244
Copyright © 2015 The Korean Society of Fisheries and Aquatic Science pISSN:0374-8111, eISSN:2287-8815
서 론
굴은단백질
,
아미노산,
타우린및미네랄등의영양성분이풍 부하여동·
서양인에게사랑받고있는수산물이다(Park et al.,
2008).
또한굴은양식생산량이2010
년도기준전체패류양식의약
75%
를차지하고2010
년도기준수출금액이66,057
천USD
에달하는우리나라의패류양식산업에서가장중요한위 치를차지하고있다(Kim, 2013). 2010
년도굴수출실적을보 면대부분냉동,
건조및통조림의형태로수출되고있으며냉동굴은주로일본과미국
(
전체냉동굴의80.2%)
으로건조굴은홍콩
,
싱가포르,
대만등의중화권으로통조림은미국(
전체 통조림의84.6%)
으로수출되고있다(Kim, 2013).
냉동,
건조 및통조림등의수출용굴가공품과달리내수용의경우는박신 을한후생굴등의형태로대부분유통되고있다(Park, 2013).
생굴의경우육조직이연약하고중장선등의소화기관에존 재하는미생물에의해빨리소화분해되기쉬운특징때문에냉 장조건에서도저장수명이짧다고보고되고있다
(Park et al.,
2008).
또한가공및유통중의부적절한온도조건에서의보관은빠른품질저하를초래한다
(Kong et al., 2006).
이러한이유 로일본은생굴의유통기한을10℃
에서4
일로규정하고있으 나우리나라에서는이에대한법적기준이없고일반적으로냉 장조건에서7
일의기한으로유통되고있다(Park et al., 2008).
하지만
Xiao and Zhang (2003)
은생굴의self-life(
유통기한)
는 주변온도에따라다르지만일반적으로1-3
일이라고보고하고 있어현재의조건으로국내에서유통되고있는생굴의경우식 품위생안전에심각한문제를초래할수있다.
생굴의유통기한연장을위한연구로는방사선조사를이용한방법
(Park et. al,
2008), modified atmosphere packaging (MAP)
를이용한방법(Xiao et al., 2011)
및초고압처리를이용한방법(Oshima et al., 1993)
등이알려져있다.
초고압처리의경우생굴특유의 조직감과풍미의저하,
방사선조사는소비자들의거부감그리고
MAP
경우경제성의단점때문에실용화되지못하고있다.
이에본연구에서는천연물유래의항균성물질을이용하여생 굴의저장기간을연장하고풍미를개선할수있는가능성에대
생굴(Crassostrea gigas)의 저장성 및 관능성에 대한 천연 첨가물의 효과
정은탁·한해나
1·김윤혜
1·이은혜
1·김덕훈
1·김지훈
1·염승목
1·김영목
1*
에스앤텍, 1부경대학교 식품공학과
The Effects of Natural Food Additives on the Self-life and Sensory Properties of Shucked and Packed Pacific Oyster Crassostrea gigas
Eun-Tak Jeong, Hae-Na Han
1
, Yunhye Kim1
, Eun-Hye Lee1
, Deok-Hoon Kim1
, Ji-Hoon Kim1
, Seung-Mok Yeom1
and Young-Mog Kim1
*SNTECH Co., Ltd., Sungnam 463-760, Korea
1
Department of Food Science and Technology, Pukyong National University, Busan 608-737, Korea
We explored the efficiency of natural antibacterial agents used to enhance the self-life and sensory properties of shucked and packed Pacific oyster Crassostrea gigas , which are in high demanded. First, we screened natural resources exhibiting antibacterial activity against food spoilage and pathogenic bacteria. Of theses, ignited oyster shell powder (IOS) and the natural food preservative, lactic acid bacteria fermented powder (LBF), were selected for further study considering the efficacy, mass production, and cost. The addition of 0.1% IOS (W/V) and 0.5% LBF (W/V) to shucked and packed oyster optimally extended the shelf-life without affecting the sensory evaluation. The results obtained in this study will provide a clue to enhance self-life in raw oyster products.
Key words: Natural food additives, Pacific oyster, Self-life, Sensory properties
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial Licens (http://creativecommons.org/licenses/by-nc/3.0/)which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
http://dx.doi.org/10.5657/KFAS.2015.0244 Korean J Fish Aquat Sci 48(2) 244-248, April 2015
Received 7 January 2015; Revised 6 February 2015; Accepted 11 February 2015
*Corresponding author: Tel: +82. 51. 629. 5832 Fax: +82. 51. 629. 5824
E-mail address: [email protected]
한연구를진행하였다
.
