions in recent ten years are described. The close relationships between the types and structures of polysaccharides and their emulsifying capacities are discussed. In addition, the absorption and bioavailability of bioactive food components loaded in polysaccharide stabilized emulsions are summarized. The main goal of the review is to emphasize the important roles of polysaccharides in stabilizing emulsions. Moreover, speculations regarded to some issues for the further exploration and possible onward developments of polysaccharides stabilized emulsions are also discussed.

Investigation on the Synthesis Process of Bromoisobutyryl Esterified Starch and Its Sizing Properties: Viscosity Stability, Adhesion and Film Properties

To confirm the suitable synthesis process parameters of preparing bromoisobutyryl esterified starch (BBES), the influences of the synthesis process parameters-amount of 2-bromoisobutyryl bromide (BIBB), amount of catalyst (DMAP), reaction temperature and reaction time-upon the degree of substitution (DS) were investigated. Then, to produce a positive effect on the properties of graft copolymers of BBES prepared in the near future, a series of BBES samples were successfully prepared, and their sizing properties, such as apparent viscosity and viscosity stability, adhesion, and film properties, were examined. The BBES granules were characterized by Fourier transform infra-red spectroscopy and scanning electron microscopy. The adhesion was examined by determining the bonding forces of the sized polylactic acid (PLA) and polyester roving. The film properties were investigated in terms of tensile strength, breaking elongation, degree of crystallinity, and cross-section analysis. The results showed that a suitable synthesis process of BBES was: reaction time of 24 h, reaction temperature of 40 °C, and 0.23 in the molar ratio of 4-dimethylaminopyridine to 2-bromoisobutyryl bromide. The bromoisobutyryl esterification played the important roles in the properties of the starch, such as paste stabilities of above 85% for satisfying the requirement in the stability for sizing, improvement of the adhesion to polylactic acid and polyester fibers, and reduction of film brittleness. With rising DS, bonding forces of BBES to the fibers increased and then decreased. BBES (DS = 0.016) had the highest force and breaking elongation of the film. Considering the experimental results, BBES (DS = 0.016) showed potential in the PLA and polyester sizing, and will not lead to a negative influence on the properties of graft copolymers of BBES.

Effect of octenyl succinic anhydride starch ester by semi-dry method with vacuum-microwave assistant

Corn starch was esterified with octenyl succinic anhydride (OSA), in which semidry method assisted with vacuum-microwave treatment was used under the alkalescent condition. The effect of vacuum treatment on esterification was studied. The products were characterized by Fourier transform infrared (FT-IR) spectroscopy, ¹H nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and X-ray diffraction. And the emulsifying properties were investigated with the emulsifying capacity (EC), emulsion droplet size and confocal laser scanning microscopy (CLSM). The degree of substitution (DS) of OSA starch increased significantly (ρ < 0.05) assisted by the vacuum-microwave treatment with the same dosage of reactant compared with the microwave only. The results confirmed the formation of OSA starch prepared by the method, all reactions occurred mainly on the surface of granules, and had no significant effect on the starch crystallinity. The OSA starch was a good polymeric surfactant with good abilities both in hydrophilic and lipophilic. The emulsifying capacity, degree of substitution of the OSA starch prepared by the method attractively showed vast potential for scale production.

Hydroxypropylsulfonation/Caproylation of Cornstarch to Enhance Its Adhesion to PLA Fibers for PLA Sizing

