The acyl migration in the production of 1,3-diacylglycerol (1,3-DAG) by immobilized lipozyme RM IM-catalyzed esterification reaction in a solvent-free system was investigated, particularly including the acyl migration of 1,3-DAG to 1,2-diacylglycerol (1,2-DAG), which affected by some of the system's parameters (substrate molar ratio, enzyme load and reaction temperature). The results showed that all parameters had strong positive influences on acyl migration. With the increasing substrate molar ratio of oleic acid to glycerol from 1:1 to 3:1, the acyl migration showed a decreasing-increasing pattern. However, the degree of acyl migration increased gradually concomitant with the increasing of enzyme load (2 – 10 wt% of substrates) and reaction temperature (45 – 75°C). The conditions for the highest yields of 1,3-DAG and the relatively low levels of acyl migration were optimized as follows: temperature 65°C, oleic acid/glycerol molar ratio 2:1, enzyme load 6%, reaction time 2 h, 0.01 MPa vacuum, 200 rpm stirring speed.
Bulk methyl linoleate was oxidized at 65°C and essentially 0% relative humidity to quantitatively evaluate the effect of the depth of the layer (i.e., the amount) of methyl linoleate on its oxidation kinetics. Oxidation was retarded when the thickness was greater than 1 mm or the volume was greater than 10 µL, and barely occurred at thicknesses greater than 5 mm. Oxidation behavior was also evaluated under a limited range of oxygen partial pressures (0.2 – 10 kPa). The saturation constant of oxygen for oxidation was estimated to be 1.23 kPa, which is significantly lower than the partial pressure of oxygen in air at atmospheric pressure.
Hydrodistillation was carried out from fresh leaves, air-dried leaves in shade, sun-dried leaves, frozen leaves and salted leaves. It was observed that air-dried in shade was the optimal choice for prolonging the pre-processing storage with the advantage of low cost and simplicity. Nine different macroporous resins (DM-21, LS-305, LS-305A, HPD-100, D001CC, XAD-16, XAD-7HP, FPC3500 and SK1B) were evaluated for the adsorption properties of perillaldehyde from hydrodistillation condensate of Perilla frutescens (L.) Britton var. crispa f. viridis leaves. The influences of phase contact time, initial perillaldehyde concentration and ethanol concentration were studied by the static adsorption/desorption method. The adsorption isotherm data were fitted well to the Freundlich model. The kinetic data were modeled using the pseudo-first order, pseudo-second order and intraparticle diffusion equations. The experimental data were well described by the pseudo-second order kinetic model. Column studies were also carried out to investigate the breakthrough and elution behavior at three different flow rates. Continuous column adsorption-regeneration cycles indicated negligible capacity loss of LS-305 during operation.
Mistletoe is a traditional medicinal plant containing bioactive phenolic compounds with, for example, anti-cancer effects. We prepared extracts rich in phenolic compounds using a high-temperature batch extraction (HTBE) method. The mistletoes used in this study belonged to the genera Scurrula, Dendrophtoe and Macrosolen, which are typical plants in Indonesia. As a result of experiments regarding antioxidant activity measured by the ABTS method, along with polyphenolic profiles in each extract, we found an extract from S. oortiana showing a high antioxidant activity of 51 µmol TEAC/g extract as well as high content of phenolic compounds (289 mg GAE/g extract) among the mistletoe extracts obtained by HTBE. Candidate compounds responsible for the effect were quercetin 4′-O-β-glucopyranoside and gallic acid; other phenolic compounds such as catechin, epicatechin, rutin and quercetin partly contributed to the antioxidant effect of mistletoe extracts obtained by HTBE.
Lipase-catalyzed geraniol synthesis of geranyl acetate via transesterification with vinyl acetate in organic solvents was investigated. The lipase from Pseudomonas fluorescens was identified as the optimal enzyme and vinyl acetate was employed as both acyl donor and solvent through transesterification. The effects of various parameters on transesterification, including enzyme loading, temperature, and agitation speed, were optimized. The optimal reaction temperature was 30°C. The external diffusion limitation could be greatly reduced by increasing the agitation speed to 240 rpm, and the internal diffusion could be ignored. Lipase operational stability research revealed that lipase activity has no obvious loss after nine batch cycles. A kinetic model based on the ping-pong bi-bi mechanism without inhibition by geraniol and geranyl acetate using the King-Altman method was proposed. Matlab was applied to simulate the model parameters. The experimental values could be satisfactorily fitted to the simulated values with a relative error of 1.88%.
