Four extraction techniques including enzyme-assisted supercritical carbon dioxide extraction (ESC-CO₂), supercritical carbon dioxide extraction (SC-CO₂), ultrasound-assisted extraction (UAE) and Soxhlet extraction (SE) were evaluated to efficiently extract the oil from Decaisnea insignis seeds in this study. Lipid profiling by GC-MS confirmed seven fatty acids and six phytosterols in all oils obtained, in which palmitoleic acid (from 475.4 ± 12.0 by SE to 604.9 ± 26.1 mg/g oil by ESC-CO₂) and β-sitosterol (from 35.6 ± 1.2 by SE to 60.9 ± 2.3 mg cholestanol equivalent/100 g oil by ESC-CO₂) predominated, respectively. Furthermore, the oil yielded by ESC-CO₂ displayed higher polyphenol content and stronger DPPH and ABTS radical scavenging capacities. These results suggested that D. insignis seed oil is considered an alternative source of palmitoleic acid, and ESC-CO₂ could be explored as an environmentally friendly technology for extracting plant oil.

Stems of brown seaweed Undaria pinnatifida are not often used because they are too difficult to masticate. This study used conventional liquid solvent extraction methods and supercritical carbon dioxide (SC-CO₂) fluid extraction to investigate the yields of various bioactive compounds in Undaria pinnatifida stems. The enzymatic (α-amylase and glucoamylase) inhibitor activities of the extracts were also examined. The SC-CO₂ with ethanol extraction produced high amounts of phenolic and flavonoid compounds, fucoxanthin, epicatechin, and gallic acid. Also, the extracts obtained by SC-CO₂ with ethanol exhibited the most potent inhibitor of α-amylase and glucoamylase among all the extracts studied, perhaps because of the high content of fucoxanthin. These results suggest that stems of Undaria pinnatifida could have value as a raw material to extract these bioactive substances.

Japanese sake reportedly contains several D-amino acids that could contribute to its characteristic flavor. In this study, component profiling of Japanese sake using combined data of gas chromatography/mass spectrometry (GC/MS)-based metabolomics and liquid chromatography/mass spectrometry (LC/MS)-based enantioselective amino acid analysis, and orthogonal partial least squares (OPLS) regression analysis was conducted. GC/MS-based metabolomics is typically the first choice in constructing taste prediction models because it can perform a comprehensive analysis of hydrophilic compounds to obtain informative, explanatory variables. Here, enantioselective amino acid profiles obtained by LC/MS were also used as explanatory variables instead of non-enantioselective amino acid data, which are part of the GC/MS results. The evaluation of prediction models by linearity (R²), predictability (Q²), and root mean square error estimation (RMSEE) indicated that enantioselective amino acid profiles improved metabolomics-based sensory prediction.

Dendropanax morbifera (DM) extract was co-fermented by Bacillus subtilis HA and Lactobacillus plantarum EJ2014 for producing poly-γ-glutamic acid (γ-PGA) and γ-aminobutyric acid (GABA). The first fermentation with B. subtilis HA resulted in a viscous broth with pH 7.85, 0.01% acidity, 0.72 mg/g peptides, 17.39 U/g protease activity, 8.44 log CFU/mL B. subtilis, 4.96 Paos_n consistency index, and 45.84 mg/mL mucilage. For the second fermentation with L. plantarum, the broth was enriched with skim milk. The co-fermented broth indicated 0.5% acidity and pH 5.1. The viable cell counts of B. subtilis decreased, whereas those of L. plantarum increased, as did the peptide content. The MSG precursor was effectively converted to GABA, which showed a concentration of 12.80 mg/mL. Therefore, the co-fermented DM extract was enriched with γ-PGA, GABA, peptides, and probiotics by the serial co-fermentation, and could be used as a potential ingredient for developing functional foods.

Subcritical water treatment with pressure-releasing distillation was proposed as a method to obtain essential oil from Japanese mint (Mentha arvensis L. var. piperascens Malinv. cv.). The extraction and fractionation were carried out between 100 °C and 220 °C, and extraction times of 5 to 60 min were investigated. Quantitative analysis of volatile component was conducted by gas chromatography. The yields of both l-menthol and l-menthone converged in the initial fractions as the extraction temperature was increased. The yields of l-menthol, l-limonene, l-menthone, and piperitone increased as the temperature was increased from 100 °C to 180 °C, but decreased as it was raised further to 220 °C. The yields of iso-menthone, 3-octanol, and l-menthyl acetate increased as temperature was increased up to 220 °C. The extraction time of 60 min showed a negative effect on the extraction, and the highest total yield (30.5 mg/g-dry leaves) was obtained at 180 °C with an extraction time of only 5 min.

