This study evaluated biochemical changes, especially those related to protein degradation, occurring in sufu fermentation with Mucor flavus at low temperature. The effects of incubation temperature on M. flavus growth, biomass accumulation and protease production were described. Results indicated that M. flavus could grow well on the surface of soybean curd and produce considerable protease to degrade soybean proteins during sufu fermentation at lower temperature such as 15°C. Almost no subunits of protein could be observed after maturation for 8 weeks in M. flavus-type sufu. Post-fermentation was the main stage responsible for the hydrolysis of protein together with the increase in the content of amino-type nitrogen and free amino acid. Our results demonstrated that M. flavus had possible application as an alternative strain for sufu manufacturing at low temperature.
Supercritical CO2 extraction was used for the recovery of valuable aroma components with application in blending steps for fast aged rum processes. Head Alcohol, Crude and Aged Sugar Cane Spirit process streams were used to firstly quantify different concentrated aroma fractions with interest in food applications. Alcohols ratio, esters composition and carboxylic acids concentration criteria were used to determine the quality of extracts. The economical profitability of this technology was especially evident for Head Alcohol and Aged Sugar Cane Spirit extracts, since the most interesting compounds were concentrated more than 300 times compared to commercial aged rum. Additional experiments were performed in the range 8-15 MPa and 313-333 K to obtain empirical correlations to predict solubility data for further scale-up applications.
The cross-sectional structure of prawns was directly observed by near infrared (NIR) spectral imaging. We evaluated boiled and non-boiled prawns immersed for 24 h in pure water, as well as in aqueous solutions of sodium chloride and trisodium phosphate (at three concentrations: 0.5%, 1%, and 4%). We used the micro-slicer spectral imaging system composed of an indium gallium arsenide (InGaAs) NIR camera with an NIR illumination device using a band-pass filter for a wavelength of 1,500 nm, which corresponds to the absorption band of ice. Cross-sectional images of the frozen prawns were taken and quantitatively analyzed. The muscular fiber structure of the prawns could be directly observed, allowing for analysis of different food additives.
In this work, it was aimed to determine the effect of packaging technique on some quality properties of “Crottin de Chavignol” type goat cheese packaged under vacuum (VP) and modified atmosphere (MAP) (%20 CO2 + %80 N2) during storage at + 4°C and also to compare these two packaging techniques to be able determine the more suitable packaging technique for “Crottin de Chavignol” type goat cheese. Sampling was carried out for physicochemical, microbiological, sensory and textural analyses at 1st day, 3rd, 6th, 9th,12th and 15th weeks. Control cheeses which were packaged under atmospheric air were unacceptable sensorially at 3rd week due to their visible mould growth. Both modified atmosphere and vacuum packaging had favourable effects on physicochemical properties, microbiological properties, color, sensory attributes of Crottin de Chavignol type goat cheese to longer the shelf life of cheese. According to the results of our study, at 15th weeks mould growth increased to 2.3 log cfu/g and 3.8 log cfu/g at MAP and VP cheese samples respectively whereas the mould growth was > 1 log cfu/g at 1.day of storage. And the taste scores of VP cheese samples were below acceptability limit at 15th weeks because of formation of oxidized flavour. The packaging type whether MAP or VP didn't significantly affected the pH, dry matter, color and textural properties except hardness, chewiness and gumminess. Hardness, chewiness and gumminess values of VP cheeses were higher than MAP cheese samples.
Effects of microwave heating (MH) and conductive heating (CH) on the glycation of ovalbumin (OVA) by glucose in dry state were compared. The temperature of OVA-glucose mixture was raised to 80°C in 13 min and kept for 0, 15, 30 and 60 min by MH and CH. SDS-PAGE analysis showed that the bands of OVA glycated by MH and CH appeared to be shifted equally to higher molecular mass. However, the amount of primary amino groups in OVA glycated by CH significantly decreased compared with those by MH. The solubility of OVA glycated by CH was higher than that by MH. These results suggested that CH accelerated the glycation of OVA in solid-state more than MH.
This review summarizes a novel hydrolytic processing of soybean proteins. Under limited hydrolytic condition, glycinin or β-conglycinin could be selectively digested in soybean proteins. The hydrolysates can be useful for an ingredient in various food applications. Selective hydrolysis may be effective for the reduction of soybean allergenicity with processing functionality.
