scholarly journals Influence of temperature and germination time on diastatic power of blue and red maize (Zea mays L.) malts

Author(s):  
Miguel Ángel Hernández Carapia ◽  
José Ramón Verde Calvo ◽  
Héctor Bernardo Escalona Buendía

Maize endosperm consists of about 70 % starch, which makes it an excellent substrate for fermentation. However, due to its low diastatic power, it is used in brewing as an adjunct, mainly. In order to include both red and blue maize as an enzyme source in the brewing process, the effect of temperature and time germination on the diastatic power of malts was studied. The research consisted in a completely randomized three-factor experimental design where the involved factors were colour of maize (blue and red), germination temperature (15, 20, and 25 °C), and germination time (3, 4, 5, 6, 7, 8, and 9 days). The response variables were germination percentage, acrospire length, malting yield, and diastatic power. Data was analysed through Analysis of variance and Comparison Multiple Tukey’s Test. Results showed that both temperature and germination time encouraged the acrospire length, which had a negative effect on malting yield. Regarding to diastatic power, it maintained an increase from third to seventh germination day, at the three tested temperatures. Additionally, as the germination temperature increased, the diastatic power also increased. The highest diastatic power for blue and red maize malts were 39 and 42 °L, respectively, and it was reached when these malts were germinated for 7 days at 25 °C. It was concluded that, by germinating both blue and red maize under the resulting optimum conditions, the obtained malts would be capable of converting their own starch.

Author(s):  
Sofia ARGYRIOU ◽  
Panayiota PAPASTYLIANOU ◽  
George STAVROPOULOS ◽  
Angeliki KOUSTA ◽  
Ioanna KAKABOUKI ◽  
...  

Helichrysum amorginum is a perennial shrub, endemic on the Greek island of Amorgos and used for medicinal, cosmetic and ornamental purposes. Information concerning germination behavior and seedling survival is considered essential for the establishment and cultivation of wild species. The objective of this study was to investigate the effect of temperature and light on germination of Helichrysum amorginum seeds. A set of experiments was conducted under completely randomized design with four replications of 200 seeds at three different suboptimal germination temperatures (15, 20 and 25°C) in light and dark conditions for 10 days. Seed material was collected from two different fields of the island (Aegiali and Katapola). The germination performance was evaluated by final germination percentage and mean germination time. The effect of temperature on seed germination percentage and mean germination time was significant in all cases. The presence of light enhanced germination, especially at the optimum temperature of 20°C. In most cases the mean germination time increased at the lower temperature of 15°C. Seeds from Aegiali exhibited higher germination ability than the seed lot from Katapola. Knowledge of seed germination behaviour is of major importance in order to establish effective protocols for seed propagation in Helichrysum amorginum.


2009 ◽  
Vol 58 (1-6) ◽  
pp. 162-168 ◽  
Author(s):  
Du Hyun Kim ◽  
Sim Hee Han ◽  
Ja Jung Ku ◽  
Kab Yeon Lee

Abstract Among the ex situ methods for the preservation of forest tree germplasm, conventional seed banking is considered the most efficient method for the majority of species whilst cryopreservation has an important role in long-term conservation. The influence of cryoprotectants prior to liquid nitrogen (LN) storage and osmoconditioning priming treatments with polyethylene glycol (PEG) after LN storage were evaluated for germination (%), germination value (GV) and mean germination time (MGT) in seeds of Cryptomeria japonica. Sugi seeds were treated with two cryoprotectants (DMSO and PVS2) before immersion into LN and stored for three days. Although the C. japonica seeds survived liquid nitrogen treatment, their viability was reduced from 25% of intact seeds to 17% in LN. The seeds treated with 35% DMSO showed higher germination (28%) as compared with seeds directly-immersed in LN without cryoprotectant treatment. In contrast, PVS2 pretreated seeds decreased germination (13%). Two concentrations of PEG priming treatments were carried out. Osmoconditioning treatment in -0.4 MPa PEG solution after removal from LN enhanced the subsequent germination percentage and decreased MGT. PEG treatments at both -0.4 and -1.2MPa to PVS2 pretreated seeds before cryopreservation partially alleviated the negative effect of PVS2. DMSO pretreated seeds immersed into LN and treated with -0.4MPa PEG maintained the 28% of germination obtained in the control conditions and reduced the mean germination time (MGT). It can therefore be summarized that pretreatment with 35% DMSO was suitable for the cryopreservation of C. japonica seeds whilst the PEG priming treatment circumvented imbibitional damage after LN exposure.


HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 402-405 ◽  
Author(s):  
Ibrahim Demir ◽  
Tuba Celikkol ◽  
Golge Sarıkamıs ◽  
Ceren Eksi

A study was made of the relationship among accelerated aging (AA), saturated salt accelerated aging (SSAA), mean germination time and second day germination percentage vigor tests, and seedling emergence and longevity storage at 5 and 25 °C for 6 and 12 months. Initial germination was above 80% for all seed lots. Seedling emergence values varied between 21% and 94% and mean emergence time between 6.5 and 11.0 days among seed lots. The SSAA test correlated with emergence better than the AA test. All combinations of SSAA temperatures (41, 43, and 45 °C for 72 h) were correlated to emergence (r = 0.95 to 0.98, P < 0.001) and emergence rate (r = 0.90 to 0.94, P < 0.001). Seed germination after 6 months of storage ranged between 21% and 98% at 5 °C and 26% and 100% at 25 °C. Corresponding values were 19% and 98% and 15% and 89% after 12 months. All combinations of AA and SSAA were related to longevity of seed lots, but significance for SSAA was higher (above P < 0.01) than AA (P < 0.05). In both tests, a higher aging temperature reduced the significance level. Mean germination time and second day germination percentages also predicted seedling emergence and longevity (P < 0.05 in all cases). Standard germination percentages were successful in predicting seedling emergence (P < 0.05), but with one exception failed to predict (P > 0.05) longevity in viola seed lots. In conclusion, although both aging tests successfully differentiated seed quality, SSAA test results better predict emergence and longevity of viola seed lots.


2020 ◽  
Author(s):  
Mafral

The independent independent variables in this study as many as 89 respondents are determined by using saturated samples. To know the influence of independent variable to dependent variable partially, used t test. While to know the effect of independent variable to dependent variable simultaneously, used F test. The assumption used in the validity test is if R-count&gt; R-table item is declared valid. The R-arithmetic shown in the table above, from each item indicates that R-arithmetic&gt; R- table so the item is declared valid. Based on the validity test of the instrument of Leadership Style, Work Motivation, and Competence on Employee Performance, all items are declared valid and reliability test results indicate that the instrument has high reliability. This means that the eligibility criteria of the Instrument of Leadership Style, Work Motivation, Competency and Employee Performance have met the criteria of good instrument requirements, that is valid and reliable. The result of regression analysis of Leadership Style obtained by tcount = 20,91 while ttable value = 1,988 tcount&gt; ttable proved variable of Leadership Style influence to Employee Performance. Work Motivation regression analysis obtained tcount = 17.62 while the value ttable = 1.988 tcount&gt; ttabel proven Motivational Work variables influence on Employee Performance. Regression analysis Competence obtained value tcount = - 06.85 while ttable =1.988 so thitung&gt; ttable and proven variable Competence have a negative effect on Employee Performance.


2019 ◽  
Vol 47 (10) ◽  
pp. 1-9 ◽  
Author(s):  
Xieping Chen ◽  
Qian Xie ◽  
Yuting Yang

Parent–adolescent communication is assumed to be an important factor affecting adolescent smoking behavior. However, the inner mechanism accounting for this association has still not been clarified in research. Our purpose in this study was to examine the relationships between parent–adolescent communication, adolescent smoking behavior, and depression, as well as gender differences in the relationship between depression and adolescent smoking behavior. Participants were 1,134 students at 6 junior high schools in China who completed the Parent-Adolescent Communication Scale, the Epidemiological Studies Depression Scale, and the Smoking Behavior Test. Results showed that parent-adolescent communication had a significant negative effect on adolescent smoking behavior and depression partially mediated the relationship between parent–adolescent communication and adolescent smoking behavior. In addition, gender moderated the relationship between depression and adolescent smoking behavior. Overall, these findings may help to promote better understanding of the relationship between parent–adolescent communication and adolescent smoking behavior.