The purpose of this study was to optimize the processing and cooking conditions to retain lutein and reduce the concentrations of oxalate and nitrate in spinach. We investigated the effects of preliminary processing, particularly cutting size and the inclusion of different additives, on changes of oxalate, nitrate, and lutein concentrations in cooked spinach. The results of this study indicated that a combination of boiling in water (100 °C for 2 min) and a 1-cm cutting size resulted in maximal removal of oxalic acid and nitrate ion (72% and 58%, respectively) and maximal retention of lutein (79%) in spinach. Although the inclusion of some adjuvants had significant effects on the concentrations of oxalic acid, nitrate ions and/or lutein at certain concentrations, these effects were not concentration-dependent. We conclude that the addition of various compounds during boiling may not consistently promote either the removal of oxalate and nitrate or lutein retention.

We previously reported that Citrus kawachiensis peel is abundant in auraptene (AUR), 3,5,6,7,8,3′,4′-heptamethoxyflavone (HMF), nobiletin (NBT), naringin (NGIN), and narirutin (NRTN). All of the above are known as citrus functional components, and a part of these is extracted from the peel into the juice during fruit squeezing. In the present study, we demonstrated that while squeezing method did not affect the composition of compounds in the juice, the contents were affected. Heat treatment for a longer duration led to AUR decomposition, while HMF, NBT, NGIN, and NRTN did not decompose. These 5 components were stable in hot ethanol after 24 h.

Resveratrol and its dimer ε-viniferin are polyphenolic compounds in red wine. Although various beneficial functions of resveratrol have been identified, those of ε-viniferin remain unclear. The present study therefore compared the effects of ε-viniferin and resveratrol on the differentiation of 3T3-L1 preadipocytes. We found that ε-viniferin more effectively suppressed intracellular lipid accumulation than resveratrol. ε-Viniferin, but not resveratrol, reduced protein expression of PPARγ and fatty acid synthase that contribute to lipogenesis, and increased expression of adipose triglyceride lipase, a lipolytic enzyme. Adiponectin protein expression, which plays a critical role in preventing type 2 diabetes and metabolic syndrome, was enhanced only by ε-viniferin. In addition, only ε-viniferin raised SIRT1 expression with increased phosphorylation of AMPK. These findings suggest that ε-viniferin is more effective than resveratrol in promoting favorable adipocyte differentiation with enhanced adiponectin expression and decreased lipid accumulation. Therefore, ε-viniferin may be a candidate phytochemical in red wine for preventing obesity.

In Japan, kombu (Laminaria japonica), a type of seaweed, has been consumed for centuries. It contains a variety of active compounds such as minerals, vitamins, and dietary fiber. The aim of this human pilot study is to investigate the effects of kombu on lifestyle-related diseases. The study had a randomized crossover design, and the subjects (N=48) freely took 6 g of roasted kombu a day for 4 weeks. The subjects' responses to the Gastrointestinal Symptom Rating Scale questionnaire suggested that the frequent intake of kombu may lead to the relief of constipation, diarrhea, and hard stools. In addition, blood tests indicated the possibility that the frequent intake of kombu can decrease the serum triglyceride levels of subjects with abnormally high serum triglyceride levels. Kombu intake might lead to relief from intestinal ailments and improvements in hypertriglyceridemia.

Fermentative yeast strain TW15 was isolated from the grape cultivar Yamasachi. It was identified as Hanseniaspora vineae based on the ribosomal D1/D2 domain, but the sequence of its 18S-26S rDNA spacer region was not identical to those retrieved from the H. vineae database. TW15 showed higher fermentation ability of medium containing a fructose and glucose mixture (55:45) compared with five other H. vineae strains and four Saccharomyces cerevisiae baking strains. The baking tests revealed that TW15 produced greater volume in baked products than did the baking strain. The preliminary sensory evaluation showed similarities between the two baked products, but the product of TW15 had a more distinct and desirable flavor. Compared with bread samples produced with the baking strain, the amount of acetoin was much higher in bread samples made with TW15. H. vineae TW15 is thus suitable for production of baked goods with palatable quality.

