Wheat Gram Research Articles

Bioassay Essential Oils on Tribolium castaneum and Tribolium confusum (Coleoptera: Tenebrionidae)

Background: Tribolium confusum and Tribolium castaneum are pests spread inside the stores and homes. These pests infest stored grains and many others seeds in the stores and bakery. These controlled by insecticides. The essential have a promising research results in controlling these pests and decreasing the insect infestations. The natural essential oils have a low effect on the human, non-target insects, and do not pollute the environments. This research is an alternative approach to natural control these two stored product pests. Methods: Four essential oils namely, Lantana camara, Acorus calamus, caraway oil and Ammi majus were estimated on two stored product insects T. confusum and T. castaneum. Encapsulation method by the technology of polymerization was followed. The nano oils at 0.5% were estimated on the 3rd larval instars. Percentages of accumulative mortality were calculated after seven days of the experiments. The effect of nano-oils on oviposition experiments made by spraying two grams of foams of the tested oils and their nano formulations mixed with 100 gram of wheat. Results data obtained detected that, the Percentage of larval mortality increase by increasing the concetrations for both insects T. confusum and T. castaneum. T. confusum tested larvae were more susceptible to the treatments than T. castaneum larvae. Nano A. majus oil showed a stronger effecte than that L. camara or A. calamus oil. Adult emergence percent and fecundity showed a highly decreasing after treatments with nano-oil L. camara, A. calamus, A. majus oils under storage conditions, compared to those of the controls or non-nano-oils. The results suggested that nano A. majus can be used as a valuable tool in pest management programs of T. confusum and T. castaneum Conclusion: The results of this work indicate that some essential oils might be helpful management of pests in the stores because of their fumigant and odor action. Essential oils of plant origin contain active ingredients which are effective against many insects. Nano formulations of essential oils, through controlled release, prevent speed violate and decay and, also increase the stability of the oils. Treated foam, using L. camara, A. majus, caraway, and A. calamus oils gave protectthe wheat seeds from two pests infestations.

Susceptibility of Ethiopian wheat varieties to granary weevil and rice weevil infestation at optimal and sub-optimal temperatures

Integrating varietal resistance with temperature manipulation during storage may provide a better option for protection of stored grains and may decrease reliance on the use of synthetic chemicals. The current study was conducted to determine the susceptibility of different varieties of wheat seed to the infestation by the granary weevil, Sitophilus granarius (L.), and rice weevil, Sitophilus oryzae (L.), at optimal (30 °C) and sub-optimal (19 °C) temperatures. Kernels of six wheat varieties namely, Danda'a, Digalu, ET-13-A2, Kakaba, Millennium, and Pavon-76 were examined over a period of 90 d. Significant interactions were detected between wheat varieties and storage temperature for progeny emergence, percentage of insect damaged kernels, grain weight loss, and amount of powder produced per gram of wheat. Kernels of Danda'a, infested with S. oryzae at 30 °C exhibited significantly lower mean progeny counts (13.3 live insects), lower percentage of grain weight loss (4.2%) and insect-damaged kernels (6.4%), and powder production (1.5 mg/g). Kernel weight and hardness index were negatively associated with percentage of insect damaged kernels and grain weight loss. Kernel diameter was positively associated with both of percentage of insect damaged kernels and grain weight loss. Wheat varieties with high Zeleny sedimentation values had lower percentage of insect-damaged kernels and grain weight loss. These results indicated that kernel weight, hardness index, and protein content are predominant factors contributing to wheat resistance against S. granarius and S. oryzae. The varieties Millennium and Danda'a can be considered with other integrated pest management approaches to reduce stored grain losses of wheat in Ethiopia.

Occurrence of toxigenic Aspergillus flavus in commercial Bulgur wheat

Aflatoxins are mutagenic, carcinogenic, and teratogenic mycotoxins. The objective of this work was to study the presence of aflatoxigenic Aspergillus in commercial Bulgur wheat in the city of Maringá, Paraná, Brazil. Thirty samples of commercial Bulgur wheat, acquired in the period of August 2011 to January 2012, were evaluated. The enumeration analysis showed that samples had up to 273.3 CFU of molds and 133.3 CFU of aflatoxigenic Aspergillus per gram of wheat. Forty-two monosporic isolates were obtained and identified as Aspergillus flavus. The isolates were analyzed regarding their aflatoxigenic potential by culture in coconut milk agar; hydroxide vapor exposure; chromatography; and polymerase chain reaction (PCR) targeting genes that code enzymes of the aflatoxins synthesis pathway. Some of the isolates were confirmed to be aflatoxin producers and several of them presented a genetic profile of aflatoxin synthesis. The obtained results demonstrated that Bulgur wheat A. flavus contamination is concerning.