The degradation of frying oil was determined using near-infrared (NIR) spectroscopy and partial least-squares (PLS) regression. One hundred and fifty six samples of frying oil (104 in a calibration set and 52 in a validation set) were obtained after use in an actual potato frying process. NIR transmission spectra of the samples were acquired directly using glass test tubes (13 mm dia.) and a NIR spectrometer. Calibration models with very high accuracy were developed for predicting acid value (AV) and total polar compounds (TPC) using PLS regression with full cross-validation. The coefficients of determination for calibration (R2) and standard error of cross-validation (SECV) were 0.99 (SECV: 0.17 mgKOH/g) and 0.98 (SECV: 1.25%) for AV and TPC, respectively. The accuracy of the NIR calibration models was tested using the validation set, yielding values for the root mean square of the prediction (SEP) of 0.17 mgKOH/g and 1.04% for AV and TPC, respectively. The results demonstrate that frying oils can be successfully monitored to a very high accuracy using NIR spectroscopy combined with glass tubes of 13 mm diameter as cells.
A novel in vitro gastric device, the Gastric Digestion Simulator (GDS), was developed for the direct observation and quantitative analysis of the food digestion process in the human stomach. In addition to simulating the chemical digestion environment, this device provides a physical digestion environment comparable to that found in the stomach by simulating peristalsis, which is assumed to contribute to solid food disintegration. The GDS was successfully used to directly observe the disintegration process of Tofu (bean curd) as a typical solid food containing protein. The size distribution and protein content of Tofu particles during the digestion experiments were investigated. The results demonstrated the difference in particle disintegration between GDS and flask shaking experiments, which may be due to the lack of peristalsis in the latter case. Moreover, the size distribution of Tofu particles after the GDS experiments was affected by the physical properties of Tofu, thus revealing the usefulness of GDS for food digestion analysis.
Finely ground extruded corn pericarp dietary fiber (ECPDF) was incorporated in wheat flour at 2%, 5%, 8%, 10% and 12% levels and the effects of ECPDF on dough rheology, raw and cooked dumpling wrapper quality were investigated in this paper. Results showed that water absorption, extensibility and ratio number had significant correlation with ECPDF replacement level; the optimal cooking time and cooking loss rate of dumpling wrapper decreased with adding EPCDF from 0%–12%; all textural parameters of raw dumpling wrappers were significantly correlated with ECPDF addition; springiness, cohesiveness and resilience of cooking samples had significant correlation with ECPDF. The highest substitution level was considered as 10% ECPDF in the range of our studies.
The water sorption properties of udon-like wheat noodle were measured at different temperatures to estimate changes in the moisture content and loss of mass; transient changes in these properties could be expressed by hyperbolic and exponential empirical equations, respectively. The maximum moisture content changed stepwise with temperature near the gelatinization temperature of wheat flour; however, the initial sorption rate with temperature obeyed the Arrhenius equation. These processes were also measured for wheat noodle with different initial diameters at 100°C. Changes in the moisture content could be expressed by a hyperbolic equation as a function of time divided by the square of the initial diameter. The loss of wheat noodle mass was proportional to the specific surface area, and the loss per specific surface area could be expressed solely as a function of time.
‘Oushuu’ is a late ripening cultivar of Pyrus pyrifolia. In the present study some of the physical and gas transport properties of this cultivar have been measured or estimated from a mathematical model written with COMSOL Multiphysics 4.2a, using the exact 3D geometry of the pear obtained with NextEngine 3D laser scanner. The experiments were done at 5, 15 and 25°C. The model was validated by conducting experiments to measure the internal concentration at different points of the fruit and comparing them with the model results. The model was shown to be successful in predicting the internal gas concentrations. Gas diffusivity of ‘Oushuu’ at 5°C was found to be 5.97 × 10−7 m2/s and its skin resistance to be 4.04 × 105 s/m. However the results at higher temperatures seem to be less accurate. As a result, a co-diffusion model was used to estimate the gas diffusivity and skin resistance of ‘Oushuu’ at higher temperatures.
Physicochemical and microbiological changes during the fermentation of bamboo shoot were investigated for 12 days at regular intervals of 48 hours. Bamboo shoot was fermented in two batches. In one batch, bamboo shoots were grated and kept for natural anaerobic fermentation at 32°C for 12 days (Batch-1) and in the second batch pieces of Garcinia pedunculata Roxb. were mixed (1%) along with shoot (Batch-2). Fresh and fermented shoots were analyzed for proximate constituents, total phenol content, antioxidant activity, reducing sugars, pH, acidity, total plate count, yeast and mould, lactic acid bacteria, Salmonella and Shigella, FTIR, and HPLC analysis for organic acids and carbohydrate profile. Marked increase in total phenolics from 97.5 mg/100 g to 255 mg and 239 mg/100 g were observed for batch-1 and batch-2 respectively. The antioxidant activity for fresh and fermented shoot (batch-1 & batch-2) was found to be 26.62, 49.20 and 55.35% DPPH radical scavenging activity respectively.
