Superior high-efficiency and high-throughput volatile flavor extraction of Japanese fermented seasonings by solvent-assisted stir bar solid extraction with reverse extraction

Fermented seasonings have pleasant flavors that stimulate our appetite. Their flavoring properties change depending on factors such as their materials and fermented conditions. Therefore, a comparative analysis of their flavor is important when evaluating their quality. However, seasonings contain high levels of various matrices such as sugars, proteins, lipids, and ethanol, making it difficult to extract aroma compounds efficiently from them. In this study, we verified a high-efficient and high-throughput volatile flavor analysis of fermented seasonings by solvent-assisted stir bar solid extraction (SA-SBSE) with reverse extraction. We applied SA-SBSE to Japanese fermented seasonings, soy sauce, miso (fermented beans), and mirin (sweet rice wine) and compared their profiles with those from other common extraction methods, headspace gas-solid-phase microextraction (HS-SPME), liquid extraction with solvent-assisted flavor evaporation (LE-SAFE), and conventional SBSE (C-SBSE). The aroma properties and profiles of extracts from SA-SBSE were close to those of the original sample, being similar to that of LE-SAFE. In addition, potent aroma compounds in each sample were extracted by SA-SBSE and LE-SAFE, which were far superior to those by C-SBSE. For quantification, SA-SBSE extracts showed a good standard curve by the standard addition method. We could quantify maltol, one of the most common potent aroma compounds in all samples, for various commercial samples by such high-throughput analysis.

Exploring the microbial diversity of novel misos with metagenomics

Interest in fermented foods, especially plant-based ones, has increased considerably in the last decade. Miso-a Japanese paste traditionally fermented with soybeans, salt, and kōji (Aspergillus oryzae grown on grains or beans)-has gained attention among chefs for its rich flavour and versatility. Some chefs have even been experimenting with making novel misos with untraditional substrates to create new flavours. Such novel fermented foods also offer new scientific opportunities. To explore the microbial diversity of these new traditional foods, we sampled six misos made by the team at a leading restaurant called Noma in Copenhagen (Denmark), using yellow peas (including a nixtamalised treatment), lupin seeds, Swedish Vreta peas, grey peas, and Gotland lentils as substrates. All misos were made with the same recipe and fermented for 3 months at 28 °C. Samples were collected at the end of fermentation for subsequent shotgun metagenomic sequencing and a genome-resolved metagenomic analysis. The taxonomic profile of the samples revealed the presence of kōji mould (A. oryzae) and Bacillus amyloliquefaciens in all misos. Various species of the genera Latilactobacillus, Lactiplantibacillus, Pediococcus and Staphylococcus were also detected. The Metagenome-Assembled Genomes (MAGs) revealed genomic sequences belonging to 12 different species and functional analyses of these MAGs were performed. Notably, we detected the presence of Exiguobacterium-the first reported instance of the genus in miso-and Average Nucleotide Identity (ANI) analyses suggest a potentially new species. We hope these results will improve the scientific literature on misos and contribute to developing novel fermented plant-based foods.

Review of the health benefits of habitual consumption of miso soup: focus on the effects on sympathetic nerve activity, blood pressure, and heart rate

High salt intake increases blood pressure, and dietary salt intake has been clearly demonstrated to be associated with hypertension incidence. Japanese people consume higher amounts of salt than Westerners. It has been reported that miso soup was one of the major sources of daily salt intake in Japanese people. Adding salt is indispensable to make miso, and therefore, in some cases, refraining from miso soup is recommended to reduce dietary salt intake. However, recent studies using salt-sensitive hypertensive models have revealed that miso lessens the effects of salt on blood pressure. In other word, the intake of miso dose not increase the blood pressure compared to the equivalent intake of salt. In addition, many clinical observational studies have demonstrated the absence of a relationship between the frequency of miso soup intake and blood pressure levels or hypertension incidence. The mechanism of this phenomenon seen in the subjects with miso soup intake has not been fully elucidated yet. However, in basic studies, it was found that the ingredients of miso attenuate sympathetic nerve activity, resulting in lowered blood pressure and heart rate. Therefore, this review focused on the differences between the effects of miso intake and those of the equivalent salt intake on sympathetic nerve activity, blood pressure, and heart rate.

