• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.72-79
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• 2014

This study was investigated the changes in quality of peeled chestnut according to peeling method, including abrasion and knife, and 3 kinds of storage temperatures. The weight loss rate of peeled chestnut during storage period was observed in all treatment groups, peeling methods showed no difference of the loss. However, the moisture content of peeled chestnut during storage in all treatments showed a tendency to decrease. Moisture content of the abrasion peeled chestnut in all treatments was higher than that of the knife peeled chestnut. In the case of a, b, and ${\Delta}E$ value of peeled chestnut chromaticity increased during storage in all treatments, whereas, L values decreased during storage. But, browning of abrasion peeled chestnut was higher than that of the knife peeled chestnut. The hardness of the abrasion and knife peeled chestnuts were the highest in $-1^{\circ}C$ storage, soluble solid content was decreased with storage time in all treatments, but showed a tendency to increase within 24 days. Palatability and texture of peeled chestnuts decreased in all treatments during storage period, 15 days after storage decreased rapidly. Thus, results showed that peeled chestnuts stored at $4^{\circ}C$ and $2^{\circ}C$ were rapidly decreased in the quality after 15 days, whereas, peeled chestnuts stored at $-1^{\circ}C$ slowly decrease in the fruit quality. It can be recommended that chestnut in vacuum film is good to maintain at $-1^{\circ}C$ storage for 15 days. Also, if we can reduce the browning of abrasion peeled chestnut, we will produce peeled chestnut of high quality.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.26-32
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• 2017

We studied the effects of dip treatments of natural extracts (Camellia sinensis, Angelica gigas, Astragalus membranaceus, Glycyrrhiza uralensis: 1% extract) on the quality of peeled 'Daebo' chestnut. After dipping treatment peeled chestnuts were vacuum packaged with $75{\mu}m$ PE+Nylon 7-layer film then stored in $4^{\circ}C$ incubator for 35days. The quality changes including the surface color and off-odor were evaluated for storage days. The natural extracts dipping treatment on peeled chestnut was effective on skin browning inhibition. Especially, Astragalus membranaceus and Glycyrrhiza uralensis extract treatments was significantly effective in reducing surface browning. The color change (${\Delta}E$) of peeled chestnut was the highest (5.6) in control, whereas that was the lowest (3.4) under Astragalus membranaceus extract treatment at 35 storage day. The natural exteacts treatments had no effect on the weight, the mositure loss rate, the firmness and the soluble solid contencts of peeled chestnuts during storage after treatment. The decaying rate of peeled chestnut was 9.0% in control, 9.0% in Camellia sinensis extract treatment, 9.0% in Angelica gigas extract treatment, 21.0% in Astragalus membranaceus extract treatment, and 7.0% Glycyrrhiza uralensis extract treatment at 35 storage day. Sensory evaluation revealed significant differences in off-odor and color attributes. After all, the score of overall sensory evaluation was the lowest in Astragalus membranaceus extract treatment and the highest in Glycyrrhiza uralensis extract treatment. As the results, the natural extract treatments, especially with vacuum packing after Glycyrrhiza uralensis extract treatment, extended the shelf-life of the peeled chestnut by inhibiting the surface browning.

• Journal of Biosystems Engineering
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• v.38 no.3
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• pp.185-191
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• 2013

Purpose: The present study focused on the estimation of soluble solids content (SSC) of chestnut using reflectance and transmittance spectra in range of VIS/NIR. Methods: Four species intact/peeled chestnuts were used for acquisition of spectral data. Transmittance and reflectance spectra were used to develop the best PLS model to estimate SSC of chestnut. Results: The model developed with the transmitted energy spectra of peeled chestnuts rather than intact chestnuts and with range of NIR rather than VIS performed better. The best $R^2$ and RMSEP of cross validation were represented as 0.54 and $1.85^{\circ}Brix$. The results presented that the reflectance spectra of peeled chestnuts by species showed the best performance to predict SSC of chestnut. $R^2$ and RMSEP were 0.55 and $1.67^{\circ}Brix$. Conclusions: All developed models showed RMSEP around $1.44{\sim}2.54^{\circ}Brix$, which is considered not enough to estimate SSC accurately. It was noted that $R^2$ of cross validation that we found were not high. For all that, grading of the fruits in two or three classes of SSC during postharvest handling seems possible with an inexpensive spectrophotometer. Furthermore, the development of estimation of SSC by each chestnut species could be considered in that SSC distribution is clustering in different range by species.

