Freeze-thaw infusion (FI) is a technique used to rapidly impregnate food materials with enzymes. We investigated whether an enzyme could penetrate both the intercellular spaces and the intracellular spaces using FI by determining the enzymatic potato starch decomposition efficiency and by assessing malto-oligosaccharide production. Malto-oligosaccharide production by FI using α-amylase was dependent on time and enzyme concentration, reaching a maximum production of 6.5 g/100 g after 60 min at 1.0% (w/v) enzyme. This corresponds to an enzymatic decomposition efficiency of 76%, compared with crushed potatoes (8.5 g/100 g). Production after infusion or immersion of unfrozen potatoes was below 1.0 g/100 g and production after immersion of freeze-thawed potatoes was 3.0 g/100 g. The results indicate that FI enables efficient intracellular impregnation, which allows for efficient enzymatic decomposition of intracellular substrates, while retaining food material shape.
Combining effect of infrared radiation (IR) heating with ultraviolet (UV) irradiation on the inactivation of mold spores isolated from citrus fruits was investigated. Fruit-related molds (Penicillium, Aspergillus, Cladosporium, Rhizopus, and Byssochlamys) were inoculated on stainless steel Petri dish and inactivated by IR heating, UV irradiation, and combined treatments with different sequence orders. Three isolates (Penicillium, Aspergillus and Cladosporium) were sensitive to IR heating, while Rhizopus and Byssochlamys spores were relatively sensitive to UV irradiation rather than IR heating. Combinations of IR heating with UV irradiation were effective in the inactivation of all mold spores. Considerable reductions in the survival of all mold spores were achievable by the combined treatment regardless of the treatment order.
In this study the combined effect of bay (Laurus nobilis L.) essential oil (0.5% v/w) with modified atmosphere (MAP) (20%CO2/80%N2) and vacuum packaging in ground chicken breast meat stored at 4°C was investigated. Microbial populations of inoculated Listeria monocytogenes AUFE 39237 in chicken meat and Escherichia coli and total viable counts (TVC) were also monitored during 0,1,3,5,7 th days of storage. MAP packaging with/without bay oil gave significantly (p<0.01) higher reductions of microbial populations. Vacuum packaging and bay oil combination was also found significantly effective (p<0.01) against E. coli in ground chicken meats. The preservative effect of MAP and vacuum packaging against some food pathogens can be increased with bay essential oil in chicken meats.
Traditionally prepared sun-dried bananas were evaluated for textural and rheological properties. Assessment of how those properties changed over a storage period of two months was also carried out. The texture analysis results that relate to large deformations of the product show that the samples were not significantly affected by storage for one month, but subsequent storage for an extra month did result in softer samples. Rheological characterisation shows that upon heating samples become more elastic, however, this behaviour was reversed upon cooling. The rheological behaviour did not change significantly over the two month storage period. Overall results indicate that textural changes are not the limiting factor in the shelf life of this product. Further work is recommended in order to improve our understanding and maximise the stability of the product over the anticipated shelf life.
Effects of a fermented barley extract P (FBEP) on uric acid (UA) metabolism in three hyperuricemia rat models were studied. First, the influence of FBEP on UA biosynthesis was examined using rats hypodermically administrated oxonic acid. Then, the influence of FBEP on dietary purine absorption was examined using rats fed a high dose of inosinic acid. Finally, the influence of FBEP on UA excretion was examined using adenine-administered rats. From the first two models, FBEP was found to be rarely, or not at all, involved in the biosynthesis of UA or absorption of nucleic acid. On the other hand, in the rats loaded with adenine, it was shown that the urinary UA of the high-dose FBEP group (4,000 mg/kg/day) was significantly elevated by 27% compared to the control group. In addition, the UA clearance value in the high-dose FBEP group was increased 2-fold compared to the control group. These results suggest that FBEP reduces serum UA by increasing urinary excretion of UA.
Starch content, starch damage, particle size distribution, pasting properties measured using a rapid visco analyser (RVA properties) of rice flour, and their relation to specific loaf volume (SLV) of rice bread with gluten were examined in rice cultivar Koshihikari and its milky-white mutant lines. Two different milling methods were used: jet-milling under semidry condition after pectinase treatment and pin-milling under dry condition. Jet-milled and pin-milled milky-white mutants and jet-milled Koshihikari produced flour with low starch damage, fine particle size, low pasting temperature, high final viscosity, large setback, high trough, and long peak time. Such flour resulted in high SLV rice bread. SLV of rice bread from pin-milled milky-white mutant was equivalent to that from jet-milled Koshihikari. Using milky-white mutants, rice flour suitable for bread-making would be produced by dry pin-milling.
In this study, the effects of microwave application on technological and rheological properties of flours produced from sound and damaged wheat by suni-bug (Eurygaster spp.) were investigated. The flour samples were exposed to microwave energy in various times (90, 120, 180, 240, 300 s) by using a closed system at 625 W. Existing of suni-bug damage in flour samples was determined by modified Zeleny sedimentation test before microwave application. Total protein, the standard and modified Zeleny sedimentation test, wet gluten, standard and modified Perten gluten indexes, falling number, and alveographe test of the flour samples were carried out. The results were evaluated statistically and summarized as below (p<0.05). The moisture values (15.2–12.0 %), wet gluten contents (28–20.4 %), proteolytic activity (40.20–6.96 %), zeleny sedimentation (31.8–15.8 ml) and alveogram energy (W) values (192–92 10-4 J) among samples decreased whereas Perten gluten index (78–100 %) and falling number values (264–397 s) of flour samples increased with processing microwave times. The total protein content of samples was not affected significantly (p<0.05) by heating with microwave treatment. These results suggested certain microwave treatment times (120–180 s) caused positive effects on thermal inactivation of insect enzyme damage of wheat according to some physicochemical quality parameters (Zeleny sedimentation, Perten Gluten index and alveogram values).