The content of synephrine, an adrenergic phenethylamine, was determined by high performance liquid chromatography (HPLC) in Shiikuwasha (Citrus depressa, Hayata) plant material (flesh and peel) during fruit development, as well as in 45 species and cultivars of Citrus genus. HPLC conditions were as follows: column, Develosil ODS-5; mobile phase, acetonitrile-H2O (2:98)-10 mM phosphoric acid and flow rate, 0.8 mL/min. In the extraction of synephrine from the sample citrus peel, a large quantity of synephrine was detected in water (100%) while no synephrine was found in the methanol extract (more than 60% concentration of methanol). Synephrine content in the peels during Shiikuwasha fruit development was gradually decreased to half the amount in January compared with that in August. Synephrine was detected in 30 of the 45 species and cultivars of Citrus genus, and was mainly found in the samples of Aurantium and Acrumen sections according to Tanaka's classification.
Keropok lekor at different processing stages were obtained and examined for total volatile bases (TVB), trimethylamine (TMA), putrescine, cadaverine and histamine and their forming bacteria. TVB and TMA levels decreased significantly (p < 0.05) after boiling from 7.29 to 4.68 mg/ 100g and 3.38 to 1.81 mg/ 100g, respectively. After cooling stage, the levels of TMA, putrescine, cadaverine and histamine in keropok lekor were increased significantly (p < 0.05). Putrescine, cadaverine and histamine level for all samples was found less than allowable level, which is 50 ppm. Bacteria forming putrescine, cadaverine and histamine reduced significantly (p < 0.05) after boiling stage and it was increased significantly (p < 0.05) after cooling stage. Before the boiling stage, microorganisms isolated producing putrescine, cadaverine and histamine were members of the family Enterobacteriaceae and also members of Staphylococcus, Pseudomonas and Micrococcus genera. Members of the genera Pseudomonas that produce biogenic amines were not found from keropok lekor after the boiling stage.
It was reported in 1984 that cellulose could be dissolved in aqueous sodium hydroxide solution when the intramolecular hydrogen bonds of cellulose were partially broken down by physical treatments such as steam explosion. Although there have been many studies on alkali-soluble cellulose, little is known about cellulose blends made from aqueous sodium hydroxide solution. Therefore, we investigated the structure and properties of cellulose-starch blend films regenerated from the solution. The blends had a porous structure with an average pore size increased from 1 to 6 μm with increased starch content. These pores were observed separately from each other, leading to high water and oil absorbencies of these blend films (the oil absorbency of the blend film containing 50 % starch was over 400 %, ten times that of cellulose film). The results of X-ray measurements, dynamic viscoelastic measurements, enzyme etching, and iodine staining suggested that cellulose and starch were miscible in the amorphous regions but incompatible in the crystalline regions of the cellulose-starch blend films.
Transitional metals, as vanadium, are known to exert noxious effects by generating oxidative stress. Addition of antioxidants in the diet could decrease the cytotoxic effect related to the oxidative stress. The present study, carried out in rats, is a contribution to explore mechanisms underlying vanadium toxicity and possible protective effects of green tea Camellia sinensis which is known to be rich in antioxidant compounds (polyphenols...). Chronic intoxication by vanadium given in drinking water was found to induce histological structure changes of renal glomeruli and tubules, but indicators of nephrotoxicity (serum creatinine and urea, urinary pH) were not perturbed. Vanadium accumulation was found to be decreased in (T+V) group, and renal histological changes were not observed. The ability of catechins to chelate metal ions, and perhaps vanadium, could explain protective effects of herbal green tea. Intraperitoneal administration of vanadium to rats (V) was found to induce an increase of lipid peroxidation levels in kidney, that was lowered in rats (T+V) drinking herbal tea. This effect was partly due to a tea-induced decrease of basal lipid peroxidation level in kidney tissues. Similar HSP72 underexpression and HSP73 overexpression were found in (V) and (T+V) rats. Vanadium-induced HSP70 underexpression was discussed in relation to the ability of the metal to inactivate some phosphatases, resulting in phosphorylation and transcriptional activity changes of heat shock factor 1 (HSF1). Besides, two forms of GRP94 (96, 98kD) were immunodetected, that appeared inversely regulated by vanadium, but not by herbal tea. This suggests that vanadium can disrupt reticulum endoplasmic function resulting in GRP94 phosphorylation and/or glycosylation changes.
