• 한국식품저장유통학회지
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• 제30권3호
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• pp.369-382
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• 2023

We examined the changes in the physicochemical quality characteristics and antioxidant activity of fresh-cut Fuji apples (Malus pumila) during processing and storage after treatment with browning inhibitors. The primary aim was to elucidate processing suitability and storability. We observed that in the processing stage of slicing fresh Fuji apples, there were no significant differences in 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging ability and ferric-reducing antioxidant power (FRAP). However, after NaClO treatment, total flavonoid and total polyphenol contents decreased. When freshcut Fuji apples were treated with browning inhibitors and stored at 4℃, the L value and hardness decreased; however, the weight loss rate increased based on the storage period of all fruit groups treated with Citrus unshiu Markovich (CuM), calcium ascorbate (CA), and ascorbic acid (AA). The pH increased after 2 days of storage in 1% CuM and after 6 days of storage in 1% CA; however, no changes in pH were observed during the storage period in 1% AA. The DPPH radical scavenging activity was generally good under storage conditions of 1% AA at 4℃ and 1% CA at 20℃. Furthermore, FRAP remained relatively constant under storage conditions of 1% CA. The quality characteristics and antioxidant activity of fresh-cut fruits during processing and storage can be used as basic data for industries. Furthermore, we can gain confidence in quality improvements by improving the production and distribution environment of fresh-cut agricultural products.

• Journal of Biosystems Engineering
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• 제25권1호
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• pp.33-38
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• 2000

This study was performed to investigate airtight storage characteristics of rough rice using airtight flexible pve container. A storage test of rough rice of 4 tonnes was carried out to determine the changes of gas composition of air in the container, grain moisture content, air temperature and relative humidity , the presence of insects ,germination rate, crack ratio , fat acidity , 1000-kernel weight, and brown rice recovery over storage period of 5 months in Suwon. Concentration of oxygen was decreased from 20% to 16% and carbon dioxide was increased of from 0.03% to 1.6%. The grain moisture content was decreased from 14.4%(w.b) to 14.1%(w.b) for 5 months storage period . Insect population levels were low but these increased after 5 months storage. Most of insects were dead, Fat acidity increased from 7.5(mg KOH/100g) to 10.2(mg KOH/100g). Other storage factors such as germination rate, brown rice recovery and 1000-kernel , and 1000-kernel weight slightly decreased and crack ratio was slightly increased. Qualities of rough rice during 5 months storage period under hemetic air conditions were maintained fairly good considering the above changes of quality factors during storage.

• Journal of Power Electronics
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• 제18권2호
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• pp.343-355
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• 2018

A wide-voltage-conversion range bidirectional DC-DC converter is proposed in this paper. The topology is comprised of one typical LC energy storage component and a special common grounded asymmetric H-bridge with four active power switches/anti-parallel diodes. The narrow output PWM voltage is generated from the voltage difference between two normal (wider) output PWM voltages from the asymmetric H-bridge with duty cycles close to 0.5. The equivalent switching frequency of the output PWM voltage is double the actual switching frequency, and a wide step-down/step-up ratio range is achieved. A 300W prototype has been constructed to validate the feasibility and effectiveness of the proposed bidirectional converter between the variable low voltage side (24V~48V) and the constant high voltage side (200V). The slave active power switches allow ZVS turn-on and turn-off without requiring any extra hardware. The maximum conversion efficiency is 94.7% in the step-down mode and 93.5% in the step-up mode. Therefore, the proposed bidirectional topology with a common ground is suitable for energy storage systems such as renewable power generation systems and electric vehicles with a hybrid energy source.

