Cereal Chem. 93(1):39-46Germinated brown rice is popular in Asia for its increased g-aminobutyric acid (GABA) content and sweeter and softer texture compared with conventional brown rice. However, most studies investigated germinated rice properties on medium-grain or aromatic rice. The objective of this study was to compare differences between a medium-grain (Jupiter) and a long-grain (Wells) rice under similar germination conditions on their milling, physicochemical, and textural properties over the course of germination. Rough rice was soaked in water at 25°C for 12 h and then incubated at 30-34°C for four germination durations. Wells had a higher breakage percentage and a greater weight decrease than Jupiter during germination. Wells had a significantly lower GABA content before germination and at the first two germination durations than Jupiter, but the GABA content in Wells significantly increased at the third germination duration to become significantly higher than that of Jupiter. There were no significant changes in gelatinization temperatures and pasting properties of germinated rice from both cultivars at different germination durations. The cooked rice hardness from Wells decreased at the longest germination duration, whereas Jupiter showed a more significant decrease in cooked rice stickiness from germination. The results demonstrate that the impacts of germination on physical, chemical, and textural properties of rice were affected by grain type and germination

The last decades have witnessed a major advancement and development in three-dimensional (3D) printing technology. In the future, the trend’s utilization of 3D printing is expected to play an important role in the biomedical field. This work presents co-extrusion of the polylactic acid (PLA), its derivatives (sPLA), and chitosan with the aim of achieving filaments for printing 3D objects, such as biomedical tools or implants. The physicochemical and antimicrobial properties were evaluated using SEM, FT-IR, DSC, instrumental mechanical test, and based on the ASTM E2149 standard, respectively. The addition of chitosan in the PLA and sPLA filaments increased their porosity and decreased density. The FT-IR analysis showed that PLA and chitosan only formed a physical mixture after extrusion. The addition of chitosan caused deterioration of the mechanical properties of filaments, especially elongation at break and Young’s modulus. The addition of chitosan to the filaments improved their ability to crystallize and provide their antimicrobial properties against Escherichia coli and Staphylococcus aureus.

A new method of obtaining functional foam material has been proposed. The materials were created by mixing the poly lactic acid (PLA) solution in chloroform, chitosan (CS) dissolved in water saturated with CO2 and polyethylene glycol (PEG), and freeze-dried for removal of the solvents. The composite foams were characterized for their structural (SEM, FT-IR, density, porosity), thermal (DSC), functional (hardness, elasticity, swelling capacity, solubility), and biological (antimicrobial and cytotoxic) properties. Chitosan in the composites was a component for obtaining their foamed form with 7.4 to 22.7 times lower density compared to the neat PLA and high porosity also confirmed by the SEM. The foams had a hardness in the range of 70–440 kPa. The FT-IR analysis confirmed no new chemical bonds between the sponge ingredients. Other results showed low sorption capacity (2.5–7.2 g/g) and solubility of materials (less than 0.2%). The obtained foams had the lower Tg value and improved ability of crystallization compared to neat PLA. The addition of chitosan provides the bacteriostatic and bactericidal properties against Escherichia coli and Staphylococcus aureus. Biocompatibility studies have shown that the materials obtained are not cytotoxic to the L929 cell line.

Cereal Chem. 93(1):47-52Germinated brown rice is considered a more nutritious and palatable cooked product than conventional brown rice. However, germination usually decreases rice milling yield and alters some physicochemical properties. Parboiling is commonly used to increase milling yield and retain nutrients, but it also changes rice color and texture. The objective of this study was to investigate the effect of parboiling on milling, physicochemical, and textural properties of a medium-grain and a longgrain rice after germination at varying durations. Germinated rice samples of three germination durations were prepared with one germination time before the optimum time at which 70% of rice revealed hull protrusion, the optimum time, and one time after. Germinated rice was then immediately parboiled at 120°C for 20 min and was then immediately dried. The milling, physicochemical, and textural properties of parboiled germinated rice from both cultivars were determined. Parboiling significantly decreased the percentage of brokens, whiteness, and the apparent amylose content and increased g-aminobutyric acid content (GABA) in the nongerminated rice and rice at the first germination duration for both cultivars. Parboiling reduced pasting viscosities for both cultivars, but Jupiter still exhibited higher pasting viscosities than Wells. Cooked parboiled germinated rice was overall softer than nonparboiled rice because of kernel splitting, but Wells remained harder and less sticky than Jupiter. In conclusion, it is beneficial to combine parboiling with germination to enhance nutritional values and improve milling properties without affecting textural properties for both rice cultivars.

