Effect of Sourdough-Yeast Co-Fermentation on Physicochemical Properties of Corn Fagao Batter.

Fagao is one of China's traditional gluten-free staple foods made with rice or corn flour. Corn Fagao prepared by co-fermentation with sourdough and yeast exhibits better quality and less staling compared to traditional yeast-fermented Fagao. The physicochemical properties of corn Fagao batter during sourdough-yeast co-fermentation were investigated. The results showed that compared with yeast fermentation, the gas production and viscosity of the batter increased with co-fermentation. The co-fermented batter showed a higher hydrolysis of starch and less amylose content. The integrity of starch granules in the co-fermented batter was damaged more seriously, and the crystallinity and short-range ordered structure were less than in the yeast-fermented batter, even though the crystal structure type of starch did not obviously change. The peak viscosity, minimum viscosity, final viscosity, decay value, and recovery value of the corn batter were reduced by co-fermentation, which improved the thermal stability of the batter and slowed down the aging. Co-fermentation also resulted in a more pronounced reduction in protein subunit content than yeast fermentation. The changes in the physicochemical properties of the corn Fagao batter help explain the improvement in quality of corn Fagao made from the co-fermentation method and may provide theoretical references for co-fermentation with sourdough and yeast to other gluten-free foods.

Transcription Factor PdTP1 Regulates the Biotransformation of Limonene to α-Terpineol and the Growth of Penicillium digitatum.

α-Terpineol, an alcoholic monoterpene with lilac-like aroma, possesses diverse biological activities and has found applications in the food, pharmaceutical, cosmetic, and agricultural industries. Our previous studies indicated that gene PdTP1 was highly expressed in Penicillium digitatum DSM 62840 during the biotransformation of limonene to α-terpineol, while its actual biological functions are not fully understood. Here, PdTP1 was functionally characterized with bioinformatics analysis, subcellular localization, transcriptional activation activity, overexpression, and RNA interference (RNAi) silencing and RNA-seq analysis. Results showed that PdTP1 protein contained a GAL4-like Zn2Cys6 DNA-binding domain and a fungal_trans domain, was located in the nucleus and cell membrane and presented transcriptional activation effect, suggesting that PdTP1 encoded a Zn2Cys6 type transcription factor. Overexpression of PdTP1 in P. digitatum promoted limonene biotransformation and increased α-terpineol production, and opposite results were observed after the silencing of PdTP1. Moreover, transcription factor PdTP1 was found to affect the growth of P. digitatum and participate in ionic stress and oxidative stress responses. RNA-seq data revealed that altering the PdTP1 expression influenced the expression of some genes related to terpene metabolism or biosynthesis, fungal growth, and stress responses. In summary, PdTP1, which encoded a Zn2Cys6 transcription factor, played important roles in improving the production of α-terpineol from limonene and regulating fungal growth and environmental stress responses.

Facet-Dependent Evolution of Active Components on Spinel Co3O4 for Electrochemical Ammonia Synthesis.

Spinel cobalt oxides (Co3O4) have emerged as a promising class of catalysts for the electrochemical nitrate reduction reaction (eNO3RR) to ammonia, offering advantages such as low cost, high activity, and selectivity. However, the specific role of crystallographic facets in determining the catalysts' performance remains elusive, impeding the development of efficient catalysts. In this study, we have synthesized various Co3O4 nanostructures with exposed facets of {100}, {111}, {110}, and {112}, aiming to investigate the dependence of the eNO3RR activity on the crystallographic facets. Among the catalysts tested, Co3O4 {111} shows the best performance, achieving an ammonia Faradaic efficiency of 99.1 ± 1.8% with a yield rate of 35.2 ± 0.6 mg h-1 cm-2 at -0.6 V vs RHE. Experimental and theoretical results reveal a transformation process in which the active phases evolve from Co3O4 to Co3O4-x with oxygen vacancy (Ov), followed by a Co3O4-x-Ov/Co(OH)2 hybrid, and finally Co(OH)2. This process is observed for all facets, but the formation of Ov and Co(OH)2 is the most rapid on the (111) surface. The presence of Ov significantly reduces the free energy of the *NH2 intermediate formation from 1.81 to -0.53 eV, and plentiful active sites on the densely reconstructed Co(OH)2 make Co3O4 {111} an ideal catalyst for ammonia synthesis via eNO3RR. This work provides insights into the understanding of the realistic active components, offers a strategy for developing highly efficient Co-based spinel catalysts for ammonia synthesis through tuning the exposed facets, and helps further advance the design and optimization of catalysts in the field of eNO3RR.

