DOI QR코드

DOI QR Code

Effects of heat treatments on the microbial reduction and germination rates of red radish sprout seeds (Raphanus sativus)

열처리 방법이 적무 새싹종자(Raphanus sativus)의 미생물 저감화 및 발아율에 미치는 영향

  • Jun, So-Yun (Department of Food Science and Nutrition, Kyungpook National University) ;
  • Lee, Yeon-Kyung (Department of Food Science and Nutrition, Kyungpook National University)
  • 전소윤 (경북대학교 식품영양학과) ;
  • 이연경 (경북대학교 식품영양학과)
  • Received : 2014.02.12
  • Accepted : 2014.06.02
  • Published : 2014.08.30

Abstract

This study was conducted to investigate the effects of various heat treatments on the microbial reduction and germination of red radish seeds for the development of effective and economical sterilization methods of improving microbial safety without reducting the germination rate. Hydrothermal treatment was conducted at 60, 65, 70, 75, 80, and $90^{\circ}C$ for 30 and 60 seconds, and dry heat treatment was performed at 70, 80, 90, and $100^{\circ}C$ for 5 minutes. In the seeds that underwent the hydrothermal treatment, time had little effect on the microbial reduction. There was no significant microbial reduction over time. However, there was significant microbial reduction as temperatures increased (p<0.001). The total plate count (TPC) was reduced by more than 3 logs, and Listeria monocytogenes was not detected at temperatures above $70^{\circ}C$. In the seeds that were subjected to the dry heat treatment, the TPC and the population of the L. monocytogenes were significantly reduced as the temperatures increased (p<0.001). After treatment at $100^{\circ}C$ for 5 minutes, the TPC and the L. monocytogenes were reduced by 3 logs. As with the microbial reduction, time had little effect on the germination. There were no significant changes in the germination after the hydrothermal treatment over time; but at the temperatures above $75^{\circ}C$, the germination rate significantly decreased as the temperature increased (p<0.001). When the seeds were soaked after the hydrothermal treatment, their germination was stimulated. The dry heat treatment at temperatures of $80^{\circ}C$ and higher significantly decreased the germination rate as the temperature increased (p<0.001). Dry heat treatment before the germination of the seeds soaked in distilled water for three hours significantly decreased the germination at temperatures greater than $90^{\circ}C$ (p<0.05). This study showed that appropriate heat treatments can increase the microbiological safety and germination of red radish seeds.

본 연구는 환경 친화적인 새싹채소류의 고품질화를 위한 경제적이고 효율적인 살균기술을 개발할 목적으로 국내산 적무 종자의 다양한 열처리 방법에 따른 발아율과 미생물 저감효과를 조사하였다. 열수처리는 60, 65, 70, 75, 80, $90^{\circ}C$에서 각각 30, 60초간 실시하였고, 건열처리는 70, 80, 90, $100^{\circ}C$에서 5분간 실시하였다. 열수 처리에 따른 미생물의 제어효과는 시간에 따른 유의적인 차이는 보이지 않았으나, 온도변화에 따른 유의적인 차이를 나타내었다(p<0.001). $70^{\circ}C$ 이상의 온도에서 총세균수는 3 logs 이상의 감소를 보였으며, L. monocytogenes는 검출되지 않았다. 건열처리는 온도변화에 따른 유의적인 차이를 나타내었다(p<0.001). $100^{\circ}C$에서 5분간 처리한 후 총세균과 L. monocytogenes 수는 3 logs 이하 감소하였다. 열수처리에 따른 발아율의 변화는 처리 전과 후 모두 시간에 따른 유의적인 차이는 보이지 않았으나, $75^{\circ}C$ 이상의 온도에서 온도 증가에 따라 유의적으로 감소하였다(p<0.001). 한편, 열수처리 후 침지시킨 종자에서 발아가 더 촉진되는 것으로 나타났다. 건열처리에 따른 발아율은 $80^{\circ}C$ 이상의 온도에서 온도 증가에 따라 유의적으로 감소하였다(p<0.001). 건열처리한 후 증류수에 3시간 침지시킨 종자의 발아율은 $90^{\circ}C$ 이상의 온도에서 유의적으로 감소하였다(p<0.05). 결론적으로 적절한 열처리는 $75^{\circ}C$, 30분 이상의 열수처리하는 방법으로, 적무 새싹채소의 종자의 미생물학적 안전성을 증가시킴과 동시에 발아율을 증가시키는 것으로 판단된다.

