A novel lectin, with a molecular mass of 18.6 kDa and a unique N-terminal amino acid sequence, was purified from dried fruiting bodies of the mushroom Hygrophorus russula (Fr.) Quél.. The purification procedure encompassed successive ion exchange chromatography on CM-cellulose, DEAE-cellulose, Q-Sepharose, SP-Sepharose and Mono S. The hemagglutinating activity of the lectin (NHRL) was stable at temperatures below 50°C and in the presence of 6 mM NaOH or 25 mM HCl. The activity was activated by Cu2+, Al3+, Fe3+, and Pb2+ ions, and inhibited by Hg2+ ions. Among the sugars tested, only mannose and fructose inhibited its hemagglutinating activity.
In this study, 35 black, oolong, and green tea samples from China were analyzed by inductively coupled plasma mass spectrometry after a digestion method was developed on the basis of a response surface methodology. Linear discriminant analysis of whole data sets was performed in order to discriminate and classify Chinese tea samples according to their origin and type. The analysis revealed an excellent separation between tea samples according to their type and origin with a discrimination efficiency of 100%. The varieties of selected elements in Chinese tea were analyzed based on their origins and types.
This study aimed to quantify effects of food mouthful size on eating effort while masticating solid foods represented by five hydrocolloid gels varying in texture by means of electromyography (EMG). Eleven subjects ate 3 (S) and 6 (L) mL mouthfuls of five gel samples in their normal way without any designated conditions. EMG activities from both masseter muscles, as jaw-closing muscles, and the suprahyoid muscles, as the jaw-opening muscles, were recorded during free eating. Differences in EMG variables were analyzed separately before the first swallow and during the entire oral processing until the last swallow. When food size was halved from L to S, entire time of oral processing, the number of chews, and the number of swallows were approximately 0.7 times more than those for L gels. The sum of muscle activities was determined by both the jaw-closing and jaw-opening muscles, and the relative values for S gels were about 0.8 of the L gels. EMG variables per chewing motion were not significantly different between S and L gels. Those observations were found to be similar for the five different gel types. These results suggest that the mastication effort can be estimated quantitatively for hydrogels with wide range of texture if a small enough mouthful size is consumed. The mastication effort for L gels was 1.4 times greater than that of S gels; however, it was never greater than 2 times the S gels.
The objectives of this study were to characterize the physicochemical properties of 5 different cassava varieties developed in the Philippines and to investigate the effect of pre-gelatinization on flour properties. The physicochemical properties were assessed by proximate, mineral and soluble sugar composition, starch, pasting and thermal properties, solubility, swelling power and particle size distribution. All dry flours showed significantly higher values for peak viscosity, hot paste viscosity and final viscosity, breakdown, pasting temperature and α-amylase activity than the corresponding pre-gelatinized flours (p < 0.05). Complete amorphization of starch contained in pre-gelatinized flours was confirmed by DSC, and it was found that pre-gelatinization caused significant increases in the content of fructose, glucose, amylose, damaged starch and mean particle size, compared to the corresponding dry flours (p < 0.05). Principal component analysis was carried out to assess the overall flour quality and the suitability of particular varieties for pre-gelatinization by steam treatment.
Effects of vacuum and modified atmosphere packaging (MAP) on microbial flora, pH, total volatile basic nitrogen (TVB-N), trimethylamine (TMA-N), the exudates and sensory attributes in Pacific white shrimp (Litopenaeus vannamei) during controlled freezing-point storage at −0.8°C for a period of 14 days were investigated. The results indicated vacuum packaging (VP), 40%CO2/30%O2/30%N2 (MAP1) and 75%CO2/10%O2/15%N2 (MAP2) were more effective for inhibiting growth of Aeromonas spp., Pseudomonas spp., H2S-producing bacteria (including Shewanella putrefaciens) and Enterobacteriaceae and decreasing TVB-N and TMA-N contents as compared to air packaging (AP). pH values of VP and MAP2 samples were significantly (P < 0.05) lower than those of AP. Formation of exudates under AP, VP, MAP1 and MAP2 increased during the storage and the value was higher with the increase of CO2 levels. Sensory evaluation indicated that the shelf-life of fresh Pacific white shrimp got extended and reached 7 days under VP, 9 days under MAP1 and 11 – 12 days for the optimum MA-packaged under MAP2 as compared to 4 days' shelf-life under aerobic storage.
