Marketing and Delivery of Quality Grains and Bioprocess Coproducts

NON-TECHNICAL SUMMARY: There is a great concern about energy use and cost in crop and crop coproduct drying, handling, and storage and we will seek ways to reduce energy use and cost. We will also seek ways to minimize quality deterioration and pesticide use during drying, handling, and storage of crops and crop coproducts. <P>

APPROACH: Key methods used by MN investigators will involve research and outreach of ways to minimize cost of energy is drying, handling, and storing MN crops and coproducts and ways to minimize deterioration of quality during drying, handling, and storage. <P>
PROGRESS: 2007/01 TO 2007/12 <BR>
The primary objective of our work in 2007 was to complete work on a model for predicting mortality of Indian meal moth [Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae)] larvae under fluctuating low-temperature conditions. The time and temperature combinations required to achieve 100% mortality of field-collected, cold-acclimated P. interpunctella larvae obtained from laboratory mortality experiments were used to develop the mortality model. Accumulation of mortality rate over time was called the Cumulative Lethality Index (CLI). Complete mortality of insect populations would occur when CLI equals one. Observed mortality of field collected, cold-acclimated P. interpunctella larvae in five 76.2-T (3,000-bu) shelled corn bins located in Rosemount, Minnesota during the winters of 2003-2004 and 2004-2005 were used to validate the CLI model (i.e., mortality model). Excellent agreement between predicted and measured time to 100% larval mortality was observed. The CLI model would be useful for developing low-temperature aeration management strategies for controlling overwintering P. interpunctella in grain bins. In addition, this model will be useful when determining if additional control measures will be required as a result of above-seasonal ambient temperatures. Information on using low storage temperatures to kill insects has been incorporated into Extension presentations given to stored-grain managers.
<BR> <BR>
IMPACT: 2007/01 TO 2007/12<BR>
It is expected that this research will lead to recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2006/01/01 TO 2006/12/31<BR>
The primary objective of our work in 2006 was to complete work on the effects of low temperatures on mortality of Indian meal moth [Plodia interpunctella (Hubner) (Lepidoptera: Pyralidae)]. We published results on the effect of broken corn on survivability of P. interpuctella larvae fed a standard laboratory diet, whole corn with 0% broken kernels, whole corn with 5 to 7% broken kernels, and 100% broken corn kernels. A conventional low-oil yellow dent corn (3.9% oil) and a high-oil corn hybrid (7.7% oil) were tested at 28oC, 65% RH, and 14 h light: 10 h day photo period cycle. Larval survival rates increased with increasing amounts of broken kernels. Larval growth rate for high-oil corn was greater than for low-oil corn. Results indicate that cleaning corn before storage could reduce Indianmeal moth problems. A model for predicting mortality of P. interpunctella larvae under fluctuating low-temperature conditions was developed. The time and temperature combinations required to achieve 100% mortality of field-collected, cold-acclimated P. interpunctella larvae obtained from laboratory mortality experiments were used to develop the mortality model. Accumulation of mortality rate over time was called the Cumulative Lethality Index (CLI). Complete mortality of insect populations would occur when CLI equals one. Observed mortality of field collected, cold-acclimated P. interpunctella larvae in five 76.2-T (3,000-bu) shelled corn bins located in Rosemount, Minnesota during the winters of 2003-2004 and 2004-2005 were used to validate the CLI model (i.e., mortality model). Excellent agreement between predicted and measured time to 100% larval mortality was observed. The CLI model would be useful for developing low-temperature aeration management strategies for controlling overwintering P. interpunctella in grain bins. In addition, this model will be useful when determining if additional control measures will be required as a result of above-seasonal ambient temperatures.
