Comparative study of vestibular projection pathway connectivity in cerebellar injury patients and healthy adults.

OBJECTIVE: Cerebellar injury can not only cause gait and postural instability, nystagmus, and vertigo but also affect the vestibular system. However, changes in connectivity regarding the vestibular projection pathway after cerebellar injury have not yet been reported. Therefore, in the current study, we investigated differences in the connectivity of the vestibular projection pathway after cerebellar injury using diffusion tensor imaging (DTI) tractography. METHODS: We recruited four stroke patients with cerebellar injury. Neural connectivity in the vestibular nucleus (VN) of the pons and medulla oblongata in patients with cerebellar injury was measured using DTI. Connectivity was defined as the incidence of connection between the VN on the pons and medulla oblongata and target brain regions such as the cerebellum, thalamus, parieto-insular vestibular cortex (PIVC), and parietal lobe. RESULTS: At thresholds of 10 and 30, there was lower connectivity in the ipsilateral hemisphere between the VN at the medullar level and thalamus in the patients than in healthy adults. At a threshold of 1 and 10, the patient group showed lower VN connectivity with the PIVC than healthy adults. At a threshold of 1, VN connectivity with the parietal lobe in the contralateral hemisphere was lower in the patients than in healthy adults. Additionally, at a threshold of 30, VN connectivity at the pons level with the cerebellum was lower in healthy adults than in the patients. CONCLUSION: Cerebellar injury seems to be associated with decreased vestibular projection pathway connectivity, especially in the ipsilateral thalamus, PIVC, and contralateral parietal lobe.

Psychosocial Support during the COVID-19 Outbreak in Korea: Activities of Multidisciplinary Mental Health Professionals.

As of April 18, 2020, there have been a total of 10,653 confirmed cases and 232 deaths due to coronavirus disease 2019 (COVID-19) in Korea. The pathogen spread quickly, and the outbreak caused nationwide anxiety and shock. This study presented the anecdotal records that provided a detailed process of the multidisciplinary teamwork in mental health during the COVID-19 outbreak in the country. Psychosocial support is no less important than infection control during an epidemic, and collaboration and networking are at the core of disaster management. Thus, a multidisciplinary team of mental health professionals was immediately established and has collaborated effectively with its internal and external stakeholders for psychosocial support during the COVID-19 outbreak.

Astragalin inhibits autophagy-associated airway epithelial fibrosis.

BACKGROUND: Fibrotic remodeling of airway and lung parenchymal compartments is attributed to pulmonary dysfunction with an involvement of reactive oxygen species (ROS) in chronic lung diseases such as idiopathic pulmonary fibrosis and asthma. METHODS: The in vitro study elucidated inhibitory effects of astragalin, kaempferol-3-O-glucoside from leaves of persimmon and green tea seeds, on oxidative stress-induced airway fibrosis. The in vivo study explored the demoting effects of astragalin on epithelial to mesenchymal transition in BALB/c mice sensitized with ovalbumin (OVA). RESULTS: The exposure of 20 µM H2O2 for 72 h accelerated E-cadherin loss and vimentin induction in airway epithelial BEAS-2B cells, which was reversed by non-toxic astragalin at 1-20 µM. Astragalin allayed the airway tissue levels of ROS and vimentin enhanced by OVA challenge. Collagen type 1 production increased in H2O2-exposed epithelial cells and collagen fiber deposition was observed in OVA-challenged mouse airways. This study further investigated that the oxidative stress-triggered autophagic regulation was responsible for inducing airway fibrosis. H2O2 highly enhanced the expression induction of the autophagy-related beclin-1 and light chains 3A/B (LC3A/B) within 4 h and astragalin blocked such induction by H2O2. This compound deterred the ROS-promoted autophagosome formation in BEAS-2B cells. Consistently, in OVA-sensitized mice the expression of beclin-1 and LC3A/B was highly induced, and oral administration of astragalin suppressed the autophagosome formation with inhibiting the induction of these proteins in OVA-challenged airway subepithelium. Induction of autophagy by spermidine influenced the epithelial induction of E-cadherin and vimentin that was blocked by treating astragalin. CONCLUSION: These results demonstrate that astragalin can be effective in allaying ROS-promoted bronchial fibrosis through inhibiting autophagosome formation in airways.