Biocontrol of mold growth in high-moisture wheat stored under airtight conditions by Pichia anomala, Pichia guilliermondii, and Saccharomyces cerevisiae.

Pichia anomala inhibits the growth of Penicillium roqueforti and Aspergillus candidus on agar. In this investigation, antagonistic activity on agar against 17 mold species was determined. The abilities of Pichia anomala, Pichia guilliermondii, and Saccharomyces cerevisiae to inhibit the growth of the mold Penicillium roqueforti in nonsterile high-moisture wheat were compared by adding 10(3) Penicillium roqueforti spores and different amounts of yeast cells per gram of wheat. Inoculated grain was packed in glass tubes, incubated at 25 degrees C with a restricted air supply, and the numbers of yeast and mold CFU were determined on selective media after 7 and 14 days. Pichia anomala reduced growth on agar plates for all of the mold species tested in a dose-dependent manner. Aspergillus fumigatus and Eurotium amstelodami were the most sensitive, while Penicillium italicum and Penicillium digitatum were the most resistant. Pichia anomala had the strongest antagonistic activity in wheat, with 10(5) and 10(6) CFU/g completely inhibiting the growth of Penicillium roqueforti. Inhibition was least pronounced at the optimum temperature (21 degrees C) and water activity (0.95) for the growth of Penicillium roqueforti. Pichia guilliermondii slightly reduced the growth of Penicillium roqueforti in wheat inoculated with 10(5) and 10(6) yeast CFU/g. S. cerevisiae inhibited mold growth only weakly at the highest inoculum level. Pichia anomala grew from 10(3) to 10(7) CFU/g of wheat in 1 week. To reach the same level, Pichia guilliermondii had to be inoculated at 10(4) CFU while S. cerevisiae required an inoculum of 10(5) CFU to reach 10(7) CFU/g of wheat.

Whole wheat grain feeding of lambs. III. Rumen metabolic responses and animal physiological adjustment to mineral buffer supplements

An intensive 17-week study was made of nine rumen-cannulated crossbred lambs off pasture when given mineral buffer supplements as they were changed from lucerne chaff diets to diets of whole wheat grain plus 2 % of ground limestone. Diets were given ad libitum. Buffers were supplied during transition (period 11) and after transition (period III). The buffers were a 1/1/1/1 mixture of powdered disodium hydrogen phosphate, sodium bicarbonate, potassium bicarbonate, and calciuns hydrogen phosphate given as 2% of the grain offered (group B) and powdered alumirn~~m hydroxide (Al(OH)3) given as 1 % by weight of the grain ofiered (group C). The wheat gram diet was low in sodium (0 008%) and contained 1.50% nitrogen. Production responses to both mineral buffer treatments resulted. Soth buffer treatments increased the voluntary intake (P < 0.01) of wheat above that of the control animals. The rate of eating (g/hr) and pattern of eating did not differ significantly between groups, or between periods I (lucerne chaff) and 111 (post-transition). Groups B and C increased in liveweight to a greater extent than did control animals (P < 0 01) and had heavier carcasses (P <0.01). Results with the mineral mixture given to group B (above) confirm our earlier report. Ingestion of aluminium hydroxide was associated with abomasal ulceration. No significant differences were found between groups in any period for total volatile fatty acids in rumen liquor. Towards the end of period 111, animals given buffer had lower proportions of acetic and higher proportions of propionic acid than did control animals (P < 0.01). Hexanoic acid was detected in all rumen liquor samples obtained in period 111, sometimes in amounts equal to 17 % of total volatile fatty acids. Lactic acid was not detected in rumen liquor in period I, but was present in large amounts in all lambs during period 11, and in lesser but substantial amounts in all lambs during period III. Levels of lactic acid in the rumen liquor in animals receiving mineral buffer supplements fell at a faster rate during period I11 ?hall did levels in control animals. There was a significant decline in rumen pH values for all groups from period I to period III (P < 0.01). Significant rumen pH differences attributable to mineral buffer treatment were apparent (P < 0 05). Buffers were associated with a less acid rumen condition than found in control animals. Relative to control animals, animals given mineral buffers showed increases in rumen buffering capacity and salivary flow rates, and an increased buffering index of the total mixed saliva. Period effects were apparent. The saliva flow rates of control lambs fed on wheat were significantly increased compared with their flow rates on the roughage diet of lucerne chaff. In general, supplementation with aluminium hydroxide and with the mixed buffer respectively yielded similar patterns of response. It is concluded that responses were not primarily due to the sodium level of the diet per se, and that alterations in the animals' electrolyte and acid-base physiology induced by buffer treatment might be contributory factors. Various possible physiological mechanisms are discussed.

