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Context Grain-based diets result in lower starch utilisation compared with traditional diets with corn silage. The best use of yellow dent corn starch, in addition to increasing animal performance, can be obtained by the inclusion of an effective fibre source in grain-based diets and/or the use of more efficient genetic groups in a tropical feedlot. Aims We assessed productive responses of young Nellore (N) bulls and 1/2 Angus × 1/2 Nellore (AN) bulls fed whole shelled corn diets, with or without sugarcane bagasse (SB). Methods A completely randomised design in a 2 × 2 factorial arrangement (two genetic groups and two diets) was used. Twenty-eight young bulls (14 N and 14 AN) were fed diets containing 0 or 31.6 g of SB/kg DM in a feedlot. Key results The average daily gain and gain:feed ratio were not affected by the diets, but AN bulls showed greater average daily gain and gain:feed ratio than N bulls (P = 0.001 and P = 0.006, respectively). The genetic groups did not affect nutrient intake, but N bulls had greater (P = 0.016) DM digestibility than AN bulls. The consumption of DM, crude protein and digestible energy was not affected by the diets. The digestibility of neutral detergent fibre, crude protein and NFC was lower (P = 0.001) for the diet with SB. The neutral detergent fibre intake was greater (P = 0.001) in the diet with SB. The DM intake variation was smaller (P < 0.05) in diets with SB and for N bulls. Conclusions The inclusion of SB up to 31.6 g/kg DM in whole shelled corn diets did not affect the productive responses of young bulls. Crossbred bulls, despite expressing lower digestibility of some nutrients and larger DM intake variation, have greater productive potential compared with Nellore bulls in a tropical feedlot with whole shelled corn diets. Implications The use of crossbred young AN bulls in tropical feedlots is a viable alternative for increasing productivity and global meat production.

Yellow dent, high amylose and waxy corn were evaluated using lab-scale conventional, enzymatic (E-milling) and intermittent milling and dynamic steeping (IMDS) processes. The application of proteolytic enzyme (E-milling) and sulfur dioxide (Conventional milling and IMDS process) during kernel hydration and their effects on overall starch yields from three corn types were studied. Despite using lower amount of SO2 (600 ppm) and shorter steeping duration (66.8%), E-milling yielded the highest amount of starch for yellow dent, high amylose and waxy corn (71.4%, 60.1% and 66.9% (db), respectively). The use of proteolytic enzyme during steeping resulted in 26.1% points higher starch yield for high amylose corn. In conventional wet milling process, the highest starch yields were obtained from yellow dent corn and the lowest from high amylose corn, the values being 70.1% and 46.2% (db), respectively. Similarly, highest starch yield (69.5%, db) was obtained from yellow dent corn from the IMDS process. Steepwater absorption for high amylose corn was on average 37.7% greater than the other two corn types for conventional process and 34.6% greater for the modified processes. Modified wet milling protocols with shorter steeping durations and requiring lesser amounts of SO2 can be used to efficiently process different corn mutants.

Objective: The objective of this study was to determine the digestible energy (DE) and metabolizable energy (ME) of yellow dent corn sourced from different meteorological origins fed to growing pigs and develop equations to predict the DE and ME of yellow dent corn from southwestern China.Methods: Sixty crossbred barrows were allotted to 20 treatments in a triplicate 20×2 incomplete Latin square design with 3 replicated pigs per dietary treatment during 2 consecutive periods. Each period lasted for 12 days, and total feces and urine during the last 5 days of each period were collected to calculate the energy contents.Results: On dry matter (DM) basis, the DE and ME in 20 corn grain samples ranged from 15.38 to 16.78 MJ/kg and from 14.93 to 16.16 MJ/kg, respectively. Selected best-fit prediction equations for DE and ME (MJ/kg DM basis) for yellow dent corn (n = 16) sourced from southwestern China were as follows: DE = 28.58–(0.12×% hemicellulose)+(0.35×% ether extract)–(0.83×MJ/kg gross energy)+(0.20×% crude protein)+(0.49×% ash); ME = 30.42– (0.11×% hemicellulose)+(0.31×% ether extract)–(0.81×MJ/kg gross energy).Conclusion: Our results indicated that the chemical compositions, but not the meteorological conditions or physical characteristics could explain the variation of energy contents in yellow dent corn sourced from southwestern China fed to growing pigs.

The nutritive value of starch, the major source of dietary energy in pigs, varies depending on its susceptibility for digestion. The botanical origin of starch determines starch structure, and therefore, digestibility. To compare digestibility of starch, fiber, gross energy (GE), crude protein, and amino acid (AA), and to characterize undigested starch of grains in growing pigs, seven ileal-cannulated barrows (initial body weight, 30 kg) were fed six diets containing 96% of one of six test ingredients (three pulse grains: zero-tannin faba bean, green field pea, or mixed-cultivar chickpea; three cereal grains: hulled barley, hard red spring wheat, or hybrid yellow, dent corn), or a N-free diet in a 7 × 7 Latin square at 2.8 × maintenance digestible energy. Grain samples were ground with a hammer mill through a 2.78-mm screen. Amylose content ranged from 29% to 34% for pulse grains and from 22% to 25% for cereal grains. The apparent ileal digestibility (AID) of starch was greater (P < 0.05) in cereal (94% to 97%) than pulse grains (85% to 90%) and was lowest (P < 0.05) in faba bean (85.3%) followed by field pea (87.2%) and chickpea (90.1%). However, apparent total tract digestibility (ATTD) of starch of all tested grains was close to 100%. Apparent hindgut fermentability (AHF, as ATTD − AID) of starch was greater (P < 0.05) in pulse grains (9.9% to 15%) than cereal grains (3.3% to 4.8%). The AHF of total dietary fiber tended to be the greatest (P < 0.10) for corn (43.5%) and lowest for wheat (25.3%). The AHF of GE was greater (P < 0.05) in pulse grains (17% to 20%) than in cereal grains (9% to 11%) and resulted in greater (P < 0.05) digestible energy (DE) contribution from hindgut fermentation for pulse grains than cereal grains (0.9 vs. 0.5 Mcal/kg). Wheat had the greatest standardized ileal digestibility of total AA (90.2%; P < 0.05). Confocal laser scanning microscopy images revealed that 20% to 30% of starch granules of pulse grains were entrapped in protein matrixes. In scanning electron microscopy images, starch granules were larger in faba bean and field pea than cereal grains. Digesta samples revealed pin holes and surface cracks in starch granules of corn and wheat, respectively. In conclusion, hindgut fermentation of starch and fiber was greater in pulse grains than cereal grains resulting in a greater DE value despite lower ileal DE for pulse grain than cereal grains. Defining the digestible and fermentable fractions of starch may enhance the accuracy of equations to predict the net energy value of these feedstuffs.

The gelatinization temperature (Tgel) of starch increases in the presence of sweeteners due to sweetener-starch intermolecular interactions in the amorphous regions of starch. Different starch botanical sources contain different starch architectures, which may alter sweetener-starch interactions and the effects of sweeteners on Tgels. To document these effects, the Tgels of wheat, potato, waxy corn, dent corn, and 50% and 70% high amylose corn starches were determined in the presence of eleven different sweeteners and varying sweetener concentrations. Tgels of 2:1 sweetener solution:starch slurries were measured using differential scanning calorimetry. The extent of Tgel elevation was affected by both starch and sweetener type. Tgels of wheat and dent corn starches increased the most, while Tgels of high amylose corn starches were the least affected. Fructose increased Tgels the least, and isomalt and isomaltulose increased Tgels the most. Overall, starch Tgels increased more with increasing sweetener concentration, molar volume, molecular weight, and number of equatorial and exocyclic hydroxyl groups. Starches containing more short amylopectin chains, fewer amylopectin chains that span through multiple clusters, higher number of building blocks per cluster, and shorter inter-block chain lengths exhibited the largest Tgel increases in sweetener solutions, attributed to less stable crystalline regions.