Soy hull polysaccharides (SHPs) were extracted from soy hull using microwave-assisted extraction and their structures were investigated by Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM). Subsequently, the effects of SHPs on the proliferation of fecal microbiota were examined. The results indicated that microwave-assisted extraction had significantly higher efficiency in extracting SHPs. The yield of microwave-assisted oxalic acid extracted soy hull polysaccharide (MOS) and microwave-assisted ammonium oxalate extracted soy hull polysaccharide (MAS) increased by 33.4% and 17.4%, when compared with oxalic acid extracted soy hull polysaccharide (OS) and ammonium oxalate extracted soy hull polysaccharide (AS), respectively. High performance liquid chromatography showed that the four polysaccharides had significant differences in their monosaccharides composition. High performance gel filtration chromatography illustrated that the molecular weights of MAS and AS were the highest. FT-IR spectra indicated that the structures of MOS and OS were similar and mainly comprised furanose, whereas MAS and AS mostly consisted of pyranose. AFM showed that the molecular chain conformation of MOS and MAS was vermicular, OS was short-rod-like, and AS was rod-like. MOS significantly promoted proliferation and diversity of fecal bacteria. Interestingly, OS enhanced the growth of Bifidobacterium spp. and Lactobacillus spp. In summary, SHPs showed more potent prebiotic activity with microwave-assisted extraction method and could have prospective applications in functional food industry.

To clarify the effects of the koji amazake and its lactic acid fermentation product amazake by Lactobacillus sakei UONUMA (LAF-amazake) on defecation status and intestinal microflora, a double-blind parallel group comparison test in healthy volunteers with relatively low stool frequency was conducted. Subjects ingested koji amazake or LAF-amazake for 1 week one bottle (108 mL, 118 g) once a day every morning. Subjects filled out daily questionnaires concerning their defecation conditions for the entire 3 weeks. First, second and third periods were the pre-test non-intake, the test food intake and the washout periods, respectively. Although there were no significant changes in intestinal microflora, it was found that defecation frequencies in the koji amazake group in the second and third periods were significantly higher when compared with those in the first period. These results indicated that the koji amazake may be a food material with constipation-relieving effects.

Anthocyanins and tannins were extracted from the skins of Cabernet Sauvignon (CS) and Muscat Bailey A (MBA) grapes. Insoluble cell wall materials (IC) were prepared from the skin, pulp, and seeds of CS and MBA. The adsorption properties of anthocyanins and tannins by IC were analyzed in a model solution.

In CS, skin IC had the potential to adsorb 12% of skin total anthocyanins, and pulp and seed IC each adsorbed 4%. In MBA, skin IC had the potential to adsorb 20% of skin total anthocyanins, pulp IC, 5%, and seed IC, 3%. In both CS and MBA, skin IC also had the potential to adsorb 30% of skin tannins. In addition, pH (2.5 to5.0) and ethanol concentration (0 to 14%) affected skin tannin adsorption. Anthocyanin adsorption was maximum at pH 3.2 in CS and pH 3.0 in MBA, and minimum at pH 3.6 in CS and pH 3.4 in MBA. Tannin adsorption was maximum at pH 3.3 and minimum at pH 4.2 in both cultivars. On the other hand, both skin anthocyanin and tannin adsorption decreased with increasing ethanol concentration in both MBA and CS. These results suggest that must pH may affect the extraction and adsorption of phenolics.

Various types of miso are manufactured in Japan, which results in diverse flavors. However, the number of miso engineers who understand the variety of miso tastes has decreased due to decreases in the miso market. To solve this problem, we examined the potential to characterize various miso tastes using mainly low-molecular-weight hydrophilic component data by metabolic profiling. Analysis was performed by orthogonal partial least squares analysis, the relative intensity data for annotated compounds as explanatory variables and the data obtained by sensory evaluation as objective variables. The OPLS prediction model of taste had high accuracy and stability, and the components important for each taste were reasonable. From the results of model construction, we also found galactose correlated to umami. These results suggested that sensory evaluations of various types of miso may be in part replaced with instrumental analyses in the future.

