DBPIA-NURIMEDIA

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승현 민
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1 J Korean Soc Food Sci Nutr 한국식품영양과학회지 39(1), 138~145(2010) DOI: /jkfn 플라멩고 딸기의수확후 Ultraviolet-C와이산화염소수또는푸마르산병합처리에따른저장중품질에미치는영향 김주연 김현진 임금옥 장성애 송경빈 충남대학교농업생명과학대학식품공학과 Effect of Combined Treatment of Ultraviolet-C with Aqueous Chlorine Dioxide or Fumaric Acid on the Postharvest Quality of Strawberry Fruit Flamengo during Storage Ju Yeon Kim, Hyun Jin Kim, Geum Ok Lim, Sung Ae Jang, and Kyung Bin Song Dept. of Food Science & Technology, College of Agriculture & Life Sciences, Chungnam National University, Daejeon , Korea Abstract The combined effect of 50 ppm aqueous chlorine dioxide () or 0.5% fumaric acid with 5 kj/m 2 ultraviolet-c () on the postharvest quality of "Flamengo" strawberries was examined. After non-thermal treatment, the samples were stored at 4±1 o C for 12 days. The combined treatment of fumaric acid/ reduced the initial populations of total aerobic bacteria and yeast and molds in the strawberries by 2.09 and 2.02 log CFU/g, respectively, compared to those of the control. In addition, after 12 days of storage the yeast and molds population in the combined treatment was 1.72 log CFU/g, compared to 5.10 log CFU/g for the control, resulting in a significant decrease of 3.38 log CFU/g. Postharvest treatments used in this study caused negligible changes in the color of the strawberries. Sensory evaluation results indicated that the combined postharvest treatment provided better sensory scores than did the control. In particular, the overall acceptability scores were higher for the combined treatment groups after 5 days of storage. These results suggest that combined treatment of either 50 ppm or 0.5% fumaric acid with 5 kj/m 2 can be useful for maintaining the quality of strawberries. Key words: strawberries, combined treatment, fumaric acid, aqueous chlorine dioxide, irradiation 서론딸기는고유의향기와색이우수하고비타민 C와함께항산화활성이있는다양한페놀성화합물함량이풍부하여최근소비량이급증하고있는데, 대부분생과로이용되고있으며잼이나아이스크림, 젤리및요구르트, 주스등의다양한가공품원료로도사용되고있다 (1-4). 우리나라에서생산되는딸기는일본등으로수출이증가하는추세이며보통과피의착색이 60~70% 정도되었을때수확을하는데, 이는국내유통되는딸기와달리수확후선별및포장을하여수출국으로수송되어소비자에게전달되기까지소요되는예상유통시간과착색이진행되는숙도를고려한것이다 (5). 그러나딸기는수확후선별, 저장및유통과정에서위해미생물증식에의한오염으로인해부패하기쉽고, 물리적손상및조직의연화등으로과육의표면이물러지는경도감소와활발한호흡작용및지나친증산작용에의한표피 건조로무게감량, 과숙으로인한변색등의외관품질저하에따른짧은 shelf-life가심각한문제점으로인식된다 (6-9). 또한수출용딸기는수확후수출국으로의수송및운반작업으로인해일반적으로국내에서유통 판매되는딸기보다품질유지및 shelf-life 증대를위한관리기술의개발이시급한실정이다. 열처리는품질저하를유도하는효소의불활성화나미생물수감소를위해식품에널리사용되어왔으나, 열처리과정에서딸기와같이수분을다량함유한과실은고유의색이나향미, 중량등의품질을저하시키며, 또한딸기에열처리공정을할경우에는인공적인색소의첨가가요구되기도한다 (3). 그리고딸기에 (10) 와이산화염소수 (4) 단일처리를통한현장에서의적용을위한연구보고가있었고또한딸기에 pulsed white light와 의물리적병합처리를적용한결과보고 (9) 는있으나, 아직화학적처리와물리적처리의적절한병합처리에따른딸기의수확후 hurdle Corresponding author. kbsong@cnu.ac.kr Phone: , Fax:

