X-ray photoelectron spectroscopic analysis of rice kernels and flours: Measurement of surface chemical composition

Polydopamine grafting polyether ether ketone to stabilize growth factor for efficient osteonecrosis repair

This study examines the biocompatibility, osteogenic potential, and effectiveness of polyether ether ketone (PEEK) composites for treating osteonecrosis, seeking to establish a theoretical basis for clinical application. A range of PEEK composite materials, including sulfonated polyether ether ketone (SPEEK), polydopamine-sulfonated polyether ether ketone (SPEEK-PDA), bone-forming peptide-poly-dopamine-sulfonated polyether ether ketone (SPEEK-PDA-BFP), and vascular endothelial growth factor-poly-dopamine-sulfonated polyether ether ketone (SPEEK-PDA-VEGF), were constructed by concentrated sulfuric acid sulfonation, polydopamine modification and grafting of bioactive factors. The experiments involved adult male New Zealand rabbits aged 24-28 weeks and weighing 2.6-4 kg. The SPEEK-PDA-BFP possesses the smallest water contact angle, indicating the highest hydrophilicity, with its surface characterized by a rich density of clustered BFP particles. The SPEEK-PDA-BFP exhibits superior adhesion, proliferation, and differentiation capabilities, along with pronounced bacteriostatic effects, which are attributed to its dense particle clusters. The SPEEK-PDA-BFP facilitates the formation of regular and dense bone trabeculae. Comparative study on treating osteonecrosis with SPEEK-PDA-VEGF and SPEEK-PDA-BFP highlighted the superior formation of mature bone trabeculae and angiogenic protein CD31 around SPEEK-PDA-VEGF. The PEEK composite materials have good biocompatibility, osteogenic activity and bone repair activity. In particular, SPEEK-PDA-VEGF composite materials have the best effect on bone repair.

Comparing parboiling and milling for selenium-enriched rice (Oryza sativa L.): Differences in selenium speciation, texture, microstructure, and sensory

Parboiled rice can effectively retain Se during milling. In this study, Se-enriched rice grains were sprayed with three different concentrations of bioSeNPs fertilizer on the leaves at heading stage and then processed into parboiled and milled rice. The aim was to investigate the effects of parboiling on Se speciation, texture, microstructure, taste, and flavor of cooked rice. The results showed that parboiling enhances the total Se content by making the bran more difficult to remove. At milling for 40 s, selenomethionine (72.6 %-80.1 %) is predominant Se speciation. Parboiled rice exhibited higher hardness, reduced stickiness, with only minor differences in chewiness. The results regarding cooking quality and microstructure indicated that parboiling restricts starch dissolution during cooking, while the protein remains distributed within starch cell gaps. The parboiling enhances umami and flavor while maintaining the original taste and flavor profile. This work provides valuable insights for application of Se-enriched rice in parboiled rice.

Impact of processing and storage on citrus fiber functionality: Insights from spectroscopic techniques

To deliver their functionality when used in applications, citrus fibers need to be rehydrated. Factors such as chemical composition, structural organization as well as chemical surface composition are known to influence this functionality. Processing and storage conditions can affect these parameters, making it challenging to maintain stable functionality. This study used Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) to evaluate the effects of preparation and storage on citrus fibers. Samples dried at different scales and stored for 360 days under room and accelerated conditions were assessed for water holding capacity (WHC), water swelling capacity (WSC), and gel rigidity (G'). The results showed a decline in WHC, WSC, and G' over time, confirming that aging negatively impacts moisture retention, particularly under higher water content or temperature. Drying scale had no effect on chemical composition or structure, but changes in the elemental surface composition of carbon and oxygen were noted. While prolonged storage altered the polysaccharides' chemical composition and structure, leading to functionality loss, XPS analysis revealed no changes in surface composition. Loss of functionality cannot be explained by chemical surface composition modifications.