Keywords

References

  1. Fu TD, Stewart KR, Ulasze KJ, Schlesser J, Tort M (2001) Use of spent irrigation water for microbiological analysis of alfalfa sprouts. J Food Prot, 64, 802-806
  2. Jun SY, Kim TH, Kwon JH, Lee YK (2009) Microbiological evaluation in situ of each process in seed sprouting. Korean J Food Preserv, 16, 971-976
  3. U.S. FDA (2000) Consumers advised of risks associated with raw sprouts. DHHS. Washington, DC, USA, 9, 99-113
  4. Fallik E (2004) Prestorage hot water treatments: immersion, rinsing and brushing. Postharvest Biol Technol, 32, 125-134 https://doi.org/10.1016/j.postharvbio.2003.10.005
  5. Nega ER, Ulrich SW, Jahn M (2003) Hot water treatment of vegetable seed - an alternative seed treatment method to control seed-borne pathogens in organic farming. J Plant Dis Protect, 110, 220-234
  6. Nesmith W (2004) Seed treatments for commercial vegetables in Kentucky. Kentucky Univ, fact sheet, PPFS-VG-09
  7. Lee JH, Shen SS, Park YJ, Ryu KY, Jee HJ (2007) Evaluation of hot water treatment for disinfection of vegetable seeds for organic farming. Res Plant Dis, 13, 157-163 https://doi.org/10.5423/RPD.2007.13.3.157
  8. Miller SA, Melanie L, Lewis I (2005) Hot water and chlorine treatment of vegetable seeds to eradicate bacterial plant pathogens. Ohio State Univ, extension fact sheet, HYG-3085-05
  9. ISTA (1996) Proceedings of the international rules for seed testing. Seed Sci Technol, 21, 25-30
  10. Alexander W, Walter PH (2005) Efficacy of heat treatment in the reduction of Salmonella and Escherichia coli O157:H7 on alfalfa, mung bean and radish seeds used for sprout production. Eur Food Res Technol, 221, 187-191 https://doi.org/10.1007/s00217-004-1125-9
  11. Park KJ, Lim JH, Kim JH, Jeong JW, Jo JH, Jeong SW (2007) Reduction of microbial load on radish (Raphanus sativus L.) seeds by aqueous chlorine dioxide and hot water treatments. Korean J Food Preserv, 14, 487-491

Cited by

  1. Establishment of Seed Treatment for Healthy Production of Peanut Sprout vol.24, pp.6, 2015, https://doi.org/10.5322/JESI.2015.24.6.755
  2. Effects of Thermal Treatments on Inactivation of Histidine Decarboxylase from Morganella morganii and Photobacterium phosphoreum vol.45, pp.3, 2016, https://doi.org/10.3746/jkfn.2016.45.3.396
  3. Effect of heat treatment on quality characteristics and antioxidant activity of Korean traditional actinidia (Actinidia arguta) cultivars puree vol.22, pp.3, 2015, https://doi.org/10.11002/kjfp.2015.22.3.408
  4. Quality Characteristics of Beef by Different Cooking Methods for Frozen Home Meal Replacements vol.35, pp.4, 2015, https://doi.org/10.5851/kosfa.2015.35.4.441
  5. LED와 QD-LED(Quantum Dot) 광처리가 적무 새싹의 생산과 품질에 미치는 영향 vol.28, pp.3, 2019, https://doi.org/10.12791/ksbec.2019.28.3.265