This experiment was carried out to evaluate the characteristic and productivity of forage corn varieties sown at the last ten days of May at Cheonan of Korea on 2017 and 2018. Forage corn varieties sown on 24th May 2017 and 25th May 2018 were emerged in 5th and 1st June, respectively. Silking date of forage corns was different among varieties(p<0.05). Stem length of forage corns was not different among the varieties, except Kwangpyeongok(KPA) and Nero IT. Stem diameter of forage corns was not different amaong the varieties. Outbreak rate of black streaked dwarf virus was lower than 3% in all varieties. Total digestible nutrient(TDN) yield was different among corn varieties(p<0.05), which was higher in P32P75, followed by P2088, P31N27, and KPA. The TDN yield of varieties had direct correlation with stem length, stem diameter and ear yield, respectively(p<0.01). Average of TDN in all varieties was 69.8%. These results suggested that forage corn variety with late-seeding adaptability is more important for increasing the productivity of forage corn If harvesting of winter forage crops have to be finished in the middle ten days of May in middle region of Korea.

This study was aimed to determine the effects of hybrid and inoculant on in vitro rumen digestibility and rumen fermentation indices of corn silage. Two corn hybrids(Kwangpyeongok (KW) vs. Pioneer 1543(PI)) were ensiled for 100 days with two inoculants(L. plantarum(LP) vs. L. buchneri(LB)) applied at 1.2 × 105 cfu/g of fresh forage. Silages were incubated in rumen fluid medium at 39℃ for 72 hours. Both of KW and PI had no difference(p>0.05) on in vitro digestibility of dry matter(IVDMD) and neutral detergent fiber(IVNDFD), while application of LB produced higher(p<0.05) IVDMD and IVNDFD than LP. Hybrid and inoculant applications did not affect(p>0.05) total gas volume, ammonia-N, total VFA, and acetate concentrations in the rumen. Applied LB was higher(p<0.05) propionate concentration than LP, while hybrids had no effect(p>0.05). Furthermore, the interaction effect(p<0.05) was occurred in propionate concentration. Butyrate concentration did not affected(p>0.05) by hybrid and inoculant applications, but there was an interaction effect between hybrid and inoculant(p<0.05). Applications of hybrid and inoculant had effects(p<0.05) on iso-butyrate and valerate, without any interaction effects(p>0.05). This study concluded that application of KW and PI has no effects on in vitro rumen digestibility and rumen fermentation indices of corn silage, while application of LB increase the rumen digestibility in both of corn hybrids.

본 연구는 색소 1호 포엽과 속대 추출물의 영양성분을 분석하고 항산화 및 항당뇨 활성을 검정하여 향후 기능성 식품으로서의 활용을 위한 기초자료로 제공하고자 수행되었다. 색소 1호 포엽과 속대 추출물의 일반성분 분석결과, 수분, 조회분, 조지방, 조단백질은 각각 6.90%, 7.31%, 0.52%, 7.07%이었다. 색소 1호 포엽 및 속대 혼합추출물의 지방산은 palmitic acid, oleic acid, linoleic acid, linolenic acid인 것으로 나타났으며 불포화 지방산의 비율은 83.33%이었다. 색소 1호 포엽 및 속대 혼합추출물의 구성 아미노산 함량을 분석한 결과 glutamic acid, aspartic acid 등을 포함한 총 17종의 아미노산이 검출되었으며 이중 glutamic acid의 함량이 736.08 mg / 100 g으로 가장 높았다. 색소 1호 포엽 및 속대 추출물의 DPPH 및 ABTS radical 소거활성은 각각 95.62% (1,000 μg/mL), 92.00% (10,000 μg/mL)이었으며 총 폴리페놀 및 플라보노이드 함량은 각각 99.87 mg/g, 25.02 mg/g이었다. 색소 1호 포엽 및 속대 추출물의 α-amylase 및 α-glucosidase 저해활성은 추출물 10 mg/mL의 처리농도에서 각각 95.86%, 76.92% 인 것으로 나타났다.

The Asian corn borer, O. furnacalis (Crambidae) and the old world bollworm, H. armigera (Noctuidae) simultaneously cause ear damage in corn in Suwon area. It has been assumed that the second generation of larvae of both insects is responsible for the damage. We, therefore, studied proper spray timing of insecticide in order to reduce the damage. A waxy corn hybrid cultivar, Ilmichal, was sown directly on four plots of a field at April 10, April 20, May 4, and May 18, 2018, respectively. A sodium channel blocker, indoxacarb, was sprayed eight times at 3- or 4-day intervals around the silking stage of corn in each sowing plot. At ear harvest time of each plot, we investigated damaged ratio and length of ear, and the numbers of both insect species. The significantly effective spray timings on reduction of ear damage were the sprays at June 29 and July 2 in the plot sown at April 10, the sprays from July 2 to 13 in the April 20-sown plot, the sprays from July 2 to 19 in the May 4-sown plot, and the sprays at July 19 in the May 18-sown plot, respectively. The damage level was positively related to the insect number. The result indicated that the spray at the silking stage of corn was effective on reduction of ear damage. It was assumed that occurrence time of neonate larvae of the insects at silking stage cause the damage, based on the experimental results using screened pots inoculated with the two species.

