Freeze-thaw infusion (FI) is a new technique for rapid impregnation of enzymes into food materials. Volume expansion has been observed when freeze-thawed potatoes were exposed to vacuum. Therefore, the effects of freezing treatment on volume expansion and enzyme impregnation were investigated. According to the progress in freezing, the volume expansion ratio increased to over 20%, and enzyme impregnation efficiency was also increased. A distinctive correlation was found between the volume expansion ratio and enzyme impregnation efficiency. During volume expansion, the air expanded in the materials, thereby pushing out the inner liquid from the materials. Thus, enzyme impregnation by FI appears to result from rapid influx of the enzyme solution into the expanding space formed in the materials.
The impact of emulsifiers on the microencapsulation of d-limonene was investigated for the wall materials gum arabic (GA) or maltodextrin (MD) and their blend. The emulsifiers used were sucrose ester (SE), polyglycerol ester (PGE), and sugar beet pectin (SBP). SBP presented good emulsification ability and higher retention of d-limonene with various types of wall materials. On the other hand, SE was not recommended because of its unstable emulsion, resulted in very low flavor retention. For PGE, the flavor retention was strongly dependent on the type of wall material. Regarding to the physicochemical properties of spray-dried powder, the combination of GA and PGE produced a stable emulsion and had high flavor retention with low surface oil, while the MD and SE combination was not recommended because of unstable emulsion and almost no flavor retention.
This study evaluated the effect of modified atmosphere packaging on shelf-life extension of ready-to-serve pizza stored at 7±1°C using microbiological and sensory analysis. The gaseous atmospheres (atm) used were: atm 1: air (control); atm 2: 100% CO2, atm 3: 100% N2 and atm 4: 50%CO2/50%N2. Total plate count, yeasts/molds, coliforms, lactic acid bacteria, psychrotrophs and anaerobic spore formers were monitored. Sampling was carried out at predetermined time intervals namely 0, 15, 30, 45 and 60 days. Results of the present work show that the limit of sensory acceptability was only reached for the aerobically stored samples somewhat before days 15 of storage. However, a significant shelf life increase of 45 days (300% increase) was achieved under modified atmospheres for baked pizza samples. From the present study it can be concluded that amongst four atmospheres examined, atm 2 (100% CO2) was best, followed by atm 4 > atm 3 > atm 1 respectively, in descending order.
Hot air assisted infrared (IR) drying of potato and carrot is carried out and product quality is compared with hot air dried samples. The synergistic effect of hot air and IR during combined mode (hot air assisted IR) drying reduced the processing time by nearly 48% as compared to hot air drying alone, besides improving the quality of products. Higher rehydration ratio and lower browning index values are observed for combined mode dried products. Photomicrographs of dehydrated carrot and potato showed superiority of product structure for combined mode dried products. The IR dried carrot had higher (by 17%) retention of carotenoid than hot air dried sample. The processing conditions such as velocity and temperature of air affected the drying characteristics during combined mode drying. Higher values of effective diffusivity of water are observed with combined mode drying.
Effect of low-pressure carbonation (LPC) on heat inactivation of yeast and bacterial vegetative cells was investigated. Microbial cell suspensions were carbonated at 0.6 MPa and 12°C for 15 min and subsequently heated for 1 min at temperatures ranging from 50°C to 70°C at 1 MPa. As a control experiment, suspensions were heat treated for 1 min under atmospheric pressure without LPC. The heat inactivation effect on yeast was not significantly changed by LPC; however, the heat inactivation efficiency on several bacteria was enhanced. The promoted inactivation was also observed for heat treatment under atmospheric pressure after LPC. The enhanced inactivation was not notable by heat treatment followed by LPC. The results suggest enhanced heat inactivation against bacteria under LPC, and the increased heat inactivation of bacteria may be due to LPC-mediated sensitization to heat.
