Differences in flavor characteristics of coffee drinks originating from different thermal sterilization processes (ultra-high temperature (UHT) and retort sterilization) were investigated. The sensory evaluation by an analytical panel revealed that the sensory characteristics of a retort-sterilized product were significantly different from those of unsterilized and UHT-sterilized products, suggesting that the sensory characteristics of the UHT-sterilized product are more similar to those of the unsterilized product. The results of gas chromatography/olfactometry analysis revealed three odorants (2-furanemethanethiol, 3-(methylthio)propanal, and 3-mercapto-3-methylbutyl formate) whose flavor dilution (FD) factors decreased in the unsterilized, UHT-sterilized, and retort sterilized products in this order and eight odorants (2-((methylthio)methyl)furan, 3-mercapto-3-methyl-1-butanol, 3-methylbutyric acid, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 4-methylphenol, and three unidentified odorants) whose FD factors increased in the unsterilized, UHT-sterilized, and retort sterilized products in this order. Changes in these odorants, which decrease or increase with an increase in the F0value (sterilization value), which serves as an indicator of heating, supported the sensory evaluation results that the retort-sterilized product is significantly dissimilar to the unsterilized and UHT-sterilized products. Electronic nose and taste-sensing measurements further supported the sensory evaluation results.
The degradation kinetics of catechin in aqueous solution in the presence of L-ascorbic acid or octanoyl L-ascorbate, which was synthesized through the immobilized-lipase-catalyzed condensation of ascorbic and octanoic acids in acetonitrile, and of various organic acids were expressed by a first-order equation. The stability of catechin was reduced by the addition of ascorbic acid or octanoyl ascorbate at a concentration of 10 mmol/L, although the rate constant, k, for degradation in the presence of ascorbic acid or octanoyl ascorbate decreased with increasing citric acid concentration. Malic, lactic and sorbic acids were also effective for decelerating the oxidative degradation by ascorbic acid and octanoyl ascorbate, but their suppressive effects on the degradation of catechin differed between the solutions containing ascorbic acid and octanoyl ascorbate. This indicates that octanoyl ascorbate acts on catechin with a different mechanism from that of ascorbic acid.
Potatoes come in many various colors of tuber peels and/or fleshes. Anthocyanin pigment is responsible for red and purple colors of colored potato varieties. We report anthocyanin determination of a red potato cultivar Kintoki-imo and other colored cultivars grown in Hokkaido, Japan, using DAD-HPLC and ESI-TOF/MS.13C-NMR and 1H-NMR analyses showed that the major Kintoki-imo anthocyanin were pelargonidin 3-(6-O-(4-O-(E)-p-coumaroyl-α-L-rhamnopyranosyl)-β-D-glucopyranoside)-5-β-D-glucopyranoside (pelanin), and pelargonidin 3-(6-O-(4-O-(E)-feruloyl-α-L-rhamnopyranosyl)-β-D-glucopyranoside)-5-β-D-glucopyranoside. The anthocyanin content per 100 g flesh tuber was 2-816 mg. The anthocyanin composition patterns of potato cultivars were classified into five types: type A contained a lot of pelanin and Pg 3-Fr.Rut-5-Glc; type B was similar to type A, except that it included purple pigments such as peonanin and Pn 3-Rut-5-Glc; type C was also close to type A, except that the peonanin content was high; type D had pelanin as the main pigment, but no peonanin; and type E had petanin as the main pigment, but no pelanin.
Multielements K, Na, Ca, Mg, Zn, Fe and Cu were estimated in 25 composite samples of sugar beet, extracted sugar beet pulp, dried sugar beet pulp, molasses, and white sugar collected during 50 days of the 2005 campaign in one beet sugar factory, and in 65 soil samples collected from the fields where beet was grown. Mean total contents of analyzed elements in sugar beet and different sugar beet based products were in the range: 18.11-37510 mg/kg dry matter (d.m.) for K, 6.54-8945 mg/kg d.m. for Na, 14.36-5220 mg/kg d.m. for Ca, 0.09-2550 mg/kg d.m. for Mg, 0.01-10.85 mg/kg d.m. for Zn, 0.42-360.4 mg/kg d.m. for Fe, and 0.07-7.09 mg/kg d.m. for Cu. Mean extractable amounts of these elements in the soils sampled in the fields where beet was cultivated were as follows: 207.6 mg/kg d.m., 60.3 mg/kg d.m., 14.4 mg/kg d.m., 404.7 mg/kg d.m., 1.44 mg/kg d.m., 9.89 mg/kg d.m. and 1.61 mg/ kg d.m., respectively. In order to get a better insight into the metal patterns of the investigated samples, three statistical techniques were used. Principal component analysis (PCA) and cluster analysis (CA) approved to be more powerful than Spearman's test in revealing the specific correlations among the variables (i.e. metal contents). PCA and CA pointed out the specific metal pattern of molasses on one hand and of sugar beet, extracted and dried sugar beet pulps on the other. Moreover, the chemometrical approach pointed out that main components that classified the metal behavior in the examined samples were the ones correlated with Na and K on one hand, and on the other hand with the remaining metals.