“Sanhua” plums of 4 cultivars were processed into juice. Pretreatment including heat blanching (HB), microwave blanching (MB) and SO2 were studied on the inactivation of polyphenoloxidase (PPO), peroxidase (POD) and nutrition qualities. Enzymatic clarification, pasteurization and UHT were also investigated on nutrition qualities. Results showed that PPO and POD could be almost inactivated by HB (95°C − 5 min) and MB (700 W − 150 s). Pretreatments extracted more phytochemicals and antioxidant activity (AA) and MB produced higher effect than other two means. The high content of phytochemicals after pretreatment could correlate with the inactivation of PPO and POD. Clarification resulted in a better extraction of nutritional compounds. Pasteurization only slightly increased and UHT remained unchanged or slightly degraded the nutrition qualities. Significant loss of nutritional compounds was found during juicing process. Our findings are useful when evaluating health benefits of plum juice.
Establishment of an analytical method on zilpaterol (ZPT), the beta-agonists, and a growth promoting agent for livestock was undertaken. Analytical method for ZPT in the beef by LC-ESI-MS/MS was adopted. Before sample extraction, a beef sample was hydrolyzed by beta-glucuronidase/arylsulfatase and 0.2 M ammonium acetate buffer solution. Afterwards, the mixture was extracted with ethylacetate and then defatted by n-hexane/methanol partitioning. Subsequently, the separated organic layer was evaporated and the dissolved solution was purified by using a Molecular Imprinted Polymer solid phase extraction. The quantitation was carried out using LC-ESI-MS/MS with C18, a non-polarity column under the gradient condition with 10 mM ammonium acetate (pH 4.3) : acetonitrile (95 : 5 (v/v), a mobile phase A) and acetonitrile (a mobile phase B). The standard calibration curve presented linearity of correlation coefficient (r2) > 0.999, analyzed from 0.2 to 10 ng/mL. The limit of quantitation in a beef showed 0.2 µg/kg. The average recoveries of intra- and inter-day experiment ranged from 100.9 to 108.5% and 103.3 to 104.5%, respectively. The repeatability and reproducibility for intra- and inter-day measurement expressed as a relative standard deviation was less than 10.0%, respectively. Therefore, the established analytical method for ZPT residue in beef was applicable to the official analytical method with the acceptable level of sensitivity, repeatability and reproducibility.
This study focused on the feasibility and stability of electronic nose in differentiating kiwi fruit according to geographical origin. Ninety kiwi fruit samples with protected designation of origin were collected from Hunan, Shaanxi, and Sichuan Provinces of China respectively. The freeze-dried kiwi fruit samples were analyzed by a PEN3 portable electronic nose coupled with pattern recognition techniques. The stability of traceability based on this method was also investigated. The difference analysis results indicated that kiwi fruit samples from different regions had their unique aroma compounds fingerprint characteristics. Principal component analysis (PCA) showed a good visualization of clusters between regions, and freeze-dried samples (before or after storage) from the three areas were successfully identified by stepwise discriminant analysis (SLDA) and soft independent modeling of class analogy (SIMCA). Therefore, it was acceptable that the electronic nose is cost-effective, practical and could be used as a potential technology for protecting or authenticating specialty agricultural products and geographical indication. But its stability for tracing needs to be further enhanced.
Various charcoals (used in food processing and water treatment) and broiler litter biochar were examined for ability to adsorb water-soluble low-level radioactive cesium (ca. 200 – 250 Bq/kg) extracted from contaminated wheat bran. Among the materials tested, steam activated broiler litter biochar was the most effective sorbent and was able to reduce the concentration of radioactive cesium to less than 10 Bq/kg. Adsorption was observed under neutral and alkaline conditions but not under acidic conditions. Cesium binding to steam activated broiler litter biochar appeared to be stable under alkaline conditions.
The aim of this study was to investigate the effect of surimi on the rheological properties of dough and the quality of noodles in terms of cooking quality, appearance, texture and sensory properties. The results showed that dough development time, stability time, elastic modulus (G′) and viscous modulus (G″) increased with increasing content of surimi in the range of 30 – 50%. Noodles with surimi exhibited lower cooking loss and water absorption. Textural analysis showed that cooked noodles with surimi displayed higher firmness, springiness and chewiness than noodles without surimi. The sensory value of noodles significantly increased when 30% and 40% surimi was added. Surimi could be used for making noodle to improve the overall quality of noodle when used in proportions between 30% and 40%.