The impact of hydroxypropylsulfonation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) fibers was investigated for ameliorating the applications such as PLA sizing. The hydroxypropylsulfonated and caproylated cornstarch (HCS) samples with different degrees of substitution (DS) were synthesized by a hydroxypropylsulfonation of acid-converted cornstarch (ACS) with 3-chloro-2-hydroxy-1-propanesulfonic acid sodium salt (CHPS-Na) and subsequently a caproylation with caproic anhydride (CA). The HCS granules were characterized by Fourier transform infrared spectroscopic and scanning electron microscopy. The adhesion was evaluated by measuring the bonding forces of the PLA roving impregnated. The mechanical behaviors of the adhesive layers were estimated by determining the properties of the films. The results of adhesion measurement were also analyzed especially through the wetting and spreading of the paste on the fiber surfaces, as well as the failure type, internal stress and mechanical behaviors of the adhesive layers among fibers. Additionally, apparent viscosity and its stability of the pastes were also determined. It was found that hydroxypropylsulfonation/caproylation was not only able to obviously improve the adhesion of ACS to PLA fibers, but also capable of further improving the adhesion of hydroxypropylsulfonated starch (HS) to the fibers. With the rise in the total DS, the adhesion gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the probabilities of interfacial failure and cohesive failure, decreased the film brittleness, and increased the van der Waals force at the interfaces. Moreover, the HCS samples with a stability of above 85% could meet the demand on the stability for sizing. Considering the experimental results of the adhesion and the analysis of the results, HCS showed potential in the application of PLA sizing.

Effect of high-intensity ultrasound irradiation on the stability and structural features of coconut-grain milk composite systems utilizing maize kernels and starch with different amylose contents

In this paper, a coconut milk composite system (glycerin monostearate as an emulsifier) with different maize additives (e.g., maize kernels and starch with different amylose contents) was treated with high-intensity ultrasound irradiation (HIUS, frequency 20 kHz). The stability and structural features of the added coconut milk emulsion were studied. Comparing the mechanical emulsifications, coconut milk with maize kernels was similar to coconut milk with high-amylose maize starch. However, coconut milk with a high proportion of amylopectin had the best stability. After ultrasonic treatment, the particle sizes were found to be smaller than those in the nonultrasound-treated coconut milk, and the particles demonstrated a monomodal size distribution. The electronegativity of the compound system was significantly improved. The electronegativity of the maize kernel and high-amylose maize starch-coconut milk systems was significantly decreased, and this change was beneficial to the stability of the systems. However, ultrasonic treatment did not change the fluid type of the coconut milk compound system (which showed pseudoplastic fluid characteristics). The proportion of amylose in maize had an important influence on the stability of the compound system. The apparent viscosity and crystallization order of the high-amylose maize starch-coconut milk system were high. However, the waxy maize starch system showed high complex viscosity and tended to be liquid with ultrasonic treatment. Ultrasound treatment reduced the particle size of coconut milk and homogenized the distribution of the system. Additionally, the amylase of the system contained amylose encapsulated in the interfacial layer after ultrasound treatment. The tiny gel beads formed by waxy maize starch had a good fusion effect on coconut milk fat/protein droplets. The results indicated that the stability of coconut-grain milk composite systems can be enhanced with the use of maize additives and ultrasound irradiation through space effects, electrostatic effects and continuous phase viscosity.

Interfacial Activity and Self-Assembly Behavior of Dissolved and Granular Octenyl Succinate Anhydride Starches

The mechanisms of granular octenyl succinate anhydride (GOSA) and dissolved OSA (DOSA) starches in emulsion stabilization were investigated. In general, DOSA starch offered better emulsification activity by generating greater ζ-potential, lower particle size as well as long-term stability in comparison to GOSA starch of close degree of substitution (DS). A compact interface in DOSA starches was determined, resulting from an increased surface loading value of 2.37 mg/m² in comparison to that of GOSA of 1.6 mg/m². Additionally, the irreversibly adsorbed and predominantly elastic interface of both DOSA and GOSA starches indicated that the DOSA starch may be a Pickering emulsifier rather than a biopolymer surfactant. This assumption was confirmed by transmission electron microscopy. Spherical micelles with average diameters of 100 nm were observed above the critical micelle concentration of 1 mg/mL. Moreover, samples G28 (representing DS of 0.028), D28, G16, and D16 could reach equilibrium interfacial tensions of 19.4, 16.5, 20.0, and 19.3 mN/m, respectively. However, due to the misleading contact angle as a result of rough surfaces and nonignorable gravity of GOSA starch, the energy escape equation failed to be employed in this study.

