• Korean Journal of Environmental Agriculture
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• v.32 no.2
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• pp.102-107
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• 2013

BACKGROUND: Pithy pear fruit are not distinguished externally from sound fruit and thus often cause unexpected economic losses. To find out the cause of pithiness, the pithiness incidence and characteristics of Japanese pear (Pyrus pyrifolia cv. Niitaka) fruit picked from a spot frequently produced pithy fruit in an orchard were compared with those of fruit picked from another spot produced sound fruit every year. And the soil chemical properties of the two spots and mineral contents in fruit, shoots, and leaves of Japanese pear trees cultivated in the two spots were also examined. METHODS AND RESULTS: The pithiness incidence was 0, 8.8, and 11.3% at 7 days before and 0 and 7 days after optimal harvest date, respectively, in the spot frequently produced pithy fruit. Flesh firmness was significantly lower in pithy fruit than in sound fruit, while soluble solids content was slightly higher in pithy fruit than in sound fruit. Unlike other mineral contents, Ca content was significantly lower in pithy fruit than in sound fruit. These results indicate that Ca deficiency in fruit is closely associated with decrease in flesh firmness and thus pithiness development. Ca content in soil of the spot frequently produced pithy fruit was also significantly lower than that in soil of the spot produced sound fruit. However, shoots or leaves did not exhibit significant difference in Ca and/or other mineral contents between the two spots, indicating that Ca deficiency in fruit is dependent on the translocation of Ca within a plant rather than soil Ca status. Although total-N, available $P_2O_5$, K, and Ca contents were significantly lower in soil of the spot frequently produced pithy fruit than in soil of the spot produced sound fruit, Mg and Na contents and pH were not different between the soil conditions. CONCLUSION(S): Fruit maturity and Ca level in fruit are closely related to the incidence of pithiness in 'Niitaka' Japanese pear.

• Journal of Biosystems Engineering
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• v.35 no.2
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• pp.124-131
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• 2010

Chlorophyll fluorescence has been researched for assessing fruit post-harvest quality and condition. The objective of this preliminary research was to investigate the potential of fluorescence spectroscopy for measuring apple fruit quality. Ultraviolet (UV) and blue light was used as an excitation source for inducing fluorescence in apples. Fluorescence spectra were measured from 'Golden Delicious' (GD) and 'Red Delicious' (RD) apples using a visible/near-infrared spectrometer after one, three, and five minutes of continuous UV/blue light illumination. Standard destructive tests were performed to measure fruit firmness, skin and flesh color, soluble solids and acid content from the apples. Calibration models for each of the three illumination time periods were developed to predict fruit quality indexes. The results showed that fluorescence emission decreased steadily during the first three minutes of UV/blue light illumination and was stable within five minutes. The differences were minimal in the model prediction results based on fluorescence data at one, three or five minutes of illumination. Overall, better predictions were obtained for apple skin chroma and hue and flesh hue with values for the correlation coefficient of validation between 0.80 and 0.90 for both GD and RD. Relatively poor predictions were obtained for fruit firmness, soluble solids content, titrational acid, and flesh chroma. This research has demonstrated that fluorescence spectroscopy is potentially useful for assessing selected quality attributes of apple fruit and further research is needed to improve fluorescence measurements so that better predictions of fruit quality can be achieved.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.199-209
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• 2017

This study detailed the effects of 1-methylcyclopropene (1-MCP) on ripening and fruit quality in red-fleshed kiwifruit (Actinidia chinensis) stored at 0 or $10^{\circ}C$ for 20 days, and $20^{\circ}C$ for 13 days. The quality of the fruit was assessed by measuring ethylene production, respiration rate, weight loss, firmness, flesh color, soluble solids content (SSC), and titratable acidity (TA), along with a sensory evaluation. Compared to untreated kiwifruit, fruit treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP for 24h at $20^{\circ}C$ prior to storage showed a delay in ripening and maintained fruit quality during storage. Ethylene production and respiration rate were affected by 1-MCP treatment only in fruit stored at $20^{\circ}C$, where the values were markedly higher compared to kiwifruit stored at 0 and $10^{\circ}C$. 1-MCP treatment resulted in a clear reduction in weight loss due to a delay in fruit ripening. The firmness of kiwifruit stored at 10 and $20^{\circ}C$ decreased significantly compared to fruit stored at $0^{\circ}C$, but 1-MCP treatment led to a reduction in this loss. Upon storage, SSC increased while TA decreased across all treatments. Sensory evaluation scores increased with decreasing firmness and acidity and increasing SSC. The shelf life of kiwifruit stored at $0^{\circ}C$ was extended without any chilling injury or color changes. In summary, the results show that 1-MCP treatment can potentially maintain quality and delay ripening of red-fleshed kiwifruit stored at all storage temperatures.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.511-513
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• 1998