The relationship between poor performance on attention tasks and increased suicidal ideation in adolescents.

Our goal was to examine the relationship between attention and suicidal ideation in a school-based adolescent population. This cross-sectional study involved 2,462 students from eight high schools in South Korea (1,021 males and 1,441 females, mean age 17.3 ± 0.6 years). The participants completed the Beck Scale for Suicide Ideation (SSI) and the Beck Depression Inventory (BDI) and took part in computerized attention tasks. Participants with high SSI scores (16 or higher) exhibited a higher mean number of omission errors (OEs) and commission errors (CEs) on the visual sustained attention tasks than did participants with low SSI scores (p < 0.001 and p < 0.001, respectively). On the divided attention tasks, the high SSI group exhibited a higher mean number of CEs than the low SSI group did (p < 0.001). In a general linear model adjusting for age, gender, and high BDI (10 or higher), membership in the high OE group in the visual sustained attention tasks was associated with high SSI scores (p = 0.015). Belonging to the high OE or CE group in the divided attention tasks were associated with high SSI scores (p = 0.024 and p = 0.035, respectively). For both the visual sustained and divided attention tasks, interactions between gender and high OE rates were significant (p ≤ 0.001 and p = 0.013, respectively). In the post hoc analysis, membership in the high OE group was associated with high SSI scores for girls. In a multiple linear regression analysis including all participants and controlling for age, gender, and BDI scores, higher numbers of OEs and CEs on the visual sustained attention tasks predicted higher SSI scores (p < 0.001 and p = 0.019, respectively). On the divided attention task, the number of CEs was positively correlated with the SSI score (p = 0.031). The findings of this study indicate an association between attention deficits and increased suicidal ideation in adolescents after controlling for depressed mood. The current results suggest a direct link between attention deficits and increased suicidality independent of depressive symptoms in adolescents.

Inhibition of airway epithelial-to-mesenchymal transition and fibrosis by kaempferol in endotoxin-induced epithelial cells and ovalbumin-sensitized mice.

Chronic airway remodeling is characterized by structural changes within the airway wall, including smooth muscle hypertrophy, submucosal fibrosis and epithelial shedding. Epithelial-to-mesenchymal transition (EMT) is a fundamental mechanism of organ fibrosis, which can be induced by TGF-ß. In the in vitro study, we investigated whether 1-20 µM kaempferol inhibited lipopolysaccharide (LPS)-induced bronchial EMT in BEAS-2B cells. The in vivo study explored demoting effects of 10-20 mg/kg kaempferol on airway fibrosis in BALB/c mice sensitized with ovalbumin (OVA). LPS induced airway epithelial TGF-ß1 signaling that promoted EMT with concurrent loss of E-cadherin and induction of α-smooth muscle actin (α-SMA). Nontoxic kaempferol significantly inhibited TGF-ß-induced EMT process through reversing E-cadherin expression and retarding the induction of N-cadherin and α-SMA. Consistently, OVA inhalation resulted in a striking loss of epithelial morphology by displaying myofibroblast appearance, which led to bronchial fibrosis with submucosal accumulation of collagen fibers. Oral administration of kaempferol suppressed collagen deposition, epithelial excrescency and goblet hyperplasia observed in the lung of OVA-challenged mice. The specific inhibition of TGF-ß entailed epithelial protease-activated receptor-1 (PAR-1) as with 20 µM kaempferol. The epithelial PAR-1 inhibition by SCH-79797 restored E-cadherin induction and deterred α-SMA induction, indicating that epithelial PAR-1 localization was responsible for resulting in airway EMT. These results demonstrate that dietary kaempferol alleviated fibrotic airway remodeling via bronchial EMT by modulating PAR1 activation. Therefore, kaempferol may be a potential therapeutic agent targeting asthmatic airway constriction.

