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http://dx.doi.org/10.13103/JFHS.2019.34.1.100

Enhancement of Konjac Storage by Controlling pH of Coagulant and Soaking Liquid  

Choi, Ung-Kyu (Department of Food Science & Technology, Koera National University of Transportation)
Publication Information
Journal of Food Hygiene and Safety / v.34, no.1, 2019 , pp. 100-105 More about this Journal
Abstract
In this study, viable cells, coliforms and food poisoning bacteria were identified according to the pH levels of the coagulant and immersion liquid during each stage in the production of konjac, and storage stability was confirmed for 3 months. A considerable number of bacteria were found in the raw material, or powdered konjac (Amorphophallus konjac), as well as in the processing water. However, it has been shown that the plastic package were safe from microorganisms. Due to the high pH of the added coagulant [2.0% $Ca(OH)_2$], no contaminating bacteria were observed after konjac jelly formation. Coliforms were not detected any of the tested steps. During the molding process, the pH of konjac was adjusted to 9.5 ~ 12.5 at intervals of 0.5, and the number of bacteria was determined. As a result, no bacteria were detected in the alkaline range above pH 11.5. The pH of the immersion liquid was adjusted to 10.0 ~ 12.5, and after hardening, the konjac were stored at room temperature for 12 weeks. As a result, no bacteria, Escherichia coli or other food poisoning bacteria were detected at pH 11.5 or higher. Based on these results, it is expected that when the pH levels of the konjac and its immersion liquid are maintained at 11.5, it should be possible to keep the product for 3 months without additional sterilization process.
Keywords
Konjac jelly; Molding process; pH 11.5; Soaking liquid;
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Times Cited By KSCI : 6  (Citation Analysis)
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1 Kishida N.: Relationship between the quality of konjac flour and the molecular matter nature of konjac-mannan. Agr. Biol. Chem. Tokyo, 43, 2391-2397 (1979).
2 Yoo M.H., Lee H.G., Lim S.T.: Physical properties of the films prepared with glucomannan extracted from Amorphophallus konjac. Korean J. Food Sci. Tech., 29, 255-260 (1997).
3 Bark S.J., Kang M.H.: The effect of dietary noodle with glucomannan on the weight loss in high fat diet-induced obese rats. J. Korean Soc. Food Sci. Nutr., 32, 893-898 (2003).   DOI
4 Bark S.J., Kang M.H.: The dietary effect of patty made with added glucomannan in high fat diet-induced obese rats. J. East Asian Soc. Diet. Life., 15, 40-48 (2005).
5 Sim J.I., Choi S.J., Jeong J.H., Choi U.K.: Establishment of optimum condition for the coagulation and antimicrobial activity of konjac jelly. Korean J. Food Culture., 29, 415-420 (2014).   DOI
6 Sim J.I., Choi S.J., Jeong J.H., Choi U.K.: Selection of the coagulant for processing and identification of antibacterial activity on foodborn pathogens of konjac Jelly. Korean J. Food Nutr., 27, 699-705 (2014).   DOI
7 Lee S.K., Sin G.L., Kim Y.H.: Effect of mixed glucomannan and whey calcium on the serum cholesterol and blood glucose in rats. J. Fd. Hyg. Safety., 20, 69-72 (2005).
8 Kim S.J., Choi W.S., You S.G., Min Y.S.: Effect of glucomannan on quality and shelf-life of low-fat chicken patty. Korean J. Food Sci. Technol., 39, 55-60 (2007).
9 Lee N.H., Choi W.S., Choi U.K.: Optimization for the antibacterial activity of konjak jelly using evolutionary operation-factorial design technique. Korean J. Food Nutr., 31, 272-277 (2018).   DOI
10 Choi H.E., Park H.Y., Kim N.Y., Jang H.S., Lee N.H., Choi U.K.: Cooking characteristics of noodle containing konjac powder and Capsosiphon fulvescens. Korean J. Food Nutr., 30, 847-851 (2017).   DOI
11 Ministry of Food and Drug Safety. Korean Food. Code. Chapter 9. General analytical method. 9-3-3.5-9-3-3.25. Retrieved from http://www.foodsafetykorea.go.kr/portal/safefoodlife/food/foodRvlv/foodRvlv.do on Apr 3. (2016).
12 Ministry of Food and Drug Safety. Method of Investigation of cause in Food poisoning. Retrieved from http://www.mfds.go.kr/index.do?searchkey=title:contents&mid=695&searchword=foodpoisoning&cd=&pageNo=1&seq=20737&cmd=v on Apr (2015).
13 Oh S.W., Hong S.P., Kim H.J., Choi Y.J.: Antimicrobial effects of chitosans on Escherichia coli O157:H7, Staphylococcus aureus and Candida albicans. Korean J. Food Sci. Technol. 32, 218-224 (2000).
14 Choi H.E., Park H.Y., Jo Y.I., Kim N.Y., Lee N.H., Choi U.K.: Effect on the characteristics of noodle by the addition of konjac powder. Korean J. Food Nutr., 30, 282-289 (2017).   DOI