Formation,characterization, and glucose response in mice to rice starch with low digestibility produced by citric acid treatment

The optimum conditions for producing rice starch enriched in slowly digestible and resistant fractions by citric acid treatment determined by a response surface methodology (RSM) model equation, were: reaction temperature, 128.4 °C; reaction time, 13.8 h; and citric acid, 2.62 mmol/20 g starch. The slowly digestible and resistant starch fractions of the optimally acid-treated rice starch totalled 54.1%, which was 28.1% higher than the control. The slowly digestible and resistant fractions of the acid-treated rice starch did not differ significantly after heat treatment, whereas those of raw rice starch decreased by 49.6–63.8%, depending on the type of heat treatment (cooking at 100 °C or autoclaving). The slowly digestible fraction of the acid-treated starch increased by 8.9–14.2%. After autoclaving, the glucose response of the acid-treated starch was lower than untreated starch, but similar to that of Novelose 330. After heat treatment, the rate of blood glucose decrease was slower for the acid-treated starch than for Novelose 330. Compared to raw rice starch, the acid-treated starch exhibited increases in apparent amylose content, blue value, dextrose equivalent, cold-water solubility and transmittance, and decreases in wavelength of maximum absorbance, viscosity, and gel-forming ability.     

Short-Term Ion Uptake by Phalaenopsis as Affected by Concentration of the Solution

ABSTRACT

Nutrient uptake over a 72 h culture period by clonal micropropagules of Phalaenopsis Tanigawa × Yukimai Dream ‘KS 370’ and ‘KS 352’ were surveyed by Ichihashi's (1997) Ichihashi, S. 1997. “Orchid production and research in Japan”. In Orchid Biology, Reviews and Prospectives, Edited by: Arditti, J. and Pridgeon, A. M. 171–212. Dordrecht, , The Netherlands: Kluwer.  [Google Scholar] nutrient solution at the original ion strength and its half and quarter. Uptake of major anions [nitrate (NO₃ ^?), phosphate (H₂PO₄ ^?), and sulfate (SO₄ ^2?)] and cations [ammonium (NH₄ ⁺), potassium (K⁺), calcium (Ca²⁺), and magnesium (Mg²⁺)] measured with an ion chromatograph increased as the ionic strength of the solution increased in both cultivars. The final uptake rates of nutrients were 0.8, 2.0, 2.1, 1.2, 3.0, 2.0, and 1.6 me L^?1, respectively in the order of ions mentioned above. The ratios of the uptake rates between cations (mono or bivalent) were almost in proportion to the ratio of their initial ion strength. Therefore, no antagonistical absorption of cations was found in that ion strength. Leaf content of phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and copper (Cu) increased as the ionic strength of the solution increased, but concentrations of iron (Fe), manganese (Mn), and zinc (Zn) were not affected significantly. Nitrogen (N) content of leaves in ‘KS 370’ after 72 h culture increased significantly by increasing the ionic strength of the solution. Root concentrations of P, K, Ca, Mg, and Fe increased as the ionic strength of the solution increased in both cultivars. The N concentrations of roots in either ‘KS 370’ or ‘KS 352’ had positive correlations with an increasing ionic strength of the solution, although they were constantly greater in ‘KS 370’ than in ‘KS 352’. The greatest fresh weight was obtained when the plants were cultured in a half strength solution. Whereas dry weight decreased in all treatments as the ionic strength of the solution decreased. These findings show that increased ion absorption affected plant dry weight. The obtained findings provide fundamental information for the closed hydroponic system of phalaenopsis cultivation.     