Bifidobacterium sp. as microbes has potential role in fermentation of nixtamalized horse dent corn (Zea mays var. indentata) to degrade complex components into folic acid-rich corn biomass. Fermentation process on both nixtamalized yellow corn and white corn by Bifidobacterium brevis and Bifidobacterium bifidum as substrat of A, B, C and D were conducted at concentration of corn folic acid inoculum 40% (w/w) and 37 °C for 0, 8, 16, and 24 hours, respectively. Based on dissolved protein yielded, the experiment result showed that the best result of optimization in fermentation of both nixtamalized yellow corn (biomass B) and white corn (biomass D) was achieved by using inoculum of B. bifidum for 16 hours with composition of folic acid of 213.58 and 297.72 μg/mL, total solids of 21.14 and 21.07%, dissolved protein of 0.42 and 0.39 mg/mL, reducing sugars of 34.2 and 37.8 mg/mL, total sugars of 104.7 and 98.6 mg/mL, total acids of 0.37 and 0.44%, N-amino of 0.28 and 0.26 mg/g, and pH 4.82 and 4.49, respectively. In this condition, biomass of B. and biomass of D indicated domination of folic acid monomer with molecular weight (MW) 442.29 and 442.59 Dalton (Da.) at relative intensity 100%, particles size of 1115.1 nm and 1075.7 nm, and particle index of 0.827 and 0.849, respectively. Meanwhile, volatile compounds were dominated by 2,3-butanediol of 4.46 and 10.65%, palmitic acid of 7.63 and 8.26%, octadecenoic acid of 6.31 and 9.5%, lactic acid of 2.37% and 0.53%, respectively.

Naturally-contaminated yellow dent corn containing 1600 μg total aflatoxin per kg was treated with 3% NaOH at 100°C for 4 min. After washing, the moisture was adjusted by autoclaving at 121°C and the product was deep fired at 196°C for 15 min to produce a corn snack. Samples were taken after each processing step. Aflatoxin levels and mutagenicity of acetone extractions of alkaline and acidified products were measured. There was over 99% destruction of the aflatoxin in the final product. Acidifying products after each stage and prior to analysis caused reformation as much as 18% of the original aflatoxin, however, the acidified final product showed no reformation at all. Mutagenicity determined by Salmonella typhimurium strains TA 98 and TA 100 decreased during processing. Mutagenicity of extracts of the final product was equal to that of the negative controls. The manufacturing process was effective in aflatoxin destruction and reduction of mutagenicity.

Two experiments were conducted to determine the DE and ME as well as the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA in corn fed to growing pigs. All corn was yellow dent corn collected from different areas in China. In Exp. 1, 60 crossbred barrows (Duroc × Landrace × Yorkshire; 40.7 ± 3.5 kg BW) were randomly allotted to 1 of 10 diets to determine the DE and ME of corns. Diets were formulated to contain 96.8% of 1 of the 10 corn samples and 3.2% of other microingredients. In Exp. 2, 11 crossbred barrows (Duroc × Landrace × Yorkshire; 30.5 ± 2.3 kg) fitted with a T-cannula at the distal ileum were assigned to a 6 × 11 Youden square design with 6 periods and 11 diets. Diets included a N-free diet based on cornstarch and sucrose and 10 test diets formulated with 96.6% 1 of the 10 corns as the sole source of AA. Chromic oxide (0.3%) was added to each diet as an indigestible marker for calculating the AA digestibility. On a DM basis, the starch, ether extract (EE), CP, NDF, and ADF contents of corns averaged 74.05% (69.98 to 78.59%), 3.83% (2.04 to 4.73%), 9.63% (7.74 to 10.43%), 10.80% (10.27 to 11.46%), and 2.27% (2.03 to 2.57%), respectively. The CV of EE, CP, and ADF was 22.59, 8.22, and 8.21%, respectively. The DE and ME of corns averaged 4,087 and 3,981 kcal/kg, respectively, and ranged from 3,999 to 4,161 kcal/kg and from 3,898 to 4,067 kcal/kg, respectively. The DE and ME values were positively correlated (P < 0.05) with the EE content. Optimal prediction equations of ME were ME = 940.35 + (0.72 × DE) + (21.88 × EE) (R2 = 0.94) or ME = 1,051.50 + (0.82 × DE) − (282.05 × ash) (R2 = 0.99). In Exp. 2, significant differences (P < 0.05) were observed in the SID of Arg, His, Phe, Ala, Pro, Cys, and Tyr. The SID of Lys (average 73.79%), Met (average 87.32%), and Thr (average 80.06%) ranged from 61.45 to 78.47%, from 74.09 to 90.91%, and from 79.19 to 85.79%, respectively. The standardized ileal digestible Met was positively correlated (P < 0.01) with the Met and CP contents. The obtained prediction equations were standardized ileal digestible Met = 31.34 + (3.43 × CP) + (116.04 × Met) and standardized ileal digestible Met = 104.92 + (294.71 × Met) − (7.03 × NDF). In conclusion, sources had an effect on the energy values and ileal digestibility of most AA in corn. The ME can be predicted by the DE combined with either the EE or ash content. The AA concentrations and SID of AA in corn varied largely.

Four trials were conducted to evaluate the effects of flint corn processing and the replacement of corn with citrus pulp (CiP) in diets for Nellore feedlot cattle. In a 103-d finishing trial, 216 Nellore bulls (350 ± 24 kg initial BW) were used in a randomized complete block design with a 2 × 4 factorial arrangement of treatments. Factors included 2 processing methods, either ground corn (GC) or steam-flaked corn (FC), with CiP replacing each corn type at 4 levels (0, 25, 50, and 75% of DM). All diets contained 12% sugarcane bagasse and 88% concentrate (DM basis). Treatments were also evaluated in metabolism trials, in which 10 ruminally cannulated Nellore steers (389 ± 37 kg) were assigned to 2 independent but simultaneous 5 × 5 Latin squares, each using 1 method of corn processing (GC and FC). Interactions ( < 0.05) between corn processing and CiP inclusion level were observed for final BW, DMI, ADG, G:F, and HCW. With FC-based diets, added CiP linearly decreased final BW ( = 0.04), whereas with GC-based diets, added CiP quadratically increased final BW ( = 0.002). With FC-based diets, the inclusion of CiP linearly increased DMI ( = 0.03) and linearly decreased ADG ( = 0.03) and G:F ( = 0.001). Increasing CiP in GC-based diets quadratically increased DMI ( = 0.001), ADG ( = 0.005), and HCW ( = 0.003). In FC-based diets, CiP inclusion had no effect on HCW ( = 0.21). Dressing percent, LM area, and 12th-rib fat were not affected by diet ( ≥ 0.05). For steers fed GC diets, CiP inclusion in the diet quadratically decreased the molar proportion of isovalerate ( = 0.001) but linearly increased ruminal butyrate ( = 0.006). No differences ( ≥ 0.16) were observed for total VFA concentrations, acetate:propionate ratio, and ruminal NH-N as CiP replaced GC. For steers fed FC diets, the molar proportion of acetate linearly increased ( = 0.002) whereas the proportion of propionate was linearly decreased ( < 0.001), resulting in a linear increase ( = 0.001) in the acetate:propionate ratio. Replacing corn with CiP linearly reduced NEm ( = 0.001) and NEg ( < 0.001) of FC-based diets but did not affect ( = 0.15) NE values of CG-based diets. Steam flaking flint corn improved cattle performance in this trial more than has been reported for dent corn in the published literature.