This study aimed to investigate the effect of using corn flakes, produced by pressurized steam chamber, on nutrient disappearance rate and energy value in three Hanwoo and three Holstein cows, implanted with a ruminal fistula. Corn flakes were categorized in 2 groups based on the chamber type: control (corn flakes produced using a steam chamber) and treatment (corn flakes produced using a pressurized steam chamber). Dry matter (DM) disappearance rate was 5.17% higher in treatment than in control (p<0.01). Starch disappearance rate was also higher in the treatment than in the control (p<0.01). Nitrogen free extract (NFE) and non-fiber carbohydrate (NFC) disappearance rates were 6.08 and 5.71% higher in treatment compared to control, respectively (p<0.01). In comparison by breed and incubation time, DM, starch, NFE, and NFC disappearance rates were higher in treatment than in control. The mean total digestible nutrients (TDN) was higher in treatment than in control (p<0.05). In comparison between Hanwoo and Holstein, TDN of corn flakes was slightly but not significantly higher in Holstein than in Hanwoo. Thus, these results indicate that the use of the pressurized steam chamber is recommended to increase the nutrient (starch, NFE, NFC etc.) disappearance rate and TDN.

This study focuses on evaluating the physico-chemical properties of extruded cassava starch added with corn flour. The raw materials were mixed at different ratios (corn flour/cassava starch 0:100, 25:75, 50:50, 75:25, 100:0 [w/w]), then extruded at different barrel temperatures (120 and 140°C) and moisture contents (20 and 25%), with the physicochemical and pasting properties of extrudates finally analyzed. The obtained results showed that the addition of corn flour to the mix resulted in an increase in specific length, lightness, yellowness, water absorption index, water solubility index, final viscosity, and setback viscosity of extrudates, while there was a decrease in redness and piece density. Other properties including the expansion ratio, reducing sugars, cold viscosity, peak viscosity, hold viscosity, and breakdown viscosity were more likely to be subjected to barrel temperature and moisture content. Mixing corn flour with cassava starch ameliorated the expansion properties, color, and some pasting properties of mixed extrudates. This study demonstrated that the use of corn flour and extrusion process with different barrel temperatures and moisture contents provided valuable data for the further development of extruded cassava starch.

본 연구는 자색옥수수 색소 1호 포엽과 속대 추출물의 항비만 활성을 검정하고자 지방분해효소 저해활성을 평가 하고 3T3-L1 지방전구세포에서 지방분화억제 효과를 검정하고자 수행되었다. Pancreatic lipase 저해 활성 결과, 색소 1호 포엽 및 속대 추출물의 100, 500, 1,000 μg/mL 농 도처리구에서 양성대조군인 orlistat 보다 높은 저해 활성을 나타내었다. 3T3-L1 지방전구세포를 배양하여 색소 1 호 포엽 및 속대 추출물의 세포독성 평가를 수행한 결과, 추출물은 모든 처리농도에서 세포 생존율에 영향을 미치 지 않은 것으로 확인되었다. 분화된 3T3-L1 지방전구세포 에서 색소 1호 포엽과 속대 추출물을 처리하지 않고 분화 시킨 대조군은 lipid droplet의 형성이 활발하게 유발되었으나 색소 1호 포엽 및 속대 추출물의 처리에 의해 농도 의존적으로 lipid droplet의 형성이 억제되는 것으로 나타났다. Real-time PCR과 Western blot을 실시하여 PPARγ와 C/EBPα 유전자 및 단백질 발현량을 측정한 결과, 추출물을 처리하지 않고 분화시킨 대조군에서는 PPARγ와 C/ EBPα의 유전자 및 단백질 발현이 증가하였으며, 추출물 처리에 의해 PPARγ와 C/EBPα의 유전자 및 단백질 발현이 유의적으로 감소하였다. 본 연구 결과는 색소 1호 포엽 및 속대 추출물이 pancreatic lipase 활성 및 지방전구 세포의 분화를 억제시킴으로써 항비만 활성 기능성 물질 로의 활용 가능성이 높음을 시사한다.

This study was conducted with two ruminally cannulated Holstein steers to examine the effect of micronized and steam flaked corn on ruminal fermentation characteristics. The in situ dry matter degradability after 48 h incubation was the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corn treatments. The steam flacked corn (3.3 mm thickness) was degraded lower (P<0.05) than the 2.9 and 3.1 mm thickness of steam flacked corn. Effective dry matter degradability and the rate of constant were the highest (P<0.05) at micronized corn (2.5 mm thickness) compared with steam flaked corns as well. The in vitro dry matter degradability after 48 h incubation was tended to higher (P=0.088) at micronized corn (2.5 mm thickness) than steam flaked corns, whereas there is no significantly difference between steam flaked corn treatments. Total volatile fatty acid concentration was higher at steam flaked corn (2.9 mm thickness) than micronized corn (2.5 mm thickness) and steam flaked corn (3.1 and 3.3 mm thickness). The acetate : propionate ratio was the highest (P=0.008) at steam flaked corn (2.9 mm thickness) and the lowest (P=0.008) at micronized corn (2.5 mm thickness). Total gas and methane production after 48h ruminal incubation was the highest (P=0.001) at micronized corn (2.5 mm thickness) compared with steam flaked corns. According to these results, the thickness of steam flaked corn as resulted corn processing is believed to do not affect methane production. However, further study is needed to better understand the present results to verify the correlation between corn processing method and their thickness on methane production using the same thickness corns by difference processing methods.