No association of the norepinephrine transporter gene (SLC6A2) and cognitive and behavioural phenotypes of patients with autism spectrum disorder.

We examined the association between the norepinephrine transporter (SLC6A2) gene and autism spectrum disorder (ASD) in a Korean population. In addition, we investigated which phenotypes of ASD are best attributed to the genotype of SLC6A2. A total of 184 subjects with ASD, their 156 unaffected siblings and both biological parents were recruited through university hospitals. We used the Autism Diagnostic Interview-Revised, the Aberrant Behaviour Checklist (ABC), the Child Behaviour Checklist (CBCL), the Stroop Colour-Word Interference Test and the Wisconsin Card Sorting Test (WCST) as quantitative measures of the ASD phenotypes. The associations between the quantitative measures and specific single-nucleotide polymorphisms (SNPs) were tested with linear regression analyses. We did not find any evidence of the over-transmission of either allele of the 10SLC6A2 SNPs in the DFAM test. At an empirical p value <0.05, findings that were consistent between the linear regression analyses and the QFAM tests were the positive associations between the A allele of rs36020 and attention problems on the CBCL and stereotypical behaviours on the ABC and between the C allele of rs1814270 and the number of trials required to complete the first WCST category. However, these associations did not remain after correction for multiple testing. The study results of this study do not support the association between the SLC6A2 and the diagnosis or phenotype of ASD. However, the study must be replicated in larger populations and with using more genetic markers.

Weekend catch-up sleep is independently associated with suicide attempts and self-injury in Korean adolescents.

The current study aims to determine the associations of insufficient sleep with suicide attempts and self-injury in a large, school-based Korean adolescent sample. A sample of 4553 middle- and high-school students (grades 7-10) was recruited in this study. Finally, 4145 students completed self-report questionnaires including items on sleep duration (weekday/weekend), self-injury, suicide attempts during the past year, the Suicidal Ideation Questionnaire (SIQ), and the Beck Depression Inventory (BDI). A multiple linear regression model showed that higher SIQ scores were associated with longer weekend catch-up sleep duration (p=0.009), higher BDI score (p<0.001), and longer time spent in a private educational institute (p=0.025). The multiple logistic regression analysis revealed that longer weekend catch-up sleep duration (p=0.011), higher BDI score (p<0.001), longer time spent in a private educational institute (p=0.046), and poorer academic record (p=0.029) were associated with suicide attempt and self-injury during the past year. The present results suggest that weekend catch-up sleep duration--which is an indicator of insufficient weekday sleep--might be associated with suicide attempts and self-injury in Korean adolescents.

Astragalin inhibits airway eotaxin-1 induction and epithelial apoptosis through modulating oxidative stress-responsive MAPK signaling.

BACKGROUND: Eotaxin proteins are a potential therapeutic target in treating the peribronchial eosinophilia associated with allergic airway diseases. Since inflammation is often associated with an increased generation of reactive oxygen species (ROS), oxidative stress is a mechanistically imperative factor in asthma. Astragalin (kaempferol-3-O-glucoside) is a flavonoid with anti-inflammatory activity and newly found in persimmon leaves and green tea seeds. This study elucidated that astragalin inhibited endotoxin-induced oxidative stress leading to eosinophilia and epithelial apoptosis in airways. METHODS: Airway epithelial BEAS-2B cells were exposed to lipopolysaccharide (LPS) in the absence and presence of 1-20 µM astragalin. Western blot and immunocytochemical analyses were conducted to determine induction of target proteins. Cell and nuclear staining was also performed for ROS production and epithelial apoptosis. RESULTS: When airway epithelial cells were exposed to 2 µg/ml LPS, astragalin nontoxic at ≤ 20 µM suppressed cellular induction of Toll-like receptor 4 (TLR4) and ROS production enhanced by LPS. Both LPS and H2O2 induced epithelial eotaxin-1 expression, which was blocked by astragalin. LPS activated and induced PLCγ1, PKCß2, and NADPH oxidase subunits of p22phox and p47phox in epithelial cells and such activation and induction were demoted by astragalin or TLR4 inhibition antagonizing eotaxin-1 induction. H2O2-upregulated phosphorylation of JNK and p38 MAPK was dampened by adding astragalin to epithelial cells, while this compound enhanced epithelial activation of Akt and ERK. H2O2 and LPS promoted epithelial apoptosis concomitant with nuclear condensation or caspase-3 activation, which was blunted by astragalin. CONCLUSIONS: Astragalin ameliorated oxidative stress-associated epithelial eosinophilia and apoptosis through disturbing TLR4-PKCß2-NADPH oxidase-responsive signaling. Therefore, astragalin may be a potent agent antagonizing endotoxin-induced oxidative stress leading to airway dysfunction and inflammation.