<BR> <BR>
IMPACT: 2006/01/01 TO 2006/12/31<BR>
It is expected that this research will lead to recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2005/01/01 TO 2005/12/31<BR>
The primary objectives of our work in 2005 were to study the effects of low temperatures on mortality of Indian meal moth (Plodia interpunctella), develop a model for predicting mortality under changing temperature conditions, and measure the effect of broken corn on survivability. We conducted a field experiment starting in fall 2004 through winter 2005 to determine the mortality of cold acclimated fifth-instar P. interpunctella under field conditions (in grain bins). Larvae were placed in cages and sampled periodically. Temperatures ranged from 0 to -15oC. Mortality increased throughout the test with 100% mortality reached after 30 to 60 days depending on depth and location in the bin. We developed a cumulative lethality index (CLI) model to estimate mortality of P. interpunctella larvae under changing temperature conditions. A CLI greater than 1 corresponds to 100% mortality. Laboratory mortality experiments were used to develop the model. Measured mortalities of field-collected, cold-acclimated P. interpunctella larvae in two 76-t shelled corn bins located in Rosemount, MN during the winters of 2003-2004 and 2004-2005 were used to validate the model. Excellent agreement between the predicted and measured mortalities was observed. Survivability of P. interpunctella larvae fed a standard laboratory diet, whole corn with 0% broken kernels, whole corn with 5 to 7% broken kernels, and 100% broken corn kernels was assessed at 28oC, 65% RH, and 14 h light: 10 h dark photo period cycle. A conventional low-oil yellow dent corn (3.9% oil, dry basis) and a high-oil corn hybrid (7.7% oil, dry basis) were tested. Larval survival rates increased with increasing amounts of broken kernels. Larval growth rate for high-oil corn was greater than for low-oil corn. Results indicate that cleaning corn before storage could reduce Indianmeal moth problems.
<BR> <BR>
IMPACT: 2005/01/01 TO 2005/12/31<BR>
It is expected that this research will lead to recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2004/01/01 TO 2004/12/31<BR>
The primary objectives of our work in 2004 were to study the effects of low temperatures on mortality of Indian meal moth (Plodia interpunctella), to model temperatures inside grain bins under various management schemes, and to use this information to develop stored grain management recommendations that will reduce problems with Indian meal moth (IMM). We collected data on mortality for laboratory cultures of fifth-instar P. interpunctella exposed to -10 degrees C for different periods of time. Laboratory larvae reached 100% mortality after 12 h exposure while cold-acclimated larvae reached 100% mortality after 312 hours. We conducted a field experiment starting in fall 2003 through winter 2004 to determine the mortality of cold acclimated fifth-instar P. interpunctella under field conditions (in grain bins). Larvae were placed in cages and sampled every 15 days. Temperatures ranged from 0 to -10 degrees C. Mortality increased throughout the test with 100% mortality reached after about 60 days. We completed a computer model to simulate temperatures of the grain bin headspace and grain within one meter of the top surface both for conditions of natural ventilation of the headspace as well as aeration of the grain bulk. Results for natural ventilation showed that for galvanized steel bin surfaces, increasing openings in the headspace to increase natural ventilation reduced headspace-air and grain temperatures. For white colored bin surfaces, minimizing natural ventilation reduced headspace-air and grain temperatures. We developed a cumulative lethality index (CLI) model to estimate mortality of P. interpunctella larvae under changing temperature conditions. A CLI greater than 1 corresponds to 100% mortality. We used simulation studies to develop practical weather-based management for controlling cold-acclimated, diapausing P. interpunctella larvae. Simulations included use of winter ambient air for twelve locations: Minneapolis-St. Paul, MN; Des Moines, IA; Grand Island, NE; Kansas City, MO; St. Louis, MO; Indianapolis, IN; Columbus OH; Lexington, KY; Wichita, KS; Oklahoma City, OK; Chattanooga, TN; and Little Rock, AR. For storage with no aeration during the three winter months, a CLI sufficient to create 100% mortality was not reached at the 0.4 m depth for any of the locations, including Minneapolis-St. Paul, MN. However, when an aeration strategy based on running the fan when the temperature at 0.4 m was less than the headspace temperature was used, CLI values sufficient to obtain 100% mortality were easily reached at 9 out of 12 locations. Even the three southern-most locations reached the 100% mortality criteria at the 0.4 m depth in an average year.
<BR> <BR>
IMPACT: 2004/01/01 TO 2004/12/31<BR>
It is expected that this research will lead to recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2003/01/01 TO 2003/12/31<BR>
Accomplishments and results for 2003 include: * Collected data for percent mortality (lower lethal temperature) of third-, fourth-, and fifth-instar larvae, pupae, and adults of P. interpunctella at different temperatures (from -30 to 0C) using minimum exposure (1 min). * Collected data on mortality for laboratory cultures of fifth-instar P. interpunctella exposed to -10C for different periods of time. * Initiated a field experiment during fall 2003 to determine the mortality of cold acclimated fifth-instar P. interpunctella under field conditions (in grain bins). Data from field tests will be compared to that obtained in the laboratory and to that predicted by computer models. The experiment is still in progress. * Completed and submitted a manuscript describing the methodology for obtaining desired cooling rates for supercooling point (SCP) determination to CryoLetters. The manuscript is currently in press. * Developed a computer model to simulate temperatures of the grain bin headspace and grain within one meter of the top surface during mechanical ventilation of the headspace. * Used simulation studies to develop practical weather-based management for controlling cold-acclimated, diapausing P. interpunctella larvae. Simulations included use of winter ambient air for eight locations in the Midwest: Minneapolis-St. Paul, MN; Des Moines, IA; Grand Island, NE; Kansas City, MO; St. Louis, MO; Indianapolis, IN; Columbus OH; and Lexington, KY. Results indicated that continuous mechanical ventilation of the grain bin headspace from December through February would reduce the temperatures of the headspace and the top grain layers to a depth of 0.4-m far below critical temperatures for more than enough hours to cause 100% mortality of over wintering P. interpunctella. It is expected that manipulation of grain bin headspace temperature during winter will result in nearly complete control of over wintering Indian meal moth stages in grain bins in several locations in the Midwest without a need for chemicals. Winter cooling will also reduce chances of insect infestation during the following spring and summer.