The aim of this present study was to develop and investigate the effect of different resistant starch (RS) as dietary fiber substitute on cookies quality evaluation. Mung bean resistant starch with pullulanase debranching and retrograded (DR-MB), mung bean resistant starch with heat-moisture treatment (HMT-MB), high-amylose (Hylon V) corn resistant starch with heat-moisture treatment (HMT-HV), Hi-maize@ particle resistant starch (Hi-M), and wheat dietary fiber (WDF) were replaced in 5%, 15%, and 25% of equivalent amount of low-gluten flour to compare water-holding capacity, sensory evaluation and texture analysis of cookies. Further discussion of the application was indicated that cookies added into DR-MB had the advantage of higher resistant starch content and greater water-holding capacity whereas the disadvantage of poor sensory evaluation. RS prepared by heat-moisture treatment had approximate water-holding capacity with wheat dietary fiber but was superior on sensory evaluation, especially the mass fraction of 25% with HMT-MB. Moreover, hardness as the main evaluated indicators of texture analysis was shown that cookies could be accepted for the majority consumers when the hardness value ranged from 450 g to 630 g, providing a better combination between objective quantitative identification and subjective sensory assessment.
The effect of carbonation with heating (CH) on the number of viable Geobacillus stearothermophilus spores was investigated in the presence of monoglycerol-caprate (MC10) or -laurate (MC12). CH was performed at 90 and 100°C, 5 MPa, for 30 or 60 min. Spore counts were reduced by 1.4 log CFU/ml after CH at 90°C for 60 min in the presence of MC10. On the other hand, after CH at 100°C for 60 min, spore counts decreased by 3 – 4 log CFU/mL or remained low after 7 days of storage. CH decreased the optical density of a spore suspension at 650 nm more than heat treatment alone, indicating that spore germination triggered by CH could be involved in the drastic decrease in spore count caused by CH in the presence of MC10 or MC12.
Shrinkage decreases the commercial value of the canned sea cucumber, and therefore size preservation during processing is the main objective of manufacturers. In this study, the efficacy of sodium phytate (SP) and sodium tripolyphosphate (ST) as a shrinkage inhibitor for use on sea cucumber was investigated. Shrinkage of the sea cucumber treated with SP and ST was monitored during processing. The canned sea cucumber treated with 10 volumes of 0.4% SP and 0.8% ST for 2 h had significantly lower shrinkage during processing compared with the control (p < 0.05). The pH of the broth of canned sea cucumbers Stichopus japonicus for the treatment was significantly higher than that for the control (p < 0.05). Results indicate that treatment with 0.4% SP and 0.8% ST is a promising way to inhibit sea cucumber from shrinking during canning.
Distillation process is closely correlated with the quality and yield of the raw spirit. The volatile properties of raw spirits from three distilling stages (head, heart and tail) of Luzhou-flavor spirit were investigated based on GC and GC-MS analyses. A total of 71 compounds were identified and ester derivatives attributed the largest number and concentration of volatile compounds in three raw spirits. The total concentration of raw spirit was decreased from the head raw spirit (5105 mg/L) to the tail raw spirit (1843 mg/L). Many volatile compounds with high concentrations such as acetaldehyde, 1-hexanol, 2-methylbutanoic acid, hexanoic acid, and ethyl hexanoate were found to decrease during distillation. Odor active value (OAV) was used to evaluate the contribution of special compounds to the whole odor of the raw spirit. Ethyl hexanoate followed by ethyl butyrate, ethyl heptanoate, ethyl octanoate, and 3-methylbutanal were found to be the most potent odor-active compounds. The liquid-liquid extraction together with GC-MS and GC analyses could be a useful tool to characterize the volatile composition of different distilling cuts of Chinese spirit. The decreasing of total content of volatile compound was determined by the ester derivate because of its high volatility and content.
Effects of dietary chrysin supplementation on blood pressure and oxidative status of rats were studied in comparison with quercetin. Rats were fed a control diet or a high-fat high-sucrose (HFS) diet with or without 0.25% flavonoids (chrysin or quercetin) for 4 weeks. In rats fed the HFS diet without flavonoids, there was a significant elevation of blood pressure, increase in aortic NADPH oxidase but not xanthine oxidase, an increase in plasma lipid peroxides, and a decrease in liver glutathione, compared to rats fed the control diet. Chrysin suppressed the elevation of blood pressure in rats fed the HFS diets at the same level as quercetin. Chrysin supplementation did not suppress the increase in NADPH oxidase activity and plasma lipid peroxides or the decrease in liver glutathione, whereas these effects were significant with quercetin. Also, the results of an in vitro experiment suggested that chrysin did not exert antioxidative effects on lipid peroxidation in a linoleic acid emulsion. These results suggest that chrysin has an antihypertensive effect similar to quercetin, but unlike quercetin is not antioxidative in normotensive rats fed a HFS diet. Thus, it is probable that a mechanism(s) other than antioxidative activity is responsible for the suppression of hypertension by chrysin.