In plants, starch is the main carbohydrate reserve and an important ingredient in human nutrition. Nutritionally, starch is classified into rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) based on the rate and degree of digestion. RS escapes enzymatic digestion in the small intestine, but in the large intestine microbial flora may ferment some RS. Malic acid is C4 carboxylic acid with two carboxyl groups. It is well known to take from 69% up to 92% of all organic acids in grape berries and leaves and is naturally produced by many organisms without showing any nutritional harm. However, properties of malic acid treated starch has not been clearly reported. The objectives of this study were to investigate the influence of pH value on low-digestible malate starch formation and digestibility in relation to structural properties of corn starch. Different pH values (1.5-8.5) of 2 M malic acid solution were reacted with corn starch in a forced-air oven at temperature of 130°C for 12 hr. Using FT-IR, carbonyl groups were detected in malate starch, indicating the formation of cross-linking by esterification. Increasing pH value of malic acid-treated sample from 1.5 to 8.5 showed an increase in degree of substitution (DS) and resulted in increase in the RS content from 18.2 to 74.8%, which was maintained after gelatinization. The granular structure of malate starches was not destroyed, and the starches maintained birefringence. This malate starch could be utilized in heat processed foods such as bread and cookies as well as in the products with reduced calories.

This study was designed to optimize ethanol extraction process of unfertilized corn silk (UCS) to maximize phytochemical contents and bioactivities. The response surface methodology (RSM) with central composite design (CCD) was employed to obtain the optimal extraction conditions. The influence of ethanol concentration, extraction temperature and extraction time on total polyphenol contents, total flavonoid contents, maysin contents, 2,2-diphenyl-1- picrylhydrazyl(DPPH) radical scavenging activities and tyrosinase inhibition were analyzed. For all dependable variables, the most significant factor was ethanol concentration followed by extraction temperature and extraction time. The following optimum conditions were determined by simultaneous optimization of several responses with the Derringer’s desirability function using the numerical optimization function of the Design-Expert program: ethanol concentration 80.45%, extraction temperature 53.49°C, and extraction time 4.95 h. Under these conditions, the predicted values of total polyphenol contents, total flavonoid contents, maysin contents, DPPH radical scavenging activity and tyrosinase inhibition were 2758.74 μg GAE/g dried sample, 1520.81 μg QUE/g dried sample, 810.26 mg/100g dried sample, 56.86% and 43.49%, respectively, and the overall desirability (D) was 0.74.

This study was conducted to examine the effect of corn (Zea mays L.) - soybean (Glycine max L.) silage prepared by intercropping method on the nutritive value of the silage, in vitro rumen fermentation characteristics, dry matter degradability, as well as milk yield and milk composition of dairy cows. In a couple of experiments intercropped corn-soybean silage (CSBS) was compared with corn silage (CS) and/or Italian ryegrass hay (IRG). Numerically, CSBS had higher crude protein, ether extract, and lactic acid contents compared to CS. In vitro rumen fermentation analysis demonstrated that up to a 24-h incubation period, both CS and CSBS showed higher total gas production, ammonia N concentration, and dry matter degradability compared to IRG (p<0.05). The investigation on animals was conducted in a commercial dairy farm located in Gyeongju, South Korea, employing 42 Holstein cows that were divided into 2 group treatments: CS and CSBS in a completely randomized design. Although no significant difference was observed in milk yield, animals fed on CSBS showed significantly higher milk protein (p<0.05) and milk fat content (p<0.01), compared to animals fed on CS. Taken together, our findings indicate that corn-soybean silage that is cultivated, harvested, and prepared through intercropping can improve the protein content of the silage, and can also enhance in vitro rumen fermentation, dry matter degradability, and performance of dairy cattle.

The aim of this study was to evaluate the effects of microencapsulation on the water absorption, DPPH radical scavenging activity (DRSA), hydroxyl radical scavenging activity (HRSA) and tyrosinase inhibition activity (TIA) in corn silk extracts. The lowest value (0.20) of water absorption index (WAI) and the highest value (95.23%) of water solubility index (WSI) were maltodextrin+cyclodextrin microencapulated corn silk extracts (MD+CD) and cyclodextrin encapulated corn silk extracts (CD), respectively. The 18.60% for DRSA value of control was increased to 89.25% for that of CD. The 16.89% for HRSA value of control was increased to 47.46%, and 7.16% for TIA value of control was increased to 39.35% for that of MD+CD, respectively. The MD+CD would be used for functional food and cosmetics materials as antioxidant and skin whitening agents. All investigated responses between control and treatment were statistically significant (p<0.05).