<BR> <BR>
IMPACT: 2003/01/01 TO 2003/12/31<BR>
It is expected that this research will lead to recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2002/01/01 TO 2002/12/31<BR>
Accomplishments and results for 2002 include: * Collected samples of Indian meal moth from several sites in Minnesota and several locations in other parts of the U.S. * Developed a technique for measuring the supercooling point for individual insects. The technique involves use of a thermocouple attached to the insect body, a low-temperature freezer, and an insulated cube designed to produce the desired cooling rate. * Determined supercooling points for a number of Indian meal moths from several different colonies and at several different life stages. * Analyzed 35 years of weather data from the north central U.S. to determine the average number of hours when the outdoor temperature is likely to be below certain specific temperatures at various times of the year. * Started development of computer models that will integrate prediction of temperatures in stored grain and in the bin headspace with prediction of Indian meal moth population.
<BR> <BR>
IMPACT: 2002/01/01 TO 2002/12/31<BR>
It is too early to assess impacts from this research, but it is likely that we will be able to develop recommendations for storage bin equipment and for stored grain management that can be used to limit insect populations without the use of chemical insecticides. Reduced use of chemical insecticides should reduce grain storage costs and reduce potential harmful environmental and human health impacts from chemical insecticides.
<BR> <BR>
PROGRESS: 2001/01/01 TO 2001/12/31<BR>
Carbon dioxide production by corn samples was used to determine the amount of time to reach 0.5% dry matter loss (DML) for five hybrids each of high-oil, normal-oil, Bt, and non-Bt corn held at 20C and at 22% and 19% moisture (wet basis). Hybrids were selected in pairs such that each high-oil hybrid was compared to a normal-oil hybrid that had similar parent genetics and each Bt hybrid was compared to a hybrid that was identical except for insertion of the Bt gene complex. We also determined microbial infection levels before and after storability tests and mold damage after storability tests (DKT levels) for all hybrids. In the normal oil/high-oil study, we also measured fat acidity levels before and after storability tests. The mean adjusted times to 0.5% DML for normal-oil and high-oil corn hybrids were significantly different at 0.05 probability level for all five hybrid pairs at 19% moisture, but time to 0.5% DML was significantly different for only two hybrid pairs at 22% moisture. The deterioration rate for high-oil corn was faster than for normal-oil content corn in most hybrid pairs at both 19 and 22% moisture. Fat acidity values were significantly different at 0.05 probability level for all hybrid pairs at both moisture levels, both before and after storability tests. Fat acidity values for high-oil corn hybrids were much higher than for comparable normal-oil content corn hybrids after the test. There was a strong positive correlation between oil content and fat acidity after storability tests at both moistures. In general, the high-oil corn hybrids had higher levels of damaged kernels (DKT) at the end of the storability tests, at both 19 and 22% moisture. Fat acidity and DKT results indicate that high-oil corn hybrids might not store as well as normal-oil content corn. For conventional and Bt corn hybrids, the mean adjusted times to 0.5% DML were significantly different at 0.05 probability level for three hybrid pairs at 19% moisture and for four hybrid pairs at 22% moisture. In some cases, time to 0.5% DML was greater for the conventional hybrid and in other cases, time to 0.5% DML was greater for the Bt hybrid. There was little difference in fungal counts and DKT values after storability tests for comparable hybrid pairs of conventional and Bt corn at both moisture levels. These results do not allow any conclusions to be drawn about the relative storability of Bt corn hybrids compared to conventional hybrids.