Soy peptides were produced by microbial protease digestion of soy proteins. Under an acidic condition (pH 3.8), soy peptide solution (5% w/v) yielded sediment during chilled storage. The object of the present study was to identify peptides in the sediment in order to elucidate the sedimentation mechanism. Peptides remaining in solution after chilled storage had a molecular mass of 200 – 5,000 Dalton (Da), based on the elution volume obtained from size exclusion chromatography. However, peptides extracted from the sediment using 30% acetonitrile-0.1% trifluoroacetic acid had a molecular mass larger than 2,000 Da. Only limited numbers of peptides ƒ (71 – 88), ƒ (340 – 362), ƒ (335 – 362) and ƒ (310 – 356) of β-conglycinin α subunit were identified in the sediment. These results demonstrated that the sediment was produced from relatively large molecular peptides derived from the C-terminal region of the β-conglycinin α subunit. Moreover, the major peptide in the sediment was sensitive to cleavage by mammalian trypsin.
A rod-shaped and Gram-positive anaerobic S-equol-producing intestinal bacterium, TM-30, was isolated from the feces of a healthy human. The 16S rRNA partial sequence of strain TM-30 exhibited 99% identity to that of Slackia sp. NATTS. TM-30 produced S-equol from daidzein. The in vitro incubation of β-estradiol with TM-30 yielded estrone, and incubation of estrone with TM-30 produced β-estradiol. The estrone producing activity was higher than the β-estradiol producing activity. The results presented herein demonstrate that the S-equol-producing human intestinal bacterium, TM-30, likely plays a role in estrone and β-estradiol metabolism in vitro.
Surface plasmon resonance (SPR) biosensors were used to develop a rapid and simultaneous detection method for three important foodborne pathogens, i.e., Escherichia coli O157:H7 (O157), Salmonella Enteritidis (SE), and Listeria monocytogenes (LM). Bacterial homogenates prepared by sonication from bacterial suspensions at various cell concentrations were analyzed using SPR biosensors and sensor chips with polyclonal antibodies specific to each of the target pathogens. The precipitates from the homogenates were demonstrated to be suitable for specific and simultaneous detection of O157, SE, and LM. By using the precipitates and a custom-built multichannel SPR biosensor, the lower detection limit for O157, SE, and LM was determined to be 0.6 × 106, 1.8 × 106, and 0.7 × 107 CFU/mL, respectively, in the presence of non-target pathogens at concentrations of 105 to 108 CFU/mL.
Antioxidant properties of defatted peanut meal (DPM) hydrolysate-glucose syrup Maillard reaction products (MRPs) were evaluated, and their effects on the oxidative stability and flavour property of Sachima during the storage were studied. DPM hydrolysate-glucose syrup was heated at 120°C for different time. With the heating time increasing, browning and intermediate products increased, free amino group content decreased. MRPs heating for 60 min had the best antioxidant properties, evaluated by 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, oxygen radical absorbance capacity and inhibition of linoleic acid autoxidation. Sachima added with 1% MRPs showed significantly (p < 0.05) lower acidity values and peroxide values than that without MRPs during 5 months storage. Results from GC-MS indicated that MRPs improved the flavour of Sachima. Based on these findings, MRPs derived from DPM hydrolysate-glucose syrup might be used in food lipids stabilization as potent natural antioxidant and flavour enhancer.