Quantification and Characterization of Food Processing Wastes/Residues

A survey was undertaken to determine the wastes/residues generated by the food processing industry in the state of Iowa by sending a questionnaire to food processors with more than ten employees. Food processors were asked to provide a company profile, information about food waste/residue generated, and information about current disposal methods. Samples of wastes/residues were obtained from food processors willing to provide them, and proximate analysis was done. The overall response rate was 82.2 percent or 365 respondents out of 444 questioned. Companies under different category of standard industrial code (SIC) could produce similar wastes/residues that were classified in the same waste/residue streams. Within the meat and seafood category, the majority (87.7 percent) of the wastes/residues were generated by SIC codes 2077 (animal, marine fats and oils) and 2015 (poultry slaughtering, dressing, and processing). Among the waste management practices reported, excluding “other,” land application accounted for 14.0 percent of the waste stream, followed by rendering with 11.4 percent, landfill with 6.7 percent, sewage on-site with 5.0 percent and animal feed production off-site with 4.3 percent. Other waste management practices (combinations of major practices or others not clearly defined) account for 55.1 percent of the allocation of the waste stream.     

Re-examination of the standard cultivation practices of rice in response to climate change in Korea

The impact of climate change has been simulated or estimated to bring about yield decline and quality deterioration of rice in Korea, a temperate country. To cope with these negative impacts, here we propose likely changes in the standard cultivation practices of rice in consideration of the current information on the progress/prediction of climate change and related physiological aspects of rice. Shifting grain-filling period could be a promising choice to optimize temperature for rice grain-filling, a crucial growth stage to productivity, hence providing rice plants with sufficient duration and solar radiation for the period. This choice, however, shortens days to flowering by the additive combined effects of high temperature by delayed transplanting, temperature rise itself by climate change, and accelerated phase change of rice by high temperature and short day-length. These combined effects may delay the time of transplanting in a great extent, hence reducing biomass accumulation of rice before flowering. In these conditions, recovering decreased biomass production is the key concern for rice productivity. This includes raising healthy seedlings by omitting the covering process, dense planting, and nutrient management to enhance plant’s uptake activity. Current standard water management, especially mid-term drainage and intermittent irrigation, would have more importance in the future since they mitigate methane emission from the paddy. Field monitoring for weeds and pests would be an important first step to identify newly developing or thriving species for establishing subsequent controlling strategies. Earlier weed control should be emphasized through adjusting time of herbicide application.     

Saponin polymorphism in the Korean wild soybean (Glycine soja Sieb. and Zucc.)

Seed saponin composition of 3025 wild soybean (Glycine soja Sieb. and Zucc.) accessions collected from nine regions of Korea was analysed by thin‐layer chromatography to determine its polymorphic variation and geographical distribution and find mutants in saponin components. The saponin composition of seed hypocotyls was primarily divided into seven phenotypes, designated as Aa, Ab, AaBc, AbBc, Aa+α, AaBc+α and AbBc+α. The predominant phenotypes were AaBc (55%), Aa (33%), AaBc+α (7.5%) and Aa+α (3.3%). The frequencies of Ab, AbBc and AbBc+α were very low (0.3‐0.5%). Codominant alleles Sg‐1^a and Sg‐1^b and dominant allele Sg‐4 occupied 98.6, 1.1 and 63.3%, respectively. Alleles Sg‐3 and Sg‐5 were found to be dominant in all the analysed accessions except the mutants. Three accessions were discovered as mutants via LC‐PDA/MS/MS. The accession CWS0115 did not produce saponin Aa and Ax, CWS2133 did not produce saponin Aa and Ab and CWS5095 did not produce any group A saponins. These newly determined mutants might be utilized in producing a new soybean variety with good taste as well as in biosynthetic studies.     

Highly hydrophobic nanofibrous surfaces genearated by poly(vinylidene fluoride)

Lotus-leaf-like nanofibrous surfaces were prepared by electrospinning hydrophobic poly(vinylidene fluoride) (PVDF) from a mixed solvent of N,N-dimethylformamide (DMF) and acetone. PVDF fibrous mats with a bead-on-string morphology were generated because the nonpolar acetone decresed the viscosity of the PVDF solution and promoted the evaporation of the solution during electrospinning process. The morphology of the nanofibirous surface was examined by scanning electron microscopy. Micron-sized beads were introduced to the electrospun PVDF mats, resulting in enhanced hydrophobicity of the electrospun mats. The addition of a small amount (0.05 vol%) of acetic acid to the polymer solution effectively improved the bead-on-string morphology of the electrospun mats, and led to a higher water contact angle (WCA). The electrospun PVDF fibrous mat showed a maximum WCA of 148.5° due to the appropriate surface roughness.     