The Molecular Effects of Ionizing Radiations on Brain Cells: Radiation Necrosis vs. Tumor Recurrence

The central nervous system (CNS) is generally resistant to the effects of radiation, but higher doses, such as those related to radiation therapy, can cause both acute and long-term brain damage. The most important results is a decline in cognitive function that follows, in most cases, cerebral radionecrosis. The essence of radio-induced brain damage is multifactorial, being linked to total administered dose, dose per fraction, tumor volume, duration of irradiation and dependent on complex interactions between multiple brain cell types. Cognitive impairment has been described following brain radiotherapy, but the mechanisms leading to this adverse event remain mostly unknown. In the event of a brain tumor, on follow-up radiological imaging often cannot clearly distinguish between recurrence and necrosis, while, especially in patients that underwent radiation therapy (RT) post-surgery, positron emission tomography (PET) functional imaging, is able to differentiate tumors from reactive phenomena. More recently, efforts have been done to combine both morphological and functional data in a single exam and acquisition thanks to the co-registration of PET/MRI. The future of PET imaging to differentiate between radionecrosis and tumor recurrence could be represented by a third-generation PET tracer already used to reveal the spatial extent of brain inflammation. The aim of the following review is to analyze the effect of ionizing radiations on CNS with specific regard to effect of radiotherapy, focusing the attention on the mechanism underling the radionecrosis and the brain damage, and show the role of nuclear medicine techniques to distinguish necrosis from recurrence and to early detect of cognitive decline after treatment.

Long-term intake of miso soup decreases nighttime blood pressure in subjects with high-normal blood pressure or stage I hypertension

The present study aimed to investigate the effects of the combination of Marukome Nenrin miso, which has natriuretic effects, and Marukome MK-34-1 miso, which has potent angiotensin converting enzyme inhibitory effects, on blood pressure (BP) in humans. A total of 40 subjects aged 40–69 years with high-normal BP or stage I hypertension were randomly assigned to two groups: 1) the miso group (32 g 2:1 w/w Nenrin and MK-34-1 with 3.8 g salt/day) or 2) the control soy food group (14.4 g soy food with 0.2 g salt/day). The levels of major nutrients were equal in the miso and control food servings, except for the fiber and Na levels, which were higher in the miso food serving. Daytime and nighttime BP were measured with an automated BP monitor. Compared with the soy food intake, miso intake for 8 weeks did not affect daytime clinical BP but significantly decreased nighttime BP without affecting pulse rate (PR). Moreover, miso shifted the nighttime BP profile to lower levels than those at baseline. Soy food intake did not change the nighttime BP profile after 8 weeks. Miso intake also tended to reduce nighttime BP in a subgroup with stage 1 hypertension compared with the results of the soy food group participants and shifted the nighttime BP profile toward lower levels than those recorded at baseline. Miso intake did not influence lipid or glucose metabolism. In conclusion, this is the first report showing that miso reduces nighttime BP in humans. Miso may do so by shrinking the fluid spaces in the body and/or deactivating the adrenergic nervous system.

Fermented foods and preterm birth risk from a prospective large cohort study: the Japan Environment and Children's study

Background

The dietary pattern of pregnant women is known to be associated with preterm birth (PTB). We investigated whether PTB was associated with intake of fermented food by using data from the Japan Environment and Children’s Study.

Methods

From a data set of 103,099 pregnancies, 77,667 cases at low risk for PTB were analyzed. The primary outcome measurements were based on PTB. Fermented food (miso soup, yogurt, cheese, and fermented soybeans) consumption was assessed by using a semi-quantitative food frequency questionnaire.

Results

Intake of miso soup, yogurt, and fermented soybeans before pregnancy significantly reduced the risk of early PTB (< 34 weeks). The adjusted odds ratio (OR) for early PTB in women who had miso soup 1–2 days/week, 3–4 days/week, or ≥ 5 days/week were 0.58, 0.69, and 0.62, respectively, compared with those who had miso soup < 1 day/week (95% confidence interval (CI) 0.40–0.85, 0.49–0.98, and 0.44–0.87). The adjusted OR for early PTB in women who ate yogurt ≥ 3 times/week was 0.62 (95% CI, 0.44–0.87) compared to those who ate yogurt < 1 time/week. The adjusted OR for early PTB in women who ate fermented soybeans ≥ 3 times/week was 0.60 (95% CI, 0.43–0.84) compared to those who ate < 1 time/week. However, the incidence of overall PTB and late PTB (34–36 weeks) was not associated with fermented food intake.