Decoding heterogeneous and coordinated tissue architecture in glioblastoma using spatial transcriptomics.

Glioblastoma multiforme (GBM) is one of the most lethal brain tumors, characterized by profound heterogeneity. While single-cell transcriptomic studies have revealed extensive intra-tumor heterogeneity, shed light on intra-tumor diversity, spatial intricacies remain largely unexplored. Leveraging clinical GBM specimens, this study employs spatial transcriptomics technology to delve into gene expression heterogeneity. Our investigation unveils a significant enrichment of tissue stem cell signature in regions bordering necrosis and the peritumoral area, positively correlated with the mesenchymal subtype signature. Moreover, upregulated genes in these regions are linked with extracellular matrix (ECM)-receptor interaction, proteoglycans, as well as vascular endothelial growth factor (VEGF) and angiopoietin-Tie (ANGPT) signaling pathways. In contrast, signatures related to glycogen metabolism and oxidative phosphorylation show no relevance to pathological zoning, whereas creatine metabolism signature is notably exclusive to vascular-enriched areas. These spatial profiles not only offer valuable references but also pave the way for future in-depth functional and mechanistic investigations into GBM progression.

Grains in a Modern Time: A Comprehensive Review of Compositions and Understanding Their Role in Type 2 Diabetes and Cancer.

Globally, type 2 diabetes (T2D) and Cancer are the major causes of morbidity and mortality worldwide and are considered to be two of the most significant public health concerns of the 21st century. Over the next two decades, the global burden is expected to increase by approximately 60%. Several observational studies as well as clinical trials have demonstrated the health benefits of consuming whole grains to lower the risk of several chronic non-communicable diseases including T2D and cancer. Cereals grains are the primary source of energy in the human diet. The most widely consumed pseudo cereals include (quinoa, amaranth, and buckwheat) and cereals (wheat, rice, and corn). From a nutritional perspective, both pseudo cereals and cereals are recognized for their complete protein, essential amino acids, dietary fibers, and phenolic acids. The bran layer of the seed contains the majority of these components. Greater intake of whole grains rather than refined grains has been consistently linked to a lower risk of T2D and cancer. Due to their superior nutritional compositions, whole grains make them a preferred choice over refined grains. The modulatory effects of whole grains on T2D and cancer are also likely to be influenced by several mechanisms; some of these effects may be direct while others involve altering the composition of gut microbiota, increasing the abundance of beneficial bacteria, and lowering harmful bacteria, increasing insulin sensitivity, lowering solubility of free bile acids, breaking protein down into peptides and amino acids, producing short-chain fatty acids (SCFAs), and other beneficial metabolites that promote the proliferation in the colon which modulate the antidiabetic and anticancer pathway. Thus, the present review had two aims. First, it summarized the recent knowledge about the nutritional composition and bioactive acids in pseudo cereals (quinoa, amaranth, and buckwheat) and cereals (wheat, rice, and corn); the second section summarized and discussed the progress in recent human studies, such as observational (cross-sectional studies, case-control studies, and cohort studies) and intervention studies to understand their role in T2D and cancer including the potential mechanism. Overall, according to the scientific data, whole grain consumption may reduce the incidence of T2D and cancer. Future studies should carry out randomized controlled trials to validate observational results and establish causality. In addition, the current manuscript encourages researchers to investigate the specific mechanisms by which whole grains exert their beneficial effects on health by examining the effects of different types of specific protein, dietary fibers, and phenolic acids that might help to prevent or treat T2D and cancer.