The potential of supercritical carbon dioxide (SC-CO2) extraction of “koku” enhancing compounds from dried herring fillet (“Migaki-nishin” in Japanese) and sturgeon liver was explored. “Koku” enhancing compounds from a water-soluble extract and a mixed water miscible SC-CO2 extract were isolated and evaluated for their effects on sensory perception. Results showed that only select compounds were found in the mixed water miscible SC-CO2 extract compared to the complicated composition of the water-soluble extract. A notable feature was that the mixed water miscible SC-CO2 extract contained “koku” enhancing compounds, e.g., nicotinamide, glycerol and creatine. This study revealed for the first time that these compounds were extracted by SC-CO2 extraction and that nicotinamide enhances “koku”. We also extracted “koku” enhancing compounds from sturgeon liver using the SC-CO2 extraction technique. Instrumental analysis revealed that the sturgeon liver contained relatively large amounts of nicotinamide and glycerol. Thus, it is suggested that this technique might be applicable to the extraction of select compounds from fish and fishery by-products.
Commercially available egg white isolates (EWI) or concentrates can not be used for ions-induced gelation because of high mineral content. In the present research new egg white isolate with reduced minerals content was applied for production of calcium induced gel. At 5.5% critical protein concentration no gel was obtained at the preheating process at 80°C for 30 min. Increased calcium ions concentration formed more elastic gels with higher hardness, adhesiveness and chewiness. There was a linear correlation between (dynamic viscosity) x (density) of the gels and chewiness, hardness and adhesiveness. Higher calcium ions concentration produced more aggregated gels with higher surface roughness. There was a linear correlation between quadratic mean of the surface roughness and maximum roughness height for the gels with different calcium concentration.
In the present study, we clarified the antidepressant-like constituents in an aqueous extract of lavender (Lavandula angustifolia) flowers. The antidepressant-like effects of the lavender extract (LE) and four fractions from the extract (Fr. 1 – 4) were evaluated using the forced swimming test (FST) in mice. Oral administration of the LE or Frs. 1, 3, and 4 significantly reduced immobility in the FST, whereas Fr. 2 had no significant effects. High-performance liquid chromatography using an authentic standard clearly showed that Fr. 3 contained a large amount of the known antidepressant-like substance rosmarinic acid (RA). Moreover, 3-(3,4-dihydroxyphenyl)lactic acid (DLA) was identified in Fr.1 as a new constituent for L. angustifoli. Oral administration of DLA (150 and 300 mg/kg) and of RA (37.5 mg/kg) significantly reduced immobility time in the FST. These results suggest that RA and DLA may participate in the antidepressant-like effects of the LE in mice.
Antioxidant activities of ten different commercially available misos were measured against four reactive oxygen species using our developed Myoglobin method and the conventional DPPH method. Antioxidant activities were characterized using 5-axe cobweb charts. The examined misos showed high antioxidant activities against peroxyl radical, hypochlorite ion, and peroxynitrite ion. Samples were classified according to antioxidant activity against peroxynitrite ion into high, medium, and low activity groups. Miso soup prepared with miso and bonito-dashi, and miso soups prepared with miso, bonito-dashi, and vegetables showed higher antioxidant activities than miso. These results suggested that miso, bonito-dashi, and vegetables contribute additively to the antioxidant activities of miso soup.
Bacillus subtilis (natto) MAFF 118147 produced a defective bacteriophage, different in DNA size from PBND8, a previously reported defective phage of B. subtilis (natto) IAM 1207. The phage, named DF118147, had a small head (diameter 40 nm) and contractile tail (17 × 264 nm). Its DNA was 13.5 kb in size and yielded a smear pattern in gel electrophoresis after digestion with Hin dIII. Following acridine orange treatment, a mutant of B. subtilis (natto) MAFF 118147, in whose culture the 13.5-kb DNA fragment was not detected, was obtained. Electron microscopy observation showed that the head and tail of the defective phage produced by the mutant were not joined. A mutant yielding no normal defective phage particles is useful as a host in which other types of bacteriophage are amplified, especially for isolating their DNA.