Instant porridge as a result of formulation using natural folic acid fortificant has potential use as complementary feeding (CF). This experiment activity aims to find out folic acid concentration in the best fortificant in preparation of formula of instant porridge on composition, characteristic of folic acid monomer and particle size. This experiment activity performed by using fortificants of A, B, C, and D were subsequently nixtamalized yellow dent corn (Zea mays var. indentata), fermented spinach (Amaranthus sp.) and mung beans (Phaseoulus radiatus) tempeh; nixtamalized yellow dent corn, fermented broccoli (Brassica oleracea L.) and mung beans tempeh; nixtamalized white dent corn, fermented spinach, and mung beans tempeh; and nixtamalized white dent corn, fermented broccoli, and mung beans tempeh added to base formula of instant porridge with folic acid concentration in fortificants 0, 100, 200, 300, 400, 600, and 800 µg/100 g (of base formula of infant porridge). The result of experiment showed that based on type of nixtamalized corn on dissolved protein, formulation optimization was achieved by using fortificants A and C at concentration of folic acid 600 and 400 µg/100 g (of base formula infant porridge). In this condition was yielded instant porridge A and C with compositions of folic acid 175.25 and 198.72 µg/mL, dissolved protein 2.09 and 1.98 mg/mL, total solids 93.12 and 97.53 %, total sugars 223.73 and 209.33 mg/mL, and reducing sugars 47.35 and 46.87 mg/mL, respectively. Compared without fortificant, this optimum condition increases dissolved protein 50.72 and 42.44 %, total sugars 22.72 and 31.03 %, and reducing sugars 74.21 and 72.44 %. Meanwhile, total solids in fortificant A decreases 4.29 %, and total solids in fortificant C increases 1.52 %. At optimum condition, identification on folic acid monomer in instant porridge using fortificants A and C were dominated by monomer with molecular weights (MWs) 442.3695 and 442.5903 Dalton (Da.). While, particle size distribution indicated particle size 1,060.6 and 1,075.2 nm with particle index (PI) 1.222 and 1.192, respectively.Instant porridge as a result of formulation using natural folic acid fortificant has potential use as complementary feeding (CF). This experiment activity aims to find out folic acid concentration in the best fortificant in preparation of formula of instant porridge on composition, characteristic of folic acid monomer and particle size. This experiment activity performed by using fortificants of A, B, C, and D were subsequently nixtamalized yellow dent corn (Zea mays var. indentata), fermented spinach (Amaranthus sp.) and mung beans (Phaseoulus radiatus) tempeh; nixtamalized yellow dent corn, fermented broccoli (Brassica oleracea L.) and mung beans tempeh; nixtamalized white dent corn, fermented spinach, and mung beans tempeh; and nixtamalized white dent corn, fermented broccoli, and mung beans tempeh added to base formula of instant porridge with folic acid concentration in fortificants 0, 100, 200, 300, 400, 600, and 800 µg/100 g (of base formula of infant porridge). The result of experiment showed that...

Cassava is a high potential feedstock for bioethanol production in Asian countries, primarily due to high yield of carbohydrate per unit land, and its ability to grow on marginal lands with minimal agrochemical requirements. The objective of this study was to compare the bioethanol production from cassava starch with corn starch using a conventional and a raw/granular starch hydrolyzing process (GSH). The fermentation performance of cassava starch was compared with three corn starch types with different amylose: Amylopectin ratios. The final ethanol concentration with cassava starch was similar to that of two corn starch types, dent corn and waxy corn for both processes. For the cassava starch, the ethanol concentration achieved with GSH process was 2.8% higher than that in the conventional process. Cassava starch yielded the highest fermentation rates of the four starches investigated, during the conventional process. Ethanol production and fermentation profiles comparable with corn, a widely used feedstock, makes cassava starch an attractive substrate for bioethanol production.

Introducing traits from dent corn to popcorn is challenging because it is difficult to recover adequate popping characteristics. QPM (Quality Protein Maize) is a dent corn variety carrying the opaque-2 (o2) mutation, specifying increased amounts of normally limiting essential amino acids, and modifier genes which restore the wild type vitreous kernel phenotype. In this study, we introgressed o2 and selected for endosperm modification using vitreousness and high 27-kD gamma zein content. In this way, we recovered high-lysine, fully poppable Quality Protein Popcorn (QPP). BC2F4 individuals with vitreous kernels were confirmed to be o2 mutants by both genotyping and SDS-PAGE. Amino acid profiling of BC2F4 individuals showed that they all have significantly increased lysine compared with popcorn parental lines. Principal Component Analysis of the amino acid profiles showed that all introgressions were grouped with corresponding QPM parental lines. Popping analysis of the BC2F5 individuals showed that while there is variability in popping volume between lines, some lines show equivalent popping to the popcorn parent. In this proof-of-concept study for QPP, we have shown that it is possible to rapidly recover sufficient popcorn characteristics in a modified o2 background using simple phenotypic, biochemical and genetic selection. Furthermore, this shows increased γ-zein is an acceptable substitute for α-zein for full poppability. Since we have developed multiple QPP introgressions, this gives good scope for ongoing hybrid production and future evaluation of agronomic performance and selection of elite hybrids. In a wider context, this study shows the potential for breeding beneficial traits into popcorn for agronomic improvement.

Two experiments were conducted to determine the effects of extrusion on energy and nutrient digestibility in corn, wheat, and sorghum fed to growing pigs. In Exp. 1, 6 diets based on raw or extruded sources of each grain and an N-free diet were formulated. Seven barrows (14.2 ± 0.9 kg) had a T-cannula installed in the distal ileum and were allotted to a 7 × 7 Latin square. Ileal digesta were collected for 2 d after 5 d of adaptation. Results indicated that extruded grains had greater (P < 0.001) apparent ileal digestibility (AID) of starch than non-extruded grains. Extrusion increased standardized ileal digestibility (SID) of all AA except Pro in corn, but SID of AA in wheat and sorghum was not affected by extrusion (Table 1). In Exp. 2, 48 barrows (15.1 ± 3.7 kg) were allotted to 6 diets based on each of the 6 grains. Pigs were housed individually in metabolism crates and feces and urine were collected quantitatively for 5 d after 5 d of adaptation. The apparent total tract digestibility (ATTD) of GE increased by extrusion of corn or sorghum, but that was not the case for wheat (interaction, P < 0.001). The ATTD of NDF was reduced by extrusion of wheat, but not of corn or sorghum (interaction, P < 0.001). Extrusion reduced (P < 0.05) the ATTD of ADF in all grains. Values for ME were greater in extruded corn and sorghum compared with non-extruded grains, but ME in wheat was not affected by extrusion (interaction, P < 0.001). In conclusion, extrusion of corn, wheat, and sorghum increased AID of starch and SID of all indispensable AA. The ME in corn and sorghum was also increased.

Performance responses to steam flaking flint corn as well as to the addition of roughage to finishing diets composed of whole flint corn were evaluated. Ninety-six Nellore bulls were stratified by initial BW (373 ± 11 kg) and randomly allotted to 16 feedlot pens (6 bulls/pen) in a randomized complete block design with 4 replicates/treatment. Dietary treatments for the 86-d feeding trial consisted of (DM basis) 1) 78.8% steam-flaked flint corn with 6% sugarcane bagasse and 0.20% urea, 2) 85% whole flint corn without sugarcane bagasse, 3) 81.9% whole flint corn with 3% sugarcane bagasse and 0.10% urea, and 4) 78.8% whole flint corn with 6% sugarcane bagasse and 0.20% urea. All diets contained 15% (DM basis) of a pelleted protein, mineral, and vitamin supplement. Compared with whole flint corn grain, flaking of flint grain decreased ( 0.47), it increased energy content of the diet ( 0.47) on G:F or on observed energy content of the diet. In summary, steam flaking of flint corn when fed in diets containing 6% sugarcane bagasse decreased DMI by 17% but increased G:F by 20% and NEg of corn calculated from feedlot performance by 23%; these responses markedly exceed those typically observed with dent corn grain. Moreover, adding 3% sugarcane bagasse to a flint whole corn grain diet optimized feedlot performance of Nellore bulls.