Characteristic and stability changes of peanut oil body emulsion during the process of demulsification using heptanoic acid.

In this paper, the changes in oil body emulsion (OBE) during heptanoic acid demulsification (HD) were investigated from the macro and microscopic points of view. Specifically, the OBE particle size increased from 3.04 to 8.41 µm, while the zeta potential absolute decreased to 2.89 mV. The interfacial tension and apparent viscosity of OBE were reduced significantly. Heptanoic acid could contribute to oil droplets aggregation. The findings indicated that high-molecular proteins, including lipoxygenase (97.58 kDa) and arachin (70.28 kDa), detached from the OBs' interface. HD caused alterations in the secondary structure of protein and the environment around proteins changed. The HD mechanism was speculated that the addition of heptanoic acid resulted in the reduction in pH and changes of environment surrounding OBE, which triggered polymerization and the phase transformation of the oil droplets. Overall, this study is vital for solving the problem of demulsification during aqueous enzymatic extraction (AEE).

The bioavailability, absorption, metabolism, and regulation of glucolipid metabolism disorders by quercetin and its important glycosides: A review.

Quercetin and its glycosides (QG), vitally natural flavonoid, have been popular for health benefits. However, the absorption and metabolism affect their bioavailability, and the metabolic transformation alters their biological activities. This review systematically summarizes the bioavailability and pathways for the absorption and metabolism of quercetin/QG in vivo and in vitro, the biological activities and mechanism of quercetin/QG and their metabolites in treating glucolipid metabolism are discussed. After oral administration, quercetin/QG are mainly absorbed by the intestine, undergo phase II metabolism in the small intestine and liver to form conjugates and are metabolized into small phenolic acids by intestinal microbiota. Quercetin/QG and their metabolites exert beneficial effects on regulating glucolipid metabolism disorders, including improving insulin resistance, inhibiting lipogenesis, enhancing thermogenesis, modulating intestinal microbiota, relieving oxidative stress, and attenuating inflammation. This review enhances understanding of the mechanism of quercetin/QG regulate glucolipid metabolism and provides scientific support for the development of functional foods.

Composition of Whole Grain Dietary Fiber and Phenolics and Their Impact on Markers of Inflammation.

Inflammation is an important biological response to any tissue injury. The immune system responds to any stimulus, such as irritation, damage, or infection, by releasing pro-inflammatory cytokines. The overproduction of pro-inflammatory cytokines can lead to several diseases, e.g., cardiovascular diseases, joint disorders, cancer, and allergies. Emerging science suggests that whole grains may lower the markers of inflammation. Whole grains are a significant source of dietary fiber and phenolic acids, which have an inverse association with the risk of inflammation. Both cereals and pseudo-cereals are rich in dietary fiber, e.g., arabinoxylan and ß-glucan, and phenolic acids, e.g., hydroxycinnamic acids and hydroxybenzoic acids, which are predominantly present in the bran layer. However, the biological mechanisms underlying the widely reported association between whole grain consumption and a lower risk of disease are not fully understood. The modulatory effects of whole grains on inflammation are likely to be influenced by several mechanisms including the effect of dietary fiber and phenolic acids. While some of these effects are direct, others involve the gut microbiota, which transforms important bioactive substances into more beneficial metabolites that modulate the inflammatory signaling pathways. Therefore, the purpose of this review is twofold: first, it discusses whole grain dietary fiber and phenolic acids and highlights their potential; second, it examines the health benefits of these components and their impacts on subclinical inflammation markers, including the role of the gut microbiota. Overall, while there is promising evidence for the anti-inflammatory properties of whole grains, further research is needed to understand their effects fully.