• 한국식품영양과학회지
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• 제27권5호
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• pp.852-857
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• 1998

Three kinds of kimchi using Chinese cabbage, leafy radish and mustard leaf were prepared by conventional method and stored at 5$^{\circ}C$ or 2$0^{\circ}C$ for 13 dyas. During storage at both temperatures, changes of the amounts of salt and ascorbic acid, pH and total acidity were determined, and the relationship of the decomposition of chlorophylls with the production of their derivaties was studied. At both storage temperatures, salt concentration of Chinese cabbage kimchi(3.7%), leafy radish kimchi(3.6%), mustard leaf kimchi(3.5%) was relatively constant during the entire storage period. However, pH and total acidity wre fluctuating with the remarkable changes during 3 days of storage. Ascorbic acid content was slowly decreased during the storage period and the decompositin rate of ascorbic and was greater at 2$0^{\circ}C$ than 5$^{\circ}C$. Among the kinds of kimchi tested, mustard leaf kimchi with the slow decomposition rate of ascorbic acid contained relatively high ascorbic acid content, while leafy radish kimchi contained the lowest content. At both storage temperatures, the production of pheophytin and pheophorbide from decomposition of chlorophyll was least in mustard leaf kimchi, but similar production rates in leafy radish and Chinese cabbage kimchi were observed.

• 한국연초학회지
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• 제24권2호
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• pp.88-93
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• 2002

This study was carried out to investigate the changes of chromatic, chemical and organoleptic characteristics of green leaf tobaccos during storage in warehouse. Eight grades(flue-cured ; A2O, B2O, C2L and D2L, burley ; A2T, B2T, C2W and D2W) of green loaves produced in 2001 were stored during 8 months(Oct. 30, 2001 to Jun. 30, 2002) in warehouse of Kimcheon(flue-cured) and Namwon(burley) Leaf Tobacco Processing factory, respectively. Moisture contents of D2L in flue-cured and four grades in burley were significantly decreased during storage in warehouse. Redness(a) values of six grades except for D2L and D2W were significantly increased during storage. Lightness(L), yellow(b) and pH values, and the contents of nicotine, total nitrogen and total sugar were not changed during storage. Irritations of flue-cured tobacco were increased, whereas tastes were decreased during storage. Irritations and tastes of burley tobacco were little changed during storage. The result suggests that the flue-cured green leaf being processed as early as possible for minimizing the deterioration of smoke taste during storage in warehouse.

• Journal of Nutrition and Health
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• 제15권1호
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• pp.39-46
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• 1982

Nitrate accumulated in vegetables can, via $NO_2$ during storage and after their ingestion, cause the formation of methemoglobin and many of which are carcinogenic in human body. Especially such vegetables with the highest consumption in Korea as chinese cabbage and raddish frequently showed that high contents of nitrate and nitrite could accumulate. Therefore, pH and the content of nitrate and nitrite of Korean pickles made of upper vegetables, viz, Baiechu Kimchi, Yulmookimchi and Kakdooki were estimated during storage at the conditions of $5^{\circ}C$ and $25^{\circ}C Storage at $25^{\circ}C$ generally led to the more rapidly than that at $5^{\circ}C$. But changes of nitrite level showed very low variation in all tested Kimchi.

• 한국축산식품학회지
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• 제38권2호
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• pp.325-337
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• 2018

This study was conducted to evaluate the effects of pre and post-rigor marinade injections on some quality parameters of Longissimus dorsi (LD) muscles. Three marinade formulations were prepared with 2% NaCl, 2% NaCl+0.5 M lactic acid and 2% NaCl+0.5 M sodium lactate. In this study marinade uptake, pH, free water, cooking loss, drip loss and color properties were analyzed. Injection time had significant effect on marinade uptake levels of samples. Regardless of marinate formulation, marinade uptake of pre-rigor samples injected with marinade solutions were higher than post rigor samples. Injection of sodium lactate increased pH values of samples whereas lactic acid injection decreased pH. Marinade treatment and storage period had significant effect on cooking loss. At each evaluation period interaction between marinade treatment and injection time showed different effect on free water content. Storage period and marinade application had significant effect on drip loss values. Drip loss in all samples increased during the storage. During all storage days, lowest CIE $L^*$ value was found in pre-rigor samples injected with sodium lactate. Lactic acid injection caused color fade in pre-rigor and post-rigor samples. Interaction between marinade treatment and storage period was found statistically significant (p<0.05). At day 0 and 3, the lowest CIE $b^*$ values obtained pre-rigor samples injected with sodium lactate and there were no differences were found in other samples. At day 6, no significant differences were found in CIE $b^*$ values of all samples.