Fatty acid polyglycerol esters are commonly used as emulsifiers in flavor emulsions. In recent years, transparent beverages based on clear flavor emulsions have been developed and are becoming increasingly popular in the market. Here, the quartz-crystal microbalance (QCM) method was applied to investigate the interaction between clear flavor emulsions containing lemon essential oil and lipid bilayers supported on electrodes. Comparative QCM resonance frequency data between clear- and cloudy-type emulsions demonstrated that clear-type emulsions showed smaller frequency changes, suggesting a size-dependent interaction with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). Furthermore, as indicated by the frequency changes, the affinity of clear-type emulsions increased with the increasing 1,2-dimyristoyl-sn-glycero-3-phosphatidyl-glycerol (DMPG) to whole lipid composition ratio. This indicated that surface regions of polyglycerol fatty acid ester emulsions may specifically interact with DMPG in mixed DMPC-DMPG systems. Our results may be helpful in understanding flavor expression and retention in cell membranes.

Clove (Syzygium aromaticum L.) is recognized to have strong antioxidant activity, as revealed by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, β-carotene bleaching, and ferric reducing power assays. The present study was undertaken to determine the radical scavenging profiles of clove extract against five reactive oxygen species (ROS: hydroxyl radical, superoxide, alkoxyl radical, peroxyl radical, and singlet oxygen) using the multiple free-radical scavenging (MULTIS) method. The clove extract was shown to be effective in scavenging singlet oxygen. Further, ROS scavenging measurements for three antioxidant components of cloves (eugenol, β-caryophyllene, and eugenol acetate) were carried out. The MULTIS measurements suggested that eugenol plays the major role in the overall scavenging activity of clove as a food. Based on the results, the singlet oxygen scavenging mechanism of eugenol is discussed. This paper presents a quantitative analysis of the comparative antioxidant capacities of foods against various types of ROS.

To evaluate the stability of rare sugars, i.e., sorbose, allose, tagatose and allulose, in food products containing rare sugar syrup (RSS) during cooking, we developed a highly sensitive analysis method using high performance liquid chromatography (HPLC) with corona charged aerosol detector (CAD) and analyzed the rare sugars in a Maillard reaction mixture and in food products available at market. In the Maillard reaction, the amounts of each rare sugar decreased at the initial pH of 6.0. Further, the increase in allulose was accelerated in reaction mixtures at pH 7.5. The stability of rare sugars, which are added to improve food functions during food processing, was greatly influenced by the pH, temperature and heating time. Surprisingly, allulose was retained at the highest level (86.0%–88.5%) under the various cooking conditions, while the other rare sugars were obviously decreased. Therefore, it was suggested that allulose can be maintained under various manufacturing conditions, including under weakly alkaline treatment.

Increased foodborne outbreaks associated with low-moisture foods contaminated with Salmonella have raised the need for further insights into their possible causes and control measures. This study investigated the effects of sucrose-induced low water activity (a_w) on heat resistance and global gene expression in Salmonella Typhimurium. Following heat treatment at 60 °C for 5 min, viable cell counts on TSA of the cells grown in TSB supplemented with 35% (w/v) sucrose for 24 h and resuspended in the same medium were 3-Log higher than those grown and resuspended in TSB without sucrose, and 1-Log higher than the cells grown in TSB and resuspended in TSB with 35% sucrose. Viability of the cells directly transferred from TSB to preheated TSB with sucrose was positively correlated with sucrose concentration. DNA microarray analysis identified sixteen up-regulated genes involved in cobalamin biosynthesis in the cells grown in the presence of 35% sucrose. Deletion of the pocR gene, which positively regulates cobalamin biosynthesis, resulted in suppression of the improvement in heat resistance of S. Typhimurium under sucrose-induced low a_w, suggesting potential contribution of this gene in increasing heat resistance of S. Typhimurium.

To investigate rutin hydrolysis in dough made with ‘Manten-Kirari’, a new Tartary buckwheat variety with trace rutinosidase activity that lacks bitterness, we performed a time course study of the residual rutin ratio in dough at different water contents and blending ratios of Tartary buckwheat flour. In the common rutinosidase variety, ‘Hokkai T8’, a large portion of the rutin was hydrolyzed within 30 min after the addition of water, whereas about 80–90% remained in the dough made with ‘Manten-Kirari’. We also investigated the residual rutin ratio in noodles such as soba-noodle and pasta containing Tartary buckwheat flour. With ‘Hokkai T8’, rutin was hydrolyzed almost completely in all noodles tested. In contrast, about 90% of rutin remained in ‘Manten-Kirari’-containing noodles. In addition, while ‘Hokkai T8’ noodles exhibited strong bitterness, ‘Manten-Kirari’ noodles lacked or had only slight bitterness. These results indicate that ‘Manten- Kirari’ holds promise as a material for rutin-rich noodles with minimal bitterness.