• 한국환경농학회지
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• 제26권2호
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• pp.171-178
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• 2007

Ethoprophos 수용액에 담가 둔 후지사과, 황금배, 신고배 내에서 ethoprophos의 확산과 축적 거동을 조사하였다. $25^{\circ}C$에서 용액의 농도 감소로부터 계산한 과일 내 축적량 곡선을 과피와 과육의 연계확산 모형으로 모사하여 ethoprophos의 유효확산계수를 결정하였다. 수분 함량이 높은 과육에서는 과일의 종류에 관계없이 ethoprophos의 유효확산계수가$\sim10^{-10}\;m^2/s$로 비슷하였다. 과피에서는 유효확산계수가 $\sim10^{-12}\;m^2/s$로 작았으며, 후지사과 > 황금배 > 신고배 순으로 작아졌다. Ethoprophos 용액의 농도에 따라 과육에서 유효확산 계수는 변하지 않았으나, 과피에서는 용액의 농도가 진해짐에 따라 유효확산계수도 커졌다. 과피에서 물질이동 속도는 과일내 ethoprophos의 축적 속도를 결정하는 중요 인자이었다.

• Journal of Biosystems Engineering
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• 제37권1호
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• pp.28-35
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• 2012

Purpose: This study performed the oscillatory test using the texture analyzer to characterize the viscoelastic behavior of apples such as the storage modulus (E'), the loss modulus (E"), the complex modulus (${\mid}E^*{\mid}$) and the energy dissipated per cycle ($W_{diss}$). Methods: The sinusoidal deformation with the frequency of 1-10 Hz and the maximum displacement of 0.1 mm were applied to the flesh tissues of Fuji, Golden Delicious and Red Delicious apples. The Lissajous figure was used to measure the phase angle(${\delta}$) between stress and strain curve. Results: Trigger force was critical to the measurement of the phase angle. E', E", ${\mid}E^*{\mid}$ and Wdiss were measured using the Lissajous figure and the phase angle. The complex modulus of Golden Delicious apple was significantly lower than those of Fuji apple and Red Delicious apple. Conclusions: Apple flesh was exhibiting more elasticity at low frequency, and more viscosity at high frequency. Dynamic compressive properties of Fuji apple were similar to those of Red Delicious apple but significantly different from those of Golden Delicious apple.

• Journal of Biosystems Engineering
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• 제22권4호
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• pp.433-438
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• 1997

The freshness of apple was evaluated by characterizing the surface texture of flesh cells. The freshness index which was related to the amount of wrinkles on the cell surface was defined to quantify the freshness. Four parameters relevant to the amount of the cell wrinkles were selected and measured using image analysis including wrinkle extraction procedure and Fast Fourier Transform of a wrinkle-extracted image. Out of 4 parameters, three parameters had highly significant correlations with the time elapsed after harvest. But it was concluded that two parameters out of such 3 parameters could be used for description of freshness index.

• Agricultural and Biosystems Engineering
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• 제3권1호
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• pp.10-17
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• 2002

Quality attributes of apple are greatly affected by the cooling rate and environmental conditions during storage. Studies were conducted to evaluate the effect of cooling rate on different quality attributes of apple. The effect of $O_2$ pulldown rate of the CA chamber on the quality of apple was also determined. Two methods were used viz. conventional CA procedure and rapid CA procedure. Apples stored by medium and slow cooling methods lost its flesh firmness significantly from an initial level of 4.55 kg to 2.83 kg and 2.27 kg, respectively on 35 days after storage whereas, in rapid cooling, the firmness level changed from 4.55 kg to 3.20 kg on 35 days after storage. At the end of 35 days of storage, titratable acidity decreased insignificantly from an initial value of 0.24l% to 0.239% in the case of rapid CA whereas in the case of conventional CA it dropped significantly to 0.215% from its initial level. The initial flesh firmness of 4.55 kg also changed significantly to 4.05 kg on 35 days after storage in conventional CA whereas in rapid CA it changed to 4.36 kg, which was found to be non-significant at 5% level of significance. Total soluble solids increased from an initial level of $12.43^{\circ}$Bx to $12.60^{\circ}C.$ Bx on 35 days after storage in rapid CA whereas it increased to $13.07^{\circ}$ Bx in conventional CA. Ascorbic acid content of apple juice decreased insignificantly from 6.67 mg/100 mL to 5.87 mg/100 mL on 35 days after storage in rapid CA whereas in conventional CA, it decreased significantly to 5.27 mg/100 mL from its initial level.

• Food Science and Biotechnology
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• 제15권2호
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• pp.177-182
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• 2006

Polyphenol oxidase (PPO) was isolated from the flesh of Fuji apples by DEAE-Cellulose, ammonium sulfate precipitation, phenyl-Sepharose CL-4B, and Sephdex G-100 chromatography. The molecular mass of the purified PPO was estimated to be 40 kDa by SDS polyacrylamide gel electrophoresis. With regard to substrate specificity, maximum activity was achieved with chlorogenic acid as substrate, followed by catechin and catechol whereas, there was no detectable activity with hydroquinic acid, resorcinol, or tyrosine as substrate. The optimum pH and temperature with catechol as substrate were 6.5 and $35^{\circ}C$, respectively. The enzyme was most stable at pH 6.0 and unstable at acidic pH. The enzyme was stable when it was heated to $45^{\circ}C$ but heating at $50^{\circ}C$ for more than 30 min caused 50% loss of activity. Reduced $ZnSO_4$, L-cystein, epigallocatechin-3-o-gallate (EGCG), and gallocatechin gallate (GCG) also inhibited activity.