We analyzed lactic acid bacteria (LAB) and yeast populations in samples of airag, undaa, and hoormog, which are varieties of traditional fermented milk produced in Mongolia. To effectively detect lactobacilli, lactococci/streptococci/enterococci, and leuconostocs for complete analysis of the complex LAB population in airag, we developed two new primer sets and examined these primer sets in three different combinations using denaturing gradient gel electrophoresis (DGGE). DGGE analysis revealed the diversity of the LAB and yeast populations in these traditional fermented milk samples; six to 11 LAB and yeast species were detected. The species common to all samples include Lactobacillus helveticus, Leuconostoc mesenteroides, Lactococcus lactis, and Kluyveromyces marxianus. Lc. raffinolactis, Enterococcus faecium/ hirae/durans/villorum/ratti, Streptococcus thermophilus, L. kefiranofaciens, L. kefiri/buchneri, Leu. citreum, and Leu. lactis were detected in multiple samples, while lactose non-fermenting Saccharomyces cerevisiae was only detected in one sample of hoormog.
Vinegar was produced from rice-, barley-, and sweet potato-shochu distillery wastewater (post-distillation slurry) using aerobic acetic acid fermentation with Acetobacter pasteurianus NBRC 3283. Among these, vinegar produced from sweet potato-shochu post-distillation slurry showed the highest antioxidative effect on U937 cells. The active compound was isolated using reversed phase HPLC and identified as caffeic acid ethyl ester using 1H-NMR and LC-MS. Caffeic acid ethyl ester as well as caffeic acid were contained in the vinegar produced from sweet potato-shochu post-distillation slurry. It was confirmed that caffeic acid ethyl ester showed an obvious antioxidative effect on U937 and HepG2 cells, but on the other hand caffeic acid did not. Caffeic acid ethyl ester was not determined in the vinegar produced from rice- and barley-shochu post-distillation slurry.
A high-concentration (20%) antihypertensive peptide solution with angiotensin I-converting enzyme (ACE) inhibitory activity was prepared from the powder of the jellyfish Stomolophus nomurai, a plague of which had recently hit Japan's fishing industry, using the drum dryer method. Three active fractions, Fr. 3-1, Fr. 3-3, and Fr. 3-6, were isolated from the peptide mixture by step-wise elution by Sep-Pak Vac C18 and further fractionated by high-performance liquid chromatography twice. The sequences of Fr. 3-1, Fr. 3-3, and Fr. 3-6 were determined as IGDEPLANYL, FGGIDDINQIGQSD, and YYAPFE, respectively. The most active peptide was identified with the synthetic peptide YYAPFE by sequence analysis, MALDI-TOF MS, and NMR spectra. Further, YYAPFQ, designed and synthesized on the basis of YYAPFE, showed the highest ACE inhibitory activity in vitro among YYAPFE, YYAPF, YYAP, YYA, and YY; however, its effect on systolic blood pressure showed a similar tendency to that of YYAPFE in spontaneously hypertensive rats.
Many allergens belong to the defense response proteins, which are produced when the plant is under various stresses. The amino acid sequences of the main wheat flour allergens associated with baker's asthma were analyzed in this study. The gene sequences of monomeric (WMAI), dimeric (WDAI), tetrameric (WTAI, which contains 1 WTAI-CM2 unit, 2 CM3 units and 1 CM16 unit) α-amylase inhibitor and fructose bisphosphate aldolase from wheat, barley and rye were obtained and characterized. Compared with other main allergens, it was shown that the fifteen proteins have a common conserved cysteine skeleton and the presence of CC and CX1-4C motifs, which are not usually found in other non-allergenic proteins. Most of these allergens have putative N-glycosylation sites. Protein structure either mediated through di-sulfide bonds or through higher order protein-protein interactions, plays a critical role in the allergenicity of allergens. It was also found that the same protein family allergens did not share similar 3D structures. With regard to the characterized sequences as well as protein structures of allergens, it is obvious that the flour proteins that have been implicated as important wheat seed allergens causing baker's asthma are complex but have some specific related behavioral traits.
To evaluate the accessibility and function of phycoerythrin (a purple-pigment protein) found in purple laver (Porphyra sp.), antioxidant activity of the phycoerythrobilin compound (chromophore of the pigment protein) formed from the dried Korean purple lavers was determined by in vitro digestion. Results suggest that the apoprotein of phycoerythrin is readily digested to release the phycoerythrobilin compound during the gastrointestinal digestion process of mammals. The peroxy radical scavenging capacity was 2.7-fold greater in the phycoerythrobilin compound than in the purple laver extracts. The various therapeutic activities of phycoerythrin appear to be associated with the phycoerythrobilin compound released during mammalian gastrointestinal digestion.
This study characterized the intensive suppressive effects of α-lipoic acid (LA) and cinnamaldehyde (CA) on excessive osteoclastogenesis, specifically in the suppression of the nuclear factor of activated T cell 1 (NFATc1) expression, which acts a master transcriptional regulator of osteoclastogenesis. We confirmed that LA inhibited NFATc1 expression in the receptor activator of nuclear factor-κB ligand-stimulated RAW264.7 cells at concentrations of 50-100 μmol/L and that LA inhibited mature osteoclast formation. To enhance the effects of LA, we assessed the effects of LA when combined with CA. We found that a formulation containing 50 μmol/L LA and 5 μmol/L CA significantly suppressed both NFATc1 expression and mature osteoclast formation, in contrast to significant inhibition with 100 μmol/L LA or 10 μmol/L CA alone. Our results suggest that concomitant use of LA with CA may have therapeutic application for multiple bone disorders.