• The Korean Journal of Food And Nutrition
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• v.25 no.3
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• pp.637-643
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• 2012

This study was performed to increase the utilization of rice and improve the productivity of jochung, traditional food in Korea. Two kinds of jochung products were prepared from steamed rice(SR) and wet-milled rice flour(WRF) by rice cultivated from 2006 to 2010. It is common to add a liquefying enzyme for rice liquefaction(4 $m{\ell}$/1,000 g rice, at $90{\sim}95^{\circ}C$, 3 h) and saccharogenic enzyme with malt(45 g/1,000 g rice, at $55{\sim}57^{\circ}C$, 6 h). In order to evaluate the quality characteristics of jochung, producing rate, pH, solidity, reducing sugar, dextrose equivalence(D.E.), viscosity, total phenolic compound, color value and sensory evaluation were carried out. In terms of the producing rate of jochung, WRF jochung was produced about 7.4% much more than SR jochung. There was no difference in producing rate between the jochung cultivated from 2006 to 2010 rice. The pH varied from 4.86~5.66, solidity was 79.48~82.28%. Color L value was 25.82~27.92, a value of 1.28~2.81, b value were 2.98~4.33. The results of sensory evaluation for jochung, as a whole, received higher score than for the commercial product(Daesang Co., Ltd, Seoul, Korea), overall acceptability score was the highest in the 2008SR. Reducing sugar, dextrose equivalence(D.E.) and total phenolic compounds were determined to be higher WRF jochung than SR jochung, while viscosity was lower WRF jochung than SR jochung. These results are thought to be due to increased surface area of rice by milling. SR jochung manufacturd by wet-milled rice flour will increase the producing rate for jochung, thereby saving manufacturing time and costs.

• Food Science and Preservation
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• v.23 no.6
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• pp.804-810
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• 2016

This study aimed to compare the quality characteristics of developed rice Jochung (E) with those of commercial-rice Jochung (A, B, C, and D). The total soluble solid, reducing sugar, and dextrose equivalent of developed rice Jochung were $80^{\circ}Brix$, 44.53%, and 56.94%, respectively. The pH and titrable acidity were 6.25 and 0.19%, respectively. The color difference value (${\Delta}E$) of developed rice Jochung was 74.42, which was significantly lower than the other samples investigated. The light transmittance and total polyphenol contents of developed rice Jochung were 56.4%T and 108.23 mg GAE/100 g, respectively. The adhesiveness values of various commercial-rice Jochung products were 29.0~66.0 sec, while that of developed-rice Jochung was 61 sec, showing good textural properties for use in manufacturing Hangwa, a Korean traditional cookie. The electron-donating values of various rice Jochung were 20.4~50.3%, among which the developed-rice Jochung showed the highest value. The reducing powers of various rice Jochung products were 0.44~0.72, while that of the developed product was 0.72, which was significantly higher than the other values. Sensory evaluation revealed that the color scores of developed- and commercial-rice Jochung products were 6.70~6.80. Flavor scores of rice Jochung products ranged from 6.00 to 7.00. Taste and mouth feeling scores of developed-rice Jochung did not significantly differ from those of commercial Jochung products. Compared to commercial-rice Jochung products, developed-rice Jochung made with malt extract exhibited high polyphenols content. However, there were no significant differences in the overall acceptability scores between commercial-rice Jochung products and the developed product. The developed-rice Jochung analyzed in this study may be useful as a traditional sweetener for various Hangwa products as a substitute for corn syrup or Jochung.

• Korean journal of food and cookery science
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• v.31 no.5
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• pp.557-564
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• 2015

This study was performed to investigate the effect of Gastrodia elata extract on the quality characteristics of Non-glutinous rice porridge Jochung, saccharide by barley malt. Non-glutionous Rice Porridge Jochung with 0% (NGR1), 5% (NGR2), 10% (NGR3), 15% (NGR4) and 20% (NGR5) Gastrodia elata extract were produced. Moisture content and Solids content the interaction of two factors, the pH decreased with increasing Gastrodia elata extract concentration. Reducing sugar was significantly higher in groups containing Non-glutinous Rice Porridge Jochung (NGR) with Gastrodia elata extract added than the control group, especially the 15% NGR4 addition group with $1.22{\pm}0.02g/L$. Free acidity contents were 27.27 meq/kg control and 29.67~41.03 meq/kg among the samples with p<0.001. There were significant levels of total phenolics and TEAC found for the antioxidant activity of the Jochung samples with Gastrodia elata extract added. Increasing the ratio of Gastrodia elata Extract in Jochung tended to decrease color value. The results showed that Jochung containng less than 15% Gastrodia elata Extract gave the highest scores in quality characteristics and sensory evaluation.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.1018-1028
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• 2015