Sitophilus zeamais (Motschulsky), the maize weevil, is a serious pest of economic importance in stored products in tropical and subtropical countries; infestation often starts in the field, but serious damage is done during maize storage. This study evaluated S. zeamais infestation on seven varieties of maize. Seven commercial maize varieties (white dent, yellow dent, orange flint, Indian flint, white popcorn, yellow popcorn and sweet corn), two temperature conditions (10 and 27 °C) and three storage times (30, 60, and 90 d) were used. The moisture contents of all maize samples were adjusted to 15.5 ± 0.5% (wet basis) prior to initiating storage trials. Numbers of live weevils, – seed damage, weight loss, and weight of powder produced were assessed at the end of each storage time. As expected, severe damage was observed at 27 °C and 90 d for all maize varieties. Exponential growth rates of S. zeamais were observed in almost all maize varieties. Among seven varieties evaluated, orange flint corn, yellow and white popcorn show resistance to S. zeamais. Nevertheless, sweet and dent corn were most susceptible to S. zeamais -infestation - Higher numbers of live S. zeamais were observed on Indian flint corn, sweet corn and yellow dent corn. Consequently, there was higher seed weight damaged and weight loss. Further, seed damaged, percentage seed weight loss and weight of powder produced was significantly and positive correlated with number of live S. zeamais (r = 0.91, P

Huitlacoche is the Aztecs name given to the smut galls on ears of maize caused by the pathogenic plant fungus Ustilago maydis [(DC) Corda.)]. It is known as maize mushroom, and it has been considered a delicacy and in Mesoamerica. The aim of the present study was to determine the responses of some maize varieties to the growth of the fungus in order to evaluate the prospect production of these smutty ears as a maize mushroom. A 2-year study was conducted in the Mediterranean region of Turkey in 2010 and 2011. Inoculations were performed by injecting inoculum into the ear through the silk channel of plants in plots. Each treatment had control plots. Average ear-gall (huitlacoche) severity and incidence of all the varieties were at the rates of 4.0 and 41.6%, respectively. However, the highest severity of ear-gall (6.5) and incidence (60.6%) were found in Karadeniz Yıldızı flint maize variety; colossal smutty ears were formed in the maize cultivars. This study showed that certain maize cultivars (flint corn and dent corn) can be used efficiently in the production of huitlacoche.

In the dry grind process, corn is ground, mixed with process water and cooked; starch is enzymatically hydrolyzed to sugars, and subsequently fermented to ethanol by yeast. The conversion of starch into ethanol, however, is not complete as distillers dried grains with solubles (DDGS) often contain more than 5% starch. The amount of unreacted starch represents inefficiencies in the process and reducing this amount is important to improving profitability of the ethanol industry. Additionally, dry grind facilities have reported seasonal variation in ethanol yields. In order to minimize variation in ethanol yields and the amount of unreacted starch in DDGS, it is important to understand the effects that storage temperature and time have on the digestibility of the corn starch. While starch quality is largely controlled by genetics and growing conditions, postharvest practices (handling, storage, and processing conditions) also affect starch composition and structure. In this study, changes in unreacted starch content of corn during storage were monitored to provide an explanation for the seasonal variation in ethanol yields observed by dry grind facilities. Yellow dent corn was harvested in 2011 and 2012 and stored indoors, outdoors, and under refrigeration for 5–12 mo. Results with the 2011 harvest corn showed unreacted starch content ranging from 2.17 to 14.1% over a 48 wk period. Unreacted starch was more influenced by storage time, initially decreasing at a rate of 0.31% per wk during the first 10 wk and steadily increased at an average rate of 0.16% per wk for the duration of storage. Results with the 2012 harvest corn, however, showed a higher average unreacted starch content of 13.0% during 20 wk of storage and no appreciable change in unreacted starch content regardless of storage temperature.

A modification on nixtamalization process of dent corn (Zea mays identata) was conducted in order to recover natural folic acid-rich corn. Nixtamalization process on varieties of white dent corn and yellow dent corn subsequently were performed by steeping solution of Ca(OH)2 at concentrations of 0, 10, 20 and 30 % (w/w corn dissolved protein) for 18 hours, and boiling at 90 °C for 15, 30, 45 and 60 minutes. Result of research showed that concentration of Ca(OH)2 solution becoming more and more high and long boiling time increased both folic acid and reducing sugar, dropped total solids and total sugar, and fluctuated dissolved protein for both types of corn. Nixtamalization optimalization of white dent corn and yellow dent corn were achieved at combination of Ca(OH)2 20 % (w/w corn dissolved protein) for 60 minutes of boiling and Ca(OH)2 30 % for 30 minutes of boiling and gave folic acid of 466.81 and 506.74 μg/mL, respectively. In this condition, it is occurred an increase of folic acid 192.3 % (1.9 folds) and 139.89 % (1.4 folds) when compared to initial material of corn. Identification on folic acid monomer and glutamic acid monomer of both nixtamalized dent corn and yellow dent corn at optimum operation condition displayed domination of folic acid monomer with molecular weight (MW) 442.56 Dalton (Da.) with relative intensity 25.51 %, and 441.73 Da. with relative intensity 100 %, while glutamic acid monomer of nixtamalized yellow dent corn and nixtamalized white dent corn were dominated by monomer with MWs of 148.27 Da. and 148.32 Da., and relative intensity 3.73 and 1.8 %.

Sitophilus zeamais (maize weevil) is one of the most destructive pests of maize stored in tropical and subtropical regions. This study determined the resistance of flint corn and dent corn to infestation by S. zeamais (Motschulsky), the maize weevil. Improved King Philip hybrid flint corn and Fontanelle 6T-510 hybrid dent corn were used in this experiment. Two temperature conditions (10 °C and 27 °C) and two storage times (15 days and 30 days) were used. Results showed that flint corn was more resistant to insect damage than dent corn at 27 °C and 30 day storage time. After 30 days storage time and 27 °C death rate was significantly higher in flint corn ( R 2 = 0.945) compared to ( R 2 = 0.634) in dent corn. Damaged seed was 10% higher in dent corn then in flint corn at 27 °C and 30 days. However, no significant difference was observed for seed weight loss between flint corn and dent corn at the same storage conditions. Both dent and flint corn were extensively cultivated in developing countries It appears that storage of flint corn may be one promising solution to reducing corn damage infestation problems in the tropics and in developing countries, but more research is needed.

The result of various process strategies on the nutrient and phytochemical composition of corn samples were studied. Fresh and cooked baby corn, sweet corn, dent corn and industrially processed and cooked popcorn, corn grits, corn flour and corn flakes were analysed for the determination of proximate, minerals, xanthophylls and phenolic acids content. This study revealed that the proximate composition of popcorn is high compared to the other corn products analyzed while the mineral composition of these maize products showed higher concentration of magnesium, phosphorus, potassium and low concentration of calcium, manganese, zinc, iron, copper, and sodium. Popcorn was high in iron, zinc, copper, manganese, sodium, magnesium and phosphorus. The xanthophylls lutein and zeaxanthin were predominant in the dent corn and the total polyphenolic content was highest in dent corn while the phenolic acids distribution was variable in different corn products. This study showed preparation and processing brought significant reduction of xanthophylls and polyphenols.

