Glucose is used as an energy source in most organisms, from bacteria to humans. The facilitative glucose transport systems are ubiquitous in living cells and are responsible for the movement of glucose across the cell membrane. Since transport of glucose is essential for life and is carefully regulated, glucose uptake assays are performed in a vast number of biological studies. Previously, the method of choice employed radio-labeled hexose derivatives, but now researchers can select several non-radioisotopic methods to evaluate glucose uptake. In the present review, we introduce the various methodologies used to conduct glucose uptake assays and evaluate their application.
By-products of Orange (Citrus sinensis (L.) Osbeck) juice processing are that are rich in flavonoids. This study investigated changes in total phenolic and flavonoid concentrations and antioxidative activities of orange peel methanol extracts in response to various heating times (0, 30, 60, 90, 120, 150 and 180 min) at 100°C, after a 48-h drying treatment at 50°C. The total phenolic and flavonoid contents of the 0 min heat-treated peel methanol extract (T0) were 21.65 ± 1.42 GAE mg/g, and 4.77 ± 0.01 CE mg/g, respectively. The phenolic content increased as the heating time increased, as shown by the 180 min heating treatment (T180; 27.99 ± 0.38 GAE mg/g), but changes in total flavonoid content were not significant between different heating time treatments. Increasing the heating time of orange peels could improve the antioxidative activities (1,1-Diphenyl-2-picrylhydrazyl radical scavenging effect, ABTS+· scavenging effect and reducing power) of methanol peel extracts, but there were no significant difference between the β-carotene bleaching inhibition of the different heating time extracts, excluding T30. According to correlation analysis, one possible factor of increasing antioxidative activities was the production of phenolic compounds during heating treatment.
Colour, texture (hardness and fracturability) and microstructure were compared in peanuts (Arachis hypogaea) that were roasted by superheated steam oven (A-1500V, SHARP) in superheated steam mode and convection mode (normal without steam) operated at three different temperatures (250°C, 200°C and 150°C) for durations between 5 to 45 min. Different temperatures required different heating times for the roasting to be completed. Colour was expressed in terms of brightness (L*), whiteness (WI), redness (a*) and yellowness (b*) for each combination of roasting temperature and time. We found that L* and WI values decreased with increased roasting time and temperature, while a* and b* values increased when roasting time was extended. All the colour values (L*, a*, b*, WI) were more affected during superheated steam roasting than during convection roasting. Temperature increase by superheated steam was faster than in convection; however the roasting procedure was completed within a shorter time in convention. Hardness and fracturability, which represent the texture quality of peanuts after roasting, decreased with roasting time. This trend was, however, not statistically significant (p > 0.05). More oil was viewed to be extracted during superheated steam roasting than during convection roasting in scanning electron micrograph.
The purpose of this study was to clarify airflow in packaging containers with ventilation for fruit and vegetables and propose a favorable package shape for efficient ventilation. Here we investigated the influences of differences in the inlet air velocity through the ventilation port and diameter of the port on the air velocity distribution in a 1-layer packaging system container for strawberries employing computational fluid dynamic (CFD) analysis. It was suggested that the air velocity increases with a rise in the inlet air velocity or ventilation port size, i.e., the volumetric flow rate, but there were regions in which airflow could be hardly generated under any inlet condition. The results suggest that elimination of these regions is a key factor in developing a packaging container with a favorable shape for ventilation efficiency.
To better handle variable temperature regimes in produce distribution, a master packaging system consisting of a double-layered gas barrier has been applied to fresh king oyster mushrooms. A secondary master package wrapping four individual 350 g packages was designed to be dismantled when moved to the 10°C retail display from the presale storage at 0°C. Different numbers of microperforations (10, 15 and 20) were tested on the inner individual packages as a control variable to create and maintain beneficial modified atmospheric conditions around the mushrooms. The microperforated individual packages could all attain an effective range of modified atmosphere during the two stages of storage at 0 and 10°C while the package with 15 microperforations best reached the desired modified atmosphere of 1 − 3% O2 and 10 − 15% CO2. The individual packages in the master packaging system had better preservation in quality attributes, such as weight loss, mold/yeast count and texture retention, compared with the control perforated packages of a normal atmosphere.