2 플라멩고딸기의수확후품질에미치는영향 139 system에관한연구는아직보고된바가없다. 따라서수확후딸기표면의초기미생물을보다효과적으로제거할수있으면서동시에품질유지를통한저장기간연장을위한수확후처리기술에관한체계적인연구가필요하다. 화학적처리중에서이산화염소 (chlorine dioxide) 는염소보다물에대한용해성이 10배, 살균력은 5배높으며염소처리시생성되는발암성화학물질을생성하지않고 ph에대한영향도받지않는다 (11-15). 또한푸마르산 (fumaric acid) 은불포화 dicarboxylic acid의하나로식품및음료산업에서신맛을내기위해식품첨가물로널리사용되는유기산이며강한살균력이있어식품의미생물학적안전성을확보하기위해사용된다 (16,17). Ultraviolet(UV) 는파장 100~400 nm 범위의전자기파를말하는데, UV 영역은크게 UV-A(315~400 nm), UV-B (280~315 nm), (100~280 nm) 로구분되며, 살균및소독에사용되는 UV는주로 이다 (18-20). 는비가열살균처리기술로써주로식품표면의미생물학적오염을줄이는데이용되며, 특히 nm 파장의 가미생물의 DNA base에손상을일으켜미생물을사멸시키는것으로알려져있다 (18-21). 조사는기존의감마선이나전자빔처리방법과비교하여, 잠재적위해요소에대한소비자거부감이적고온도와수분의영향을크게받지않으며설치및조사비용이저렴한장점을가지고있다 (22-25). 따라서본연구에서는국내에서생산되고있는수출용딸기 " 플라멩고 " 품종의수확후미생물학적안전성확보와저장성증대를위해, 이산화염소수및푸마르산용액의화학적처리와 조사의물리적처리에대한단일처리와 hurdle system을위한병합처리에따른딸기의저장중미생물수감소및품질변화에미치는영향을조사하여그결과를보고하는바이다. 재료및방법재료본연구에서사용된딸기는강원평창지역딸기재배농가에서실험당일수확된신선한 " 플라멩고 " 품종으로, 과피의착색이 60~70% 진행된시료를구입한직후저온을유지하며즉시실험실로운반되어실험에사용하였다. 시료는외관상태와숙도및크기가전체적으로균일하며표면에흠이없고무게가개당약 15±1 g인것으로선별한후, 화학적및물리적처리를하지않은수확후딸기를대조구 (control) 로하여처리구와저장온도 4±1 o C에서 12일간저장하면서비교하였다. 조사 조사는제작된 UV 살균기 (80 cm 55 cm 4 cm) 의상, 하부에 254 nm 파장의 unfiltered germicidal emitting lamps(sylvania, G15T8, Phillips, Haarlem, Netherlands) 를설치하였고, 강도는시료 tray 상에서 UV light meter (UV-340, Lutron Electronic Co., Taipei, Taiwan) 를이용하여 3 반복하여측정하였다 (5 W/m 2 ). 본연구에서사용된 조사선량은 5 kj/m 2 이었고조사시간은 16분 40초이었으며, 미생물의 photoreactivation을최소화하기위해암실조건에서조사하였다. 화학적처리선별된딸기는증류수, 50 ppm 이산화염소용액, 0.5% 푸마르산용액에각각 5분간침지하였고, 시료표면에균일하게처리하기위해 poly-glove를착용한손으로딸기가손상되지않도록부드럽고조심스럽게휘저어주었다. 침지후, 각각 clean bench에서약 2시간동안 air-dried 상태로표면에남아있는수분을건조시켰다. 이산화염소용액은 chlorine dioxide generator system(ch 2O Inc., Olympia, WA, USA) 을이용하여농도가 50 ppm이되게제조하였다 (16). 푸마르산용액은시판되고있는푸마르산 (Sigma- Aldrich, MO, USA) 을이용하여농도가 0.5% 가되게하여제조하였다. 병합처리병합처리는먼저 50 ppm 이산화염소용액이나 0.5% 푸마르산용액에각각 5분간침지한후 5 kj/m 2 조사를연속적으로수행하였다. 처리후, 시료는 4±1 o C에서 12일동안 polyethylene terephthalate(pet) 수출용딸기용기 (500 g) 에처리구에따라개별적으로포장하여실험에사용하였다. 미생물생육측정딸기시료를멸균된 scalpel로채취하여멸균 bag에넣고 3분동안 stomacher(mix 2, AES Laboratoire, Combourg, France) 에서균질화시켰다. 균질화된시료는멸균된거즈를이용하여거르고 0.1% 멸균펩톤수로 10배수연속희석한후각각의배지에분주하여 3반복수행하였다. 총호기성세균은 plate count agar(pca, Difco Co., Detroit, MI, USA) 를사용하여 37 o C에서 3일간배양하고, 효모및곰팡이는 potato dextrose agar(pda, Difco Co.) 를사용하여 25 o C에서 5일간배양후형성된 colony를계수하였다. 검출된미생물수는시료 g당 colony forming unit(cfu) 로나타냈다. 색도측정색도는색차계 (CR-400 Minolta Chroma Meter, Konica Minolta Sensing Inc., Tokyo, Japan) 를사용하여 Hunter L, a, b 값을각시료의다른표면을반복측정한뒤평균값으로나타내었다. L value는 0(black), +100(white), a value는 -80(greenness), +100(redness), b value는 -80(blueness), +70(yellowness) 을나타내며, 이때사용된표준백판의 L, a, b 값은각각 L=97.41, a=-0.02, b=1.93이었다.