Industrial wastewater containing heavy metals can become a serious environmental pollutant if not treated appropriately. Conventional treatment to remove toxic heavy metals can be expensive and may generate large amounts of toxic sludge. Regenerated natural wastes such as eggshells and eggshell membrane which are easily available, inexpensive, biodegradable, and have high adsorbability, can act as promising ‘green’ alternatives to remove heavy metal pollutants from wastewater. Here, we studied the adsorption capacity of eggshells with membrane (ESWM), eggshell membrane (ESM), and eggshells (ES) for the removal of nickel and silver ions in synthetic wastewater. Reaction time (1 to 72 h), metal ion concentration (25 to 200 mg/L), adsorbent dosage (0.1 to 0.8 g/20 mL), temperature (15°C to 45°C), and pH (1 to 9) were evaluated. Post-treatment nickel and silver concentrations were later analyzed using a spectrophotometer. Our results indicated increased removal of nickel and silver ions with increased adsorbent (all three ESWM, ESM, and ES) dosage, whereas the removal of nickel and silver ion decreased with increasing initial metal concentration. Among ESWM, ESM, and ES, ESM has the highest removal capacity and was the best adsorbent. The 0.8 g of ESM could remove 90.91% of nickel ions (100 mg/L) at 25°C, pH 5.76 and 24 h. On the other hand, approximately 100% of silver ions (25 mg/L) could be removed by 0.2 g of ESM at 25°C, pH 5.2, and 24 h. There was no difference in the adsorbability of ES and ESWM on nickel and silver ions. In summary, all three adsorbents, ESWM, ES, and ESM, can remove heavy metal ions from aqueous solution, with ESM having the highest efficiency. Hence, eggshell and its derivatives can be promising ‘green’ adsorbent materials for treating wastewater containing nickel and silver ions.
The milk proteins were mixed with lactose in the same proportions and conditions as skim milk, which were casein-lactose (CN-L) (1: 1.6) and casein-whey protein isolate-lactose (CN-WPI-L) (1: 0.2456: 1.579) models. These two models at different pHs (6.6, 8.0) and skim milk powder were treated in a microwave field at 400 w for 15 min. Functional properties (solubility), structure, digestibility and antioxidant activities of casein-lactose Maillard reaction products were investigated. The results indicated that the digestibility of glycated milk proteins (CN-L) was higher than that of native protein. The improved solubility and enriched antioxidant peptide fraction showed that could be a promising method for dietary supplements. The fluorescence intensity was increased a lot, and environmental scanning electron microscope (ESEM) analysis showed that protein granule was changed from regular and smooth flaky to nubbly and amorphous structure. Then the results will have a great impact on the development of novel food structures with improved properties.
Starches from two local cultivars of taro from North-Eastern region of India were characterized and compared with potato and rice starches. The cultivars were Kani and Garu. Average granule size of the taro starches were much smaller than potato starch, but comparable to the rice starch. A-type X-ray diffraction (XRD) pattern similar to rice starch was observed for the taro starches. The Fourier transform infra red (FT-IR) spectra of all the four starches were almost similar in nature. The peak gelatinization temperature (Tp) for Kani, Garu and rice starches were 74.7, 74.1 and 72.5°C, respectively while that of potato starch was 65.6°C. The pasting temperature of Kani starch was highest at 88.3°C and significantly different from the other starches. The peak, hold, final, breakdown and setback viscosities of Kani starch were lowest among the starches but were close to Garu and rice starches, but much lower than potato starch.
Single disruption of seven acid phosphatase genes (aphB-H) demonstrated that the aphC gene is mainly responsible for acid phosphatase production in the soybean-koji culture of the miso koji mold, A. oryzae KBN630. None of the single disruptions of aphB-H affected growth in the culture. Both the acid phosphatase activity and 5′-IMP dephosphorylation activity of the aphC disruptant decreased by 95% compared to the wild-type strain. Utilizing the promoter of the A. oryzae taaG2 gene, AphC was successfully overproduced in A. oryzae and secreted into liquid culture medium. The purified AphC had a molecular mass of 69.0 kDa, a pH optimum of 4.5, and a temperature optimum of 50°C. AphC exhibited high dephosphorylation activity towards the umami flavor enhancers, 5′-IMP and 5'-GMP, supporting the idea that AphC is involved in degradation of disodium 5′-ribonucleotides supplemented in miso products.
Effects of cellulose, lignin and hemicellulose on the retrogradation of rice starch were investigated by RVA, Texture profile analysis, FTIR, XRD and SEM. Results showed that those three elements all delayed the retrogradation of rice starch. Among them, the best effect was hemicellulose, cellulose second, and lignin was the worst. RVA expressed that the addition group had lower but more stable pasting temperature and setback. Texture profile analysis demonstrated that the addition group had a lower hardness but higher adhesiveness. XRD analysis indicated that the addition group had no change in crystalline structure but had a lower degree of crystallinity being compared with the control group. FTIR revealed that addition of them had an interaction with starch by hydrogen-bond and a lower absorbance ratio (A1047/A1022). SEM confirmed that cellulose, lignin and hemicellulose will associate with starch, through reducing the chances of starch chains combining with themselves so as to retard staling.