WANDERING OF LARVAE OF CRYPTOLESTES FERRUGINEUS (COLEOPTERA: CUCUJIDAE) AMONG WHEAT KERNELS

AbstractWandering of Cryptolestes ferrugineus (Stephens) larvae was demonstrated in the laboratory among wheat kernels at 30 °C and 15.5% moisture content, initially infested at an adult density of 0.4 adult per gram of wheat. The majority of the wandering larvae were first (37.3%) and fourth (56.0%) instars.

Survival of Salmonella montevideo on Wheat Stored at Constant Relative Humidity

Eleven samples of Ottawa variety hard red winter wheat were inoculated with a standardized suspension of Salmonella montevideo . The contaminated wheat samples were placed in constant relative humidity (RH) chambers held at 25 C. Relative humidities were 7, 11, 22, 33, 43, 53, 62, 75, 84, 92, and 98%. Constant RH at 25 C was maintained with different saturated salt solutions in the sealed chambers. Periodic counts of viable S. montevideo cells per gram of wheat were made over a 28-week sampling period. Viable counts of S. montevideo on wheat held at 7, 11, and 22% RH decreased from an initial 10 6 cells/g of wheat to a final count of 10 4 cells/g in each sample. Samples stored at 33, 43, 53, and 62% RH decreased from 10 6 viable cells/g to 3.6 × 10 3 , 10 3 , 10 2 , and 20 viable cells/g, respectively. No viable S. montevideo cells were detected in the samples held at 75, 84, 92, and 98% RH after 22, 16, 26, and 16 weeks, respectively.

Survival of Salmonella montevideo on Wheat Stored at Constant Relative Humidity1

Eleven samples of Ottawa variety hard red winter wheat were inoculated with a standardized suspension of Salmonella montevideo. The contaminated wheat samples were placed in constant relative humidity (RH) chambers held at 25 C. Relative humidities were 7, 11, 22, 33, 43, 53, 62, 75, 84, 92, and 98%. Constant RH at 25 C was maintained with different saturated salt solutions in the sealed chambers. Periodic counts of viable S. montevideo cells per gram of wheat were made over a 28-week sampling period. Viable counts of S. montevideo on wheat held at 7, 11, and 22% RH decreased from an initial 10 cells/g of wheat to a final count of 10 cells/g in each sample. Samples stored at 33, 43, 53, and 62% RH decreased from 10 viable cells/g to 3.6 x 10, 10, 10, and 20 viable cells/g, respectively. No viable S. montevideo cells were detected in the samples held at 75, 84, 92, and 98% RH after 22, 16, 26, and 16 weeks, respectively.

AN INTERPRETATION OF THE MOISTURE DESORPTION ISOTHERM OF WHEAT

It is shown that the moisture desorption isotherm of wheat can be interpreted in harmony with Cassie's theoretical assumptions regarding adsorption on localized sites by the equation[Formula: see text]where N is the number of adsorbed molecules per gram of wheat and S is the number of localized sites. Kf/(1 + Kf) is a Langmuir-type factor for adsorption of the low energy fraction of molecules, and K′fn is a factor for adsorption of the normally condensed fraction of molecules. In agreement with theory K′,n,and S are independent of temperature. The dependence of K on temperature gives a value of −6.27 kcal/mole for the partial molal enthalpy of dilution of the low energy fraction of molecules, which is in the order of magnitude of a hydrogen bond. The analysis also illuminates the practice of the drying of wheat. An exact correspondence appears to exist between the calculated values of S and the apparent surface (or equilibrium) moistures observed in studying the diffusion of moisture out of wheat. The theoretical relation[Formula: see text]is therefore given for predicting apparent surface moisture contents in the vacuum drying of wheat, where[Formula: see text]