Prediction and interpretation of hydraulic permeability for nonwoven fabrics considering hypothetical 2-D layer

The permeability defined by Darcy’s law indicates the degree of ability that a fluid can flow through nonwoven media under a differential pressure in laminar flow. The permeability generally indicates the specific permeability or absolute permeability. On the other hand, if the fluid is water, the permeability indicates the hydraulic conductivity or permeability coefficient. The permeability is one of the important properties for nonwoven media and a prediction of the permeability acts as a bridge between the manufacturing technology and performance requirements. Because capillary channel theory aims to make the flow of fluid easier and more understandable, many models are based on capillary channel theory. On the other hand, the theory has a limitation in that it is unsuitable for high porosity media. In this study, a very thin downstream layer, which was suggested by Lifshutz [9], was introduced to derive a prediction model of hydraulic permeability. Needle-punched and spunbonded nonwoven fabrics with various basis weights were used in the cross-plain water permeability test. From this ‘thin layer’ model, reasonable agreement between the predicted and experimental results was obtained.     

Fragmentation of Waxy Rice Starch Granules by Enzymatic Hydrolysis

Small starch particles were prepared by hydrolyzing waxy rice starch using α‐amylase and then ultrasonicating in ethanol. Differential scanning calorimetry (DSC) revealed that a mild hydrolysis for 3 hr increased the melting enthalpy of the starch, which might indicate that the hydrolysis was selective in the amorphous regions. Later, at 6–24 hr, the hydrolysis rate was reduced, with gradual decreases in DSC melting enthalpy, indicating that the crystalline regions were eroded simultaneously. X‐ray diffraction patterns revealed the same trend as the DSC results. Average diameter of starch granules or particles was decreased dramatically in both volume‐ and number‐based measurements (5.94→1.64 μm, and 0.45→0.18 μm, respectively) during the early stage of rapid hydrolysis (up to 3 hr). Native waxy rice starch exhibited a particle size distribution with a major peak at 5.6 μm. After hydrolysis for 3 hr, the volume distribution of starch granules changed to two major size peaks at 0.5 and 3.6 μm. The starch fragment of 0.5 μm was assumed to consist of crystalline blocklets. With excessive hydrolysis (24 hr) or ultrasonication, however, starch particle diameter was increased, indicating that the particles might be swollen or aggregated into clusters.     

Osmoregulatory ability and stress responses during freshwater adaptation of black porgy (Acanthopagrus schlegeli) treated with exogenous prolactin

The effects of ovine prolactin (oPRL) on osmoregulatory ability (electrolyte balance, plasma osmolality and activity of gill chloride cells and gill Na⁺/K⁺‐ATPase) and stress responses (plasma cortisol, glucose, aspartate aminotransferase: AST and alanine aminotransferase: ALT) were investigated in black porgy transferred to freshwater (FW). Fish in seawater (SW) were injected twice at a 24 h interval with oPRL (at 1, 3, or 5 μg g^–1 body weight) or vehicle (0.9% NaCl) and then transferred to FW. They were sampled 3 days after the transfer. With oPRL at 5 μg g^–1, levels of plasma Na⁺ and Cl^? and osmolality were significantly higher than in saline‐treated fish, whereas gill CCs number and Na⁺/K⁺‐ATPase activity were lower. Also, the 5 μg g^–1oPRL treatment led to significantly lower plasma cortisol levels than did saline treatment. However, there were no significant differences in plasma AST and ALT between groups. These results support the positive osmoregulatory role of PRL in black porgy during FW adaptation.