Gluten-free bread baked with yam flour (Jinennjyo; Dioscorea japonica), wheat starch, sugar (sucrose), compressed yeast, and water showed similar bread making properties, such as bread height (mm) and specific volume (cm3/g), to that of wheat bread. Yam flour was dialyzed against water and separated into nondialyzable (high-molecular-weight (HMW)) fraction and dialyzable (low-molecular-weight (LMW)) fractions. The fractions were dried and used separately in bread making in the same manner. The results indicated that the HMW or LMW fractions showed poor bread making properties when used individually, whereas bread baked with a mixture of the HMW and LMW fractions exhibited good bread making properties. Next, the LMW fraction was separated into peptide and sugar subfraction by paper chromatography. Addition of the peptide subfraction to the HMW fraction resulted in better bread making properties than addition of the sugar subfraction.
Astaxanthin is a natural xanthophyll abundantly found in Haematococcus pluvaris with strong antioxidant property and it is found to be useful in many biological functions. Recent scientific findings indicate that astaxanthin shows low oral bioavailability due to its lipophilicity. However, the influence of emulsion droplet size on astaxanthin bioavailability is yet to be studied. This study was performed to investigate the effects of emulsion droplet size reduction on the bioavailability of astaxanthin emulsion through oral administration. In vivo study was carried out to evaluate the rate and extent of absorption of macro and nanosized emulsion an oil solution formulation. The nanosized emulsion shows increased Cmax and AUC0-∞ and decreased Tmax values with a reduction of the emulsion globule size. The AUC0-∞ of nanosized compared to macrosized emulsion and oil solution was increased by 110% − 140% and 140% − 200% respectively.
Bioprocesses like germination and fermentation tends to improve the nutritional quality of cereal based foods. It has been demonstrated that the bioprocesses reduce the phytate contents and improves the bioavailability of minerals in cereals. The present study explains the effect of germination and fermentation on the mineral availability, phenolic and phytic acid contents of some of the Pakistani wheat cultivars. Three wheat cultivars (Fsd-08, Lasani-08 and Shafaq-06) were germinated, fermented or germinated plus fermented. Phytic acid contents were found to be maximum in control i.e without any treatment (1.27%, 1.44%, 1.47%) followed by germinated flour (1.10%, 1.24%, 1.28%) and minimum was found in germinated and fermented flour (1.02%, 1.04%, 1.02%). Similarly, polyphenol content decreased significantly due to processing techniques (Control: 0.74%, 0.67%, 0.64%; germinated flour: 070% 0.63%, 0.62%; germinated and fermented flour: 0.67%, 0.60%, 0.57%). Total and HCl extractable minerals (Ca, Mn, Zn, Cu, Fe, Na and K) improved as an effect of bioprocesses like germination and fermentation. There was a good relation observed between reduction in non-nutritional compounds and increase in mineral extractability by germination and fermentation treatments.
The apparent viscosity (ηaH) of aqueous macromolecule solutions with and without sucrose was measured. In addition, the apparent reduced viscosity (ηared), the intrinsic viscosity ([η]), the dependence of apparent specific viscosity (ηasp) on water activity (Aw), and the activation energy of apparent viscosity (Ea) were analyzed to compare the inter-macromolecular interactions among six aqueous macromolecule solutions at a fixed concentration. The macromolecule solutions tested were 2% polyethylene glycol (PEG35000, MW = 35 kDa), dextran (DexT40, MW = 40 kDa), apple pectin, citrus pectin, sodium alginate, and 0.5% xanthan. Based on the dependence of ηaspand Eaon Aw, as well as the difference in ηa red and its relationship with [η], the apparent viscosity behavior of the macromolecule solutions tested was classified into three groups. In Group A which consists of PEG35000 and DexT40, the macromolecules are diluted enough such that intermolecular interactions are very weak. In Group B which consists of pectins and alginate, the macromolecules are in contact with one another such that inter-macromolecular interactions become stronger and the addition of sucrose affects the macromolecular interactions. In Group C which consists of xanthan, macromolecular chains are physically entangled with partial aggregations such that inter-macromolecular interactions are very strong, but the addition of sucrose has almost no effect on the interaction.