<BR> <BR>
IMPACT: 2001/01/01 TO 2001/12/31<BR>
It appears that high-oil hybrids do not store quite as well as their normal-oil counterparts. This means that it might be necessary to store high-oil hybrids at slightly lower moisture contents, or at lower temperatures, or for shorter periods of time to avoid quality loss. It does not appear that the relative storability (at least in terms of mold growth) of Bt hybrids is any better or any worse than that of comparable non-Bt hybrids and thus Bt and non-Bt hybrids can be managed the same way in drying and storage systems.
<BR> <BR> PROGRESS: 2000/01/01 TO 2000/12/31<BR>
Carbon dioxide production by corn samples was used to determine the amount of time to reach 0.5% dry matter loss (DML) for one hybrid each of high-oil, normal-oil, high-oil Bt, and high-oil non-Bt corn held at 20 degrees C and at 22% and 18% moisture (wet basis). In the high-oil/normal-oil test at 22% moisture, the high-oil hybrid (Northrup King NK4206) reached 0.5% DML in about 10% less time than did the hybrid containing a normal level of oil (Northrup King NK4242). At 18% moisture, storage times to reach 0.5% DML were about the same for the two hybrids. After storability tests at both moisture levels, however, the high-oil corn had much lower levels of mold damage and much better U.S. Grade Nos. than did the normal-oil corn. Both the high-oil and normal-oil varieties reached 0.5% DML slightly sooner than predicted by using Steele (1967) equations that were developed for conventional corn. In the Bt/non-Bt test, at both moisture levels, Bt corn (Pioneer 37H97Bt) took slightly longer to reach 0.5% DML than did non-Bt corn (Pioneer 37H97). Both hybrids, which were also high-oil hybrids, reached 0.5% DML slightly sooner than would be predicted for corn having a normal amount of oil and a normal amount of mechanical damage, and much sooner than would be predicted for corn having the low levels of mechanical damage measured in this test. Corn quality (as indicated by levels of mold damage) was comparable for Bt and non-Bt corn samples after the storability tests. This work falls under AREERA Goal 1, Program 9.
<BR> <BR>
IMPACT: 2000/01/01 TO 2000/12/31<BR>
It's too soon to draw any conclusions from this work, but early indications are that there are not major differences in storability for high-oil and Bt corn hybrids and their conventional counterparts. Preliminary results indicated a need for testing of additional hybrids.
<BR> <BR>
PROGRESS: 1999/01/01 TO 1999/12/31<BR>
In 1999, we conducted research to 1) verify or improve predictions for the effect of changing moisture on storability of shelled corn; 2) re-examine the effects of different sample storage methods on results of grain storability tests; 3) develop strategies for using aeration during humid weather to recondition overdry soybeans in storage; and 4) we started work to evaluate storability of value-enhanced corn varieties compared to storability of conventional corn varieties. 1) In our storage tests where corn moisture was either increased or decreased part way through the storage period, we found that the mathematical model that we have been using to predict effect of moisture change on the deterioration rate of stored corn gave results that were fairly close to the measured values. 2) We examined the effect of different methods of handling and storing corn samples on the results of tests to measure corn storability. Comparisons included carbon dioxide production for corn samples that were tested immediately after harvest, after cold storage at high moisture (about 22%), and after cold storage at low moisture and subsequent rewetting to the desired moisture level. Tests were conducted at 4, 8, and 22 months after harvest. Results indicated that deterioration rates and mold infection levels were very similar for all three sample-storage methods. 3) We modified a natural-air corn-drying model for use in simulation of soybean reconditioning. We then used the model and 30 years of upper Midwest weather data to simulate different aeration strategies for reconditioning overdry soybeans in storage. Results indicated that it is possible to cost effectively bring dry soybeans back to market moisture by aerating them during humid weather. It is important though, to stir beans or to remove layers of beans during the reconditioning process to prevent bin damage and to prevent rewetting to levels that are too high for safe storage. 4) We collected samples of high-oil corn and Bt corn in fall of 1999 and will be conducting storability tests on these samples over the next year.
<BR> <BR>
IMPACT: 1999/01/01 TO 1999/12/31<BR>
Results from our storability tests give us confidence that our test procedures and modeling methods are appropriate and that no major changes are needed in our future work. Results from our soybean reconditioning studies will allow farmers and commercial grain storage managers to avoid the large economic losses associated with handling and marketing of overdry soybeans.