This study was performed to investigate the effects of Gastrodia elata extract on the quality characteristics of glutinous rice porridge Jochung saccharide by barley malt. Glutinous rice porridge Jochung contatining 0%, 5%, 10%, 15%, 20% of Gastrodia elata extract were produced. Soluble solid contents and pH increased as content of Gastrodia elata extract increased. Free acidity contents were 24.87 meq/kg (control) and 25.67~42.03 meq/kg (GR2~GR5) (p<0.001 among samples). There was significant total phenolics and TEAC obtained for antioxidant activity of Gastrodia elata extract Jochung samples. Increased the ratio of Gastrodia elata extract in Jochung tended to decrease the color value. Results show Jochung containg less than 15% Gastrodia elata extract resulted in the highest scores for quality characteristics and sensory evaluation. Correlations between antioxidant activity and parameters were found to be statistically significant.

• The Korean Journal of Food And Nutrition
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• v.27 no.3
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• pp.414-420
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• 2014

This study was performed to increase the yield and to reduce the processing times for the preparation to improve the productivity and quality of rice jochung, a traditional food in Korea. In order to evaluate the quality characteristics and yield of jochung, the viscosity, color value, mineral contents and the sensory evaluation were measured. Jochung is prepared from steamed rice (STR), wet-milled rice flour (WRF) and dry-milled rice flour (DRF) by processing methods of rice and reacting times (6 hours or 13 hours) of liquefaction and saccharification. There is commonly added liquefying enzyme for rice liquefaction (0.4%/10 kg rice, at $85{\sim}90^{\circ}C$ for 1 hour or 4 hours) and saccharogenic enzyme with malt (2.5% or 4.5%/10 kg rice, at $56{\sim}60^{\circ}C$ for 5 hours or 9 hours). The inner structural properties of WRF showed the more distinct shape regular structure of uncombined starch particles but the DRF closely maintained particles of rice flour observed by SEM. If processing times for liquefation and saccharification were reduced from 13 hours to 6 hours, the yield of jochungs prepared with WRF increased 8%, the DRF 7%, and the STR 3% respectively and the sensory evaluation as well as color values and overall desirability received high scores. The viscosity, color a and b values of jochung processed with WRF for 6 hours were lower than that processed for 13 hours. The viscosity and color a, b value and Ca content were decreased in the jochung processed with WRF or DRF for 6 hours, but Mg, P and K were increased than that of STR. Jochung processed by 0.4% liquefying enzyme and 2.5% malt with WRF for 6 hours will increase the yield, save manufacturing times and costs and will thereby enable cost-effective techniques.

• Food Engineering Progress
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• v.13 no.4
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• pp.235-242
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• 2009

The purpose of this study is to establish fundamental research data for quality characteristics of Jochung by analyzing traditional manufacturing process. Two different processed rices (non-glutinous rices cooked by steaming and using an electronic rice cooker) were compared in terms of water solubility index (WSI), water absorption index (WAI), paste viscosity, reducing suger content, solid content, and dextrose equivalent over soaking time. Reducing sugar content increased for the soaked non-glutinous rice, steamed sample and microwaved sample. After 4 hr, the WSI decreased as the soaking time increased. However, there was no significant difference between WAI of the raw non-glutinous rice and the soaked non-glutinous rice. As soaking time increased, paste and breakdown viscosity increased significantly. Rice was prepared by soaking in water for 12 hr followed by the saccharification time (4, 8, or 12 h) for manufacturing Jochung. The solid content and reducing sugar content of the Jochung increased as the soaking time increased. Reducing sugar content and dextrose equivalent of Jochung from steamed rice (cooked hard) were higher than those from microwaved ones. The amount of reducing sugar and dextrose equivalent was highest in Jochung from steamed rice cooked hard (saccarification for 12 hr), with 59.40${\pm}$0.11% and 76.99${\pm}$1.78, respectively. In conclusion, the highest quality characteristics were obtained in Jochung manufactured with non-glutinous rice soaked for 12 hr followed by sacharification for 12 hr.