3 140 김주연 김현진 임금옥 장성애 송경빈 관능검사 딸기의병합및단일처리에따른저장기간중품질변화를분석하기위해훈련된 panel 요원 10명 ( 충남대학교식품공학과대학원생 ) 으로시료의외관적상태 (appearance), 조직감 (firmness), 향 (odor) 및종합적기호도 (overall acceptability) 에대한관능검사를실시하였다. 이때각처리된시료에대한평점은선정된기준에의거한 9점기호척도법 (9~8점: 매우좋음, 7~6점 : 좋음, 5~4: 보통, 3~2: 나쁨, 1: 매우나쁨 ) 으로평가하였다. 통계처리 모든실험은 3회반복하여측정하였고, 그결과는평균값 ± 표준편차로나타냈으며통계적분석은 SAS(Statistical Analysis System program, SAS Institute Inc., Cary, NC, USA) 프로그램을이용하여각처리구간의유의성 (p<0.05) 검증을위해분산분석 (analysis of variance, ANOVA) 후 Duncan's multiple range test로다중비교를실시하였다. 미생물생육측정 결과및고찰 딸기에이산화염소수, 푸마르산용액및 를각각단일처리와병합처리한후저장중총호기성세균과효모및곰팡이의미생물수변화를조사하였다 (Table 1, 2). 저장초기대조구의경우딸기의총호기성세균은 3.09 log CFU/g이었고, 물로세척한처리구는 2.68 log CFU/g으로 0.41 log CFU/g의초기미생물수감소를보였는데이러한 결과는새싹채소의증류수세척처리구에서대조구와비교하여초기미생물이약 0.40 log CFU/g 감소했다는이전보고 (26) 와유사하다. 반면에 와이산화염소, 푸마르산의단일처리구는 2.14, 1.89, 1.68 log CFU/g으로각각 0.95, 1.20, 1.41 log CFU/g의감균효과를나타냈고, 이산화염소와, 푸마르산과 병합처리구는 1.20, 1.00 log CFU/g으로 1.89, 2.09 log CFU/g의초기미생물수감소를보였다 (Table 1). 이러한미생물수감소는저장중에도지속되었는데, 저장 5일에대조구의미생물수가증가하여 4.59 log CFU/g이었고, 와이산화염소, 푸마르산의단일처리구는 3.21, 2.74, 2.27 log CFU/g으로각각 1.38, 1.85, 2.32 log CFU/g의균감소를보였으며, 이산화염소와, 푸마르산과 병합처리구는 1.75, 1.49 log CFU/g으로 2.84, 3.10 log CFU/g의유의적인 (p<0.05) 미생물수감소를나타냈다. 대조구와모든처리구에서저장기간동안미생물수가증가하는결과를나타냈는데, 이는 Park 등 (27) 의저장중딸기의총호기성세균이증가하는경향을보였다는보고와일치한다. 또한저장 12일에푸마르산과 처리구가 1.78 log CFU/g으로대조구의 5.12 log CFU/g과비교하여 3.34 log CFU/g의유의적인 (p<0.05) 차이로가장큰감균효과를나타냈다. 딸기의저장중효모및곰팡이수의경우에도총호기성세균의결과와비슷한경향을나타냈는데, 저장초기대조구의경우 3.02 log CFU/g이었고물로세척한처리구는 2.64 log CFU/g으로 0.38 log CFU/g의감소를보였다 (Table 2). 또한 와이산화염소, 푸마르산의단일처리구는 2.02, Table 1. Change in the populations of total aerobic bacteria of non-thermal treated strawberries during storage at 4 o C (log CFU/g) Treatment Storage time (days) ±0.05 a1) 2.68±0.01 b 2.14±0.04 c 1.89±0.05 d 1.68±0.12 e 1.20±0.17 f 1.00±0.00 g 3.36±0.07 a 2.89±0.04 b 2.35±0.03 c 2.06±0.17 d 1.78±0.01 e 1.26±0.18 f 1.20±0.00 g 3.68±0.23 a 3.22±0.13 b 2.72±0.04 c 2.42±0.08 d 1.93±0.08 e 1.48±0.05 f 1.26±0.17 g 4.59±0.14 a 3.92±0.17 b 3.21±0.04 c 2.74±0.04 d 2.27±0.03 e 1.75±0.18 f 1.49±0.04 g 4.80±0.17 a 4.14±0.06 b 3.44±0.08 c 2.91±0.05 d 2.43±0.03 e 1.83±0.01 f 1.52±0.17 g 5.12±0.04 a 4.42±0.03 b 3.72±0.03 c 3.21±0.08 d 2.72±0.01 e 2.11±0.17 f 1.78±0.08 g 1) Means in the same column followed by different letters are significantly (p<0.05) different by Duncan's multiple range test. Table 2. Change in the populations of yeast and molds of non-thermal treated strawberries during storage at 4 o C (log CFU/g) Treatment Storage time (days) ±0.03 a1) 2.64±0.03 b 2.02±0.17 c 1.48±0.05 d 1.32±0.04 ed 1.16±0.08 e 1.00±0.00 e 3.20±0.03 a 2.74±0.12 b 2.11±0.02 c 1.60±0.04 d 1.37±0.06 e 1.20±0.02 fe 1.16±0.28 e 3.47±0.17 a 2.97±0.02 b 2.35±0.06 c 1.74±0.24 d 1.40±0.08 e 1.42±0.10 e 1.16±0.01 f 4.35±0.06 a 3.75±0.03 b 2.87±0.12 c 2.08±0.01 d 1.61±0.17 e 1.63±0.06 e 1.17±0.08 f 4.76±0.04 a 3.97±0.01 b 3.18±0.08 c 2.21±0.17 d 1.96±0.02 e 1.87±0.13 e 1.40±0.12 f 5.10±0.01 a 4.20±0.17 b 3.36±0.01 c 2.53±0.06 d 2.27±0.10 e 2.03±0.02 e 1.72±0.05 f 1) Means in the same column followed by different letters are significantly (p<0.05) different by Duncan's multiple range test.