The objective of this work was to quantify the potential anticancer flavonoids (quercetin, kaempferol, isorhamnetin, apigenin and luteolin) by a rapid, reliable and accurate reverse phase high performance liquid chromatography (RP-HPLC) among 100 edible vegetables and fruits commonly consumed in Harbin city, China. The predominant flavonoids found in the largest abundance in all of the analyzed foods were kaempferol, followed by luteolin and quercetin. The maximum content of quercetin, kaempferol, isorhamnetin, apigenin, luteolin and total flavonoids in foods amounted to 379.7±19.7mg kg-1, 482.0±21.0mg kg-1, 333.6±14.4mg kg-1, 139.3±5.2mg kg-1, 179.5±10.6mg kg-1 and 853.0mg kg-1 fresh weight (FW), respectively. Potherb mustard, lettuce (red), toona leaf, celery leaf, garlic, garlic stalk, apple, date, ginger (with peel) and radish leaf (red root, small) were major food sources of flavonols and flavones. This study contribute to the establishment of China's flavonoid database and provide a basis for the assessment of the daily flavonoid intake.
Nucleotide sequence and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of the 3’-portion of the mitochondrial 16S RNA gene (rDNA) coding sequence was used to authenticate flying fish paste in ago-noyaki. Flying fish paste in ago-noyaki samples was quantified using image analysis of the PCR-RFLP profile. PCR products from standard ago-noyaki samples were digested with AfaI and MunI restriction endonucleases and their electrophoresis patterns were analyzed to produce standard equations for digestion: AfaI digestion: y = 0.0084x + 0.0757, R2 = 0.977 and MunI digestion: y = 0.0091x + 0.0153, R2 = 0.974. This method was then applied to analyze five and two commercially available ago-noyaki and noyaki products, respectively. The results confirmed proper E-mark labeling of ago-noyaki.
Endogenous tocopherols in extracted lipids from four cultivars of broad beans (Vicia faba) were determined by high-performance liquid chromatography. The molecular species and fatty acid (FA) distribution of triacylglycerols (TAG) isolated from their total lipids were analyzed by a combination of AgNO3 thin-layer chromatography (AgNO3-TLC) and gas chromatography (GC), and then examined in relation to the tocopherol distribution. γ-Tocopherol was present in the highest concentration (51.2-55.6 mg/kg beans), followed by α-tocopherol (15.2-16.3 mg/kg beans) and δ-tocopherol in small amounts (1.2-1.5 mg/kg beans). Fourteen TAG molecular species were identified and quantified by successive applications of AgNO3-TLC and GC. Oleodilinolein (18.9-21.8%) and trilinolein (21.0-23.9%) were the main components; the other species were found in minor quantities (less than ca. 10.0%). These results suggest that the tocopherol content, FA distribution and TAG molecular species in broad beans are not dependent on the cultivation areas during the growing season.
Polyamines, putrescine, spermidine and spermine, are important constituents of all mammalian cells and are essentially involved in a variety of regulatory step during normal and malignant cell proliferation. Okara and soymilk fermented with Lactobacillus were combined to form soy yogurt, which is rich in polyamine content. We investigated the effect of soy yogurt on polyamine levels in intestines and blood of rats. The ingestion of soy yogurt induced the increase of mucosal polyamine level in small intestine. Although the polyamine level in cecum was increased by the ingestion of soy yogurt, the polyamine levels in large intestine and blood were not increased. It was found that the ingestion of polyamine-rich soy yogurt could affect the polyamine level in only small intestinal mucosa. The large intestine seems to regulate the polyamine level to prevent own cells from hyperproliferation. It was assumed that blood kept polyamine level constant in spite of the level changes in intestines.
Novel real-time PCR-based quantitative methods were developed for three GM maize events; MON863, NK603 and TC1507. The quantitative methods were designed to amplify an event-specific segment for MON863 and NK603, and a construct-specific segment for TC1507. We also developed an event-specific quantitative method for T25. The conversion factor (Cf), which is required for calculating the GMO amount, was determined using three types of real-time PCR equipment; the ABI PRISM 7700,7900HT and 7500. The quantitative methods were evaluated by blind testing in an interlaboratory study using the ABI PRISM 7700 and 7900HT, and in a multilaboratory trial using the ABI PRISM 7500. The trueness, precision, and limit of quantitation were determined. Although the biases expressing the trueness for MON863, TC1507, and T25 were slightly high, all the data suggested that the developed methods were suitable for identification and quantification of these GM maize events.