Carp egg phosphopeptide (EPP) with Ca binding activity was isolated from tryptic hydrolysate by ultrafiltration and hydroxylapatite chromatography. EPP mainly consists of 3.99 ± 0.12% P (w/w) and 20.36 ± 0.50% serine residues (w/w). In vitro EPP exhibited high Ca binding ability which was slightly lower than that of casein phosphopeptide (CPP) and could inhibit the formation of insoluble Ca salts. In vivo the effects of EPP on increasing Ca bioavailability were further studied in Ca-deficiency rats. All rats were randomly divided into five groups, one group served as the normal group to feed with a normal-Ca diet including CaCO3 for 8 weeks, another as the Ca-deficiency group to feed with a low-Ca diet for 8 weeks, the other three groups to feed with the low-Ca diet for 4 weeks and then randomly assigned to the control group and two experimental groups. The control group was switched to the normal-Ca diet for 4 weeks. The experimental groups were fed with the normal-Ca diet containing EPP and CPP for 4 weeks respectively (marked as the EPP group and CPP group). During the experimental period, Ca absorption and its accumulation in bone was significantly increased by EPP supplementation. The levels of serum Ca, bone mineral density, bone Ca content and biomechanical properties of the EPP group were significantly higher than those of control group (p < 0.05), but similar to the CPP group (p > 0.05). EPP is expected to become a novel Ca nutraceutical additive in food industry due to enhancing Ca bioavailability by its intake.
The objective of the present work was to investigate water distribution in porcine muscle during wet-curing using both the low-field (LF) NMR T2 components and traditional methods. Longissimus muscles were cut into 1 cm3 and immersed in brine solution (15% NaCl, w/w) at 4°C. The analysis of NMR and AOCO indicated that with increasing curing time there was greater uptake of water by the meat. Population of T2 suggested that redistribution occurred between the protein-associated water, immobilized water and free water: the immoboilized water increased while the others decreased. Aw and pH decreased during curing while WHC increased at first then kept decreasing after curing for 1h. DSC indicated that actin and myosin in meat were denatured. The conclusion is that with the swelling of meat structure by NaCl, water transferred from brine to meat surface firstly, then continued moving into the muscular tissue and converted to immobilized water mostly.
The palatability of boiled soybean vegetable with respect to maltose production was investigated using seven cultivars of soybean vegetables. Although sucrose is the most abundant free sugar (ca. 90%) in raw soybean vegetables, maltose was also shown to contribute to palatability (sweetness). Maltose production was found to be related to both β-amylase activity and starch gelatinization temperature. Of the seven cultivars studied, ShinTamba-Guro' had the lowest starch gelatinization temperature (55°C) and the highest maltose content, while ‘Fuki’ had the highest starch gelatinization temperature (> 70°C), lowest β-amylase activity and did not produce maltose, with boiling treatment. Sweetness was proposed as one of the factors related to the palatability of soybean vegetable, and was affected by the content and composition of sucrose and/or maltose.
Accelerated Solvent Extraction of flavan-3-ols from grape seed was carried out to determine the effect of extraction conditions (solvent type, temperature, extraction time, particle size, and cycle number) at the constant pressure (10.3 MPa). The highest flavan-3-ols amount was obtained with 70% acetone. The recovery of flavan-3-ols increased with extraction temperature and maximized at 120°C. There was an almost two-fold increase in the amount for flavan-3-ols extracted when the average particle size decreased from 0.725 mm to 0.512 mm. The highest extraction yields were achieved at an extraction time of 20 min. Two cycles for ten min each were also found to recover the maximum amount of flavan-3-ols.
d-Psicose is expected to be widely used as a raw material for various foods in the future due to its beneficial health properties and rheological characteristics. To provide the functional effects of d-psicose to consumers, this sugar needs to be stable during food processing. To evaluate the stability of d-psicose, we investigated changes in d-psicose concentration during caramelization and the Maillard reaction, both of which are important reactions that typically occur during food processing; and during general food processing. During caramelization and the Maillard reaction, the concentration of d-psicose is decreased as the reaction temperature and pH are increased. During food processing, a similar tendency was observed: d-psicose degradation ranged from 3.3% (fig jam) to 10.8% (sponge cake). We concluded that although d-psicose degradation occurs at elevated temperatures and pHs, d-psicose loss can be minimized by controlling the temperature and pH during the cooking process.
Factors affecting the formation of psicose in food products during cooking were investigated based on psicose formation from fructose in various food products and during the caramelization process. Psicose was produced upon heating not only in fructose meringue that had a high fructose content and was alkaline, but also in dried apple that was weakly acidic. Optimized conditions for psicose formation were determined by experiments on fructose caramelization. From the results, we concluded that the following factors affect psicose formation in food products during cooking: high temperatures, high pH, high fructose concentration, and extended cooking time. Of these, the pH of the food was the most important factor for psicose formation in food products.