4 플라멩고딸기의수확후품질에미치는영향 , 1.32 log CFU/g으로각각 1.00, 1.54, 1.70 log CFU/g의감균효과를나타냈고, 이산화염소와, 푸마르산과 병합처리구는 1.16, 1.00 log CFU/g으로 1.86, 2.02 log CFU/g의초기미생물수감소를보였다 (Table 2). 총호기성세균의증가경향과동일하게저장 5일에는대조구의효모및곰팡이수가증가하여 4.35 log CFU/g인반면에 와이산화염소, 푸마르산의단일처리구는 2.87, 2.08, 1.61 log CFU/g으로각각 1.48, 2.27, 2.74 log CFU/g의균감소를보였으며, 이산화염소와, 푸마르산과 병합처리구는 1.63, 1.17 log CFU/g으로 2.72, 3.18 log CFU/g의유의적인 (p<0.05) 미생물수감소를나타냈다. 저장중대조구와모든처리구에서효모및곰팡이수가증가하여저장 12일에는푸마르산과 처리구가 1.72 log CFU/g으로대조구의 5.10 log CFU/g과비교하여유의적으로 (p<0.05) 3.38 log CFU/g의가장큰감균효과를나타냈다. 본연구결과에서대조구와물세척의경우는저장중초기균수에서많은증가폭을보이는반면비가열단일처리구와특히병합처리구의경우소폭의증가를보였기에딸기의초기미생물사멸뿐만아니라저장중미생물의생육에도영향을끼치는것으로판단된다. 특히저장중푸마르산과 병합처리구는저장초기와큰유의적인변화가없지만대조구는저장 5일에균수가많이증가한것을볼수있는데이것은푸마르산에의해딸기표면의 ph가낮아져서세균의생육이저해된것으로판단된다. 또한본연구에서푸마르산처리가다른단일처리구보다미생물수감소에더효과적일뿐만아니라전체처리구중에서는푸마르산과 병합처리구가다른처리구와비교하여유의적인 (p<0.05) 차이를나타내며가장효과적이라는결과는클로버새싹채소에푸마르산처리와 조사후병원성미생물수가감소했다는이전결과보고 (26) 와일치한다. Jin 등 (4) 의딸기에 50 ppm 이산화염소수처리후대조구와비교하여저장초기총호기성세균과효모및곰팡이를각각 1.35, 1.45 log CFU/g 감소시킨결과를본연구결과와비교하였을때, 50 ppm 이산화염소수단일처리구의경우감균효과는유사하지만 조사와병합처리구의경우단일처리구보다유의적으로 (p<0.05) 저장중딸기의미생물수를감소시켰다. Marquenie 등 (9) 의딸기의 pulsed light 와 1 kj/m 2 단일처리구와병합처리구모두대조구와비교시, 딸기의저장중곰팡이의생육저해에유의적인효과가없음을나타냈는데, 이러한결과와본연구결과를비교하였을때, 저선량의 조사보다는본연구에사용된고선량의조사처리가미생물억제에효과적이고, 조사와다른물리적처리와의병합보다는화학적처리와의병합처리가저장중딸기의미생물생육저해에더효과적이라고판단된다. Kim 등 (28) 의항균성필름을사용한포장에따른딸기의저장중총호기성세균과효모및곰팡이수는저장 9일 이후에차이를나타냈고그차이는대조구와비교하여약 0.5 log CFU/g 정도이었으며, 저장 21일에는약 1.6 log CFU/g의감소를나타낸결과와비교할때, 본연구결과에서의저장중딸기의감균효과가더우수함을뒷받침해준다. 또한황련추출물 500 ppm 처리후대조구와비교시, 딸기의저장초기총호기성세균을 0.4 log CFU/g, 저장 3일과 10일각각 0.70, 0.59 log CFU/g 감소시켰다는보고 (27) 와딸기에전기분해수를 20분처리후초기총호기성세균을 1.99 log CFU/g 감소시키고저장 3일과 7일은각각 1.89, 2.84 log CFU/g 감소시켰다는결과 (29) 와비교해보았을때, 본연구에서처리한병합처리구가매우효과적임을시사한다. 따라서푸마르산, 이산화염소수의화학적처리와 와같은물리적처리와의병합처리는수확후딸기표면의초기미생물수를감소시키고, 저장중미생물생육을저해하는효과적인비가열처리기술로써딸기의미생물학적안전성을확보할수있다고생각된다. 색도변화딸기는성숙이진행되면서점차녹색이없어지고딸기고유의밝은적색을나타내고과숙이되면검붉은적색으로변한다 (30). 그러므로딸기의외관적품질을결정하는중요한요소중하나인표면색도변화를저장중측정하였다 (Table 3). 딸기의 Hunter L value는처리직후 40 이상의값을나타냈으며저장기간동안대조구와모든처리구간에는유의적인 (p<0.05) 차이가없었고, 초기측정값에비해큰변화를나타내지않았다. 또한딸기의 a value는 39 이상의값을나타냈고대조구와모든처리구에서유의적인차이가없었으며, 모두저장 5일까지계속적으로증가하다 7일이후에는감소하는경향을보였다 (Table 3). 