Shared molecular mechanisms and transdiagnostic potential of neurodevelopmental disorders and immune disorders.

The co-occurrence and familial clustering of neurodevelopmental disorders and immune disorders suggest shared genetic risk factors. Based on genome-wide association summary statistics from five neurodevelopmental disorders and four immune disorders, we conducted genome-wide, local genetic correlation and polygenic overlap analysis. We further performed a cross-trait GWAS meta-analysis. Pleotropic loci shared between the two categories of diseases were mapped to candidate genes using multiple algorithms and approaches. Significant genetic correlations were observed between neurodevelopmental disorders and immune disorders, including both positive and negative correlations. Neurodevelopmental disorders exhibited higher polygenicity compared to immune disorders. Around 50%-90% of genetic variants of the immune disorders were shared with neurodevelopmental disorders. The cross-trait meta-analysis revealed 154 genome-wide significant loci, including 8 novel pleiotropic loci. Significant associations were observed for 30 loci with both types of diseases. Pathway analysis on the candidate genes at these loci revealed common pathways shared by the two types of diseases, including neural signaling, inflammatory response, and PI3K-Akt signaling pathway. In addition, 26 of the 30 lead SNPs were associated with blood cell traits. Neurodevelopmental disorders exhibit complex polygenic architecture, with a subset of individuals being at a heightened genetic risk for both neurodevelopmental and immune disorders. The identification of pleiotropic loci has important implications for exploring opportunities for drug repurposing, enabling more accurate patient stratification, and advancing genomics-informed precision in the medical field of neurodevelopmental disorders.

Inhibitory effects and reactions of gallic acid, catechin, and procyanidin B2 with nitrosation under stomach simulating conditions.

Nitrite widely exists in meat products, and has the functions of bacteriostasis, antisepsis, and color development. However, in an acidic environment, nitrite will react with amines, and further generate nitrosamines with carcinogenic and teratogenic effects. Polyphenols have good antioxidant and nitrite-scavenging effects. This study aimed to evaluate the inhibitory effects of gallic acid, catechin, and procyanidin B2 on the nitrosation reaction under stomach simulating conditions and discuss the potential inhibitory mechanism. The nitrite scavenging rate and nitrosamine synthesis blocking rate of gallic acid, catechin, and procyanidin B2 under different reaction times and contents was determined by UV-vis spectrophotometry. The possible products of the reaction of the three polyphenols with nitrite were analyzed by high-performance liquid chromatography-mass spectrometry (HPLC-MS) to reveal the mechanism of inhibiting nitrification. The results showed that the scavenging rate of the three polyphenols on nitrite and the blocking rate of nitrosamine synthesis increased with the increase of the content and reaction time. The ability of the three polyphenols to inhibit nitrosation was catechin > procyanidin B2 > gallic acid. HPLC-MS analysis showed that under simulated gastric juice conditions, the three phenolics were oxidized by nitrous acid to form their semiquinone radicals as the intermediates and nitrosated derivatives, while nitrite might be converted to ˙NO. These results suggested that gallic acid, catechin, and procyanidin B2 could inhibit nitrosation reactions in an acidic environment and may be used as food additives to reduce nitrite residues and nitrosamines in food.

Encapsulation and Characterization of Proanthocyanidin Microcapsules by Sodium Alginate and Carboxymethyl Cellulose.

Proanthocyanidins are important compounds known for their antioxidant and radical scavenging properties, but they are highly sensitive to light, heat, oxygen, and pH. In our study, proanthocyanidin was encapsulated using sodium alginate and carboxymethyl cellulose to enhance controlled release, pH stability, metal ion tolerance, temperature resistance, time release, the microencapsulation of food additives stability, antioxidant capacity analysis, and the storage period tolerance of proanthocyanidin. Fourier transforms infrared (FTIR) analysis and full-wavelength UV scanning indicated the successful immobilization of proanthocyanidins into the polymeric microcapsules. The flowability and mechanical properties of the microcapsules were enhanced. Moreover, proanthocyanidin microcapsules exhibited higher thermal, pH, metal ion, time, and microencapsulation food additive stability. In addition, due to their high antioxidant properties, the proanthocyanidin microcapsules retained a greater amount of proanthocyanidin content during the gastric phase, and the proanthocyanidin was subsequently released in the intestinal phase for absorption. Thus, the study provided a systematic understanding of the antioxidant capabilities and stability of proanthocyanidin microcapsules, which is beneficial for developing preservation methods for food additives.