2013 ◽  
Vol 5 (3) ◽  
pp. 325-331 ◽  
Author(s):  
Reyhaneh AZIMI ◽  
Hassan FEIZI ◽  
Mohammad KHAJEH HOSSEINI

The goal of this study was to evaluate concentrations of nanosized TiO2 at 0, 5, 20, 40, 60 and 80 mg L-1 with bulk TiO2 for possible stimulatory effects on wheatgrass seed germination and early growth stage. After 14 days of seed incubation, germination percentage improved by 9% following exposure to 5 ppm nanosized TiO2 treatment comparing to control. Similar positive effects occurred in terms of germination value and mean daily germination. Application of bulk TiO2 particles in 80 ppm concentration greatly decreased the majority of studied traits. Therefore phytotoxicity effect observed on wheatgrass seedling by application of bulk TiO2 particles in 80 ppm concentration. Exposure of wheatgrass seeds to 5 ppm nanosized TiO2 and bulk and nanosized TiO2 at 60 ppm obtained the lowest mean germination time but higher concentrations did not improve mean germination time. In general, there was a positive response by wheatgrass seed to some concentrations of nanosized TiO2. Usage of nanoparicles in order to improve germination and establishment of range plant in adverse environments similar to rangeland could be possible.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7318
Author(s):  
Anita Ptak ◽  
Paula Taciak ◽  
Wojciech Wieleba

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.


Author(s):  
RASUL TARVIRDILU ASL ◽  
HÜSEYİN MURAT YÜKSEL ◽  
OZAN KEYSAN

The main aim of this study is to optimize an axial flux eddy current damper to be used in a specific aviation application. Eddy current dampers are more advantageous compared to conventional mechanical dampers as they are maintenance-free due to contactless structure and have higher reliability, which is very desirable in aerospace applications. An initial eddy current brake prototype is manufactured and the test results are used to verify the 3-D finite element simulations. The effect of temperature on the brake performance is investigated. Finally, a multiobjective genetic algorithm optimization is applied to find the optimum pole number and geometric dimensions of the eddy current brake in order to achieve the desired torque-speed characteristic while the total weight of the brake is minimized. It is found that the mass and volume of the initial prototype can be halved by implementing this optimization algorithm.


2012 ◽  
Vol 9 (1) ◽  
pp. 141-147
Author(s):  
Baghdad Science Journal

The reliability of optical sources is strongly dependent on the degradation and device characteristics are critically dependent on temperature. The degradation behaviours and reliability test results for the laser diode device (Sony-DL3148-025) will be presented .These devices are usually highly reliable. The degradation behaviour was exhibited in several aging tests, and device lifetimes were then estimated. The temperature dependence of 0.63?m lasers was studied. An aging test with constant light power operation of 5mW was carried out at 10, 25, 50 and 70°C for 100hours. Lifetimes of the optical sources have greatly improved, and these optical sources can be applied to various types of transmission systems. Within this degradation range, the device life for system application is estimated to be more than 100 h at 70 ºC at a constant power of 5mW.


1975 ◽  
Vol 84 (2) ◽  
pp. 239-243 ◽  
Author(s):  
A. Bassiri ◽  
I. Rouhani ◽  
S. R. Ghorashy

SUMMARYSeeds of wild safflower, Carthamus oxyacantha Bieb., collected from the Bajgah area, Iran, were subjected to chilling and/or scarification and their germination and emergence characteristics and seedling growth were studied in two laboratory experiments. Seeds of Arak 2811 variety of cultivated safflower, C. tinctorius L., harvested from the same area at the same time was used for comparison.In the first experiment, the untreated, scarified, chilled at 0 °C for 1 month, and chilled and scarified wild seed and seed of the variety Arak 2811 were incubated at six different temperatures (5, 10, 15, 20, 25 and 30 °C) and their germination percentage and seedling lengths were recorded. In the second experiment, the seeds of the above five treatments were planted in a silty clay loam at room temperature (23 ± 2 °C) and their emergence and seedling heights were noted.In all cases, the cultivated variety, Arak 2811, had higher germination and emergence percentages and seedling heights than the wild type. Germination of both strains was greatly reduced at the two extreme temperatures (5 and 30 °C). The optimum temperatures for germination of the wild and the cultivated strains were between 15 and 20 °C.Scarification of the wild seed did not improve the germination or emergence percentages and chilling of the seed for a month at 0 °C reduced the emergence of the wild seed. Temperature of germination, however, seemed to be an important factor affecting germination and seedling growth of wild safflower.


Sign in / Sign up

Export Citation Format

Share Document