이러한결과는미숙한상태의딸기가저장중성숙됨에따라 a value가증가하여최고점에이르는시기에고유의밝은적색을나타내다가과숙되면서안토시아닌의변화와함께점차감소한다는보고 (30) 와일치한다. b value는저장초기 31 이상의값을나타냈고 L, a value 결과와동일하게대조구와모든처리구간에는유의적인차이를보이지않았으며, 저장기간이증가할수록 a value와는반대로지속적으로감소하는경향을나타냈다. Zheng 등 (31) 의딸기의저장 14일동안 L value가일정한패턴없이유의적인차이를보이지않았다는결과와 Tanada-Palmu와 Grosso(32) 의저장중딸기의 a value는증가하였고 b value는감소하였다는보고는본연구결과와일치한다. 또한 Vicente 등 (6) 의보고에서열처리후딸기의저장중 L value는대조구에비해급격히증가하였고 Jeong 등 (29) 의전기분해수처리구의경우 Hunter 색도값이모두대조구보다유의적으로높게측정되었으며 Terefe 등 (3) 의고압처리와처리온도가증가할수록대조구와비교하여 L과 a value 값이유의적으로증가했다는보고와비교했을때, 본연구에서의비가열처리구는딸기가지니는고유의색과

5 142 김주연 김현진 임금옥 장성애 송경빈 Table 3. Change in Hunter color values of non-thermal treated strawberries during storage at 4 o C Color parameter 1) Treatment Storage time (days) L a + FA 2) + + FA ±0.35 a3) 40.29±0.24 a 40.46±0.36 a 40.66±0.22 a 40.29±0.23 a 40.57±0.69 a 40.46±0.61 a 39.61±0.60 a 39.63±0.54 a 39.62±0.25 a 39.77±0.13 a 39.73±0.69 a 39.61±0.67 a 39.63±0.74 a 38.99±0.21 a 39.42±0.67 a 38.94±0.66 a 39.16±0.35 a 39.20±0.06 a 39.21±0.89 a 38.92±0.30 a 40.45±0.74 a 40.46±0.25 a 40.40±0.63 a 40.39±0.59 a 40.46±0.25 a 40.44±0.65 a 40.47±0.44 a 40.35±0.67 a 40.33±0.15 a 40.37±0.30 a 40.33±0.60 a 40.37±0.04 a 40.37±0.38 a 40.35±0.60 a 41.68±0.60 a 41.63±0.72 a 41.68±0.69 a 41.66±0.78 a 41.65±0.16 a 41.69±0.59 a 41.64±0.64 a 37.87±0.47 a 38.02±0.25 a 38.05±0.60 a 37.81±0.17 a 37.95±0.65 a 38.03±0.14 a 37.96±0.66 a 43.15±0.47 a 42.97±0.33 a 42.96±0.25 a 43.11±0.22 a 42.96±0.65 a 42.95±0.39 a 43.13±0.53 a 38.25±0.33 a 37.97±0.14 a 38.26±0.70 a 38.27±0.21 a 38.25±0.60 a 37.99±0.65 a 38.29± ±0.47 a 42.31±0.51 a 42.30±0.47 a 42.32±0.64 a 42.32±0.53 a 42.31±0.51 a 42.33±0.56 a 39.15±0.70 a 39.06±0.54 a 39.05±0.59 a 39.16±0.36 a 39.03±0.33 a 39.15±0.74 a 39.30±0.61 a 40.98±0.35 a 40.96±0.65 a 41.09±0.47 a 40.99±0.79 a 40.94±0.51 a 40.98±0.60 a 40.97±0.64 a b + FA ±0.44 a 31.13±0.30 a 31.16±0.69 a 31.16±0.60 a 31.13±0.56 a 31.19±0.16 a 31.13±0.74 a 29.49±0.33 a 29.49±0.37 a 29.47±0.72 a 29.49±0.38 a 29.47±0.56 a 29.46±0.60 a 29.48±0.87 a 28.07±0.66 a 28.06±0.33 a 28.08±0.47 a 28.05±0.47 a 28.03±0.17 a 28.06±0.44 a 28.07±0.59 a 28.89±0.10 a 28.85±0.18 a 28.88±0.11 a 28.84±0.24 a 28.86±0.41 a 28.86±0.17 a 28.85±0.80 a 27.93±0.47 a 27.96±0.51 a 27.99±0.25 a 27.97±0.13 a 27.93±0.67 a 27.96±0.66 a 27.99±0.32 a 27.51±0.47 a 27.54±0.30 a 27.56±0.69 a 27.50±0.22 a 27.54±0.72 a 27.50±0.51 a 27.51±0.56 a 1) L: degree of whiteness (0 black +100 white), a: degree of redness (-80 greenness 100 redness), b: degree of yellowness (-80 blue 70 yellowness). 