• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1906-1912
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• 2014

To evaluate the effect of freezing temperature on quality of blueberries, blueberry fruit was frozen at -20, -45, and $-70^{\circ}C$ immediately after harvest. After 24 hr of freezing, frozen blueberries were stored at $-20^{\circ}C$ for 2 months. Blueberries were thawed at $4^{\circ}C$ or $25^{\circ}C$ and subjected to subsequent analyses of drip ratio, fruit hardness, pH of juice, color, and sugar content. Frozen berries at all three temperatures did not show any significant difference in pH or sugar content compared with fresh berries. The drip ratio of berries decreased as the freezing temperature decreased. Thawing conditions significantly affected the drip ratio of berries frozen at $-20^{\circ}C$. Hardness of berries was significantly reduced after freeze-thawing. Freezing and thawing reduced total aerobic bacteria and yeast/mold numbers by more than 2 log regardless of freezing or thawing temperature ($4^{\circ}C$ or $25^{\circ}C$). Cross-section of blueberries did not show different shapes by freezing temperature. Further studies such as sensory evaluation are needed to determine the optimum freezing temperature regarding quality and cost.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.151-158
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• 1998

This study was carried out to evaluate the effect of substrates and nutrient solution supplying methods in the media culture using perlite and its mixtures with rice hull, carbonized rice hull. cocopeat on the growth and fruit qualify of hydroponically grown cucumber. Three substrates. Perlite(70%) +rice hull(30%) perlite(70%) +carbonized rice hull(30%) and perlite(70%)＋cocopeat(30%) were compared with perlite medium. Supplying methods of nutrient solution were composed of drip irrigation, modified drip irrigation(covered with cheesecloth between drip hose and substrate) and mist system Leaf area of cucumber Plants was lowest in perlite medium while it was highest in mixture of perlite and cocopeat. NAR was higher in the plot of mixture with cocopeat. and same trend was observed in LAI and CGR. T/R ratio was higher in Perlite and perlite mixture with rice hull. Fruit Yields increased in the plot of modified drip irrigation system. When perlite mixture with rice hull used as a substrate. mist system was recommended. Perlite mixture with carbonized rice hull was observed favored in conventional drip irrigation system. Marketable yield and the number of fruit per plant increased and the malformed fruit decreased in the plot of modified drip irrigation system with the mixtures of Perlite and cocopeat.

• Journal of Biosystems Engineering
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• v.33 no.2
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• pp.115-123
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• 2008

This study was conducted to develop an automatic soil water content control system for greenhouse, which consisted of drip irrigation nozzles, soil water content sensors, an on/off valve, a servo-motor assembly and a control program. The control logic adopted in the system was Ziegler-Nichols algorithm and rising time, time constant and over/undershoot ratio as control variables in the system was selected and determined by various control experiments to maintain small delay time and low overshoot. Based on the experimental results, it was concluded that the control system developed in the study could replace the unreliable conventional greenhouse soil water management.

• Animal Bioscience
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• v.34 no.12
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• pp.1987-1994
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• 2021

Objective: The present study aimed to evaluate the effects of varying standardized ileal digestible lysine:threonine (SID Lys:Thr) ratio in the diet on the performance and meat quality of finishing pigs. Methods: In total 192 crossbred pigs ([Landrace×Yorkshire]×Duroc, 17 weeks old), with an initial body weight (BW) of 70.6±3.9 kg were used in an 8-wk trial. Pigs were randomly allotted to one of six dietary treatments based on their initial BW and sex (8 replications; 4 pigs per pen, 2 barrows and 2 gilts). The pigs in the 6 treatments were fed diets having different SID Lys:Thr ratios such as 1:0.65, 1:0.66, 1:0.67, 1:0.68, 1:0.69, and 1:0.70. Results: A linear increment (p<0.05) in average daily gain (ADG) and trends in reduction in feed conversion ratio (FCR) were observed during day 29 to 56 of the experiment and the apparent total tract digestibility (ATTD) of dry matter tended to increase linearly (p = 0.094) at the end of the experiment (day 56) with the increase in the dietary SID Lys:Thr ratios. The backfat thickness and lean percentage increased (linear effect, p<0.05) on day 28. In addition, at day 56, a linear (p<0.05) increment in lean percentage was observed. Significant quadratic responses (p = 0.02) for pH and drip loss at day 7 (p = 0.02), a linear increase (p<0.05) in cooking loss and drip loss at day 7, and a trend in quadratic response (p = 0.07) in the lightness of meat color (L^*) were observed, whereas other meat quality indices were unaffected by varying the SID Lys:Thr ratios. Conclusion: The SID Lys:Thr ratio for maximum ADG, minimum FCR and enhanced digestibility was found to be 0.70. However, for carcass trait and meat quality, the SID Lys:Thr ratio of 0.65 was enough.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.492-499
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• 2009

Effect of drip irrigation on soil salinity control and growth of vegetable crops was studied in the three reclaimed lands of Korea in 2007. Drip irrigation was done one or two times per month for reduction of salt stress by using vinyl hose with tiny holes laid on ridge surface under black plastic film mulch during growing season of cabbage and chinese cabbage. It was observed that drip irrigation was generally effective to soil salinity control, but soil salinity variation of some place was not fully solved to lower down under level of free salt stress. It is also considered that high salinity of runoff water spilled out from cultivation ridge plays another key role for soil salinity management. Consequentially, this soil salinity variation might be one of factors brought low average yield and low commercial ratio of agricultural products. Relation between soil salinity and head growth of cabbage and chinese cabbage was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the heaviest head can be estimated was $6.1dS^{\circ}{\S}m^{-1}$ for cabbage and $5.7dS\;m^{-1}$ for chinese cabbage transplanted at optimum season.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.45-58
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• 2021