Developing Lipase Inhibitor as a Novel Approach to Address the Rice Bran Rancidity Issue─A Critical Review.

Rice bran is a valuable byproduct from the food processing industry, which contains abundant protein, essential unsaturated fatty acids, and numerous bioactive compounds. However, its susceptibility to rancidity greatly restricts its wide utilization. Many strategies have been proposed to delay the rancidity of rice bran, but most of them have their respective limitations. Here, we proposed that developing rice ban lipase peptide inhibitors represents an alternative and promising prescription for impeding the rancidity of rice bran, in contrast to the conventional stabilization approaches for rice bran. For this reason, the rancidity mechanisms of rice bran and the research progress of rice bran lipases were discussed. In addition, the feasibility of utilizing in silico screening and phage display, two state-of-the-art technologies, in the design of the related peptide inhibitors was also highlighted. This knowledge is expected to provide a theoretical basis for opening a new avenue for stabilizing rice bran.

Demulsification of Emulsion Using Heptanoic Acid during Aqueous Enzymatic Extraction and the Characterization of Peanut Oil and Proteins Extracted.

Peanut oil body emulsion occurs during the process of aqueous enzymatic extraction (AEE). The free oil is difficult to release and extract because its structure is stable and not easily destroyed. Demulsification can release free oil in an oil body emulsion, so various fatty acids were selected for the demulsification. Changes in the amount of heptanoic acid added, solid-liquid ratio, reaction temperature, and reaction time were adopted to investigate demulsification, and the technological conditions of demulsification were optimized. While the optimal conditions were the addition of 1.26% of heptanoic acid, solid-liquid ratio of 1:3.25, reaction temperature of 72.7 °C, and reaction time of 55 min, the maximum free oil yield was (95.84 ± 0.19)%. The analysis of the fatty acid composition and physicochemical characterization of peanut oils extracted using four methods were studied during the AEE process. Compared with the amount of oil extracted via other methods, the unsaturated fatty acids of oils extracted from demulsification with heptanoic acid contained 78.81%, which was significantly higher than the other three methods. The results of physicochemical characterization indicated that the oil obtained by demulsification with heptanoic acid had a higher quality. According to the analysis of the amino acid composition, the protein obtained using AEE was similar to that of commercial peanut protein powder (CPPP). However, the essential amino acid content of proteins extracted via AEE was significantly higher than that of CPPP. The capacity of water (oil) holding, emulsifying activity, and foaming properties of protein obtained via AEE were better than those for CPPP. Overall, heptanoic acid demulsification is a potential demulsification method, thus, this work provides a new idea for the industrial application of simultaneous separation of oil and proteins via AEE.

Smart antimicrobial system based on enzyme-responsive high methoxyl pectin-whey protein isolate nanocomplex for fresh-cut apple preservation.