2) FA: fumaric acid. 3) Means in the same column followed by different letters are significantly (p<0.05) different by Duncan's multiple range test. 관련된외관적품질유지측면에서부정적인영향을미치지않아기존의다른처리방법보다바람직하다고생각된다. 관능적품질검사딸기의비가열처리후저장중외관적상태, 조직감, 향및종합적기호도를 9점기호척도법으로조사한관능적품질특성에대한결과는 Table 4와같다. 딸기의관능적품질에대한점수는저장기간이경과함에따라대조구를포함하여모든처리구에서전체적으로낮아지는경향을나타냈다. 저장 3일까지딸기의외관적상태는대조구를포함하여모든처리구에서 8점이상의높은점수로유의적인차이가없었으나, 저장 5일부터 조사와병합처리구가유의적으로 (p<0.05) 높은점수를나타냈다. Jeong 등 (29) 의딸기의저장중관능적품질변화에서외관적상태는저장 7일까지대조구와처리구간에유의적인차이를보이지않았다는결과와비교시, 본연구에서는차이를나타냈는데그이유는딸기의품종및수확시기의차이에따른다고판단된다. 대조구와비교할때물세척처리구가가장큰외관적품질저하를나타냈으며, 비가열처리구중에서는 조사, 이산화염소와, 푸마르산과 병합처리구가다른처리구보다외관적인측면에서높은선호도를보였다 (Table 4). 조사처리를한모든처리구에서외관적품질에대한높은점수를얻은것은화학적처리를할경우는딸기표면에수분이직접닿기때문이라고생각되며 병합처리구의경우에는표면에남아있을수있는수분을 조사 시거의제거할수있기때문에영향을덜받은것이라고판단된다. 저장중딸기의조직감은외관적품질과비슷한패턴으로저장초기대조구를포함하여모든처리구에서유의적인차이를보이지않았으나, 물세척처리구에서는대조구와비교하여낮은점수를보였다. 그러나 처리구와두병합처리구는저장 5일부터다른처리구와비교하여유의적으로 (p<0.05) 높은선호도의점수를나타냈다. 따라서본연구의저장중미생물수측정결과에서대조구와비교하여병합처리구의유의적인미생물생육저해효과와조직감의높은점수와는연관성이있다고판단되고, 저장중딸기과피조직의연화로인한조직감의저하는수확후딸기자체의자가분해효소와미생물오염과관련성이있다는보고 (8,27,30) 와일치한다. 또한본연구에서얻어진관능적품질중 조사된처리구의조직감결과는 Pombo 등 (10) 의딸기에 4.1 kj/m 2 의 를조사한처리구에서저장중조직의연화를늦추어대조구와비교하였을때경도가유의적으로높게나타나저장성을연장시켰다는보고와일치함을보여준다. Terefe 등 (3) 의고압처리와온도의병합처리된딸기의품질변화에서고압처리시간이증가할수록조직이연화되어경도가감소한다는결과와비교했을때, 본연구에서처리한병합처리구가저장중딸기의조직감측면에서신선도유지가가능함을보여준다. 딸기의향에대한관능적품질은저장초기대조구를포함한모든처리구에서유의적인차이를보이지않았고, 저장기

6 플라멩고딸기의수확후품질에미치는영향 143 Table 4. Sensory evaluation of non-thermal treated strawberries during storage at 4 o C Organoleptic parameter Appearance Firmness Odor Treatment + FA+ + FA+ + FA+ Storage time (days) ) 8.80±0.62 a 8.80±0.33 a 8.90±0.32 a 8.80±0.42 a 8.90±0.32 a 8.90±0.67 a 8.70±0.82 a 8.60±0.67 a 8.90±0.32 a 8.70±0.69 a 8.70±0.48 a 8.80±0.79 a 8.80±0.50 a 8.60±0.69 a 8.40±0.70 a 8.60±0.66 a 8.70±0.48 a 8.70±0.48 a 8.60±0.52 a 8.70±0.68 a 8.50±0.33 a 8.30±0.67 a 8.60±0.47 a 8.50±0.53 a 8.50±0.63 a 8.40±0.52 a 8.50±0.47 a 7.50±0.71 a 7.50±0.47 a 7.70±0.67 a 7.60±0.70 a 7.70±0.67 a 7.70±0.82 a 7.70±0.67 a 7.80±0.71 a 7.50±0.53 a 7.80±0.65 a 7.90±0.57 a 7.80±0.33 a 7.80±0.63 a 7.90±0.74 a 7.30±0.35 ba 6.90±0.74 b 8.00±0.66 a 7.40±0.47 ba 7.30±0.67 b 7.90±0.48 a 8.10±0.87 a 5.80±0.69 ba 5.40±0.44 c 6.30±0.79 b 5.80±0.60 ba 5.80±0.84 