• 한국식품저장유통학회지
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• 제7권2호
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• pp.133-138
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• 2000

The research was conducted to measure the effect of temperature on respiratory and quality characteristics of 'Tsugaru' apple(Malus domestica Borkh) during storage at 4$^{\circ}$C, 10$^{\circ}$C and 20$^{\circ}$C. Respiration rate of the apple just after harvest was 7.57 mL CO$_2$/kg/h at 20$^{\circ}$C. It was decreased rapidly and was 2.86 mL CO$_2$/kg/h after storage for 45 days at 20$^{\circ}$C. The apples showed the highest ethylene production rate at 10$^{\circ}$C and 20$^{\circ}$C after 14 days, and at 4$^{\circ}$C after 28 days during storage. Weight of the apple was reduced by 2.9% after 120 days at 4$^{\circ}$C and by 6.1% after 45 days at 20$^{\circ}$C. Color difference of peel and pH increased with the temperatures but titratable acidity and flesh firmness showed the reverse trends during storage. According to the subjective quality test, it could be suggested that the shelf-life of the apple is 86 days at 4$^{\circ}$C, 65 days at 10$^{\circ}$C and 37 days at 20$^{\circ}$C, respectively.

• 한국식품과학회지
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• 제18권1호
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• pp.71-76
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• 1986

CA저장시 탄산가스농도에 따른 딸기의 pH, 적정산도, 유기산류 및 Brix 변화를 조사하였다. 저장기간이 경과함에 따라 pH 및 적정산도는 처리구간의 명확한 차이를 나타내지 않고 pH의 증가 ($\gamma\;=0.9615$)에 반하여 적정산도는 감소하는 경향 ($\gamma\;=-0.8483$을 보였다. 아스코르브산 함량은 대조구의 경우 저장 2주일까지는 CA저장구보다 높게 유지되었으나 그 이후부터는 급속히 감소되었으며 CA저장구중 용기내의 공기를 탄산가스로 30%치환시킨 저장구가 저장 5주일후에도 초기함량의 28%가 보존되었다. 검출된 유기산중 말산은 전반적으로 저장중 계속 감소되었는데 공기중에 탄산가스를 30% 혼합시킨 저장구가 다른 저장구에 비하여 완만하게 감소되었으며 피루브산은 대주고의 경우 저장기간중 계속 감소되었으나 CA저장구는 저장 2주일후 그 함량이 급속히 증가된 후 감소하는 경향을 보였다.

• 한국식품영양과학회지
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• 제33권1호
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• pp.201-206
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• 2004

쑥 분말의 첨가와 원료육 등급이 돼지고기 햄의 저장성에 미치는 영향을 검토하기 위하여, 규격돈(B등급) 및 경산모돈(E등급)에 쑥 분말을 첨가한 것과 첨가하지 않은 네 종류의 돼지고기 햄을 제조하였다. $L^{*}$ 값은 $B_{o}$ 및 $B_{+}$ 햄은 저장 후기가 높았으며, $E_{o}$ 햄은 저장 2주째 가장 높았고, $E_{+}$ 햄은 저장 중 변화가 없었다. 그러나 B등급육 햄의 $L^{*}$ 값이 E등급육 햄보다 높았으며, $a^{*}$ 값은 E등급육 햄이 높았다. 햄의 pH는 저장 중 감소하다가 저장 8주까지 증가하였다. 아질산 잔류량은 저장 2주까지 급격히 감소하였으며, 쑥 분말의 첨가는 아질산 잔류량의 감소에 영향을 미쳤다. VBN 함량은 저장초기 6.90∼7.90 mg%이던 것이 저장 중 증가하여 8주 째에는 14.07∼14.83 mg%를 나타내었다. TBARS는 저장 중 증가하였으며, 쑥 분말을 첨가한 것이 첨가하지 않은 것보다 저장 4주와 6주 째에 더 낮았다. 총균수는 모든 햄이 저장 중에 증가하였으며, 쑥 분말의 첨가는 총균수에 영향을 미치지 않았다.