The effects of sweet potato-shochu distillery by-product on growth of Bifidobacterium in milk were examined to consider its potential use as a food ingredient. Addition of sweet potato-shochu distillery wastewater to 10% skimmed milk powder medium enhanced organic acid production and the numbers of Bifidobacterium lactis BB-12, while increasing its concentration. The low molecular fraction (< 1 kDa) from sweet potato-shochu distillery wastewater had a growth-stimulating effect on Bifidobacterium. The low molecular fraction was separated by gel permeation chromatography to yield the O-1 fraction, whose main component was oligosaccharides consisting of glucose, galactose and uronic acids, and the P-1 fraction whose main component was heterogeneous peptides. A combination of the O-1 and P-1 fractions significantly stimulated growth of Bifidobacterium, although the individual fractions had no effect on Bifidobacterium growth. Of the 10 Bifidobacterium species tested, the sweet potato-shochu distillation wastewater stimulated the growth of Bifidobacterium lactis BB12, Bifidobacterium longum B66, Bifidobacterum infantis JCM 1210 and Bifidobacterum adolesentis JCM 1275. The present results indicate that sweet potato-shochu distillery wastewater can be used as an enhancer of fermentation by Bifidobacterium.
A chitosan (CS)-ferulic acid (FA) salt was prepared. FA release from CS-FA and bile acid (BA) adsorption by CS-FA were investigated in vitro. CS-FA released FA into artificial gastric juice or a medium containing BA. Two functions were recognized on alginate or pectin gel beads containing CS-FA: FA release and BA adsorption. Anti-hypertensive effects of CS, FA or CS-FA on hypertensive rats were tested. In rats given a diet containing CS-FA or FA, elevation of systolic blood pressure was suppressed compared to the control diet group, but no difference in food intake or body weight was observed between groups.
The efficiency of the extract of Persian walnut leaves in stabilizing sunflower oil during oven storage test was studied. The extract of the walnut leaves was prepared with microwave assisted extraction at concentration of methanol 60%. The yield extraction was 32% and the total phenolics were found to be 3704.32±87.60 mg as gallic acid /100g dry leaves. Flavonoids as a part of phenolics were 25.1% of the total phenols (932.2÷3704.32×100=25.1%). The antioxidant activity was measured by reducing ability assay and DPPH radical scavenging assay. Reducing ability assay (EC50 0.143±0.007 mg/ml) and DPPH radical scavenging activity (EC50 0.080±0.010 mg/ml) revealed that this extract has a high antioxidant activity. Oxidative stability of sunflower oil by walnut leaves was compared with BHA and TBHQ. The results revealed that 320 ppm (0.32 mg/ml) of the Persian walnut leaves extract was comparable with 200 ppm BHA.
Mice fed either a diet containing 6% lard, fish oil or Erabu sea snake lipids for 16 weeks were intraperitoneally injected L-lactic acid or glucose (25 mg/kg) following injection of physiological saline and subjected to swimming tests at 30 min after each injection. The swimming time ratio of lactic acid to saline injections was greater in mice fed sea snake lipids than those fed lard (p < 0.01) or fish oil (p < 0.05), and significantly greater than that of glucose to saline injections only in mice fed sea snake lipids (p < 0.01) but not those fed lard or fish oil. Increased endurance by injected glucose was not observed in mice fed any of the diets. These results indicate that dietary lipid type affects the endurance of mice injected with L-lactic acid, and Erabu sea snake lipids may contain factors that regulate lactic acid metabolism effectively.
In diabetic patients, compliance to diet therapy has been an ongoing concern. We thus examined the effects of an aspartame-and acesulfame K-containing sweetener (PZ) on postprandial hyperglycemia in mild and borderline diabetics. In two sets of crossover, randomized, placebo-controlled, double-blind tests, subjects with mild or borderline diabetes were challenged with meals consisting of white rice, and two side dishes flavored with PZ (PZ meal) or sugar (Control meal); or with sweets flavored with PZ (PZ sweets) or sugar (Control sweets). The use of PZ (PZ meal and PZ sweets) significantly reduced postprandial levels, particularly at 1 h, of blood glucose and insulin when compared to sugar (Control meal and Control sweets). The results demonstrated that PZ as a sugar substitute enabled the suppression of postprandial hyperglycemia in mild or borderline diabetics without compromising palatability, sweetness or patient QOL.