ba 6.50±1.52 ba 6.60±0.84 a 6.20±0.79 a 6.00±0.82 a 6.20±0.44 a 6.10±0.33 a 6.20±0.79 a 6.30±0.82 a 6.20±0.66 a 5.80±0.79 ba 5.40±0.97 b 6.50±0.71 a 6.00±0.82 ba 5.90±0.74 ba 6.30±0.82 a 6.40±0.53 a 3.90±0.63 b 3.70±0.67 b 5.00±0.32 ab 3.90±0.60 b 3.80±0.63 b 5.30±0.82 a 5.20±0.79 a 4.50±0.71 a 4.20±0.63 a 4.60±0.70 a 4.50±0.71 a 4.70±0.67 a 4.60±0.84 a 4.70±0.67 a 3.80±0.47 ba 3.70±0.66 b 4.50±0.59 a 3.90±0.63 ba 3.80±0.71 b 4.40±0.52 a 4.50±0.32 a 3.10±0.33 b 2.90±0.74 b 4.20±0.49 b 3.10±0.67 b 3.20±0.69 b 4.30±0.40 a 4.30±0.62 a 3.60±0.60 a 3.60±0.70 a 3.70±0.69 a 3.60±0.42 a 3.60±0.70 a 3.70±0.33 a 3.70±0.71 a Overall + FA+ 8.70±0.57 a 8.60±0.33 a 8.80±0.42 a 8.80±0.47 a 8.70±0.66 a 8.80±0.44 a 8.80±0.42 a 7.90±0.32 a 7.80±0.33 a 8.10±0.69 a 8.00±0.47 a 7.90±0.65 a 7.90±0.41 a 8.00±0.55 a 6.30±0.70 b 6.20±0.44 b 6.70±0.60 ba 6.30±0.60 b 6.40±0.65 b 6.50±0.33 ba 6.90±0.47 a 4.70±0.69 cd 4.50±0.33 d 5.00±0.67 bc 4.80±0.65 bc 4.80±0.66 bc 5.40±0.66 ba 5.60±0.47 a 3.50±0.67 b 3.40±0.32 b 3.90±0.44 ba 3.50±0.53 b 3.50±0.66 b 4.10±0.65 a 4.30±0.54 a 1) Means in the same column followed by different letters are significantly (p<0.05) different by Duncan's multiple range test. 간이지남에따라전체적으로점수가감소하였다. 저장중물세척처리구는대조구보다낮은점수를보였으며, 대조구를포함하여모든처리구에서향에관련하여유의적인차이를나타내지않았다. 저장기간에따른딸기의종합적기호도는저장 5일부터두병합처리구가높은점수를나타냈으며, 푸마르산과 병합처리구가 6.9로가장높은점수를나타냈다. 이러한결과는병합처리구가대조구나다른처리구보다외관적상태및조직감, 향에서얻은높은점수등으로인하여관능적품질에대한종합적점수에영향을미친것으로판단된다. 딸기의관능적품질은저장중미생물수가유의적으로 (p<0.05) 감소된이산화염소수와, 푸마르산과 병합처리구에서높은관능점수를나타내어관능적품질과미생물생육간의상관관계가있는것으로판단된다. 그러므로이산화염소, 푸마르산의화학적처리와 의물리적처리의적절한병합처리가수확후딸기의저장 유통중에오염될수있는위해미생물수감소와외관적품질저하억제에효과적인수확후처리기술이며, 푸마르산과 병합처리가미생물수감소와품질유지측면을동시에향상시킬수있는가장효과적인 hurdle system 중의하나라고판단된다. 요약수출용딸기 " 플라멩고 " 품종의수확후미생물학적안전성확보와저장성증대를위해, 50 ppm 이산화염소수또는 0.5% 푸마르산용액과 5 kj/m 2 조사병합처리에따른저장중미생물수감소및품질변화에미치는영향을조사하였다. 비가열처리후, 딸기는 4±1 o C에서 12일동안저장하면서실험을수행하였다. 딸기의초기미생물수에있어서대조구와비교하여, 푸마르산- 병합처리구에서총호기성세균과효모및곰팡이를각각 2.09, 2.02 log CFU/g 감소시켰다. 또한, 저장 12일에푸마르산과 병합처리구의효모및곰팡이수는 1.72 log CFU/g으로대조구의 5.10 log CFU/g과비교하여 3.38 log CFU/g의유의적인차이로가장큰감균효과를나타냈다. 비가열처리구는대조구와비교하여딸기의저장중 Hunter 색도값에부정적인영향을끼치지않았다. 관능검사에있어서는병합처리구가대조구와다른처리구보다높은점수를얻어저장중관능적품질유지에도효과가있는것으로나타났다. 특히, 딸기의종합적기호도는저장 5일부터두병합처리구가높은점수를나타냈다. 따라서본연구결과, 50 ppm 이산화염소또는 0.5% 푸마르산과 조사의병합처리가수확후딸기의