The hydration kinetics of transgenic corn types flint DKB 245PRO, semi-flint DKB 390PRO, and dent DKB 240PRO was studied at temperatures of 30, 40, 50, and 67 °C. The concentrated parameters model was used, and it fits the experimental data well for all three cultivars. The chemical composition of the corn kernels was also evaluated. The corn cultivar influenced the initial rate of absorption and the water equilibrium concentration, and the dent corn absorbed more water than the other cultivars at the four temperatures analyzed. The effect of hydration on the kernel texture was also studied, and it was observed that there was no significant difference in the deformation force required for all three corn types analyzed with longer hydration period.

[EN] Corn (Zea mays) kernel processing companies evaluate the quality of kernels to determine the price of a batch. Human inspectors in labs inspect a reduced set of kernels to estimate the proportion of damaged kernels in any given lot. The visual differences between good and damaged kernels may be minor and, therefore, difficult to discern. Our goal is to design a computer vision system that enables the automatic evaluation of the quality of corn lots. To decide if an individual kernel can be accepted or rejected, it is necessary to design a method to detect defects, as well as quantify the defective proportions. A setup to work inline and an approach to identify damaged kernels that combines algorithm-based computer vision techniques of novelty detection and principal component analysis (PCA) is presented. Experiments were carried out in three colour spaces using 450 dent corn kernels previously classified by experts. Results show that the method is promising (92% success) but extensions are recommended to further improve results. ª 2013 IAgrE. Published by Elsevier Ltd. All rights reserved., We acknowledge the support of the Spanish company DACSA Maiceras Españolas S.A. in supplying the dent corn samples

BACKGROUND Cereal grains provide a large portion of caloric intake in diets for humans, but not all cereal grains provide the same amount of energy. Therefore, an experiment was conducted to determine and compare the metabolizable energy (ME), the apparent ileal digestibility (AID), and the apparent total tract digestibility (ATTD) of gross energy (GE) and nutrients in eight cereal grains when fed to pigs. RESULTS Rice had greater (P < 0.05) AID of GE than other cereal grains, greater (P < 0.05) AID of starch than yellow dent corn, dehulled barley, rye, and wheat, and greater (P < 0.05) ATTD of GE than yellow dent corn, rye, sorghum, and wheat. Dehulled barley, rye, and sorghum had less (P < 0.05) AID of starch than other cereal grains. Dehulled barley had greater (P < 0.05) ATTD of GE than rye. Dehulled oats had the greatest (P < 0.05) ME compared with other cereal grains, whereas rye had the least (P < 0.05) ME. CONCLUSION Dehulled oats provide more energy to diets and should be used if the goal is to increase caloric intake. In contrast, sorghum and rye may be more suitable to control diabetes and manage body weight of humans. © 2013 Society of Chemical Industry

Efficiently utilizing the nongrain portion of the corn plant as ruminant food and the grain for ethanol will allow the optimization of both food and fuel production. Corn and corn stover could be more effectively used if they were harvested earlier before dry down. Corn harvested at different moisture contents (MCs) may exhibit different processing characteristics for the ethanol industry, because of differences in physical and chemical properties. Therefore, the objective of this study was to investigate the effect of corn harvest MC on dry-grind fermentation characteristics and dried distillers grains with solubles (DDGS) composition. Pioneer hybrid 32D78 was harvested at seven different dates from August 21 to November 23, 2009, with harvest MCs ranging from 73 to 21% (wb). The corn samples with different harvest MCs were evaluated by a conventional dry-grind process. Final ethanol concentration from the corn with harvest MC of 54% (kernel dent stage) was 17.9% (v/v), which was significantly h...

Two corn hybrid varieties [normal yellow dent corn (NC) and high oil corn (HOC)] and two levels of supplemental fat (0 vs. 30 g yellow grease/kg diet, YG) were evaluated in two 4 × 4 Latin square experiments involving eight Holstein steers with ruminal and duodenal cannulas. In Experiment 1, corn varieties were processed by dry rolling. In Experiment 2, they were processed by steam flaking. Non fat-supplemented NC and HOC diets contained 2.7 and 4.8 g of fatty acids (FA)/kg diet, respectively. Fat supplementation increased FA content to 4.9 and 7.1 g FA/kg diet for NC and HOC diets, respectively. With dry rolled corn varieties (Experiment 1), there were no treatment interactions on ruminal, postruminal and total tract digestion of OM, starch and N. There were interactions (P≤0.05) between corn variety and supplemental YG on ruminal aNDFom and postruminal FA digestion. With dry rolled NC, supplemental YG decreased ruminal aNDFom digestion, and postruminal FA digestion. Whereas, with dry rolled HOC, supplemental YG increased ruminal aNDFom digestion, but did not affect postruminal FA digestion. YG decreased (P 0.05) total tract digestion of OM, starch, aNDFom and N, but increased (2.5%, P≤0.05) dietary DE. Ruminal (P 0.05) on ruminal, postruminal and total tract digestion of OM, aNDFom, starch and N. There were interactions (P≤0.05) between corn variety and supplemental YG on intestinal FA digestion. With the NC diets, YG decreased FA digestion; whereas with the HOC diets, supplemental YG increased FA digestion. Supplemental YG did not affect (P>0.05) ruminal digestion, postruminal, or total tract digestion of OM, aNDFom, starch, N. Diet DE value was greater (3.1%, P≤0.05) for YG supplemented diets. There were no corn variety effects (P>0.05) on ruminal, postruminal and total tract digestion of OM, aNDFom, starch and N. Postruminal FA digestion was greater (6.7%, P

The effects of harvest moistures and frozen storage times on corn wet-milling yields and the pasting properties of the resulting starch were studied. Pioneer hybrid P-0916-XR harvested at three moisture contents (49, 35, and 21% wb) were stored frozen for three days or for five months, followed by wet-milling. The pasting properties of the resulting starch were evaluated with a Rapid Visco Analyzer. The yields of starch and germ increased by 1.2 and 1.9 percentage points, respectively, when harvest moisture decreased from 49 to 21% wb, whereas the yields of steep water solids, total fiber, and gluten decreased by 2.1, 0.7, and 0.6 percentage points, respectively. The frozen corn had lower coarse fiber yields but higher cellular fiber yields. The starch pasting properties showed that peak and breakdown viscosities decreased by 8% (3,824 ± 36 versus 3,520 ± 38 cP) and 13% (2,336 ± 47 versus 2,029 ± 60 cP), respectively, when harvest moisture decreased from 49 to 21% wb, whereas peak time increased ...

The Dynamic Dewpoint isotherm method directly determines sample aw using chilled-mirror technology, while changes in sample weight are tracked gravimetrically. The objective of this research was to compare the Dynamic Dewpoint isotherms to saturated salt slurry isotherms for five materials: dent corn starch, isolated soy protein, microcrystalline cellulose, crystalline sucrose, and corn flakes. The Dynamic Dewpoint isotherms were obtained using the AquaSorp Isotherm Generator between 0.10 and 0.95 aw at 25°C. Comparison working isotherms were obtained using 12 saturated salt slurries, between 0.064 and 0.973 aw in desiccators and proximity equilibration cells at 25°C. The Dynamic Dewpoint isotherms exhibited similar sorption behavior to the saturated salt slurry isotherms, except for corn flakes, where there was a marked decrease in moisture content compared to the saturated salt slurry isotherms between 0.40 and 0.70 aw. This difference was attributed to the slow diffusion of water into the very dense la...