The production of medium‐ and short‐grain rice in the mid‐Southern U.S. rice‐growing region is increasing. This work aimed to identify the quality traits of importance to the markets for these grain types. Twenty‐five medium‐ and short‐grain milled rice samples were collected and analyzed for physical, gelatinization, pasting, and starch structural properties. Six samples were from Arkansas (AR), five from California (CA), and 14 imported (IM). Cluster and principal component analyses showed that the AR samples had greater gelatinization temperature, enthalpy, and percentages of amylopectin long chains (B2 and B3 chains) but lesser kernel whiteness, total setback viscosity, and percentage of amylopectin short chains (A chains) than the CA samples. With the exception of one sample from Taiwan, chemometrics indicated that the IM samples differed from the AR samples (cluster A) in some properties and were grouped into three clusters (clusters B, C, and D). Cluster B samples had properties that were similar to the CA samples; cluster C samples had lower gelatinization temperature and peak viscosity but greater percentages of amylose and A chains than the AR samples; and cluster D samples had lesser paste breakdown but greater final viscosity and percentage of B1 chains than the AR samples. Kernel width, color, and chalk were the primary sources of variation in milled rice appearance. In relation to structure and functionality, the percentages of amylopectin A and B3 chains and amylose content were the major sources of variation.

The germination process activates amylolytic enzymes that can produce rice syrup through mashing, however the factors affecting enzyme activities and soluble saccharides have not been investigated. This study characterized amylolytic enzymes activities, including α‐amylase, β‐amylase, and α‐glucosidase, and soluble saccharides from germinated rice cultivars of four rice cultivars, including waxy, short grain, medium grain, and long grain, under aerobic and anaerobic germination conditions over 4 days and then mashed at 55, 65, 75, and 85 °C. The results showed that the long‐grain rice had higher activities of all three enzymes, whereas the waxy rice exhibited lower activities. Glucose and maltose were the predominant saccharides at low mashing temperatures of 55 °C and 65 °C; saccharides of degree of polymerization 3 to 7 became significant at mashing temperatures of 75 °C and 85 °C. The amount and composition of saccharides were strongly influenced by rice cultivar, and germination and mashing conditions. The findings highlight the importance of rice components and starch structure on the amount and composition of soluble saccharides from germinated brown rice. Practical Application Rice syrup is commercially produced by the addition of external bacterial enzymes to brown or milled rice. Germinated brown rice is naturally rich in nutrients and amylases, both are produced during the germination process. Because of the presence of naturally activated amylases, germinated brown rice could be used to produce rice syrup without the addition of external enzymes while preserving the nutrients from germination of brown rice.

Reconstructing the chemical and structural characteristics of the plant cell wall represents a promising solution to overcoming lignocellulosic biomass recalcitrance to biochemical deconstruction. This study aims to leverage hydroxyproline (Hyp)‐O‐glycosylation, a process unique to plant cell wall glycoproteins, as an innovative technology for de novo design and engineering in planta of Hyp‐O‐glycosylated biopolymers (HypGP) that facilitate plant cell wall reconstruction. HypGP consisting of 18 tandem repeats of “Ser–Hyp–Hyp–Hyp–Hyp” motif or (SP4)18 was designed and engineered into tobacco plants as a fusion peptide with either a reporter protein enhanced green fluorescence protein or the catalytic domain of a thermophilic E1 endoglucanase (E1cd) from Acidothermus cellulolyticus. The engineered (SP4)18 module was extensively Hyp‐O‐glycosylated with arabino‐oligosaccharides, which facilitated the deposition of the fused protein/enzyme in the cell wall matrix and improved the accumulation of the protein/enzyme in planta by 1.5–11‐fold. The enzyme activity of the recombinant E1cd was not affected by the fused (SP4)18 module, showing an optimal temperature of 80°C and optimal pH between 5 and 8. The plant biomass engineered with the (SP4)18‐tagged protein/enzyme increased the biomass saccharification efficiency by up to 3.5‐fold without having adverse impact on the plant growth.