We investigated the effects of 22 kinds of rice flours with different characteristics on the textural properties and whiteness of heat-induced fish meat gel without preheating. Amylose (AM), setback viscosity (SV), peaking time (PT), and crude protein (CP) positively affected the breaking force of fish meat gel. In contrast, breaking strain had a positive correlation with PT and CP, but a negative correlation with median particle size (MPS). Heat-induced gels with two added rice flours, prepared with a jet mill or a hammer mill, provided no significant differences in breaking force and breaking strain compared with gels containing rice starch. These flours were characterized by higher CP, AM, SV, and PT, as well as lower MPS, compared with the other flours. The whiteness of the gels with rice flour, except for one sample, was significantly higher than that of gels containing rice starch. Therefore, particle size, AM, PT, protein content, and SV of rice flour are important factors for producing high quality fish meat gel.
In the present study, we investigated the anti-proliferative effects of four tea catechins: (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg) and (-)-epigallocatechin gallate (EGCg) in human T lymphocytic leukemia Jurkat cells. Each catechin induced a significant cytotoxic effect on Jurkat cells. Combinations of EGCg with other catechins additively potentiated anti-proliferation, extracellular hydrogen peroxide formation, c-Jun N-terminal kinase (JNK) activation and interferon (IFN)-γ mRNA expression. Catalase partly but significantly abolished the cytotoxicity induced by EGC or EGCg, whereas it did not influence the EC- or ECg-induced effect. Among the tea catechins, ECg synergistically enhanced the EGCg-induced JNK phosphorylation and IFN-γ expression. The present findings provide evidence that tea catechins are able to concertedly induce cytotoxicity through the JNK/IFN-γ pathway in both a hydrogen peroxide-dependent and -independent manner.
Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the volatiles in thirty-five samples of cooked rice (Oryza sativa L.) including the low-amylose rice cv. ‘Oborozuki’, normal-amylose rice, and glutinous rice. A distinct flavor is exhibited in cooked glutinous rice (containing no amylose) because of the high amount of unsaturated aldehydes; therefore, low-amylose rice might also have a glutinous-like flavor due to the decrease in amylose. Thus, volatile profiles were analyzed to determine the relationships with amylose content. The profiles of 42 volatiles in three types of cooked rice were compared. There were significant differences between glutinous and non-glutinous rice samples. Several volatiles detected at significant levels in the glutinous samples were characterized as glutinous-rich volatiles. These volatiles were predicted to be negatively correlated with amylose content. However, of the 22 glutinous-rich volatiles, only indole had significant negative relationship with amylose content. These results suggest that glutinous-rich volatiles are not affected by decreases in amylose content.
A β-1,4-mannanase producing bacterium was isolated from soil collected in Akita Prefecture, Japan. The bacterium was identified as Paenibacillus polymyxa KT551 and was shown to produce a novel β-1,4-mannanase. The novelty of the enzyme was established by its N-terminal amino acid sequence, molecular weight and isoelectric point. The isolated β-1,4-mannanase showed activity against mannotetraose, mannopentaose and mannohexaose to produce mannobiose, mannotriose and mannotetraose. However, the enzyme exhibited no activity against mannobiose and mannotriose. Moreover, the crude enzyme preparation of the bacterium had no or minimal β-mannosidase or α-galactosidase activity. Therefore, the enzyme preparation from P. polymyxa KT551 holds potential for the efficient production of mannooligosaccharides from natural resources of galactomannans.
In this study, we investigated the use of koji molds for starch hydrolysis in unripe apples. During preliminary assessments of storage conditions, starch was completely broken down within 2 weeks at room temperature. However, in dried unripe apple pulp, starch remained after 7 months of storage at room temperature. Furthermore, we examined the abilities of various Aspergillus species to hydrolyze starch in dried unripe apple pulp; A. oryzae showed greater hydrolysis ability than A. awamori or A. awamori var. kawachii. Subsequently, various A. oryzae were inoculated into agar plate medium containing dried unripe apple pulp powder as the only nutritional source. Among the tested koji molds, A. oryzae AOK 139 showed the greatest growth, presumably because of its comparatively high cellulase expression. Because the starch in apples is located within walled cells, we conclude that hydrolysis requires the use of koji molds with high cellulase activity and productivity.