Corn grits are commonly used adjuncts in the brewing industry in the United States, especially for lager beers. The major challenge of using a high amount of adjuncts in the brewing process is reduced levels of nutrients available to yeast during fermentation, which negatively affects the growth and functioning of yeast, and results in sluggish fermentation. The problem is usually addressed by adding external nutrition. The objective of this work was to assess the suitability of corn components other than brewer&rsquo, s grits to improve the fermentation rates. Water obtained after soaking of corn germ, a vital source of lipids and soluble proteins, was investigated as a source of nutrient during brewing of 40:60 (w/w) corn grits and malt mixture. Performance of water-soluble nutrients from germ of two corn verities, yellow dent corn and flint corn, was investigated. Germ soak water was added during corn grits slurry formation before mashing. The addition of germ water increased the free amino nitrogen levels by 37% and Zn concentrations by 3.6 times in the wort, which resulted in up to a 28% higher fermentation rate (between 48 to 72 h of fermentation) and shortened the fermentation time from 120 to 96 h. The use of water obtained from the soaking of flint corn germ resulted in a similar shortening of fermentation time. In another approach, nutrient-rich concentrated germ soak water was directly added into the wort, which also resulted in similar improvements in the fermentation rate as those from adding germ soak water during slurry formation. Due to leaching of micronutrients and soluble proteins, the oil concentrations in the germ increased by more than 30%, enhancing its economic value.

Dent corn (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) sample sets representative of commonly grown hybrids and diverse physical attributes were analyzed for alkaline cooking performance. The influence of kernel characteristics including hardness, density, starch properties (thermal, pasting, and crystallinity), starch content, protein content, and prolamin content on alkaline cooking performance was also determined. Corn nixtamal moisture content was lower for hard, dense kernels with high protein contents; sorghum nixtamal moisture content was lower for kernels with low moisture contents and low starch relative crystallinities. Statistically significant (P < 0.05) regression equations showed that corn nixtamal moisture content was influenced by TADD (tangential abrasive dehulling device) index, kernel moisture content, starch content, and protein content; sorghum nixtamal moisture content was influenced by starch relative crystallinity, kernel moisture content, and abrasive hardness in...

Hydroxycinnamic acid derivatives (HADs) and anthocyanins in corn (Zea mays L.) have recently been reported to have anticarcinogenic, anti-hypertensive, antidiabetic, antifungal, antioxidant, and anti-melanogenic activities. Five HADs and anthocyanins in corn were quantified by HPLC according to cultivars and heat processes. In addition, major anthocyanin of a black waxy corn was isolated and identified by several instrumental analysis, and its content was also quantified by HPLC according to heat processes. Of the ten corn cultivars, five waxy corn cultivars had moderate five HADs contents except "Baksa" waxy corn with higher two free cinnamic acids (FCAs), p-coumaric and ferulic acids. In contrast, three dent corn cultivars contained higher levels of three polyamine conjugates (PCs), CFP, DCP and DFP, and especially "P3394" had the highest amount of the three PCs. Two sweet corn cultivars had generally intermediate HADs levels between waxy and dent corn cultivars. Of the three colored-waxy corns, a black Mibaek waxy corn had the highest anthocyanin content. During heat processes, levels of two FCAs in the black waxy corn generally increased, whereas no significant change on three PCs contents was observed except the puffing process. Roasting, retort and puffing processes significantly increased two FCAs and especially, the puffed black waxy corn had the highest amount of FCAs. Meanwhile, most heat treatments except retort process, considerably decreased total anthocyanin contents, and especially the puffed black waxy corn had nearly no anthocyanin. Level of one major anthocyanin, pelargonidin 3-glucoside (P3G) isolated from a black waxy corn was appreciably decreased by heat treatments except retort process, which greatly increased P3G content. These results suggest that the retorted black waxy corn may be a promising high quality functional corn product.

The interrelationships among the grain protein, oil, fatty acids, starch, Na, K, Fe concentrations and chemical grain characteristics were determined by correlation analyses in thirty-five commercial dent corn hybrids. An increase in oil content of the corn is accompanied by a decrease in starch content and by an increase in caproic acid content. The correlation coefficients involving protein content of corn hybrids with oil content (r = 0.066) and with saturated fatty acid (SFA) (r = −0.247*) evidence that protein content is more related to fatty acid distribution than the oil quantity. Linear relationships between refractive index (RI) (nD40 °C) and saturated fatty acid (r = 0.369**) and between refractive index and oleic acid (r = 0.364**), and between iodine number (IN) and unsaturated fatty acid (UFA) were determined. In addition, oleic acid is strongly correlated with linoleic (r = −0.769**) and linolenic acids (r = −0.335**).

White dent corn was nixtamalized in a Ca(OH) 2 [1.2% (w/v)] solution, at a 1:3 corn/water ratio, at 70, 80, 90 and 100 °C for 1 h, with and without mechanical agitation. After cooking the nixtamalized grains were steeped for 48 h. During cooking, kinetics of soluble and suspended solids and total sugar were determined, while that in the grain was determined the pericarp removed. During steeping, water and calcium absorption kinetics were determined in grains and apparent diffusion coefficients were calculated using Fick’s second law. Changes in thermal properties were determined. Cooking temperature and agitation had significant effects on the chemical and physical properties of grains and nejayote. Soluble and suspended solids and total sugar in nejayote showed a linear trend over time for different temperatures, while pericarp removal during both cooking and steeping reached over 90%. Cooking temperature had a significant effect on water and calcium absorption in grains. Calcium and water diffusion were described adequately using Fick’s model. Water and calcium diffusion coefficients values were 2.07–3.52 × 10 −10 m 2 s −1 and of 0.332–1.43 × 10 −10 m 2 s −1 , respectively. Gelatinization temperature and enthalpy were significantly influenced by the temperature and time of the cooking.

The objective of this study was to develop a method to characterize the diffusivity of different components of yellow-dent corn kernels. The equation D = D 0 ⅇ − C / T M n was proposed to describe the moisture diffusivity of yellow-dent corn kernel components. In the equation D (m2/s), T (K), and M (dry basis) are moisture diffusivity, temperature, and moisture content, respectively; whereas D0 (m2/s), C (K), and n are parameters for each component. In order to determine these parameters, each component was separated from the corn kernels and its drying curves were measured at controlled conditions using a Moisture Sorption Analyzer. The parameters were determined by an optimization algorithm that minimized the sum of squares of differences between the measured and calculated moisture contents. As moisture sorption data can provide typical drying curves obtained under well specified and controlled external conditions, the minimization algorithm involved the inversion of the typical drying equation governing the transfer of moisture through the corn kernel. Thus, Fick's second law of diffusion, solved using the COMSOL Multiphysics package, was used to describe moisture transfer in the drying samples. Information obtained in this study is needed to model moisture transfer within corn kernels during the drying process and minimize drying-induced stress cracks.

The physico–chemical, thermal and pasting properties of fractions obtained during three successive reduction milling of degermed grains of four corn types (popcorn, sweet corn, dent corn, and white corn) was studied. Popcorn and white corn gave higher coarser fraction (14–20 mesh) yield than dent and sweet corn. Protein content progressively decreased with increase in fineness in the particle size. Fractions of first reduction stage showed higher fat content and L ∗ value; and lower b ∗ value than the fractions from second and third reduction stages. L ∗ value increased whereas ‘ a ∗ ’ and ‘ b ∗ ’ values decreased with increase in fineness of the fractions. T o , T p and Δ H gel , peak viscosity, breakdown, setback and final viscosity increased while pasting temperature decreased with increase in fineness of the fractions. The results showed that the successive reduction dry milling of a single corn type could produce fractions with varied characteristics.