The present study was undertaken to evaluate the effect of soybean trypsin inhibitor (STI) on the generation of oxygen free radical in pancreas of mice during different growth periods. Mice were divided into three groups and fed with different diets for 1, 2, 3, 4 and 5 weeks separately. The results showed that, MDA content of STI group was increased in the first two weeks, and its maximum appeared in the 3rd week, then it was dropped. Glutathione (GSH) content in serum and pancreas and total anti-oxidative capacity (T-AOC) in serum were dropped in the first two weeks, their minimum appeared in the 3rd week, then they were increased. However, the change of glutathione peroxidase (GSH-Px) in serum and pancreas and T-AOC in pancreas showed opposite trend. The present study indicates that the effect of STI on free radicals level in vivo of mice is relative to growth periods.
Apple fruit (cultivar sunfuji) contained procyanidin B2, (−)-epicatechin, and chlorogenic acid as major polyphenols. The concentration increased in the order procyanidin B2 < (−)-epicatechin < chlorogenic acid. Nitrite reacted with the polyphenols in methanol extracts of apple fruit both in an acidic buffer solution (pH 2.0) and at the pH of acidified saliva. The rate of the reaction increased in the order chlorogenic acid < (−)-epicatechin < procyanidin B2. During the reactions, nitrous acid (pKa = 3.3) was reduced to nitric oxide (NO) by the polyphenols, and nitroso compounds of procyanidin B2 and (−)-epicatechin were produced. Our conclusion are that (i) the nitroso compounds can be produced by the reaction of NO with radicals of procyanidin B2 and (−)-epicatechin, which are formed by the nitrous acid-dependent oxidation of procyanidin B2 and (−)-epicatechin, and that (ii) polyphenols such as chlorogenic acid and (−)-epicatechin, which will react with nitrous acid slowly in the gastric lumen, can be transported to the intestine when apple is ingested.
The aim of the study was to evaluate antioxidant activity of aqueous extract from Beijing roast duck through assessments of scavenging activity of 1,1-diphenyl-2-picrylhydrazil (DPPH) and 2,2′-azinobis(3-ethylbenothiazoline-6-sulphonic acid) diammonium salt (ABTS) and reducing power. Compared with non-roast duck, the antioxidant activity of roast duck extract was strongly improved. The different molecular weight compounds of ducks extracts were obtained through ultrafiltration, and fraction two (MW, 2 – 5 kDa) had the highest antioxidant capacity in all the four fractions. Furthermore, the roast duck extract was significantly found to increase the superoxide dismutase (SOD) activity and cell viability and to inhibit the malonaldehyde (MDA) content in the H2O2-treated Caco-2 cells, suggesting that the roast duck extract attenuated cellular oxidative damage. The fraction three and four (MW < 2 kDa) represented the strongly protective effect against cellular oxidative damage in the four fractions. Thus, the roast duck was considered to possess an effective antioxidant activity.
Rebaudioside A (RA), a natural high potency sweetener, is isolated from the leaves of the Stevia rebaudiana plant, and has potential for wide use in our diet today. To investigate the effect of RA on the changes of microbial diversity in animal intestinal tract, the viable cell count and denaturing gradient gel electrophoresis (DGGE) method were used to monitor the microbial number and species in vivo, and before that, we also evaluated its infuence on the growth of some selected bacteria in vitro. Our results indicated that the RA had little or no effect on the growth of E. coli O157 H7, S. typhimurium, L. monocytogenes and B. longum, while could promote the growth of L. plantarum and inhibit that of S. aureus in vitro; moreover, the viable cell count and DGGE results confrmed that the RA posed little pressure on the composition of total bacteria, enterobacteria and lactobacilli in vivo. In conclusion, RA posed little pressure on the growth and the composition of microbes, suggesting it is safe for gut microbes.
In the present study, functional and pasting properties of 3 locally grown exotic rice varieties were compared with 3 popular imported rice varieties. Various parameters such as water and oil absorption capacities, gelation properties, pH, water activity, emulsion activity and stability, foaming capacity and pasting properties were evaluated. Results obtained showed significant differences in water absorption (3.82 – 10.86) and oil absorption capacities (2.18 – 6.37) with pH and aw varying between 6.07 – 6.45 and 0.62 – 0.68, respectively among various rice samples. Emulsifying activity (5.48%) and stability (98.3%), and foaming capacities (3.98%) were highest in glutinous rice. Significant differences were observed in pasting parameters of rice starch especially in relevance to peak time, peak viscosity, final viscosity (range 513 – 1077 cP) and setback. Results generated in this study pertinent to functional and pasting properties is envisaged to be useful in exploiting the potentiality of local rice grain varieties at international market levels to develop new rice based food products.