Phosphorylation/caproylation of cornstarch to improve its adhesion to PLA and cotton fibers

To investigate the influence of phosphorylation/caproylation on the adhesion of cornstarch to polylactic acid (PLA) and cotton fibers for improving its applications, such as in PLA and cotton sizing, herein, a series of phosphorylated and caproylated cornstarch (PCS) samples with different total degrees of substitution (DS) were synthetized by the phosphorylation of acid-converted cornstarch (ACS) with sodium tripolyphosphate (STP) and subsequent caproylation with caproic anhydride (CA). The PCS granules were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The adhesion was evaluated by determining the bonding forces of the impregnated PLA and cotton roving. The results of the adhesion measurements were also analyzed, especially for the wetting and spreading of the pastes on the fiber surfaces as well as the failure type and internal stress of the adhesive layers among the fibers. In addition, the viscosity stabilities of the pastes were determined. The results showed that phosphorylation/caproylation was capable of obviously improving the adhesion of starch to PLA and cotton fibers. As the total DS increased, the bonding forces gradually increased. The two substituents improved the wetting and spreading, reduced the internal stress, lowered the layer brittleness, and decreased the probabilities of interfacial failure and cohesive failure, thereby favoring the improvement of the adhesion. The PCS samples with stabilities above 85% could meet the stability requirement for sizing. Based on the experimental results of the adhesion and the analysis of the results, it can be concluded that PCS shows potential for applications in PLA and cotton sizing.

PCS samples were prepared for improving the adhesion of starch to PLA and cotton fibers.

Stabilizing Oil-in-Water Emulsion with Amorphous and Granular Octenyl Succinic Anhydride Modified Starches

The effects of pre-gelatinization on the capacity of amorphous and granular octenyl succinic anhydride (OSA) starches as an emulsifier were compared. The full loss of the granular structure after gelatinization were confirmed by X-ray scattering measurements. The particle size of the emulsions prepared by granular starches with the degree of substitution of 0.021 and 0.045 was 717.8 and 391.5 nm, respectively, whereas it was only 307.2 and 283.9 nm of the amorphous OSA starch emulsions, respectively. Furthermore, after 30 days of storage, the particle size of granular OSA starch emulsions increased to 910.1 and 520.9 nm, respectively. However, this value only increased to 376.6 and 335.2 nm in emulsions stabilized with the amorphous OSA starch, respectively. These were attributed to an increased interfacial thickness, rate of interfacial adsorption, and compact packing on the surface, resulting from the flexible assembly behavior of amorphous starch chains compared to granular OSA. In addition, emulsions stabilized via amorphous OSA starches displayed a higher elastic moduli, indicating a greater number of interactions between starch chains and adjacent droplets.

Combined effects of octenylsuccination and oregano essential oil on sweet potato starch films with an emphasis on water resistance

The perishable character of moist food products demands packages with antimicrobial activity and water resistance. Oregano essential oil (OEO) and starch octenylsuccination were first jointly applied to formulate antimicrobial and water-resistant sweet potato starch films. The results showed that octenylsuccination powerfully retarded the coalescence of oil droplets in film casting process and favoured their homogeneity in the dried films. OEO incorporation dose-dependently conferred antimicrobial activity upon the films, which was further enhanced by octenylsuccination to some degree. For a specific film, comparable inhibitory efficacies were observed against S. aureus and E. coli. Either octenylsuccination or OEO incorporation alone decreased film strength, rigidity, water content, water solubility and water vapor permeability while increasing film extensibility to a less degree than their combination. More importantly, synergistic effects between OEO incorporation and octenylsuccination were concluded on film water content, water solubility and extensibility.