This study investigated the dietary effect of total mixed ration (TMR) based on high roughage content on the growth performance, carcass characteristics, and meat quality of Hanwoo steers. Twenty-four Hanwoo steers (average body weight, 195.3±4.7 kg; age, 8.5 mon) were randomly allocated to three experimental groups according to forage and concentrate ratio (DM basis): 25:75 (control), 50:50 (T50), and 70:30 (T70). Productivity in the fattening period and final body weight were significantly higher in the control. Average daily gain and feed conversion ratio were the same among treatments. Serum parameters, cholesterol, blood urea nitrogen, and total protein were higher in the control. Carcass weight was comparable in the control and T50 but feeding more roughage was significantly correlated with a higher intramuscular fat. Shear strength and drip loss were higher while n-6/n-3 was lower in T70 compared to the other groups. However, meat color was not significantly different among treatments. In terms of free amino acid contents, glutamic acid and glycine were higher in the control than T50 and T70. Overall, feeding Hanwoo steers with high forage content TMR had the lowest n-6/n-3 ratio of fatty acid content but highest intramuscular fat, shear strength, and drip loss. High forage content TMR is the best feed for Hanwoo steers that gives more benefits for human health and consumption but also provides the best meat grade and quality, which is important in the beef market in Korea.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.74-79
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• 1995

This study was made to investigate the effects of soil moisture content according to irrigation methods on the storability and quality of cucumber. The fresh weight loss of cucumber fruit harvested in drip irrigation plot was more than that in conventional irrigation plot at both 13$^{\circ}C$ and 24$^{\circ}C$ storage temperature. Dry weight ratio decreased during storage, and was higher in conventional irrigation plot than drip irrigation plot both 13$^{\circ}C$ and 241 storage. The decrease of dry weight ratio was higher at 24$^{\circ}C$ than 13$^{\circ}C$. Vitamin C was not influenced by soil moisture content, but decreased during storage at 13$^{\circ}C$ and 24$^{\circ}C$ The decrease of vitamin C at 24$^{\circ}C$ in 8 days after storage was twice as much at 13$^{\circ}C$. Firmness was measured differently in two parts of cucumber ; fruit stalk and blossom part. The firmness of fruit stalk part was higher than that of blossom part. This phenomena was observed continuously at until final day at 13$^{\circ}C$ and 24$^{\circ}C$ storage. But the difference of firmness was not showed in soil moisture content. Vitamin C, firmness and other quality characteristics were not influenced by soil moisture content during cultivation. The different soil moisture content according to irrigation methods did not affect the storability and quality of cucumber.

• Journal of Animal Science and Technology
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• v.66 no.1
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• pp.115-124
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• 2024

This study investigated the impact of clay mineral 'illite' (IL) on the growth performance, apparent total tract digestibility, and meat-carcass grade quality in growing-finishing pigs. One hundred fifty pigs were divided into two groups with fifteen pens/group and five pigs/pen, a control group that was fed with a corn-soybean meal-based diet and IL treated group were fed a meal-based diet supplemented with 0.5% IL. Compared to the control, IL supplementation increased average daily feed intake (ADFI) and reduce gain to feed ratio (G:F) in the pigs during days 43 to 70 and 99 to 126 and increased dry matter during days 42 and 126, and backfat thickness on day 98 (p<0.05). The drip loss was reduced on day 7, meat firmness tended to increase with dietary IL supplementation. In summary, dietary 0.5% IL supplementation improved ADFI, nutrient utilization of dry matter, and firmness and reduced G:F and drip loss of growing-finishing pigs.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2495-2500
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• 2008

We simulated the mixing characteristics in micro T-channel using Lattice Boltzmann Method. We studied the relation a mixing length and pressure-drop due to inlet and outlet ration in Reynolds number 0.5, Peclet number 500 and Schmidt 1000. The ratio of a down-inlet to up-inlet was $0.5{\sim}1.5$ times, up-inlet to outlet was $1{\sim}3$ times and outlet length was 250 times to up-inlet. The mixing length decrease linearly as outlet ratio decreased, and pressure-drip increase non-linearly. Initial stage of micro channel mixture was fast by down-inlet ratio, however, the mixing length is not influence.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.710-715
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• 2014

To date, the quality and safety of frozen bokbunja have not been clearly assessed. To produce high-quality frozen bokbunja, the optimal freeze-thaw conditions need to be explored. The most popular cultivar (Rubus occidentalis) in Korea was selected for this study. To determine the changes in the quality of frozen R. occidentalis berries, different freezing temperatures were used. The berries were frozen at -20, -45, and $-70^{\circ}C$ immediately after harvest. The drip ratio, hardness, pH, sugar content, color, and anthocyanidin content of the frozen and thawed samples were analyzed. The drip ratio, sugar content, and hardness of the berries correlated significantly with the freezing temperatures. The color and pH of the berries were not significantly affected by the freezing conditions. Frozen leaks between cells reduced significantly with decreasing temperatures. The freeze-thawing process significantly reduced the total aerobic bacteria and inhibited the growth of yeast/mold in the berries to about 2 log scales.