재료 및 방법
시료
본연구에사용된참굴
(Pacific oyster, Crassostrea gigas)
은경 남통영시소재대원식품에서당일수확한것을현장에서박신 하고500 g
의생굴을250 mL
의충진수(
해수와담수비율2:1)
로충진포장하여빙장조건에서신속히연구실로운송하였다.
생굴의저장성및관능성향상을위해천연물유래항균소재 로굴패각분말과
유산균발효분말을사용하였다
.
굴패각분말은
1,800℃
에서소성하고분쇄한것으로부산시기장군에소재하고있는
㈜
비와이에코에서제조한굴패각분말(
제품명:
이온화칼슘
TYPE IC-60)
을사용하였고유산균발효분말은경기도성남시소재
㈜
에스앤텍에서판매하고있는식품용천연 첨가물을제공받아사용하였다.
미생물 시험법
생굴에서의 미생물 검사는
American Public Health Asso- ciation (1984)
의방법에 따라시료를 균질화하고Son et al.
(2014a)
이보고한방법에따라일반세균수와위생지표세균수를측정하였다
.
충진수의경우에는시료1 mL
을취하여Son et al. (2014a)
의방법에따라측정하였다.
pH
생굴에서의
pH
측정을위하여생굴25 g
과75 mL
의 멸균 증류수를넣어균질기(Stomarcher® 400 circulator; Seward, Worthing, UK)
에서230 rpm
의속도로90
초간균질화시킨후 측정하였다.
관능시험
본연구에서실시한관능검사는검사목적과취지를충분히 숙지시킨
20-30
세의패널요원8
명을선정하여10
점척도법으 로관능검사를실시하였다.
외관,
향,
맛,
질감,
짠맛,
비린맛,
이 취및종합적인선호도의각항목에대해관능적특성이높을수 록높은점수를주도록하였다.
통계분석
실험분석얻어진결과에대한통계처리는시료에대해평균
±
표준오차로나타내었으며분석은Duncan’s multiple range test
로평균간의유의성(P<0.05)
로검정하였다(Steel and Tor- rie, 1980).
결론 및 고찰
천연 첨가물의 첨가에 의한 생굴의 저장성 연장
생굴은쉽게변질되는특성을가지고있고유통중에미생물 오염및자가효소활성으로인하여맛
,
색,
향등의손실이초래 되어보존기간이짧아생물상태로는유통이매우짧다(Kong et al., 2006; Park et al., 2008; Xiao and Zhang, 2003).
또한굴 을가열살균하면저장기간을연장시킬수있으나가열처리에 따른생굴본래의독특한풍미와조직감의변질때문에바람직 하지않다(Oshima et al., 1993; Park et. al, 2008; Xiao et al.,
2011).
이러한이유때문에가열살균에의한영양성분파괴,
기호성및조직감이저하되기쉬운수산물의경우천연추출물을
이용하여저장성을연장에대한연구가보고되어있다
(Kang
et al., 2014; Song et al., 2009).
하지만생굴의경우에는이러한 연구에대한보고가전무하여본연구에서천연첨가물을이용 하여생굴의저장성연장에대한가능성을평가하였다.
연구의 초기단계에생굴의저장성연장에대한한약재,
허브및해조류 추출물등의추출물의영향을조사하였으나기대만큼의효과가 나타나지않았고맛,
색,
향등의관능적인평가도부정적이었다(
결과미제시).
이에식품의저장성향상을위한목적으로사용되고있는천연첨가물인유산균발효분말
(0.5%, w/v)
과굴패각분말
(0.1%, w/v)
을이용한생굴의저장성연장효과에대해가능성을확인하고연구를진행하였다
.
현재우리나라에서생굴의유통에대한법적기준은없지만 굴수협등의경매현장에서는일반세균수및위생지표세균등 의미생물학적지표에대한분석이실시간으로불가능하기때 문에
pH
측정기를이용한충진수의pH
를모니터링하는방법 을사용하고있으며그기준은pH 6.3
으로정하고있다.