The anti-allergic effects of commercial products from cooked burdock (burdock salad, fried up burdock and burdock boiled with vinegar) were investigated by analyzing their inhibitory effects on the enzymatic activity (cyclooxygenase-2, lipoxygenase, phospholipase A2 and hyaluronidase) and the suppression of degranulation from rat basophilic leukemia (RBL)-2H3 cells. The methanol extract of burdock boiled with vinegar did not inhibit the cyclooxygenase-2 activity in the experiments. Those of the burdock salad and fried up burdock exhibited inhibitory activities in all the experiments. The burdock salad extract strongly inhibited lipoxygenase, phospholipase A2 and hyaluronidase. Thus, commercial cooked burdock, in addition to raw burdock, has bioactivities corresponding to an anti-allergic effect.
Simultaneous enrichment broth (SEB) was developed for the single-enrichment simultaneous screening of six major food poisoning bacteria. After enrichment in SEB for 18 h at 37°C, viable counts of six major food poisoning bacteria (Staphylococcus aureus, Salmonella spp., Escherichia coli O157:H7, Vibrio parahaemolyticus, Bacillus cereus, and Listeria monocytogenes) were sufficient for 5' nuclease multiplex real-time PCR assay using existing primers and probes. By labeling the probes with three different fluorescent dyes, the assay could be carried out in 2 tubes. The whole process, including enrichment and PCR, was completed within 24 h and the detection limits for the target bacteria from the food sample (boiled chicken) were 36 cfu/25 g for S. aureus, 5.3 cfu/25 g for Salmonella spp, 2.9 cfu/25 g for E. coli O157:H7, 2.0 cfu/25 g for V. parahaemolyticus, 5.5 cfu/25 g for B. cereus, and 6.2 cfu/25 g for L. monocytogenes. The results were comparable to conventional methods that require 4-6 days.
Using various rice flours prepared by different milling methods, the relationship between rice flour properties and specific loaf volumes of one-loaf bread made from rice flour with wheat vital gluten were studied. Damaged starch content of rice flour varied from 1.0% to 22.1%. A significant negative correlation was verified between damaged starch content and specific loaf volume of one-loaf bread. Rice flour with low damaged starch content mainly consisted of compound starch granules, aggregated polyhedral single starch granules and smooth surface cells surrounded by the cell wall. The structures of starch granules and cells were maintained in rice flour with low damaged starch content. Rice flour with high damaged starch content consisted of only fine irregular particles without the apparent rice starch structure, or contained fractured large and small cells with rough surface. Although there was not significant correlation between specific loaf volume and median particle size, rice flours which were successful at making bread with high specific loaf volume commonly showed a peak centered around 60 µm with a smaller amount of larger size particles in the particle distribution profile. Thus, the flour particle size distribution appears to affect the specific loaf volume of one-loaf bread. Both the damaged starch content and the profile of particle size distribution were important for high specific loaf volume of one-loaf bread. Less damage to starch and cell structures while lowering the particle size during milling process is critical in obtaining better flour for rice one-loaf bread making.
Chlorella powder (CP), a dietary supplement made from a green alga, contains abundant lutein (2.8 mg/g), but the bioavailability of lutein in CP has not been evaluated. In the present study, we assessed the effect of a single ingestion of CP (3 or 6 g) in tablet form on serum lutein concentrations in humans (n = 21). At 1 d, serum lutein concentrations increased from baseline values by 34% (25.6 nM/mg-lutein intake) after 3 g CP and by 66% (21.4 nM/mg-lutein intake) after 6 g CP. These results suggest that lutein in CP is highly bioavailable.
Mycotoxin inhibits the growth of Saccharomyces cerevisiae mutants with disrupted stress response genes, but no that of wild type yeast even at high concentrations. The S. cerevisiae genome database (SGD) project has recently generated many gene disruptants, including those with disrupted stress responseassociated genes. The present study examined the relationship between mycotoxicity and the disruption of functional yeast genes, especially those involved with stress responses. Growth tests showed a major impact in strains other than those with disrupted stress response genes as well as mycotoxin susceptibility of several strains by sodium dodecyl sulfate.