Subthreshold attention-deficit/hyperactivity disorder is associated with functional impairments across domains: a comprehensive analysis in a large-scale community study.

This study compared children who experience attention-deficit/hyperactivity disorder (ADHD) symptoms but do not meet criteria (i.e., subthreshold ADHD) with those with the full syndrome and healthy controls. Presence of ADHD symptoms was determined in a nationwide community sample of 921 children, aged 8-11 years. The main outcome measures comprised attentional symptoms, comorbidity profiles, academic performance, and neurocognitive ability (i.e., ADHD Rating Scale, Child Behavior Checklist, Learning Disability Evaluation Scale, and Stroop Color-Word Test, respectively). Subthreshold ADHD was equally prevalent in boys and girls, and more prevalent in low-income families. Throughout all the outcome measurements, subthreshold ADHD was both a significantly milder condition than full syndrome ADHD and a significantly more severe condition than non-ADHD status. The findings were consistent across the total as well as the subtest scores, and after correction for multiple comparisons (p < 0.0017). Children with subthreshold ADHD were found to experience significant symptoms and functional impairments. The results of this study support the clinical relevance of subthreshold ADHD in a childhood population. Subthreshold diagnostic criteria for ADHD may be more sensitive in detecting ADHD symptoms in girls than the full syndrome criteria, and subthreshold clinical, cognitive, and behavioral symptoms of ADHD may occur in a subset of children who are possibly more sensitive to their environment. Further consideration about the diagnostic threshold for ADHD may particularly benefit girls and children in low-income families.

Bisphenol A in relation to behavior and learning of school-age children.

BACKGROUND: Bisphenol A (BPA) has been shown to affect brain and behavior in rodents and nonhuman primates, but there are few studies focusing on its relationship to human neurobehavior. We aimed to investigate the relationship between environmental exposure to BPA and childhood neurobehavior. METHODS: Urinary BPA concentrations and behavioral and learning characteristics were assessed in a general population of 1,089 children, aged 8-11 years. The main outcome measures were the Child Behavior Checklist (CBCL) and the Learning Disability Evaluation Scale (LDES). RESULTS: Urinary levels of BPA were positively associated with the CBCL total problems score and negatively associated with the learning quotient from the LDES. The linear association with the CBCL anxiety/depression score and the quadratic association with the LDES listening score were significant after correction for multiple comparisons. CONCLUSIONS: Environmental exposure to BPA might be associated with childhood behavioral and learning development. The results suggest possible nonmonotonic relationships.

Impact of family environment on the development of tic disorders: epidemiologic evidence for an association.

BACKGROUND: Although family education generally is recommended in the treatment of tic disorders, few studies have focused on the relationship between family environment and diagnosis of tic disorders. METHODS: Presence of DSM-IV tic disorders was determined in a general population of 921 children in Korea from 2008 to 2009. Clinical risk factors were assessed, including comorbidity with attention-deficit/hyperactivity disorder; family-related factors such as the number of family members and primary caretaker of the child; and socioeconomic factors in the form of paternal education level and household yearly income. Multivariable logistic regression analyses were performed to estimate the association between a list of clinical, familial, and social variables and the odds of developing tic disorders. RESULTS: At Bonferroni corrected thresholds, a higher risk of tic disorders was significantly associated with the number of changes in primary caretaker, whereas a lower risk was associated with increasing number of children in the family. CONCLUSIONS: Family-related environmental factors may play a role in the development or exacerbation of tic disorders. The results advocate the importance of family education when treating children with tic disorders, and further research is needed on the contextual risk factors of tic disorders.

