Improvement of sorghum-wheat blended flours by E-beam irradiation: Physicochemical properties, rheological behavior, microstructure, and quality properties

To enhance the processing suitability of blended flours, this study used 4 kGy E-beam irradiated (EBI) sorghum flour in different ratios blended with wheat flour and further verified the improvement mechanism of the processed products under the optimal ratios. The results suggested that the EBI can mitigate the deterioration of the blend flour farinograph properties while enhancing the gas release during dough fermentation. Under the same addition ratio, the irradiated blend flours showed higher expansion height, gas release, cavitation time, and gas retention coefficient than the control flours. Also, irradiated blend flours retained a gluten network at a higher addition rate (20 %). Moreover, the irradiated blend flours were optimized at 10 % as its pasting and thermal properties were improved. Notably, this ameliorating effect promotes a decrease in hardness and chewiness and an increase in cohesion of the bread cores, presenting better textural attributes and delaying the aging rate during storage. The findings are instructive for applying EBI technology in the manufacture and quality improvement of mixed grain breads and open a new research avenue for processing sorghum staple foods.

Insight into how E-beam pretreatment promotes sodium hypochlorite oxidation for structure-property improvement of cassava starch: A molecular-level modulation mechanism

To investigate the role of E-beam treatment on the structure-properties of oxidized starch, this study investigated the influence of E-beam (1, 3, 6 kGy) pretreatment combined with NaClO oxidation (1% and 3%) on the multi-scale structural, physicochemical, and digestive properties of cassava starch. Results showed that E-beam treatment did not affect the starch surface, but the oxidative modification increased granule surface roughness. Also, the synergistic modification preserved starch growth rings, FT-IR patterns and crystal types. Further investigations revealed that E-beam induced starch molecular degradation, leading to decreased molecular weight, depolymerization of long chains, and a loss of short-range order. Moreover, oxidation treatment exacerbated the disruption in starch molecular structure, as evidenced by crystallinity loss, viscosity, and enthalpy reduction. Notably, E-beam induces starch yellowing; however, oxidative modification increases starch whiteness. Additionally, the synergistic modification improved native starch's lower solubility and enhanced the resistant starch content. Results suggest that E-beam pretreatment can enhance oxidative modification by promoting the exposure of active sites of starch molecules without destroying starch structure and can be considered an advanced, green, and efficient pretreatment for modified starch in the future.

Facile Synthesis of Self-Adhesion and Ion-Conducting 2-Acrylamido-2-Methylpropane Sulfonic Acid/Tannic Acid Hydrogels Using Electron Beam Irradiation

Tannic acid (TA) can be used as an additive to improve the properties of hydrogels, but it acts as a radical scavenger, which hinders radical polymerization. In this study, we successfully and easily synthesized a TA-incorporated 2-acrylamido-2-methylpropanesulfonic acid (AMPS) hydrogel using an electron beam (E-beam) in a one-pot process at room temperature. TA successfully grafted onto AMPS polymer chains under E-beam irradiation, but higher TA content reduced grafting efficiency and prevented hydrogel formation. Peel strength of the AMPS hydrogel increased proportionally with TA, but cohesive failure and substrate residue occurred above 1.25 phm (parts per 100 g of AMPS) TA. Tensile strength peaked at 0.25 phm TA but decreased below the control value at 1.25 phm. Tensile elongation exceeded 2000% with TA addition. Peel strength varied significantly with substrate type. The wood substrate had the highest peel strength value of 150 N/m, while pork skin had a low value of 11.5 N/m. However, the addition of TA increased the peel strength by over 300%. The ionic conductivity of the AMPS/TA hydrogel increased from 0.9 S/m to 1.52 S/m with TA content, while the swelling ratio decreased by 50% upon TA addition and increased slightly thereafter.

Effects of cold plasma, gamma and e-beam irradiations on reduction of fungal colony forming unit levels in medical cannabis inflorescences

Background

The use of medical cannabis (MC) in the medical field has been expanding over the last decade, as more therapeutic beneficial properties of MC are discovered, ranging from general analgesics to anti-inflammatory and anti-bacterial treatments. Together with the intensified utilization of MC, concerns regarding the safety of usage, especially in immunocompromised patients, have arisen. Similar to other plants, MC may be infected by fungal plant pathogens (molds) that sporulate in the tissues while other fungal spores (nonpathogenic) may be present at high concentrations in MC inflorescences, causing a health hazard when inhaled. Since MC is not grown under sterile conditions, it is crucial to evaluate current available methods for reduction of molds in inflorescences that will not damage the active compounds. Three different sterilization methods of inflorescences were examined in this research; gamma irradiation, beta irradiation (e-beam) and cold plasma to determine their efficacy in reduction of fungal colony forming units (CFUs) in vivo.

Methods

The examined methods were evaluated for decontamination of both uninoculated and artificially inoculated Botrytis cinerea MC inflorescences, by assessing total yeast and mold (TYM) CFU levels per g plant tissue. In addition, e-beam treatment was also tested on naturally infected commercial MC inflorescences.

Results

All tested methods significantly reduced TYM CFUs at the tested dosages. Gamma irradiation reduced CFU levels by approximately 6- and 4.5-log fold, in uninoculated and artificially inoculated B. cinerea MC inflorescences, respectively. The effective dosage for elimination of 50% (ED₅₀)TYM CFU of uninoculated MC inflorescence treated with e-beam was calculated as 3.6 KGy. In naturally infected commercial MC inflorescences, e-beam treatments reduced TYM CFU levels by approximately 5-log-fold. A 10 min exposure to cold plasma treatment resulted in 5-log-fold reduction in TYM CFU levels in both uninoculated and artificially inoculated B. cinerea MC inflorescences.