Total polyphenol content and antioxidant activities of non-edible parts (seed and peel) of eight tropical fruits were analyzed and compared with those of their edible parts. The antioxidant activity was evaluated based on the ability of the fruit extracts (seed, peel and pulp) to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radicals, and the ferrous ion-chelating capacity. Total polyphenol content in seed, peel and pulp ranged from 0.2 to 153, 5.0 to 124, and 1.0 to 12 mg/g DW, respectively. Non-edible parts of the tropical fruits were found to have significant antioxidant activities. Among them, mango seed, mango peel, starfruit peel and avocado peel showed higher antioxidant potential by the DPPH and ABTS radical scavenging assays. The DPPH and ABTS radical scavenging abilities were highly correlated with total polyphenol content. Kiwano and papaya peels showed strong ferrous ion-chelating capacity, although they did not have high polyphenol content and DPPH and ABTS radical scavenging activities.
The effects of Lactobacillus fermentum ATCC9338 on the metabolism of daidzein and on the composition of intestinal flora were assessed for adult mice. Lactobacillus fermentum ATCC9338 altered the equol production status in the in vitro incubation of daidzein with fecal flora of mice. For in vivo investigation, mice were fed an AIN-93M purified diet for 19 days followed by a 0.05% daidzein diet for 4 days in the in vivo experiment. The LD group received L. fermentum for 10 days. The control (CD) group did not receive lactic acid bacteria. In analysis of plasma isoflavonoids, plasma equol concentration tended to be high in the LD groups. However, no significant differences in plasma daidzein and equol concentrations were observed between the LD and CD groups. In analysis of the composition of intestinal flora, the occupation ratio of Lactobacillales was significantly higher in the LD group. We demonstrated that Lactobacillus fermentum ATCC9338 could affect the intestinal flora and in vitro fecal equol production in mice.
Gynura bicolor DC. is a traditional vegetable in Japan and its leaves are characterized by the fact that their adaxial and abaxial sides are green and reddish purple, respectively. Two novel poly-acylated anthocyanins (bicolnin and bicolmalonin) and a known one (rubrocinerarin) were isolated from the leaves of G. bicolor as major anthocyanins. These anthocyanins were identified to be cyanidin 3-O-[β-D-glucopyranoside]-7-O-[6-O-(E)-(4-O-(6-O-(E)-caffeoyl-β-D-glucopyranosyl)-caffeoyl)-β-D-glucopyranoside]-3′-O-[6-O-(E)-caffeoyl-β-D-glucopyranoside] (bicolnin), cyanidin 3-O-[6-O-malonyl-β-D-glucopyranoside]-7-O-[6-O-(E)-(4-O-(6-O-(E)-caffeoyl-β-D-glucopyranosyl)-caffeoyl)-β-D-glucopyranoside]-3′-O-[6-O-(E)-caffeoyl-β-D-glucopyranoside] (rubrocinerarin), and cyanidin 3-O-[4, 6-di-O-malonyl-β-D-glucopyranoside]-7-O-[6-O-(E)-(4-O-(6-O-(E)-caffeoyl-β-D-glucopyranosyl)-caffeoyl)-β-D-glucopyranoside]-3′-O-[6-O-(E)-caffeoyl-β-D-glucopyranoside] (bicolmalonin) by MS and NMR analyses. These three anthocyanins exhibited higher antioxidative activities compared to cyanidin 3-glucoside as evaluated by 1, 1-diphenyl-2-picrylhydrazyl and oxygen radical absorbance capacity assays.
Theanine is a unique amino acid present in green tea. It is partly responsible for the taste of green tea and possesses various psychological effects. Theanine has a preferred taste, like umami and sweetness. Therefore, theanine may improve unpleasant tastes such as bitterness and sourness of foods. To investigate new uses of theanine, we investigated its taste-modifying effect by human sensory evaluation. A reduction in sourness was observed with theanine addition. Investigation of the mechanism of taste improvement found that sourness is relatively improved by theanine addition due to the increase in pH and the addition of the umami taste.
Extracts of Aspergillus spp., Monascus purpureus, Rhizopus microsporus, and Eurotium repens, which are filamentous fungi used in the manufacture of fermented foods including sake, shoyu, miso, shochu, tofuyo, tempeh and katsuobushi, were examined for peroxynitrite scavenging activity. Extracts of Eurotium repens, used in the molding step in the manufacture of katsuobushi, exhibited the highest activity of all the tested extracts. Peroxynitrite scavengers were isolated from Eurotium repens extract and were identified as auroglaucin, dihydroauroglaucin, isodihydroauroglaucin, tetrahydroauroglaucin and flavoglaucin. Tetrahydroauroglaucin exhibited the highest peroxynitrite scavenging activity of the isolated compounds, and showed suppressive effects on the expression of blood adhesion molecules, intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1), in human umbilical vein endothelial cells (HUVECs) after induction with tumor necrosis factor (TNF-α).