Relationship between blood manganese levels and children's attention, cognition, behavior, and academic performance--a nationwide cross-sectional study.

Manganese (Mn) is neurotoxic at high concentrations. However, Mn is an essential element that can protect against oxidative damage; thus, extremely low levels of Mn might be harmful. Our aim was to examine whether either high or low environmental Mn exposure is related to academic and attention function development among school-aged children. This cross-sectional study included 1089 children 8-11 years of age living in five representative areas in South Korea. Blood Mn, blood lead, and urine cotinine were measured. We assessed IQ with the Wechsler Abbreviated Scale of Intelligence; attention with a computerized continuous performance test called the Attention-deficit/hyperactivity disorder (ADHD) Diagnostic System (ADS), the Korean version of the Stroop Color-Word Test, the Children's Color Trails Test (CCTT), and the ADHD Rating Scale; academic functions with the Learning Disability Evaluation Scale (LDES); and emotional and behavioral problems with the Korean version of the Child Behavior Checklist (CBCL). We further assessed the presence of ADHD using a highly structured diagnostic interview, the Diagnostic Interview Schedule for Children Version IV (DISC-IV). The median blood concentration of Mn was 14.14 µg/L. We observed a nonlinear association between the CCTT2 completion time and the CPT commission error (F=3.14, p=0.03 and F=4.05, p=0.01, respectively). We divided the data into three groups: lower (<8.154 µg/L), and upper 5th percentile (>21.453 µg/L) and middle 90th percentile to determine whether a lack or overload of Mn could cause adverse effects. After adjusting for urine cotinine, blood lead, children's IQ, and other potential confounders, the high Mn group showed lower scores in thinking (B=-0.83, p=0.006), reading (B=-0.93, p=0.004), calculations (B=-0.72, p=0.005), and LQ (B=-4.06, p=0.006) in the LDES and a higher commission error in the CPT (B=8.02, p=0.048). The low Mn group showed lower color scores in the Stroop test (B=-3.24, p=0.040). We found that excess Mn in children is associated with lower scores of thinking, reading, calculation, and LQ in the LDES and higher scores of commission error in the ADS test. In contrast, lower Mn in children is associated with lower color scores in the Stroop test. The findings of this cross-sectional study suggest that excess exposure or deficiency of Mn can cause harmful effects in children.

Association of the catechol-o-methyltransferase gene polymorphisms with Korean autism spectrum disorders.

This study evaluated the family-based genetic association between autism spectrum disorders (ASDs) and 5 single-nucleotide polymorphisms (SNPs) in the catechol-o-methyltransferase gene (COMT), which was found among 151 Korean ASDs family trios (dominant model Z = 2.598, P = 0.009, P FDR = 0.045). We found a statistically significant allele transmission or association in terms of the rs6269 SNP in the ASDs trios. Moreover, in the haplotype analysis, the haplotypes with rs6269 demonstrated significant evidence of an association with ASDs (additive model rs6269-rs4818-rs4680-rs769224 haplotype P = 0.004, P FDR = 0.040). Thus, an association may exist between the variants of the COMT gene and the occurrence of ASDs in Koreans.

Risk factors for suicidal ideation of the general population.