• Journal of the Korean Society of Food Culture
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• v.30 no.5
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• pp.656-666
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• 2015

This study was performed to investigate the effect of Gastrodia elata powder on the quality characteristics of Jochung with barley malt. Grain syrups with 0, 2.5, 5, 7.5, and 10% Gastrodia elata powder were produced. The pH value decreased with higher volume of Gastrodia elata powder and showed a significant difference between the samples (p<0.05). Total polyphenol content was 77.45~129.25 mg/100 g, and DPPH radical scavenging ability was $36.70{\sim}57.09{\mu}mol$. Sensory score of Jochung containing 2.5% Gastrodia elata powder was similar to that of control. Jochung containing less than 7.5% Gastrodia elata powder gave the highest scores in terms of quality characteristics and sensory evaluation. The data from different procedures were compared and analyzed by multivariate techniques (correlation matrix, principal component analysis). Correlations between antioxidant activity and the analyzed parameters were found to be statistically significant (p<0.05).

• Journal of the East Asian Society of Dietary Life
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• v.25 no.6
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• pp.979-989
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• 2015

The purpose of this study was to investigate the usage and perception jochung Self-administered questionnaires were collected from 445 living residents in the Daegu and Gyeongbuk areas. When purchasing jochung, respondents answered that they considered both health and taste. Recognition rate scores for jochung were in the order of 'brown rice', 'balloon flower', 'plum', and 'corn'. On the other hand, recognition rate scores for 'purple radish', 'sword bean', and 'sasa quelpaertensis' were very low. Preference and intake levels of jochung were in the order of 'plum', 'corn', 'sorghum', 'strawberry' and 'balloon flower'. On the other hand, preferences for 'purple radish', 'sword bean', and 'Hovenia dulcis' were very low. Reasons for eating jochung as a sweetener were identified as due to 'family, friend, or neighbor' (40.1%) and 'for health' (39.2%), and 54.6% ate it once or twice per week. Consumers showed low preference for different jochung used as sweeteners, and did not exactly recognize the characteristics of various jochung. Furthermore, 70.8% replied "increasing" prospects for jochung consumption. To increase consumption of jochung, there is a need for greater hygiene and safety with regards to jochung products as well as variations and improvements in quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.1
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• pp.132-137
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• 2010

This study was performed to investigate the effect of apple and maltitol as ingredients on the quality of Jochung, a grain syrup. Four kinds of Jochung products were prepared from steamed-rice, apple juice, heated-apple sarcocarp (at $70^{\circ}C$, 60 min), and a mixture (sarcocarp : maltitol＝5:1, w/w) by saccharifying (at $55^{\circ}C$, 8 hrs) with a malt (100 g/500 g rice), mixing the ingredients (steamed-rice : ingredient＝5:5, w/w), filtering, and heating the filtrate (at $95^{\circ}C$, 2 hrs): product (A) with apple juice added before saccharified, product (B) with apple juice added after saccharified, product (C) with heated-apple sarcocarp added after saccharified, and product (D) with the mixture added after saccharified. The product (D) had the lowest pH value ($4.60\pm0.01$) of any other products. The contents of reducing sugar and total phenolic compound were the highest in the product (A) among all the products, which comprised $68.10\pm6.71$% and $7.36\pm0.85$ mg/g, respectively, resulting in good quality. The solidity and the dextrose equivalence had the highest value in the product (B) and the product (C), respectively. The malic acid content ($4.10\pm0.02$%) of the product (D) was the highest of any other organic acids identified by HPLC. Hunter L, a, and b values of the product (D) were the highest compared to other products. In sensory evaluation, the product (A) had generally higher score in all sensory attributes. It was concluded from the chemical and sensory evaluation that adding the apple juice before saccharified might be an effective method for manufacturing good quality rice-Jochung.

• Applied Biological Chemistry
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• v.44 no.2
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• pp.88-91
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• 2001

Mixtures of rice and sweet persimmons to make sweet syrup, jochung, were saccharified by barley malt. Soluble solid contents, reducing sugar and free sugar contents, and sensory quality were determined in jochungs, which were prepared from various ratios (10 : 0, 7 : 3, 5 : 5, 3 : 7) of rice to sweet persimmons. Amylase activity had the highest value, 10466 Unit, after 3 hrs during saccharification process at $55^{\circ}C$. In HPLC determination of free sugars, maltose in saccharifying liquids found the highest amount followed by fructose and glucose. With increasing amounts of sweet persimmons, fructose and glucose contents increased while maltose content decreased. The soluble solid contents reduced as the sweet persimmons proportions increased. The control group without sweet persimmons showed highest value, $58^{\circ}Brix$, in soluble solid content. There appeared to be a slight decrease in reducing sugar and free sugar contents as proportion of sweet persimmons increased. Jochung prepared at high amounts of sweet persimmon had better scores in overall acceptance.