• 한국식품저장유통학회지
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• 제1권1호
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• pp.29-36
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• 1994

This study was carried out for the establishment of optic harvest date and storage condition of 'Fuji' apple for CA storage. Apples were picked at 10 day intervals from 17 Sept to 27 Oct.. Apples were analyzed for respiration rata, weight flesh firmness, titratable acidity, soluble solid, total sugar, reducing sugar, surface color and thiault value. In 1990, the optimal harvest season could be judged between 17 Oct. and 27 Oct. from the results of respiration rate rise and change of quality properties. Apples harvested on 27 Oct. wert stored at 2$^{\circ}C$ and 90~95% RH in 1%O2 + 3%CO2, 3%O2 + 3%CO2 and air for 9 months. After 9 months of storage, apples kept in CA storages had beater quality than apples kept in refrigeration storage. Especially, apples kept in 1%O2, + 3%CO2 were fumer and more acid than those kept in 3%O2 + 3%CO2 At the sensory evaluations, apples stored in CA were rated higher quality than apples stared refrigeration.

• 원예과학기술지
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• 제30권5호
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• pp.527-533
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• 2012

'후지'(/M.9, 8년생) 나무를 대상으로 '후지' 사과의 수확 전 AVG처리와 수확 후 열처리에 따른 과실의 저장성 향상에 미치는 영향을 구명하기 위하여 본 실험을 수행하였다. '후지' 사과에 AVG $75mg{\cdot}L^{-1}$을 만개 후 150일과 175일에 처리한 후 과실을 만개 후 185일부터 10일 간격으로 3회에 걸쳐 수확하여 저장하였을 때, 호흡량과 에틸렌 발생량은 AVG처리 과실이 무처리 과실에 비해 현저히 낮았다. 그리고 산 함량과 경도는 더 높게 나타났다. 내부 갈변은 무처리 과실에서는 모두 발생하였지만, AVG 처리 과실은 마지막 수확 일을 제외하고는 발생하지 않았다. '후지' 사과를 $38^{\circ}C$에서 3일, $46^{\circ}C$에서 6시간 동안 열처리 후 CA 저장하였을 때 호흡량과 에틸렌 발생량은 무처리 과실에 비해 현저히 억제되었다. 내부 갈변 발생률은 $46^{\circ}C$ 열처리(5%)와 $38^{\circ}C$ 열처리(14%)가 무처리(38%)에 비해 적었다. 그러나 산 함량은 열처리한 과실이 무처리 과실에 비해 낮았다.

• Preventive Nutrition and Food Science
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• 제19권2호
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• pp.108-114
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• 2014

Four Korean kernel fruit (apple, pear, persimmon, and mandarin orange) juices were obtained by household processing techniques (i.e., blending, juicing). Whole and flesh fractions of each fruit were extracted by a blender or a juicer and then examined for phytochemical content (i.e., organic acids, polyphenol compounds). The antioxidant capacity of each juice was determined by ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays. Results revealed that juices that had been prepared by blending whole fruits had stronger antioxidant activities and contained larger amounts of phenolic compounds than juices that had been prepared by juicing the flesh fraction of the fruit. However, the concentration of ascorbic acid in apple, pear, and mandarin orange juices was significantly (P<0.05) higher in juice that had been processed by juicing, rather than blending. The juices with the highest ascorbic acid (233.9 mg/serving), total polyphenols (862.3 mg gallic acid equivalents/serving), and flavonoids (295.1 mg quercetin equivalents/serving) concentrations were blended persimmon juice, blended mandarin orange juice, and juiced apple juice, respectively. These results indicate that juice extraction techniques significantly (P<0.05) influences the phytochemical levels and antioxidant capacity of fruit juices.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 1998년도 정기총회 및 제13차 학술발표회 진행표 및 발표논문 초록집
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• pp.35-45
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• 1998

• 현장농수산연구지
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• 제8권1호
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• pp.21-29
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• 2006

우리사과의 재배노력 절감으로 대외경쟁력 향상을 위한 기초 자료로 활용코자 몇가지 실험을 수행한 결과는 다음과 같다. 사과 수확시 및 선별시 과경에 의한 과피의 상처발생은 선별시 보다 수확시에 많이 발생하였고 대과에서 상처발생이 심하였다. 사과 수확시 과경을 절단하면서 수확하면 과경을 절단하지 않고 수확하는 것보다 수확량이 반이하로 줄어서 수확노력이 배 이상 소요된다. 사과 선별기의 접시와 집적판 사이의 간격이 0cm인 경우에 소과에서 과피에 상처가 적게 발생하였다. 사과의 과경을 절단하여 저장하는 것이 과경을 무절단하여 저장하는 것 보다 과중이 크게 감소되어 저장시에는 사과의 과경을 절단하지 않도록 하여야 할 것으로 생각되며 사과의 과경절단 유무에 따른 사과의 경도는 차이가 없었다. 경와부 밖으로 돌출된 사과과경의 길이는 사과의 크기와 차이가 없는 경향 이었다. 따라서 사과의 과경을 절단하지 않음으로서 과경절단에 소요되는 노력절감 및 과경절단 비용을 소득화 하고 원활한 대일 수출, 품질유지 등에 기여하였으면 한다.