The aim of this study was to investigate risk factors of suicide ideation in general population. A total of 1,116 adults were sampled with randomization in an urban area. After excluding 116 participants due to incomplete answer, 1,000 participants (500 males; mean age 39.6 ± 11.6) completed self-report questionnaire including the Center for Epidemiologic Study Depression Scale (CES-D), the Beck Scale for Suicide Ideation (BSI), the Spielberger State-Trait Anger Expression Inventory (STAXI), the Barratt Impulsiveness Scale (BIS), and questions on weekday sleep duration. Results showed higher scores on the BSI were related with higher scores on the STAXI, CES-D, a family history of psychiatric illness, and short or long sleep duration (≤ 5 or ≥ 10 hr) (adjusted R (2) = 0.151, P < 0.001, P < 0.001, P = 0.001, and P = 0.008, respectively). The predictive power of the STAXI scores, the presence of psychiatric family history and short or long sleep duration was stronger in the high CES-D group with scores of 16 or higher (adjusted R (2) = 0.275, P < 0.001, P < 0.001, and P < 0.001, respectively). These findings suggest that suicide idea in general population may be related with the presence of family history for psychiatric illness, depressive mood, high anger and short or long sleep duration.

Injury of the Vestibulocerebellar Tract and Signs of Ataxia in Patients with Cerebellar Stroke.

BACKGROUND: The vestibulocerebellar tract (VCT) is responsible for maintaining balance, spatial orientation, and coordination. Damage to the vestibular system is accompanied by symptoms of balance disorder or ataxia. This study aimed to compare cerebellar dysfunction according to VCT damage in patients with cerebellar stroke. METHODS: Six patients with cerebellum injury were recruited. This study measured ataxia and hand function related to visuomotor integration and manual dexterity using the Purdue pegboard test. The primary and bilateral secondary VCTs were reconstructed to investigate the integrity of pathways using diffusion tensor imaging (DTI). RESULTS: The ataxia sign was positive in five patients (83%) at onset. In the result of the pegboard test, all patients had hand dysfunction in the dominant hand (100%). Likewise, all patients also had non-dominant hand dysfunction (100%). On the DTI tractography, the left and right primary VCTs of the patients demonstrated a 25% injury rate. Furthermore, the injury rates of ipsilateral and contralateral secondary VCTs were 50% and 58%. CONCLUSIONS: Ataxia is related to secondary VCTs, and hand dysfunction is also related to VCTs. Therefore, we believe that the current study will be helpful in evaluating and providing a clinical intervention strategy for patients with ataxia and hand dysfunction following cerebellar injury.

Validation of the AOAC method for analyzing fatty acids in meat by-products for the Korean Food Composition Database.

The constituents of meat and meat by-product are susceptible to degradation processes, especially, the control of oxidative processes is critical. The main factors that influence their lipid oxidation are fat content and fatty acid composition. The aim of this study was to validate AOAC method 996.06 for analysis of fatty acid in meat by-products and to provide their accurate, precise, and reliable information in the Korean Food Composition Database. A total of 19 fatty acids were identified. The head, small intestine, stomach, and heart of pigs and the feet of chickens contained higher contents of total fatty acids, whereas the blood of cow had the lowest content. In particular, meat by-products other than the liver, blood, and stomach of cows and the stomach and small intestine of pigs contained higher contents of unsaturated fatty acids. Their main fatty acids were oleic acid, palmitic acid, linoleic acid, and stearic acid. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01223-8.

Injury of the vestibulocerebellar tract in a patient with intracerebral hemorrhage: A case report.

OBJECTIVE: The vestibulocerebellar tract (VCT) is an important pathway of the central vestibular system, and plays a role in posture reflexes as well as perception of the head and body motion in spatial direction. We report on a patient with intracerebral hemorrhage (ICH), who showed injury of the VCT, which was demonstrated by diffusion tensor imaging (DTI). CASE DESCRIPTION: This study recruited an 81-year-old male patient presented with quadriparesis due to ICH on both cerebellar hemispheres and 5 control subjects. A patient had the dizziness that was occurred when he moved and the motor weakness in lower limb. The primary and secondary VCTs of a patient with total 25 score of Scale of the Assessment and Rating of Ataxia were reconstructed using DTI. RESULTS: The results of DTI parameters of primary VCT showed that the tract volumes of primary VCT in both hemispheres of a patient showed significant decrease compared to those of control subjects. All of DTI parameters of ipsilateral secondary VCT in left hemisphere of a patient were within the reference range. Additionally, the ipsilateral secondary VCT in right hemisphere and the contralateral secondary VCTs in both hemispheres of a patient were not reconstructed. CONCLUSION: We suggest that a patient's ataxia appears to be related to injury of the VCT. Therefore, we believe that the current study would be helpful in evaluating and clinical managing patients with ataxia following cerebellar injury.