The increase in pectin methylesterase (PME) activity on fresh-cut apple surface can smartly trigger the controlled release of bactericidal agents encapsulated within intelligent responsive Pickering emulsions. In this study, we developed a PME-responsive nanocomplex (W-H-II) to stabilize Pickering emulsion containing thyme essential oil (TEO), preserving fresh-cut apples. W-H-II, formed by heat-induced whey protein isolate (WPI) and high methoxyl pectin (HMP) (pH 4.5, 85 °C, 15 min, WPI:HMP ratio 1:2), exhibited good pH stability due to the stabilizing effects of hydrophobic, hydrogen bonding, and electrostatic interactions. The presence of PME triggered the demethylation of HMP within W-H-II, conferring PME response characteristics. Subsequently, a bacteriostasis experiment with pectinase-producing Bacillus subtilis provided evidence of PME-triggered TEO release from W-H-II-stabilized Pickering emulsion. Furthermore, microscopy techniques were employed to verify the demulsification behavior of the emulsion when PME activity ranged from 0.25 to 2.50 U mL-1. Finally, the PME-responsive TEO Pickering emulsion effectively preserved fresh-cut apples. Stored for 6 days at 5 °C and 10 °C, as the PME activity on the apple surface increased, the decay rate of the coated group was 0 %, with a total colony count below 3.0 log CFU g-1. This study introduces a novel intelligent preservation strategy for storing fresh-cut apples.

Research Progress of Protein-Based Bioactive Substance Nanoparticles.

Bioactive substances exhibit various physiological activities-such as antimicrobial, antioxidant, and anticancer activities-and have great potential for application in food, pharmaceuticals, and nutraceuticals. However, the low solubility, chemical instability, and low bioavailability of bioactive substances limit their application in the food industry. Using nanotechnology to prepare protein nanoparticles to encapsulate and deliver active substances is a promising approach due to the abundance, biocompatibility, and biodegradability of proteins. Common protein-based nanocarriers include nano-emulsions, nano-gels, nanoparticles, and nano complexes. In this review, we give an overview of protein-based nanoparticle fabrication methods, highlighting their pros and cons. Additionally, we discuss the applications and current issues regarding the utilization of protein-based nanoparticles in the food industry. Finally, we provide perspectives on future development directions, with a focus on classifying bioactive substances and their functional properties.

Lipid oxidation in foods and its implications on proteins.

Lipids in foods are sensitive to various environmental conditions. Under light or high temperatures, free radicals could be formed due to lipid oxidation, leading to the formation of unstable food system. Proteins are sensitive to free radicals, which could cause protein oxidation and aggregation. Protein aggregation significantly affects protein physicochemical characteristics and biological functions, such as digestibility, foaming characteristics, and bioavailability, further reducing the edible and storage quality of food. This review provided an overview of lipid oxidation in foods; its implications on protein oxidation; and the assessment methods of lipid oxidation, protein oxidation, and protein aggregation. Protein functions before and after aggregation in foods were compared, and a discussion for future research on lipid or protein oxidation in foods was presented.

Drying kinetics and quality dynamics of ultrasound-assisted dried selenium-enriched germinated black rice.

Black rice is a functional food due to its higher protein, fiber, iron, antioxidant compounds, and other health benefits than traditional rice. The ultrasonic (US) pretreatments (10, 20, and 50 min) followed by hot-air drying (50, 60, and 70 °C) were applied to study the drying kinetics, mathematical modeling, thermodynamics, microstructure, bioactive profile, volatile compounds and to lock the nutritional composition of selenium-enriched germinated black rice (SeGBR). Ultrasonic-treated samples exhibited a 20.5% reduced drying time than control ones. The Hii model accurately describes the drying kinetics of SeGBR with the highest R2 (>0.997 to 1.00) among the fifteen studied models. The activation energy values in US-SeGBR varied from 3.97 to 13.90 kJ/mol, while the specific energy consumption ranged from 6.45 to 12.32 kWh/kg, which was lower than untreated. The obtained thermodynamic attributes of dried black rice revealed that the process was endothermic and non-spontaneous. Gallic acid, kaempferol, and cyanidin 3-glucoside were present in high concentrations in phenolics, flavonoids, and anthocyanins, respectively. The HS-SPME-GC-MS investigation detected and quantified 55 volatile compounds. The US-treated SeGBR had more volatile compounds, which may stimulate the release of more flavorful substances. The scanning electronic micrograph shows that the US-treated samples absorbed high water through several micro-cavities. Selenium concentration was significantly higher in US-treated samples at 50 °C than in control samples. In conclusion, ultrasound-assisted hot-air drying accelerated drying and improved SeGBR quality, which is crucial for the food industry and global promotion of this healthiest rice variety.