• Food Science and Preservation
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• v.8 no.4
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• pp.385-392
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• 2001

This study was to investigate the inhibiting effect of electrolyzed oxidizing (EO) water with/without freezing point depressing agents on polyphenol oxidase (PPO) activity of peeled chestnut. 0.85% sodium chloride, 0.5% citron and 0.5% lemon juice were used to freezing point depressing agents. The content of total phenolics was 13.36 mg% at the earlier stage of storage, and then suddenly increased at around 8∼1ldays. At the 11th day, PPO activity of untreated chestnut was 1,152 units, that was higher than any ethers. EO water adding lemon and citron juice showed synergistic effects on the enzyme inhibition, and their PPD activities were 143.3 and 180.22 units after 4 weeks, respectively. Sensory analysis showed that acceptance of peeled chestnuts was dependent on color and taste, which was related to PPO activity and sweetness. The peeled chestnut treated with EO water added citron or lemon juice tended to show the highest score fur acceptance.

• Journal of Biosystems Engineering
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• v.24 no.5
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• pp.407-414
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• 1999

To evaluate the quality of flame-peeled chestnuts, their physical and chemical properties were analyzed. The physicochemical properties of flame-peeled chestnuts, including geometrical shape, texture and chemical composition, were compared to those of hand-peeled ones. For the flame-peeled chestnuts, some properties in heated and non-heated sections were separately analyzed. The color, texture such as springness, cohesiveness, adhesiveness, hardness and chewiness, moisture content, and reducing sugar of the heated section of the flame-peeled chestnuts were significantly different with their non-heated section. But the physicochemical properties of the non-heated section of the flame-peeled chestnuts were similar to those of the hand-peeled ones.

• Food Science and Preservation
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• v.14 no.5
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• pp.462-468
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• 2007

In this study, the quality effect of soaking in alum water, soaking in electrolyzed oxidizing water, and freezing during storage, on peeled chestnuts, were analyzed. When soaked in 0.1% (w/v) alum water, peeled chestnuts showed good characteristics in terms of weight loss, decomposition, and color preservation. However, texture and taste qualities rapidly decreased with increases in storage time. When soaked in twice their own weight of electrolyzed oxidizing water(pH 2.61, ORP 1,142 mV) for 10 min, the samples were preserved in an optimally edible condition. When frozen at $-10^{\circ}C$ for 5 min, the samples were suitable for use as material for processed chestnut produce, as was also the case when pretreatment with electrolyzed oxidizing water was employed.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.07a
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• pp.217-223
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• 2000

• Journal of Korean Society of Forest Science
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• v.102 no.1
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• pp.7-14
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• 2013

This study investigated the optimum condition of abrasion peeling machine and pellicle peeling ability of chestnut (Castanea spp.) varieties for the efficient production of peeled chestnuts. The optimum conditions were 50 minutes peeling time and 27 rpm of drum rotation speed and chestnut pellicle peeling ratio was 89.3%. Among 8 Korean chestnut varieties which were peeled under the optimum condition (27 rpm/50 min), 'Tsukuba (89.3%)', 'Tanzawa (72.2%)' and 'Ishizuchi (70.9%)' showed the highest ratio of pellicle peeling ratio. 'Tsukuba' had the most excellent peeled (grade I) chestnuts (77.3%), followed by 'Ishizuchi (46.7%)', and 'Tanzawa (45.0%)'. Regarding the chestnuts quality for commercialization, 'Tsukuba' had the most excellent peeled chestnuts (90.5%), followed by 'Tanzawa (74.8%)', and 'Ishizuchi (74.3%)'. 'Mipung (37.2%)' had the most broken and injured chestnuts and 'Tsukuba (5.9%)' had the least broken and injured chestnuts. Therefore this study concluded that 'Tsukuba' was the superior variety for producing high value-added processed chestnuts.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.07a
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• pp.207-216
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• 2000

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.84-89
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• 2015

The effects of dip treatments of chemicals (ascorbic acid, citric acid, calcium chloride: 1% solution) and physicals (vacuum packing, $50^{\circ}C$ distilled water) on the browning and quality of 'Daebo' peeled chestnut were studied. During the storage, the surface color of the samples showed higher ${\Delta}E$ values and lower L values than that of the initial sample. The color with the normal packing treatment hardly changed, unlike in the chemical and physical treatments. The calcium chloride treatment showed less color change than other treatments. The marketable quality was maintained for 10 days with the normal packing and for 35 days with the chemical and physical treatments. Thus, the chemical and physical treatments, especially with vacuum packing after 1% calcium chloride treatment, extended the shelf-life of the 'Daebo' peeled chestnut by inhibiting the browning.