A total of 960 Lohmann Brown laying hens were used to study the effects of the main cereal of the diet and geometric mean diameter (GMD) of the cereal on productive performance and egg quality from 20 to 48 wk of age. The experiment was a completely randomized design with 6 treatments arranged factorially with 2 cereals (dent corn vs. durum wheat) and 3 GMD of the cereal (hammer-milled to pass through 6-, 8-, or 10-mm screens). Each treatment was replicated 8 times (20 hens per replicate). All diets were formulated to be isonutritive and contained 50% of either corn or wheat. Productive traits were recorded every 4 wk and egg quality was measured at 48 wk of age. The only significant effect detected was for feed intake (P < 0.05) that was greater for hens fed coarse-ground cereals (10-mm screen) than for hens fed medium and fine-ground cereals (8- or 6-mm screen). None of the egg quality parameters studied were influenced by dietary treatment. We conclude that neither type of cereal nor GMD affected productive performance or egg quality of young brown hens, except for feed intake that increased with the coarser particle size.

The effect of a specific dry fractionation process (FWS fractionation process) was evaluated on final ethanol and glucose concentration of 11 yellow dent corn hybrids in this dry grind corn process. In dry fractionation a dry de-germ de-bran process (similar to conventional corn dry milling) is used to separate germ and pericarp (bran) fiber prior to fermentation of the endosperm (grit) fraction. Fermentation results of grits produced from the FWS process were similar to whole corn samples and better than previously reported results on fermentation of grits from other dry fractionation processes. Further investigation showed that the amount of fat in FWS fractionated grits were 2–5 times more than grit samples from a commercial corn dry milling plant; suggesting reduced germ separation with more than 50% of germ not recovered and lost with the grits fraction. Final ethanol concentration for different corn hybrids varied from 12.7 to 13.8% (v/v) for whole corn and 13.4 to 14.7% (v/v) for grits samples. Dry fractionation (removal germ and bran) prior to dry grind processing, significantly affects the fermentation characteristics of corn hybrids. Corn dry fractionation can increase final ethanol concentration and recover germ and fiber as valuable coproducts.

Quantitative trait loci (QTL) influencing three main kernel composition traits, starch, protein and oil concentrations, in unselected F 2:3 and selected BC 2 F 2 maize populations derived from the same cross of a dent corn inbred Dan232 × an elite popcorn inbred N04 under the same conditions were detected. Four and two QTL for starch, four and three QTL for protein, and four and one QTL for oil were detected in the two populations, respectively, with three QTL jointly detected. The proportion of phenotypic variation explained by a single QTL was 5.2–10.6%, 5.0–14.3%, and 6.2–8.5% for the three traits. Ten QTL had favorable alleles contributed by Dan232. Several QTL detected in this study had identical or similar chromosome regions to those previously identified with other maize germplasms. No QTL with opposite effects for kernel composition traits and popping characteristics were detected in the same or near marker intervals. This reflected that some QTL detected in this study seemed to contribute to trait variation in a diverse array of maize populations and environments, and the opportunity existed for improving popcorn's nutritional quality while maintaining acceptable popping characteristics. Inconsistent broad sense heritability and trait correlation estimates were also observed in the two populations.

The effect of processing temperature on structural changes in wheat, corn, and high amylose corn starch granules was investigated and related to the mechanical properties of gels and microcellular foam (MCF). Scanning electron micrographs (SEM) showed that wheat starch granules form ghosts with thicker walls than dent corn granules. The granule wall was permeable to water and appeared to be at least partially permeable to the solubilized contents of the granule. The ghost walls became visibly porous after heating at 95°C for 60 min and were completely solubilized by heating to 120°C. High-amylose corn starch (HACS) granules were completely dissolved by heating to 140°C. Gels made with wheat starch had higher gel strength and dynamic modulus compared to dent corn starch gels. The density, compressive strength and modulus of MCF were lower in samples cooked for 60 min. The density of dent corn MCF was higher than that of wheat starch which may have accounted for higher compressive strength and modulus in the corn sample. MCF made from HACS had higher surface area and lower density, compressive strength, and modulus than the other starches tested. There were no significant differences in pore volume or surface area due to extended cooking times.

Two experiments were conducted to evaluate the effects of NutriDense low-phytate corn in conjunction with increasing added dietary fat on growing and finishing pig performance. Diets in both experiments were corn-soybean meal-based, with yellow dent or NutriDense low-phytate corn and 0, 3, or 6% added choice white grease arranged in a 2 x 3 factorial design. There were 25 to 28 pigs per pen and 7 pens (replications) per treatment in both experiments. In Exp. 1, a total of 1,162 gilts with an initial BW of 44.6 kg were used in a 28-d growth study. A constant true ileal digestible (TID) Lys:ME ratio of 2.80 g/Mcal and available P:ME ratio of 0.90 g/Mcal were maintained in all treatment diets. Overall (d 0 to 28), there were no corn source x added fat interactions (P >/= 0.79). Regardless of corn source, ADG and G:F increased (linear, P = 0.03) with increasing added fat. There were no differences (P >/= 0.34) in pig growth performance between those fed NutriDense low-phytate or yellow dent corn. In Exp. 2, a total of 1,128 gilts with an initial BW of 81.6 kg were used in a 28-d growth study. A constant TID Lys:ME ratio of 2.15 g/Mcal of ME and available P:ME ratio of 0.75 g/Mcal were maintained in all treatment diets. Overall (d 0 to 28), there was a tendency (P = 0.07) for a corn source x added fat interaction for G:F, which can be explained by the improved G:F in pigs fed yellow dent corn only when 6% fat was added to the diet, whereas G:F was improved at both 3 and 6% added fat in pigs fed NutriDense low-phytate corn. There were no differences (P >/= 0.18) in growth performance between pigs fed NutriDense low-phytate or yellow dent corn. These results indicate that increasing added fat improved growth performance regardless of the corn source. In addition, growth performance was similar for pigs fed NutriDense low-phytate or yellow dent corn.

Two experiments were conducted to measure the energy and nutrient digestibilities in NutriDense corn and other cereal grains. An additional objective was to evaluate the effect of balancing diets with AA on the values measured for DE and ME of corn varieties. In Exp. 1, 6 growing pigs were fitted with a T-cannula in the distal ileum and allotted to a 6 x 6 Latin square design to measure apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values for CP and AA in NutriDense corn, yellow dent corn, barley, wheat, and sorghum. Diets based on each of the 5 cereal grains were formulated, along with a N-free diet. Results of this experiment showed that the AID for most indispensable AA were greater (P < 0.05) in NutriDense corn and wheat than in the other cereal grains. The SID for Lys in NutriDense corn (77.6%) was greater (P < 0.05) than in yellow dent corn (68.5%), and sorghum (56.9%), but not different from wheat (75.1%) and barley (71.7%). The SID for Arg and Met in NutriDense corn also were greater (P < 0.05) than in yellow dent corn (88.1 and 87.2% vs. 84.5 and 82.8%, respectively). For the remaining indispensable AA, no differences in SID between NutriDense corn and yellow dent corn were observed. For all AA, the lowest values (P < 0.05) for AID and SID were obtained for sorghum. If calculated as grams of standardized ileal digestible AA per kilogram of DM, concentrations of all indispensable AA in NutriDense corn were greater (P < 0.05) than in yellow dent corn, but barley and wheat had greater concentrations of most AA than yellow dent corn and NutriDense corn. In Exp. 2, 12 growing barrows were placed in metabolism cages, and the DE and ME of NutriDense corn and yellow dent corn were measured. Both grains were used in diets without or with crystalline AA supplementation. Each diet was fed to 6 pigs in a 2-period, changeover design. The DE and the ME in NutriDense corn (4,004 and 3,922 kcal/kg of DM, respectively) were greater (P < 0.01) than in yellow dent corn (3,878 and 3,799 kcal/kg of DM, respectively). Values for DE and ME were not affected by the addition of crystalline AA to the diets. It is concluded that NutriDense corn has a greater value than yellow dent corn in diet formulations due to increased concentrations of digestible, indispensable AA and energy. However, barley and wheat have greater concentrations, whereas sorghum has lower concentrations, of many digestible AA than NutriDense corn.