Tomato fruits(Lycopersicon esculentum $M_{ILL}$.) picked at mature (from mature green to breaker) and ripe (from pink to red) stage were packed into two layers in corrugated fiberbox and transported 200km and 400km from the harvested site. Loss (abrasion + cracking) in marketability was lowest (11.0%) from mature + 200km transport, followed by mature + 400km transport(13.5%), ripe + 200km transport(28.5%), and ripe + 400km transport (45.5%). When data were pooled by fruit maturity, firmness of mature fruit was 1.55 times higher than ripe fruit. However, vitamin C content was 1.25 times higher in ripe fruit than in mature fruit. Fruit transported longer distance and packed in bottom layer within a box exhibited lower firmness and vitamin C content in both maturity. It was concluded that it is desirable to transport relatively shorter distance for ripe tomato and longer distance for less ripe fruit.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.145-148
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• 2001

This research was conducted to find out whether controlled atmosphere(CA) can maintain Satsuma Mandarin fruit fresh longer compared to cold storage. Fruit harvested in Nov. 1998 at Jeju Province were stored in three different CA condition including cold storage. The CA treatments consisted of combinations of 3%, 5% and 10.9% $CO_2$ with 1% and 3-3.9% $O_2$, respectively. Weight and firmness were maintained higher in static CA chambers than in the cold storage. Soluble solid content in fruit of cold storage increased until 2 months of storage and thereafter sharply decreased, whereas that of CA-stored fruit increased slowly throughout the storage period of 120 days. Citric acid decreased obviously in all the treatments with a partially longer retention in CA chambers during storage. Sensory evaluation clearly showed that CA could extend market period of Satsuma Mandarin fruit.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.20 no.2
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• pp.59-63
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• 2014

The quality changes of 'Fuyu' persimmon fruits chill-injured on tree with different time periods were evaluated during storage of 6 weeks at $0^{\circ}C$. There was no significant difference among treatments in the weight loss, which increased with storage time. Firmness was found to be very important factor determining the quality level of persimmon fruit during the storage. The increased chill-injured period decreased the firmness, indicating the rapid fruit softening. While the firmness of the persimmons not exposed to chill-injured condition was not changed significantly during the storage period, the firmness of persimmon fruits chill-injured for 1, 3, and 5 days decreased from 26.7, 16.1, 10.8 N to 18.2, 12.22, and 5.8 N for 6 weeks. The total solids content and total acidity did not significantly change during the storage period. The amount of ethylene production from the chill-injured fruits was almost 2 times higher than that without low temperature injury. The results indicated that persimmon fruit injured by low temperature exposure directly affected to the changes of its ethylene production and firmness during storage.

• Journal of Biosystems Engineering
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• v.37 no.3
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• pp.177-183
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• 2012