Tartary buckwheat is targeted as a healthy food because its food contains large amounts of polyphenols such as rutin and quercetin, especially. Quercetin is a substrate for POX activity, which sometimes plays important roles for quality changes in foods. Therefore, to obtain a basic understanding of the roles of Tartary buckwheat POX, we purified and characterized POX in Tartary buckwheat seeds. POX was purified (76.7 fold, final yield 4.77%). Tartary buckwheat seeds bore a single major POX (MW 46.8 kDa). Kinetic studies revealed that POX had lower Km values for quercetin (0.32 mM) and o-dianisidine (0.316 mM) than for ABTS (1.86 mM) and guaiacol (0.958 mM). POX showed greater activity under acidic pH conditions. Optimum pH of POX was the same pH as Tartary buckwheat dough. In addition, optimum temperature was around 20°C, corresponding to the temperature where dough is usually handled. Therefore, POX in Tartary buckwheat may play an important role in quality changes in food.
Propolis is a resinous substance collected by honeybees from various plant sources and whose composition depends on the area of collection. This study examined the antioxidant activity of red propolis from Shandong, China. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant activities using four assays: 2,2-diphenyl-1-picrylhydrazyl free radical-scavenging, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization, ferric ion reducing antioxidant and oxygen radical absorbance capacity assays. Red propolis from Shandong, China showed strong antioxidant activity across all assay systems used. Furthermore, the major constituents in EEP from Shandong, China were identified by HPLC analysis using photodiode array detection, and each component was quantitatively analyzed. In total, 17 compounds were identified: 9 flavonoids, 5 aromatic carboxylic acids and 3 phenolic acid esters. Red propolis from Shandong, China contains a large amount of the antioxidant compounds galangin and phenethyl caffeate (101.6 and 32.7 mg/g of EEP, respectively).
The purpose of this study was to isolate strains from traditionally fermented Yangjiang lobster sauce, those can use as potential starter culture for the pure fermentation under controlled conditions of temperature and pH. The result was found that seven strains isolated by PDA medium, and then they were evaluated for production of protease on skim milk agar. Especially three strains, which Rhizopus oryzae, Aspergillus oryzae and Pichia burtonii exhibited high proteolytic activities with area of clear zone. Seven strains identified by morphological and phylogenetic analysis, which studies based on the 16S, 18S ribosomal gene sequences and 26S rDNA D1 / D2 sequence, showed that two pathogens strains survived in traditional Yangjiang lobster sauce. The research investigated effects of pH and temperature on activity and stability of protease, effect of metal ions and NaCl on protease activity in three high proteolytic activity strains.
Beneficial effects of collagen peptide ingestion to reduce serum triacylglycerides have been reported, suggesting that the physiological conditions of adipocytes are modulated following collagen peptide ingestion. In this study, the effects of prolylhydroxyproline, a major digestive product of ingested collagen peptide in the blood, on the differentiation of mouse 3T3-L1 preadipocytes in vitro were investigated. 3T3-L1 preadipocytes were induced to differentiate to adipocytes and treated with prolylhydroxyproline, or with an amino acid mixture of proline and hydroxyproline as a control. The amount of lipid was not affected by these treatments. However, the size of the lipid droplet was significantly smaller when treated with prolylhydroxyproline compared to the amino acid mixture or the non-treated control. Proton-coupled oligopeptide transporters were expressed in non-differentiated and/or differentiated 3T3-L1 cells. These results suggest that prolylhydroxyproline might modulate the morphology of lipid droplets by incorporation into adipocytes through the transporters.