Some studies support the effectiveness in controlling nematodes in fishes for human consumption by freezing at –20°C and by cooking at 74°C by microwave process. The aim of this work was to analyse the effect of different treatments over anisakids from Argentinean fishes. The known anisakids in fishes from Argentina belong to genera Hysterothylacium, Terranova, Anisakis, Contracaecum and Pseudoterranova, being the three latest recognised as pathogens for human. Living larvae of anisakids obtained from fishes were used for survival assessment. Some parasites were kept in NaCl (0.85%) at 4-5.5°C until death. Anisakis, Terranova, Pseudoterranova, Contracaecum and Hysterothylacium survived during 330, 75, 75, 210 and 90 days, respectively. For freezing, microwaving and salting treatments, infected fillets were exposed at –20°C until 24 hours, 1 minute at 64.05°C and 75.56°C and to salt during 24 hours, respectively. No surviving anisakids were observed neither after freezing nor salting. Anisakis sp. survived at 64.05°C.
Soymilk-like white opaque liquid was prepared from whole soybean seeds without imbibition by the nama-shibori method. The solid content of the resulting liquid (non-imbibed soymilk) increased with an increase in blender revolutions and milling time, becoming almost equivalent to that of standard soymilk (imbibed soymilk) after milling at 12,000 rpm or more for 8 min. The precipitate obtained from the non-imbibed soymilk was lower than that from imbibed soymilk after milling for 4 min; however, it was higher after milling for 8 min. The non-imbibed soymilk showed bimodal particle size distribution, differing from imbibed soymilk prepared by milling at 12,000 rpm or less, which showed a unimodal distribution. The findings suggest that non-imbibed soymilk is of slightly lower quality than imbibed soymilk prepared from imbibed soybean seeds, but overall the differences were considered minimal.
Excess intake of sucrose or fructose induces adiposity and insulin resistance syndrome, which subsequently lead to diabetes mellitus and hypertension. We evaluated the effects of Eucalyptus globulus leaf extract (ELE) on the postprandial changes in peripheral fructose concentrations during oral sucrose tolerance test in humans. When subjects (n = 18) ingested 25 g of sucrose, both fructose and glucose concentrations in peripheral blood increased transiently and peaked at 30 min after ingestion. Administration of ELE (3 g) 5 min before sucrose ingestion resulted in a significant decrease in the rise in fructose concentration, although no significant effect on glucose concentration was observed. These results suggest that, in humans, ELE ingestion reduces acute hyperfructosemia after sucrose consumption by inhibiting intestinal fructose absorption (but not the sucrase reaction).
Abstract: In order to determine the influence of prolonged exercise on sensitivity to sweet taste, we investigated the relationship between physical fatigue and palatability and/or taste intensity by performing sensory evaluation tests. The subjects hiked up a 36-km mountain trail for 12 h, and we used 100- and 300-mM sucrose solutions as test samples. The taste intensity and palatability of the sucrose solutions did not change significantly during exercise. However, a slight change in palatability was observed. In particular, the palatability of the 300-mM solution increased with an increase in the degree of physical fatigue towards the end of the exercise.
The aim of this study was to produce valuable products from potato pulp, which is a byproduct of potato starch production and contains a high concentration of starch. We used the pulp as a substrate for polygalacturonase (PG) production in solid-state fermentation by a recombinant Aspergillus oryzae strain, PGB3. To generate PGB3, we constructed the PG gene (pgaB) overexpression vector pGBmR, and used that vector to transform the A. oryzae strain, RIB40. PGB3 carries a PG gene under control of the Taka-amylase gene promoter. When cultured in potato pulp solid medium, PGB3 grew more rapidly and produced 4.5 times more PG than RIB40. We observed maximum production (173 U/g) of PG after 2 days of culture of PGB3 in potato pulp solid medium. This high-level PG production from potato pulp demonstrates its potential as a useful substrate in fermentation.