The effect of modified starches on the adsorption of cigarette mainstream smoke composition

OSA modified porous starch acts as an efficient carrier for loading and sustainedly releasing naringin

To select an efficient carrier for loading and sustainedly releasing naringin (NAR), complexes of porous starch (PS) and NAR (PS-NAR) as well as those of octenyl succinic anhydride (OSA) esterified PS and NAR (OSAPS-NAR) with different degree of substitution (DS) were prepared by an ultrasonic method with an ethanol solution. The micro-morphological features, structural and thermal properties of complexes and their constituents were characterized, and in vitro release rate and kinetic of NAR from complexes were investigated. The findings revealed that NAR was successfully loaded in PS/OSAPS in an amorphous form, and the NAR's loading efficiency improved as DS increased, reaching 86.85 % at DS 0.0427. NAR cumulative release rate from the complexes in simulated digestion fluids was much higher than that of free (unloaded) NAR, but decreased as DS increased. NAR's in vitro release from complexes mainly depended on the carrier rather than NAR itself, and OSAPS with higher DS had stronger protection and slower release effect on NAR. The results would provide a new means for starch-based carrier construction to develop an efficient delivery and sustainedly releasing system for NAR, thus broadening the application ranges both for modified starch and citrus flavonoids such as NAR.

Composite starch films as green adsorbents for removing benzo[a]pyrene from smoked sausages

Benzo[a]pyrene (BaP), which is emitted during the processing of smoked sausages, accumulates in sausages and poses a serious threat to human health. This study focused on the removal of BaP from sausages and accompanying particulate matter (PM) during the smoking of sausages by films formed by combining corn starch (CS) with K-carrageenan (KC)/sodium alginate (SA). Initially, the effects of different additions of KC and SA on the rheological analysis, thermogravimetric analysis (TGA) and film-forming properties of the composite films were investigated. The BaP reduction capacities of CS-KC and CS-SA composite films in sausage were 41.1%-47.0% and 54.2%-56.5%, respectively, because the three-dimensional mesh structure of the composite films provided a large number of adsorption sites. Finally, kinetic studies demonstrated that BaP control in composite films is mainly achieved by intraparticle diffusion. Therefore, due to its excellent recyclability and biodegradability, composite starch film has a promising application in smoked meat products.

Preparation, characterization and in vitro digestion of octenyl succinic anhydride-modified porous starch with different degrees of substitution

Octenyl succinic anhydride modified porous starch (OSA-PS) with degrees of substitution (DS) from 0.0123 to 0.0427 were prepared by aqueous phase method. From SEM, PS had a porous structure which showed a rough and corrosive surface after esterification with OSA. FT-IR revealed the characteristic peaks of OSA-PS at 1725 cm-1 and 1570 cm-1. From 1H NMR spectra, OSA-PS displayed extra chemical signal peaks at 0.85 ppm, 1.25 ppm and 1.96 ppm. These results fully demonstrated that OSA groups were successfully grafted onto PS. Furthermore, as DS increased, the specific surface area (5.6464 m2/g), pore volume (0.9959 × 10-2 cm3/g) and methylene blue adsorption capacity (24.3962 mg/g) of OSA-PS reached the maximum, while its relative crystallinity (26.8112 %) and maximum thermal decomposition temperature (291.96 °C) were the minimum. In vitro digestion studies showed that with the increase of DS, OSA-PS' contents of rapidly digestible starch and slowly digestible starch decreased from 9.06 % to 6.27 % and 28.38 % to 14.61 %, respectively. In contrast, its resistant starch had an increase in content from 62.56 % to 79.12%. The results provided an effective method for obtaining a double-modified starch with high specific surface area and anti-digestibility, thus broadening the industrial application of starch.

Modified porous starch for enhanced properties: Synthesis, characterization and applications

Native starches have low water solubility at room temperature and poor stability, which demand modifications to overcome. Porous starch as a modified one shows enhanced adsorptive efficiency and solubility compared with its native starch. In contrast, some inherent disadvantages exist, such as weak mechanical strength and low thermal resistance. Fortunately, modified porous starches have been developed to perform well in adsorption capacity and stability. Modified porous starch can be prepared by esterification, crosslinking, oxidation and multiple modifications to the porous starch. The characterization of modified porous starch can be achieved through various analytical techniques. Modified porous starch can be utilized as highly efficient adsorbents and encapsulants for various compounds and applied in various fields. This review dealt with the progress in the preparation, structural characterization and application of modified porous starch. The objective is to provide a reference for its development, utilization, and future research directions.

Comparison of functional properties of porous starches produced with different enzyme combinations

To obtain porous starch granules with higher absorption capacities, three types of enzyme combinations were adopted to modify wheat and maize starches: (1) sequential α-amylase (AA) → glucoamylase (GA); (2) sequential branching enzyme (BE) → GA; and (3) sequential AA→BE→GA. The results indicated that AA→BE→GA treatment had a most optimal influence on porous starches. Compared to AA→GA and BE→GA, the mesopores in wheat starch granules treated with AA→BE→GA decreased by 52.82 and 48.70%, respectively. Conversely, the macropores increased by 216.68 and 138.18%, respectively. While for maize starch, the percentages of mesopores and macropores hardly changed after three enzyme combinations. Comparing the three enzyme treatments showed that pore volume (0.005 and 0.007 cm³/g) and pore size (36.35 and 26.54 nm) were largest in the AA→BE→GA treated wheat and maize starches, respectively. Compared to the AA→GA and BE→GA, the adsorption capacities for oil, dye and heavy metal ions, wheat starch treated with AA→BE→GA increased by 46.61 and 242.33%, and 44.52 and 134.41%, and 28.83 and 271.72%, respectively. Correspondingly, that of maize starch increased by 29.71 and 133.29%, and 42.92 and 79.93%, and 28.16 and 161.43%, respectively. These results may provide a new and valuable enzyme combination for optimising porous starch granules with higher absorption capacities.

Preparation and characterization of core-shell oil absorption materials stabilized by modified fumed silica

The core-shell oil absorption material (OAM) with fumed silica shell was achieved from Pickering polymerization. The modified fumed silica wall could well stabilize both Pickering emulsion and Pickering polymerization. The particle size of encapsulated OAMs decreased with the increasing concentration of fumed silica and remained unchanged when the concentration was more than 1 wt.%. This fumed silica shell had little effect on the oil absorption rate of OAM. The importance was that the shell reversed the surface property and improved the alkali resistance of OAM. We believe that our core-shell OAMs could reach the self-healing ability of the oil well cement.

Synthesis and characterization of amylose grafted poly(acrylic acid) and its application in ammonia adsorption

Amylose grafted poly(acrylic acid) (Am-g-PAA) was synthesized by graft copolymerization of amylose with acrylic acid. The structure of Am-g-PAA was confirmed by (1)H NMR and FT-IR spectra. The morphology, crystallinity and thermal properties of amylose and Am-g-PAA were investigated by SEM, XRD and TGA, respectively. The highest degree of substitution (DS) of carboxyl group was 1.96 which was obtained after reacted for 1h at 60°C. Acrylic acid to anhydroglucose mole ratio for DS was 19.81. It was found that a large number of carboxyl groups were grafted on the backbone of amylose. It was also found that ammonia adsorption capacity of amylose increased by grafting poly(acrylic acid) on the backbone of amylose.