We have been investigating the immunopotentiating activity (biological response modifier (BRM)-like activity) of different fruits and attempting to clarify whether the level of this activity is consistent with the content of vitamins or other major nutrients in these fruit. In this study, we focused on kiwi fruit, which contains vitamin C and polyphenol and has a high BRM-like activity and anti-oxidant activity. We evaluated differences in this activity according to the strain and maturity. To determine the anti-oxidant effects of oral kiwi fruit intraperitoneal administration, mice were administered kiwi fruit juice. It was found that the BRM-like activity of green kiwi fruit was slightly higher than that of gold kiwi fruit, but the differences were slight between strains and maturity level. After oral administration of kiwi fruit juice to mice, cytokine production increased. The evaluation of urinary oxidative stress markers revealed marked inhibition of in vivo oxidative stress following oral kiwi fruit administration. These results suggest that kiwi fruit intake has beneficial effects on the body, increasing cytokine production and exerting anti-oxidant effects.
Ganoderma sinense were available in the form of log-cultivated and sawdust-cultivated fruit bodies, solid-fermentation products and liquid-fermentation mycelia. From these four forms, water extracted polysaccharides were prepared and their antioxidant properties were investigated. Among the four forms of G. sinense, mycelia showed the largest extraction polysaccharide content (14.68%). Compared with ascorbic acid, the extracted polysaccharides from four forms exhibited stronger capability of inhibiting lipid oxidation in a linoleic acid system and more efficient radical-scavenging activity on 2, 2-diphenyl-1-picrylhydrazyl (DPPH).The extracted polysaccharides from four forms could scavenge hydroxyl radicals and showed good reducing powers evidenced by their low EC50 values (< 13 mg/mL). However, the scavenging ability on superoxide-anion radicals was not found in our investigation. All extracted polysaccharides possessed good antioxidant properties except for scavenging ability on superoxide-anion radicals and could be utilized as a new dietary supplement and functional food or tea.
Chemical and physical studies were conducted to investigate the potential use of emu (Dromaius novaehollandiae) eggs in the food industry. The proximate composition of the yolk and albumen of emu eggs was determined for the first time and revealed to be slightly different from hen eggs in lipid and water content. Though the increase in volume of emu whole eggs by whipping was smaller than that of hen eggs, the whip was more stable. However, freezing dramatically decreased the whipping capacity of emu whole eggs. The most significant difference found was when emu eggs were subjected to heat-induced coagulation; both the albumen and yolk of emu eggs had a softer texture compared to hen eggs. These characteristics are promising for processed food production, especially for softening products. A cake, for example, made with emu eggs was revealed to be softer than a cake made with hen eggs.
Alcoholic beverages made from purple rice grains contained 11.0 to 11.5% (v/v) ethanol and a higher amount of phenolic compounds. Alcoholic beverages made from purple rice grain were brilliant red, similar to the color of red wine, especially those made from uncooked purple rice. The amount of anthocyanin in beverages made from cooked and uncooked rice was 36 and 88 μg/mL, respectively. The DPPH radical scavenging activity of the alcoholic beverages made from purple rice was much higher than that of beverages made from ordinary brown and polished rice. The lipid peroxidation inhibitory activity of the alcoholic beverage made from uncooked purple rice was also the strongest. In the course of this study, we produced purple rice wine that was red and exhibited antioxidative activity.
Antioxidant activity, antihypertensive activity and allergenicity of quinoa and amaranth were investigated and compared with those of seven cereals: buckwheat, barley, wheat, rice, foxtail millet, Japanese millet and millet. The radical scavenging activities of quinoa and amaranth were 42.3 and 22.6 mg gallic acid equivalent/g, respectively; thus, the pseudocereals have stronger radical scavenging ability than cereals. On the other hand, the antioxidant ability against linoleic acid was not very strong. Quinoa exhibited high angiotensin I converting enzyme (ACE) inhibition activity, which was equal to that of buckwheat. The ACE inhibition activity of amaranth was lower than that of quinoa, but higher than that of rice and wheat. Quinoa and amaranth did not show a positive reaction band against wheat protein antibodies.
Antioxidant capacities (AOCs) and total phenolic (TP) content of 11 species of Polygonaceae from Mongolia were evaluated using diphenyl picrylhydrazyl radical (DPPH), oxygen radical antioxidant capacity (ORAC) and Folin-Ciocalteu (F-C) assays. Additionally, total quercetin content was determined by high performance liquid chromatography (HPLC) after acid hydrolysis. These plant extracts showed high AOCs using both DPPH (111.9-950.5 μmol Trolox equivalent (TE) /g.dw) and ORAC assays (770.7-2307.9 μmol TE/g.dw), and high TP contents (20.84-113.86 mg Gallic acid equivalent (GAE)/g.dw). AOCs were positively correlated with TP content (DPPH: r = 0.98; ORAC: r = 0.83). Moderate correlations were observed between AOCs and total quercetin content (DPPH: r = 0.58; ORAC: r = 0.51). These results suggest that quercetin glycosides may be one of the important contributors to AOCs of Mongolian Polygonaceae species.
To investigate the effect of a deoxygenating agent (deoxy) and a nitrogen-atmosphere package (nitro) on the quality, especially flavor, of Koshihikari stored at 30°C for 12 months, volatile compounds of the cooked stored rice were analyzed by gas chromatography-olfactometry (GC-O), GC-mass spectrometry and sensory evaluation. Sensory evaluation revealed that the deoxy-rice was very similar in quality to non-stored rice (fresh-rice), although the non-treated stored rice (control-rice) and nitro-rice had a stale flavor and undesirable taste. Furthermore, GC-O analysis indicated that the number of volatile compounds in the deoxy- and fresh-rice was significantly less than in the control- and nitro-rice. Therefore, it was suggested that the technique of storing harvested rice with a deoxygenating agent could maintain the flavor of harvested rice at room temperature.
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