Conclusion

PTB low-risk women with a high consumption of miso soup, yogurt, and fermented soybeans before pregnancy have a reduced risk of early PTB.

Electronic supplementary material

The online version of this article (10.1186/s12199-019-0782-z) contains supplementary material, which is available to authorized users.

Newly manufactured Marukome MK-34-1 miso with angiotensin-converting enzyme inhibitory activity and its antihypertensive effects in genetic hypertensive rat models

We newly manufactured miso rich in angiotensin-converting enzyme (ACE) inhibitory activity (Marukome MK-34-1, shinki miso) and investigated its antihypertensive properties in rat models of genetic hypertension. ACE inhibitory activity was tenfold higher in shinki miso than in commercially available Marukome Nenrin miso (nenrin miso). The inhibitory activity of shinki miso was confined to <3 kDa fractions and was detected in several fractions with high polarity by C₁₈ high-performance liquid chromatography. Systolic blood pressure (SBP) increased age-dependently in stroke-prone spontaneously hypertensive rats (SHRSP/Izm) given a 0.6% (w/v) NaCl solution (salt solution group) that matched the salt content of the miso solutions. This SBP increase was attenuated in both the 5% nenrin and 5% shinki miso solution groups compared to the salt solution group. The reduction in SBP was greater in rats fed shinki than in rats fed nenrin miso. Similarly, in a salt-induced hypertension model with Dahl rats, the 5% nenrin miso solution attenuated the rising SBP observed in the salt solution group. Moreover, combining 5% nenrin miso with 5% shinki miso (2:1, v/v) (awase miso group) significantly decreased the SBP per gram salt intake by 8% compared with the nenrin miso treatment. However, there were no differences in urinary Na excretion between the nenrin and awase miso groups. In conclusion, we produced a new miso with potent ACE inhibitory activity that reduced spontaneous and salt-induced hypertension. These results suggest that salt sensitivity is decreased by the addition of shinki miso to nenrin miso.

Reduction of Biogenic Amines during Miso Fermentation by Lactobacillus plantarum as a Starter Culture

Lactobacillus plantarum D-103 isolated from a miso product that possesses amine-degrading activity was used as a starter culture in miso fermentation (25°C for 120 days) in this study. The salt content in control samples (without starter culture) and inoculated samples (inoculated with L. plantarum D-103) remained constant at 10.4% of the original salt concentration throughout fermentation, whereas the pH value decreased from 6.2 to 4.6 during fermentation. The inoculated samples had significantly lower (P < 0.05) levels of total volatile basic nitrogen than control samples after 40 days of fermentation. After 120 days of fermentation, the histamine and overall biogenic amine contents in inoculated samples were reduced by 58 and 27%, respectively, compared with control samples. To our knowledge, this is the first report to demonstrate that application of a starter culture with amine-degrading activity in miso products was effective in reducing the accumulation of biogenic amines.

Potential modulation on P-glycoprotein and CYP3A by soymilk and miso: in vivo and ex-vivo studies

P-glycoprotein (P-gp) and CYP3A4 both play very important roles in drug bioavailability, resistance and interactions. Our in vitro studies indicated that P-gp function was activated by many isoflavones. This study investigated the in vivo effects of soymilk and miso, isoflavone-rich soy foods, on P-gp and CYP3A by tracing the pharmacokinetics of cyclosporine (CSP), a probe drug of P-gp. Rats were orally administered CSP with and without soymilk or miso. A specific monoclonal fluorescence polarisation immunoassay was used to determine the blood concentration of CSP. The results showed that soymilk and miso significantly decreased the C(max) of CSP by 64.5% and 78.3%, and reduced the AUC(0-540) by 64.9% and 78.3%, respectively. Mechanism studies revealed that the activities of P-gp and CYP3A4 were induced by soymilk and miso. In conclusion, ingestion of soymilk and miso significantly activated the functions of P-gp and CYP3A.