Dual cross-linked starch hydrogel for eugenol encapsulation and the formation of hydrogen bonds on textural hydrogel

Physical and chemical cross-linked hydrogels combining N, N'-Methylenebisacrylamide (MBA)-grafted starch (MBAS) and sorbitol were successfully prepared and encapsulated with eugenol in this work. The dense porous structure with diameter of 10-15 μm and strong skeleton after restructuring inside the hydrogel was confirmed by SEM. The band shifts between 3258 cm^-1 and 3264 cm^-1 clarified the presence of a large number of hydrogen bonds in physical and chemical cross-linked hydrogels. The robust structure of the hydrogel was confirmed by mechanical and thermal property measurements. Molecular docking techniques were used to help understand the bridging pattern between three raw materials and to assess the advantageous conformation, which demonstrate sorbitol is beneficial to improve the characteristics of textural hydrogel by the formation of hydrogen bonds, creating a denser network, structural recombination and new intermolecular hydrogen bonds between starch and sorbitol afforded considerably junction zones. Compared to ordinary starch-based hydrogels, eugenol-loaded starch-sorbitol hydrogels (ESSG) exhibited a more attractive internal structure, swelling properties, viscoelasticity. Moreover, the ESSG showed excellent antimicrobial activity for typical undesired microorganisms in foods.

Moderate Reduction in Nitrogen Fertilizer Results in Improved Rice Quality by Affecting Starch Properties without Causing Yield Loss

The quality and starch properties of rice are significantly affected by nitrogen. The effect of the nitrogen application rate (0, 180, and 230 kg ha^-1) on the texture of cooked rice and the hierarchical structure and physicochemical properties of starch was investigated over two years using two japonica cultivars, Bengal and Shendao505. Nitrogen application contributed to the hardness and stickiness of cooked rice, reducing the texture quality. The amylose content and pasting properties decreased significantly, while the relative crystallinity increased with the increasing nitrogen rates, and the starch granules became smaller with an increase in uneven and pitted surfaces. The proportion of short-chain amylopectin rose, and long-chain amylopectin declined, which increased the external short-range order by 1045/1022 cm^-1. These changes in hierarchical structure and grain size, regulated by nitrogen rates, synergistically increased the setback viscosity, gelatinization enthalpy and temperature and reduced the overall viscosity and breakdown viscosity, indicating that gelatinization and pasting properties were the result of the joint action of several factors. All results showed that increasing nitrogen altered the structure and properties of starch, eventually resulting in a deterioration in eating quality and starch functional properties. A moderate reduction in nitrogen application could improve the texture and starch quality of rice while not impacting on the grain yield.

High-efficacy antimicrobial acyclic N-halamine-grafted polyvinyl alcohol film

With N,N'-methylenebisacrylamide (MBA) and polyvinyl alcohol (PVA) as raw materials, a polymer (PVA-MBA) containing N-halamine precursor functional groups was obtained via grafting reaction between the active hydroxyl groups on PVA and α, β-unsaturated functional groups of MBA under the catalysis of sodium carbonate in an aqueous solution. An acyclic N-halamine precursor-grafted PVA (MBA-PVA) film was formed by simply spreading PVA-MBA aqueous solution in a glass dish and drying it. An antimicrobial acyclic N-halamine-grafted PVA (PVA-MBA-Cl) film was achieved by spraying the diluted sodium hypochlorite solution onto the surface of PVA-MBA film. The performance test of PVA-MBA-Cl film under the optimal preparation conditions showed that the tensile performance and the hydrophobicity were improved, compared to the PVA film. The storage stability test indicated that the oxidative chlorine content Cl+ (atoms/cm2) of the as-prepared PVA-MBA-Cl film only reduced by 14.3% after storage for 9 weeks, showing that the antibacterial N-halamine functional groups in PVA-MBA-Cl film has excellent storage stability under room temperature. Antibacterial test showed that the PVA-MBA-Cl film had very strong antibacterial efficacies and could completely kill 1.28 × 106 CFU/mL S. aureus and 1.89 × 106 CFU/mL E. coli within 1 min. Therefore, PVA-MBA-Cl film will have more potential applications in food package.