A dilution protocol originally developed for the isolation of single bacterial cells was modified to suite the specificities of fungal growth. The modified protocol was used to study the growth kinetics of single spores of Aspergillus flavus and Fusarium verticillioides on yellow dent corn meal. Both aw and temperature significantly influenced the distributions of the colony growth rates and lag phases and the rate at which individual spores of both isolates completed the lag period. An interaction between aw and temperature was noted on the spread of the distributions of these growth parameters. The histograms of the single spore colony growth rates and lag phases generally became wider the more compromising the conditions for growth became, indicating a greater variation in growth ability at these conditions. The rate at which the single spores passed through the lag phases generally decreased with decrease in temperature and/or aw, with an interaction again noted between these two factors on the rate. These results show the potential range and variability in growth of individual fungal spores at the lowest inoculum level possible.

The adsorption and desorption isotherms of yellow dent corn were determined at 25, 30 and 37 °C by the gravimetric method. The GAB, Oswin, Halsey, Henderson, Chung-Pfost and polynomial models were fitted to the experimental sorption data. The isotherms exhibited Type II behaviour and were temperature dependent as the equilibrium moisture content decreased with increase in temperature. Hysteresis was also observed at all temperatures investigated. According to the goodness of fit test applied, the GAB model best described the experimental data followed by the Oswin, Chung-Pfost, polynomial and Henderson models. The Halsey model was the least adequate. The monolayer moisture content was found to decrease with increasing temperature, and was higher for desorption than adsorption. The isosteric heat of sorption was determined using the Claussius–Clapeyron equation, and it was found to markedly decrease at the average temperatures investigated with increase in moisture content.

In the present work we investigated the joint kinetics of the overall water and calcium uptake in Yellow Dent corn during the alkaline treatment process with three different temperature profiles. The behavior of the difference of moisture gain and calcium gain in the whole grain and the behavior of calcium gain in the pericarp and in the internal part of the grain suggest that the water and calcium uptake in alkaline solution is a complex process governed by a series of kinetic stages of diffusion and reaction with loss of material. Results show that even though the diffusion pathways for the water and calcium uptake during alkaline treatment are the same, the rates of diffusion and reaction with loss of material of water and calcium in different component parts of the grain are different and greatly influence by temperature. Comparing the three kinetic stages observed during soaking at room temperature (24 °C) the effect of soaking at an initial boiling temperature value of 98 °C was found to accelerate the three kinetic stages by 1080 min and to observe an additional fourth kinetic stage during the last minutes of the soaking period. The results also show that the alkaline cooking at 98 °C of the corn kernel during 15 min greatly accelerates the calcium reaction with pericarp material that results in the loss of most of the pericarp structure during the first 30 min of the steeping stage. Comparing the four kinetic stages observed during soaking at an initial boiling temperature value the effect of the cooking period was found to accelerate the four kinetic stages by 1155 min and to observe an additional fifth kinetic stage during the last minutes of the steeping stage.

To identify high-valued coproducts from commercially processed corn germ, it was necessary to determine the effect of processing conditions on corn germ proteins. We found that significantly less protein was extracted from commercial wet-milled as compared to dry-milled corn germ using Tris, sodium dodecyl sulfate (SDS) buffer containing 14 mM 2-mercaptoethanol at 100 degrees C for 10 min. SDS-polyacrylamide gel electrophoresis (PAGE) revealed a number of proteins with molecular masses ranging from approximately 10 to 66 kDa for the dry-milled corn germ as compared to only a few significant protein bands centered around 23 kDa in the wet-milled corn germ. The protein content of the wet- and dry-milled corn germ was approximately the same; however, nonprotein nitrogen values were significantly greater for the wet-milled than for the dry-milled germ. The distribution of fractionated germ protein freshly excised from the embryo of yellow dent corn kernels was more similar to that of dry-milled than wet-milled corn. SDS-PAGE of laboratory preparations of wet-milled corn germ more closely resembled commercial dry- than wet-milled corn germ, which could be attributed to limited microbial growth during steeping in the laboratory preparations.

The objective of this study was to determine the relationship between the amount and type of lipids, starch composition and structure, and storage proteins on popcorn expansion and to evaluate whether popcorns could be discriminated from other types of corn based on the protein elution parameters. Seven commercial Argentinean popcorn samples were used in the study and significant differences were observed in the popping volume of these popcorns. A significant negative correlation was observed between oleic acid and popping volume and a positive correlation was observed between linoleic acid and popping volume. Popcorn starch properties were significantly different from normal corn but no particular measured attribute of starch correlated with popping volume. α-Zein proteins and glutelins significantly correlated with popcorn expansion volume with R2 = 0.963 and 0.744, respectively. The elution patterns of corn proteins could also be used to discriminate between different types of corn including p...

A mathematical model is employed to describe sulfur dioxide (SO 2 ) diffusion and reaction during steeping of dent corn. Experiments are performed to measure change of SO 2 content of grain during process. A computer-aided nonlinear optimization technique is used to estimate the effective diffusion coefficients and rate constants in the temperature range 25–55 °C. The effective diffusion coefficient for SO 2 varied between 2.27×10 −11 and 6.24×10 −11 m 2 /s and had an Arrhenius activation energy of 24.3 kJ/mol. The reaction rate of SO 2 in dent corn followed first-order kinetics, with rate constants in the range of 0.80×10 −6 –5.38×10 −6 s −1 and activation energy of 49.16 kJ/mol.

Yellow dent corn soaked in deionized water at 52°C for 24 h without addition of SO2 was wet-milled using a modified 100-g laboratory procedure employing ultrasound treatment at different points in the milling process and compared to conventional wet milling and milling-only corn. Starch yields from ultrasound treatments varied from 66.93 to 68.72% and were comparable to conventional wet milling (68.92%). The ultrasound treated samples produced 6.35 to 7.02 more percentage point starch compared to the milling-only corn. Compared to the starch from milling-only corn, the ultrasound-produced starches showed a significant increase in whiteness and decrease in yellowness that are comparable to starches produced by conventional wet milling. Ultrasound treatment after the second grinding produced the highest starch yield and the lowest protein content in the resulting starch. The ultrasound-treated starches exhibited different pasting properties as evidenced by higher paste viscosities.

In the present work we investigated the kinetics of the overall water uptake by three corn varieties (Cacahuazintle corn, Yellow Dent corn and Chalco corn) soaked in water and in alkaline solution with two different concentrations of Ca(OH) 2 . The behavior of the difference of moisture gain as a function of soaking time at room temperature suggest that the water uptake in alkaline solution is a kinetic process governed by physical changes in corn components, which depend on the Ca(OH) 2 concentration and the endosperm type of the corn kernel. Our results show that the uptake of water takes place in different kinetic stages of reaction and diffusion process. Each stage was correlated with a specific structural change that occurs in the pericarp, in the aleurone layer and in the outermost structure of the endosperm. The endosperm type and pericarp thickness were found to extend the reaction and diffusion process, the harder the endosperm and thicker the pericarp of the corn kernel the slower the kinetic process.