Purpose: In near infrared spectroscopy, interactance configuration of a light source and a spectrometer probe can provide more information regarding fruit internal attributes, compared to reflectance and transmittance configuration. However, there is no through study on the parameters of interactance measurement setup. The objective of this study was to investigate the effect of the parameters on the estimation of soluble solids content (SSC) and firmness of muskmelons. Methods: Melon samples were taken from greenhouses at three different harvesting seasons. The prediction models were developed at three distances of 2, 5, and 8 cm between the light source and the spectrometer probe, three measurement points of 2, 3, and 6 evenly distributed on each sample, and different number of fruit samples for calibration models. The performance of the models was compared. Results: In the test at the three distances, the best results were found at a 5 cm distance. The coefficient of determination ($R_{cv}{^2}$) values of the cross-validation were 0.717 (standard error of prediction, SEP=$1.16^{\circ}Brix$) and 0.504 (SEP=4.31 N) for the estimation of SSC and firmness, respectively. The minimum measurement point required to fully represent the spectral characteristics of each fruit sample was 3. The highest $R_{cv}{^2}$ values were 0.736 (SEP=$0.87^{\circ}Brix$) and 0.644 (SEP=4.16 N) for the estimation of SSC and firmness, respectively. The performance of the models began to be saturated when 60 fruit samples were used for developing calibration models. The highest $R_{cv}{^2}$ of 0.713 (SEP=$0.88^{\circ}Brix$) and 0.750 (SEP=3.30 N) for the estimation of SSC and firmness, respectively, were achieved. Conclusions: The performance of the prediction models was quite different according to the condition of interactance measurement setup. In designing a fruit grading machine with interactance configuration, the parameters for interactance measurement setup should be chosen carefully.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.270-278
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• 2022

This study was conducted using deep learning technology to classify for 'Mihwang' peach maturity with RGB images and fruit quality attributes during fruit development and maturation periods. The 730 images of peach were used in the training data set and validation data set at a ratio of 8:2. The remains of 170 images were used to test the deep learning models. In this study, among the fruit quality attributes, firmness, Hue value, and a^* value were adapted to the index with maturity classification, such as immature, mature, and over mature fruit. This study used the CNN (Convolutional Neural Networks) models for image classification; VGG16 and InceptionV3 of GoogLeNet. The performance results show 87.1% and 83.6% with Hue left value in VGG16 and InceptionV3, respectively. In contrast, the performance results show 72.2% and 76.9% with firmness in VGG16 and InceptionV3, respectively. The loss rate shows 54.3% and 62.1% with firmness in VGG16 and InceptionV3, respectively. It considers increasing for adapting a field utilization with firmness index in peach.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.583-591
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• 2011

'Formosa' plums were picked at three maturity stages according to skin redness, treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP at $10^{\circ}C$ for 24 h and then stored for 21 days at $10^{\circ}C$. Ethylene production, respiration rate, firmness, color, TSS, TA, and ethanol concentration were determined. Total phenolic content, total flavonoid content, and antioxidant capacity were determined periodically by separating the flesh from the peel. Ethylene production and respiration rate were strongly inhibited in all stages of the 1-MCP-treated fruit, while ethylene production dramatically increased in all stages of non-treated fruit until 11 days after harvest, after which it decreased until the end of the experiment. The respiration rate of the stored fruit increased for 11 days in stages 1 and 2 and for 7 days in stage 3 and decreased after. 1-MCP-treated fruit in all stages showed delay in fruit quality changes such as firmness, TA, skin color, and ethanol concentration, but non-treated fruit did not. Total phenolic contents, total flavonoid contents and antioxidant capacity of 'Formosa' plums were not affected by 1-MCP treatment or maturity stage. However, those values were higher in the peel than in the flesh.

• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.191-196
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• 2013

This study was conducted to investigate the effect of temperature during transportation and continuing shelf-life on fruit quality and the occurrence of physiological disorder to set up the appropriate exportation temperature condition in Asian pear (Pyrus pyrifolia Nakai) 'Hanareum'. In the experiment of simulated exportation headed for USA, the fruits transported at $1^{\circ}C$ showed less weight loss than those of $5^{\circ}C$. Market temperature appeared as a key factor for keeping freshness of exported pear fruits rather than transportation temperature. Quality factors such as high flesh firmness and low incidence of fruit rot and physiological disorders including core breakdown and pithiness were attained at the fruits maintained at $18^{\circ}C$. Approximately two times higher incidence of physiological disorders and of fruit decay rates were observed in the fruits distributed at $25^{\circ}C$ than the those of $18^{\circ}C$. Therefore, temperature management during marketing resulted as an important factor for maintaining fruits quality in the process of pear fruit exportation.