Structural breakdown of starch-based foods during gastric digestion and its link to glycemic response: In vivo and in vitro considerations

The digestion of starch-based foods in the small intestine as well as factors affecting their digestibility have been previously investigated and reviewed in detail. Starch digestibility has been studied both in vivo and in vitro, with increasing interest in the use of in vitro models. Although previous in vivo studies have indicated the effect of mastication and gastric digestion on the digestibility of solid starch-based foods, the physical breakdown of starch-based foods prior to small intestinal digestion is often less considered. Moreover, gastric digestion has received little attention in the attempt to understand the digestion of solid starch-based foods in the digestive tract. In this review, the physical breakdown of starch-based foods in the mouth and stomach, the quantification of these breakdown processes, and their links to physiological outcomes, such as gastric emptying and glycemic response, are discussed. In addition, the physical breakdown aspects related to gastric digestion that need to be considered when developing in vitro-in vivo correlation in starch digestion studies are discussed. The discussion demonstrates that physical breakdown prior to small intestinal digestion, especially during gastric digestion, should not be neglected in understanding the digestion of solid starch-based foods.

Optimization of process parameters for bio-enzymatic and enzymatic saccharification of waste broken rice for ethanol production using response surface methodology and artificial neural network-genetic algorithm

Reducible sugar solution has been produced from waste broken rice by a novel saccharification process using a combination of bio-enzyme (bakhar) and commercial enzyme (α-amylase). The reducible sugar solution thus produced is a promising raw material for the production of bioethanol using the fermentation process. Response surface methodology (RSM) and Artificial neural network-genetic algorithm (ANN-GA) have been used separately to optimize the multivariable process parameters for maximum yield of the total reducing sugar (TRS) in saccharification process. The maximum yield (0.704 g/g) of TRS is predicted by the ANN-GA model at a temperature of 93 °C, saccharification time of 250 min, 6.5 pH and 1.25 mL/kg of enzyme dosages, while the RSM predicts the maximum yield of 0.7025 g/g at a little different process conditions. The fresh experimental validation of the said model predictions by ANN-GA and RSM is found to be satisfactory with the relative mean error of 2.4% and 3.8% and coefficients of determination of 0.997 and 0.996.

Porous antimicrobial starch particles containing N-halamine functional groups

The porous antimicrobial starch particles containing N-Halamine functional groups (PST-MBA-Cl particles) were synthesized by a crosslinking polymerization between starch (ST) and N, N'-methylenebisacrylamide (MBA), and then a chlorination of amide groups of MBA. The synthetic process used only water as the solvent and was environmentally friendly. The results showed that under the optimal preparation conditions, the as-synthesized PST-MBA-Cl particles could have a Cl⁺% of 8.60 %. Antimicrobial tests showed that PST-MBA-Cl particles had very powerful antimicrobial efficacy against both Staphylococcus aureus and Escherichia coli and could completely kill Staphylococcus aureus with a concentration of 2.1 × 10⁶ CFU/mL and Escherichia coli with a concentration of 5.6 × 10⁶ CFU/mL within a contact time of one minute. Furthermore, the N-Halamine functional groups of PST-MBA-Cl particles also showed excellent stability under storage and reproducibility. Therefore, the as-synthesized PST-MBA-Cl particles will have potential applications in water disinfection.

Improvement of Quality Properties and Shelf Life Stability of New Formulated Muffins Based on Black Rice

Effects of partial (50%) and total replacement of wheat flour with black rice flour on the phytochemical, physico-chemical, sensorial, and textural properties of muffins were studied. Partial or total replacement of wheat flour with black rice flour in muffins improved their nutritional and antioxidative properties with a positive effect on microbiological and color stability during the storage period in accelerated conditions. The low gluten muffins had an anthocyanin content of 27.54 ± 2.22 mg cyanidin-3-glucoside (C3G)/100 g dry weight (DW), whereas the gluten free muffins had 46.11 ± 3.91 mg C3G/100 g DW, with significant antioxidant values. Retention of 60% and 64% for anthocyanins and 72% and 80% for antioxidant activity after baking was found. The fracturability and hardness scores increased with the addition of black rice flour, whereas firmness and chewiness increased for gluten free muffins. The confocal analysis revealed a tendency of glucidic components to aggregate, with gathers of small bunches of black rice starch granules comprising anthocyanin. The results allowed designing two new value added bakery products, low and free gluten muffins, with significant high amounts of bioactive compounds, suggesting the functional potential of black rice flour.