7 144 김주연 김현진 임금옥 장성애 송경빈 저장 유통중에오염될수있는위해미생물의감소와외관적품질유지에효과적인살균처리기술이라고판단된다. 감사의글 본연구는농촌진흥청공동연구사업의연구비의지원에이루어진것으로감사를드립니다. 문 1. Nielsen T, Leufven A The effect of modified atmosphere packaging on the quality of Honeoye and Korona strawberries. Food Chem 107: Ragaert P, Devlieghere F, Loos S, Dewulf J, Van- Langenhove H, Foubert I, Vanrolleghem PA, Debevere J Role of yeast proliferation in the quality degradation of strawberries during refrigerated storage. Int J Food Microbiol 108: Terefe NS, Matthies K, Simons L, Versteg C Combined high pressure-mild temperature processing for optimal retention of physical and nutritional quality of strawberries (Fragaria ananassa). Inno Food Sci Emerg Technol 10: Jin YY, Kim YJ, Chung KS, Won MS, Song KB Effect of aqueous chlorine dioxide treatment on the microbial growth and qualities of strawberries during storage. 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J Food Sci 69: Kim YJ, Kim MH, Song KB C, bined treatment of fumaric acid with aqueous chlorine dioxide or irradiation to inactivate Escherichia coli O157:H7, Salmonella enteric serovar Typhimurium, and Listeria monocytogenes inoculated on alfalfa and clover sprouts. LWT-Food Sci Technol 42: Park WP, Chung SK, Cho SH Changes in the keeping quality of strawberry and cucumber treated with Korean medical herb extracts. Korean J Postharv Sci Technol 7: Kim YM, Lee SB, Cho SH, Lee DS Fabrication of polyethylene films coated with antimicrobials in a binder and their application to modified atmosphere packaging of strawberries. Korean J Postharv Sci Technol 7: Jeong JW, Kim JH, Kwon KH, Park KJ Disinfection effects of electrolyzed water on strawberry and quality changes during storage. Korean J Food Preserv 13: Kim JG, Hong SS, Jeong ST, Kim YB, Jang HS

8 플라멩고딸기의수확후품질에미치는영향 145 Quality changes of "Yeobong" strawberry with CA storage conditions. Korean J Food Sci Technol 30: Zheng Y, Wang SY, Wang CY, Zheng W Changes in strawberry phenolics, antocyanins, and antioxidant capacity in response to high oxygen treatments. LWT-Food Sci Technol 40: Tanada-Palmu PS, Grosso CRF Effect of edible wheat gluten-based films and coating on refrigerated strawberry (Fragaria ananassa) quality. Postharv Biol Technol 36: (2009 년 10 월 13 일접수 ; 2009 년 11 월 19 일채택 )

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