<BR> <BR> PROGRESS: 1998/01/01 TO 1998/12/31<BR>
In a collaborative project with Iowa State University and USDA-ARS-GMPRC in Manhattan KS, we examined the appropriateness of algorithms that are currently used to adjust allowable storage time for changing temperature conditions. We conducted storage tests using 18, 22, and 26% moisture shelled corn where storage temperature was changed from 15 to 25C, or from 25 to 15C, after dry matter loss reached 0.25%. In another test, storage temperature was cycled between 15 and 25C on a 24-h basis. Experimental results were relatively close to those predicted by using traditional storage time equations and algorithms. In another project, we are examining the effect of different methods of handling and storing corn samples on the results of tests to measure corn storability. Comparisons include carbon dioxide production for corn samples that were tested immediately after harvest, after cold storage at high moisture (about 22%), and after cold storage at low moisture and subsequent rewetting to the desired moisture level. Tests were conducted at four and eight months after harvest, and another test will be conducted about fourteen months after harvest. So far, it appears that all three sample-storage methods give similar results in carbon dioxide evolution tests. We have also evaluated the relationship between corn dry matter loss in storage and visible mold damage. Mold damage was measured using human grain graders who determined total damaged kernels (DKT) and a machine vision system, which gave readings for percentage of kernel surface area covered by mold. Corn samples having mechanical damage levels of 0, 15, and 30% were stored at a temperature of 20C and moisture levels of 18 and 22% wet basis. Mold damage was evaluated at dry matter loss levels of 0.25, 0.5, 0.75, and 1.0%. We found that the amount of dry matter loss (DML) that could be tolerated before DKT levels exceeded 5% (the maximum level allowed for US No. 2 corn) varied with corn moisture and level of mechanical kernel damage. For example, at 0% mechanical damage, 18% moisture corn could be stored until more than 1.0% dry matter was lost before DKT reached 5%, while 22% moisture corn produced 5% DKT with only 0.25% DML. At 30% mechanical damage, 18% moisture corn produced 5% DKT at 0.5% DML and 22% moisture corn produced 5% DKT at just 0.2% DML.

<BR> <BR>
PROGRESS: 1997/01/01 TO 1997/12/31<BR>
We are using carbon dioxide production by fungi to assess grain storability and are using machine vision to evaluate grain quality. We studied the storability of diseased 16 to 22% moisture wheat (Fusarium head blight, or scab) with and without cleaning on a gravity table. In all cases, cleaning slightly increased storability. Also, 16% moisture wheat stored much longer than predicted. In a collaborative study with Iowa State University and the USDA-ARS Grain Lab in Manhattan KS, we are comparing actual versus predicted storability of corn under changing temperature conditions. Preliminary results indicate that algorithms used to model temperature changes give reasonably accurate predictions. We are just starting a study evaluating mold damage, US grade, and percent surface area covered by mold for corn that has experienced various levels of dry matter loss.
<BR> <BR>
PROGRESS: 1996/01 TO 1996/12<BR>
We are using carbon dioxide production by fungi to assess grain storability and using machine vision to evaluate grain quality. We studied the storability of diseased wheat (Fusarium head blight, or scab) with and without cleaning on a gravity table. In another study, we used eight different corn varieties to test our hypothesis that corn composition can be used to predict relative storability. We found that cleaning increased the storability of 20% moisture wheat by 12 to 43%. In our corn storage tests, composition values were too similar for our model for predicting storability to work well. Also, we found that storability rankings (best to worst) were not consistent from one year to the next. Our machine vision work resulted in development of a new on-line calibration procedure that gives us more consistent readings under changing lighting conditions, a procedure for quantifying mold coverage on corn kernels, and a batch analysis procedure for analyzing kernel mechanical damage that is much simpler and faster, but only slightly more variable than analyzing kernels one at a time.
<BR> <BR>
PROGRESS: 1995/01 TO 1995/12<BR>
We used carbon dioxide production to assess deterioration rate in storage for two varieties of scab-infected and scab-free hard red spring wheat at 16, 18, and 20% moisture. We also measured vomitoxin levels before and after storage. In most cases, scab-free wheat stored slightly better than scab-infected wheat and a variety that is known to resist scab also showed some resistance to grain storage fungi. Past recommendations for wheat drying and storage were based on corn storage data, but our results indicated that 16% moisture wheat could be stored much longer than corn held under similar conditions. Vomitoxin levels were variable, but did not seem to change appreciably during storage. In another study, we tried to use corn composition to predict relative storability. We measured protein, oil, starch, sugar, fiber, and mineral content; equilibrium relative humidity (ERH); and deterioration rate at 22% moisture and 20C for eight different corn varieties. Unfortunately, the eight varieties had similar composition and our model for predicting ERH and relative deterioration rate proved to be inadequate for such small differences in composition. Work continues to refine the model.