To determine whether fermented rice extract (FRe) has bifidogenic growth-stimulating effects in vitro, the effects of FRe on the growth of lactic acid bacteria and bifidobacteria were evaluated. Treatment with 0.2% FRe stimulated the growth of three strains of lactic acid bacteria (Lactobacillus acidophilus, Streptococcus thermophilus, and Bifidobacterium lactis), significantly increasing the number of cells by 11 – 53 fold after 12 – 18-h incubation compared with the control (p < 0.05). HPLC analysis indicated that the panose content of the FRe powder was 6.7%. The growth-stimulating effects of FRe on bifidobacteria and lactic acid bacteria were likely due to panose, and additional unknown and/or known substances in the FRe. Based on these results, we propose that FRe could be used as a growth stimulator for bifidogenic and lactic acid bacteria in pharmaceutical and food applications.
Specific antioxidants have previously been found to target particular reactive oxygen species. For example, histidine-dipeptides neutralize hypochlorite, while ascorbic acid targets peroxynitrite and ferulic acid scavenges hydroxyl radicals. In this study, we investigated the effects of a mixture of these antioxidants on oxidative stress in middle-aged men. Seventeen male volunteers ingested an antioxidant mixture containing histidine-dipeptides, vitamin C, and ferulic acid for 8 weeks. DNA damage in peripheral leukocytes was measured at 4-week intervals using comet assays. For comparison, oxidative status in twelve normal volunteers who did not ingest the test drink (control group) were examined. DNA damage was remarkably reduced at the 8- and 12- week follow-ups. Plasma LDL-cholesterol levels were also reduced at 8 weeks. In contrast, notable changes in DNA damage were not observed in the control group. In addition, the antioxidant mixture administered in this trial did not produce toxic effects on the liver, kidney, or pancreatic function. Thus, such antioxidant combinations may contribute to the maintenance of health in middle-aged men.
High-temperature steam treatment of wood materials results in sterilization and improved digestibility; however, in some cases deleterious degradation products are generated. Steam-treated sawdust-based spent mushroom substrate (S-SSMS) was prepared from non-treated SSMS (N-SSMS) after the cultivation of Maitake (Grifola frondosa) mushroom by autoclaving. Wistar rats were assigned to three groups: control group, fed a basal diet; N-SSMS group, fed a 25% N-SSMS diet; and S-SSMS group, fed a 25% S-SSMS diet for 26 days. The effects of S-SSMS on the growth performance, serum biochemical parameters, fecal composition, and cecal pH of rats were investigated. There were no significant differences in body weight gain, feed efficiency, and serum biochemical parameters among the groups. However, fecal weight and protein amount of N-SSMS and S-SSMS groups were significantly higher than those of the control group, while cecal pHs of N-SSMS and S-SSMS groups were lower than that of the control group. Based on these observations, S-SSMS has potential as a feed additive for monogastric animals.
Soybean broth (SB) is a waste product in the manufacturing of boiled soybean-based foods. We cultured the SB with six pure strains of microorganisms (Aspergillus oryzae, Aspergillus sojae, Rhizopus oligosporus, Zygosaccharomyces rouxii, Bacillus subtilis (natto), and Tetragenococcus halophilus) used commercially in the production of fermented soybean foods, including miso, soy sauce, natto and tempeh, and examined their cytotoxicity and apoptosis-inducing effect on U937 cells. Ethyl acetate extracts of all cultures showed cytotoxicity against U937 cells, although that of SB did not in the range of concentrations tested. Further, ethyl acetate extracts of SB after culturing with A. sojae (ESBA) and ethyl acetate extracts of SB after culturing with B. subtilis (natto) (ESBB) elicited DNA fragmentation. The DNA fragmentation elicited by ESBA was prevented by pretreatment with a general caspase inhibitor (Z-Asp-CH2-DCB), implying induction of caspase-dependent apoptosis. Assays for caspase activity showed that apoptosis induction was associated with caspase-3, -8, and 9, which are the principal caspases involved in apoptosis. Thus, SB was conferred cytotoxicity upon culturing with the microorganisms used in this study; in particular, SB cultured with A. sojae induced apoptosis in U937 cells.
Cyanobacteria contain substances of high biological value and are used to meet the high demands of the global food and pharmaceutical industries. In this study, we prepared a hot water extract of the edible cyanobacterium, Nostochopsis, and evaluated its possible use as an ingredient in cosmetics. Specifically, a hot water extract of Nostochopsis was assayed for tyrosinase inhibitory activity. Tyrosinase, a key enzyme in skin melanin synthesis, was strongly inhibited by the Nostochopsis hot water extract, which reduced α-melanocyte-stimulating hormone-induced melanin synthesis in B16 mouse melanoma cells. Thus, Nostochopsis hot water extract may be suitable as an ingredient in cosmetics.
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