The effect of roasting on capsaicinoids, volatile compounds, and fatty acids in Capsicum annuum L. (red pepper) seeds.

Capsaicinoids, volatile compounds, and fatty acids were analyzed in red pepper seeds to determine any changes at different roasting temperatures. The contents of capsaicin and dihydrocapsaicin decreased as roasting temperatures increased. 3-Ethyl-2,5-dimethylpyrazine, 2,3,5,6-tetramethylpyrazine, 2-methoxy-3-(2-methylpropyl)pyrazine, 1-methylpyrrole, hexanedial, benzeneacetaldehyde, 2-acetylfuran, and butane-2,3-diol were newly detected in red pepper seeds roasted at 100 °C. Concentrations of pyrazines, pyrroles, oxygen-containing heterocyclic compounds, carbonyls, and alcohols increased rapidly in red pepper seeds as the roasting temperature increased. Such compounds could contribute roasted, grilled, and sweet odor notes to roasted red pepper seeds. Linoleic acid was the predominant fatty acid in all red pepper seeds. There were no significant differences in polyunsaturated fatty acids in red pepper seeds as roasting temperature increased. In conclusion, roasting red pepper seeds could be used in thermally processed foods because during roasting their pungency is reduced, desirable savory odors are enhanced, and the levels of polyunsaturated fatty acids remain unchanged.

Effect of amino acids in the Maillard reaction products generated from the reaction flavors of Tenebrio molitor (mealworm) protein and d-xylose.

In this study, Tenebrio molitor (mealworm) protein and reducing sugar were thermally reacted without (MP-RF) or with amino acids (MPA-RFs, A is then replaced with three-letter abbreviation of amino acid used in the reaction), and their Maillard reaction products (MRPs) and sensory characteristics were compared to explore the amino acids that contributed to desirable meat-related odor attributes in MP-RF. The odor characteristics perceived from MP-RF were changed based on the amino acid that was added to MP-RF and then reacted. Noticeably, a 'dried shrimp-like' attribute, which was the most intense in MP-RF, was weakened in all MPA-RFs. The 'meaty' and 'sulfur-like' odor notes were higher in MP-RF reacted with cysteine (MPCys-RF) than those in MP-RF and most MPA-RFs. In addition, 2-methyl-3-furanthiol and 2-furfurylthiol, which are the most important key odorants in a meat flavoring material, were also found only in MPCys-RF. These results show that the meaty flavoring potential of MP-RF was significantly enhanced when reacted with cysteine.

The aroma profile and aroma-active compounds of Brassica oleracea (kale) tea.

This study was to understand characteristic aroma properties of kale tea made by roasting kale leaves by profiling its aroma composition and screening its aroma-active compounds. Secondary metabolites of glucosinolates such as ally isothiocyanate, 3-butenyl isothiocyanate, 3-methylthiopropyl isothiocyanate, and 5-methylthiazole were the primary aroma compounds of raw kale but were less abundant in kale tea. Dimethyl trisulfide, cyclohex-2-en-1-ol, benzeneacetaldehyde, and 4-vinylguaiacol were quantitatively major aroma compounds in kale tea. Pyrazines, aldehydes, sulfides, and 4-vinylguaiacol were newly produced only in kale tea. In particular, 2-ethyl-6-methylpyrazine exhibiting the highest flavor dilution factor was the most potent aroma-active compound of kale tea, followed by methional, 2-ethyl-5-methylpyrazine, 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, two unknown compounds, dimethyl disulfide, furfural, benzaldehyde, and dimethyl trisulfide. These compounds contributed to roasted, sulfur-like/pungent, and sweet aroma characteristics, which were main aroma properties of kale tea. In addition, (E)-hex-2-enal and (Z)-hex-3-en-1-ol contributed to the green and grassy aromas of kale tea.