Conclusions

Although gamma irradiation was very effective in reducing TYM CFU levels, it is the most expensive and complicated method for MC sterilization. Both e-beam and cold plasma treatments have greater potential since they are cheaper and simpler to apply, and are equally effective for MC sterilization.

Application of radiation for the synthesis of poly(n-vinyl pyrrolidone) nanogels with controlled sizes from aqueous solutions

Controlling of sizes of nanogels is very important for any biomedical application. In the present study we report a facile and reproducible method of preparing biocompatible nanogels of poly(N-vinyl pyrrolidone) (PVP) which were synthesized by using either electron beam (e-beam) (NGEB) or gamma irradiation (NGG) of dilute aqueous solutions. Nanogels with different hydrodynamic sizes were obtained at the variance of the polymer molecular weight, concentration, type of radiation source hence dose rate and total absorbed dose. For the first time a comparative study of gamma and e-beam irradiation was made on the same polymer with the aim of controlling sizes of nanogels in the range of 30-250 nm. Moreover the stability of radiation-synthesized nanogels was followed up to 2 years in refrigerated solution and found to retain their original sizes and distributions enabling their long-term storage and use. The synthesized nanogels were characterized by using dynamic light scattering (DLS), gel permeation chromatography (GPC), scanning electron microscopy (SEM) and atomic force microscopy (AFM) techniques. This work provides a clue to the fundamental question of how to control sizes of nanogels without using any additives which are indispensable with the other techniques. The technique is applicable to any water soluble polymer.

Influence of gamma and electron beam sterilization on the stability of a premixed injectable calcium phosphate cement for trauma indications

Premixed calcium phosphate cements (CPC's) are becoming the material of choice for injectable cements as a result of their effective delivery to the target implantation site. For orthopaedic use, it is of vital importance that the attributes of these CPC's are not compromised by irradiation sterilization. Therefore, the aim of this study is to determine the influence of irradiation sterilization on a range of premixed CPC's, with an emphasis on improving product shelf life through the use of optimal packaging configurations and annealing steps. Electron spin resonance (ESR) confirmed the presence of free radicals in the inorganic phase of the CPC paste following irradiation. The inclusion of a 24-h annealing step was the only successful method in reducing the degree of free radical formation. Based on the results of injectability force testing, it was revealed that an annealing step greater than 24-h significantly altered the viscosity, however; at 24-h the key attributes of the CPC paste were minimally effected. Overall, it was established that vacuum packing the CPC paste, placing the contents into a foil pouch, gamma irradiating at the minimal dose required and using an annealing step of ≤ 24-h, has the potential to extend the shelf life of the cement.

How copper corrosion can be retarded--New ways investigating a chronic problem for cellulose in paper

To better assess the stabilization effects of chemical treatments on Cu(II)-catalyzed cellulose degradation, we developed Cu(II)-containing model rag paper with typical copper corrosion characteristics using e-beam radiation. The paper can be prepared homogeneously and quickly compared to tedious pre-aging methods. Using the Cu(II)-containing model rag paper, the stabilization effects of various chemicals on Cu(II)-catalyzed degradation of cellulose were tested. Benzotriazol was highly effective in retarding the degradation of the Cu(II)-containing model rag paper under hot and humid aging condition, as well as under photo-oxidative stress. Tetrabutylammonium bromide reduced Cu(II)-catalyzed degradation of cellulose, but its efficacy was dependent on the accelerated aging conditions. The results with the alkaline treatments and gelatin treatment suggested that their roles in the degradation mechanisms of cellulose in the presence of Cu(II) differ from those of benzotriazol and tetrabutylammonium bromide.

Electron beam inactivation of Tulane virus on fresh produce, and mechanism of inactivation of human norovirus surrogates by electron beam irradiation

Ionizing radiation, whether by electron beams or gamma rays, is a non-thermal processing technique used to improve the microbial safety and shelf-life of many different food products. This technology is highly effective against bacterial pathogens, but data on its effect against foodborne viruses is limited. A mechanism of viral inactivation has been proposed with gamma irradiation, but no published study discloses a mechanism for electron beam (e-beam). This study had three distinct goals: 1) evaluate the sensitivity of a human norovirus surrogate, Tulane virus (TV), to e-beam irradiation in foods, 2) compare the difference in sensitivity of TV and murine norovirus (MNV-1) to e-beam irradiation, and 3) determine the mechanism of inactivation of these two viruses by e-beam irradiation. TV was reduced from 7 log10 units to undetectable levels at target doses of 16 kGy or higher in two food matrices (strawberries and lettuce). MNV-1 was more resistant to e-beam treatment than TV. At target doses of 4 kGy, e-beam provided a 1.6 and 1.2 log reduction of MNV-1 in phosphate buffered saline (PBS) and Dulbecco's Modified Eagle Medium (DMEM), compared to a 1.5 and 1.8 log reduction of TV in PBS and Opti-MEM, respectively. Transmission electron microscopy revealed that increased e-beam doses negatively affected the structure of both viruses. Analysis of viral proteins by SDS-PAGE found that irradiation also degraded viral proteins. Using RT-PCR, irradiation was shown to degrade viral genomic RNA. This suggests that the mechanism of inactivation of e-beam was likely the same as gamma irradiation as the damage to viral constituents led to inactivation.