Effect of Soybean Protein Concentrate Preparation on Copy Numbers and Structural Characteristics of DNA from Genetically Modified Soybean.

To regulate the degradation of transgenic DNA and lay theoretical foundations for the rational utilization of genetically modified (GM) products, variations in copy numbers and structural characteristics of DNA from GM soybean event GTS 40-3-2 during soybean protein concentrate (SPC) preparation were evaluated. Results showed that defatting and the first ethanol extraction were key procedures inducing DNA degradation. After these two procedures, copy numbers of the lectin and cp4 epsps targets decreased by more than 4 × 108, occupying 36.88-49.30% of the total copy numbers from raw soybean. Atomic force microscopy images visually revealed the degradation of DNA that thinned and shortened during SPC preparation. Circular dichroism spectra suggested a lower helicity of DNA from defatted soybean kernel flour and a conformation transition of DNA from B-type to A-type after ethanol extraction. The fluorescence intensity of DNA decreased during SPC preparation, verifying the DNA damage along this preparation chain.

Optimization of Extrusion Treatments, Quality Assessments, and Kinetics Degradation of Enzyme Activities during Storage of Rice Bran.

Over the years, extrusion has been a multi-step thermal technique that has proven to be the most effective process to stabilize rice bran (RB). This study aimed to investigate the effects of extrusion treatment and temperature (15, 25, and 40 °C) on the storage stability, lipid oxidation, peroxidase, and peroxide values, free fatty acids, fatty acid composition, and protein variations of RB over 60 days. The study offers novel insights into the changes in RB's protein and amino acid compositions during extrusion and storage, which has not been extensively explored in prior research. After extrusion processing, peroxidase activity (POD) and lipase activity (LPS) were significantly reduced. However, peroxide value (PV), free fatty acids (FFA), and malondialdehyde content (MDA) observed a significantly increased by 0.64 mEqO2/kg, 8.3 mg/100 g, and 0.0005 µmol/L respectively. The storage stability of RB after extrusion shows that the POD, LPS, FFA, PV, and MDA were positively correlated with storage duration and temperature. The oleic acid/linoleic acid ratio in processed RB by extrusion had no significant changes during storage. The total and essential/non-essential amino acid ratios showed a downward trend of 5.26% and 8.76%, respectively. The first-order kinetics was the best-fitting model to describe the enzymatic inactivation and degradation of extruded RB during storage. The extrusion treatment did not affect the crude protein and the essential subunits of protein. Overall, the optimized extrusion procedure exhibited promising results in stabilizing the RB.

Precise determination of energy transfer upconversion coefficient for the erbium and ytterbium codoped laser crystals.

Energy transfer upconversion (ETU) coefficient plays a crucial role in investigating complex laser systems as it greatly influences both the laser output behavior and heat generation. For some quasi-three-energy-level lasers based on Er3+ doped, Ho3+ doped and codoped gain media, the available theoretical studies relied on some unreasonable approximations due to the lack of spectroscopic data, notably the ETU coefficient. We put forward what we believe is a novel approach to overcome the difficulties caused by wavelength jump occurred in aforementioned laser systems. Based on net gain cross-section analysis and rate equations modelling, the functional relationship between the ETU coefficient, the laser power and pump power at the jumping wavelength are established. ETU coefficients and their temperature dependences of Er,Yb:YAB crystals with different crystal doped concentrations are experimentally determined for the first time. The results reveal that the ETU process in Er,Yb:YAB laser system is 5∼35 times stronger than that in Er3+ and Yb3+ codoped phosphate glass. The determination of these spectroscopic data paves the way for precise modelling of laser system based on Er,Yb:YAB or similar gain media.