또한생 식용생굴의경우,
식품의약품안전처의식품의기준및규격 에서분원성대장균은230 MPN/100 g
이하로규정되어있다(Korea Food Standards Codex, 2015).
이에굴패각분말과유 산균발효분말을첨가한실험군의저장성연장효과를조사하기위하여
4℃
에서저장중pH,
일반세균수및위생지표세균의변화를모니터링하였다
.
Table 1
에나타낸것처럼0.1%
의굴패각분말과0.5%
의유 산균발효분말을동시에첨가한실험군이대조군및각각첨가 한다른실험군에비해충진수와생굴에서pH
유지효과및일 반세균수와위생지표세균실험에서가장효과적인것으로나 타났다.
특히
0.1%
의굴패각분말과0.5%
의유산균발효분말을첨가 한실험군은실험기간동안충진수와생굴에서일반세균수와 위생지표세균의변화가거의없어저장성연장효과가가장뛰어난것으로나타났다
(Table 1).
또한모든시료에서식품의약품안전처의식품의기준및규격인생식용굴의섭취기준
(
분원 성대장균230 MPN/100 g
이하)
이유지되고있어4℃
에서5
일 간의저장기간중에는위생학적인문제는없는것으로나타났 다(Table 1, B; Korea Food Standards Codex, 2015).
pH
변화의경우,
실험0
일차에는충진수와생굴의모든시료에서
pH
가6.3
이상으로굴수협의경매기준을충족하고있으나저장기간이연장됨에따라
pH
는점진적으로감소하는경향 을나타내었다(Table 1).
이는저장기간중충진수와생굴의pH
가점진적으로감소한다는Son et al. (2014b)
의연구결과와도 일치한다.
굴에대한여러연구에의하면생굴의글리코겐이해 당과정을통해젖산이되기때문에글리코겐함량의감소와pH
의감소는밀접한관계가있어결론적으로pH
는생굴의품질지 표로써적합하다고판단하고있다(Son et al., 2014b; Pottinger, 1948; Hunter and Linden, 1923).
이들보고에서는굴의pH 6.3
이상은“Very good”, 6.2-5.9
는“good”, pH 5.8
은“off”, pH 5.7- 5.5
는“musty”, 5.2
이하는“sour”
또는“putrid”
로판정한다.
이 러한결과를본연구결과에적용해보면대조군에서는저장3
일이후pH
가5.8
이하로급격한품질저하가나타나지만, 0.1%
굴패각분말과
0.5%
유산균발효분말을첨가한실험군의경우5
일까지도pH 5.8
이상을유지하고있다(Table 1, B).
이상의결 과를종합해보면0.1%
굴패각분말과0.5%
유산균발효분말 의첨가는대조군과비교하였을때최소
2
일이상의저장기간 연장효과가있는것으로나타났다.
천연 첨가물의 첨가에 의한 생굴의 관능성 향상
생굴의 품질향상과 관련하여 초고압 기술(Oshima et al.,
1993),
유기산처리(Kim, 2002),
감마선조사(Park et al., 2008)
등과같은다양한가공기술에대한연구가많이이루어지고있 다.
하지만이러한방법은부패에관여하는미생물사멸에는효 과적이지만굴의조직감과풍미를떨어뜨리고,
특히변색을유 발하는단점을가지고있다.
또한지금까지생굴의보존성을증 가시키면서조직감및풍미등의관능적인식품학적품질을보 존또는향상시키는연구는미비한실정이다.
이에본연구에서 는생굴의저장성연장에어느정도효과가있는것으로나타난 굴패각분말과유산균발효분말의첨가에의한생굴의저장기 간중의관능학적식품품질변화에대한영향을분석하였다.
분석항목은굴의외관,
향,
맛,
질감,
짠맛,
비린맛,
이취및종 합적인선호도를측정하였고관능적특성이높을수록높은점 수를주도록하였다.
생굴저장기간중에대조군과비교하였을 때,
굴패각분말과유산균발효분말첨가에따른관능적인변화는큰차이는없는것으로나타났다
(Table 2).
하지만저장기간이증가함에따라관능적으로부정인평가가증가하기시작 하였으며저장
5
일이후로는이취가극심하여관능평가를진행 할수없었다.
특히저장4
일이후로는모든시료에서종합적인 선호도(total preference)
가5.0
이하로부정적인견해가뚜렷하 였다.
이상의결과를종합해보면,
봉지굴의제조공정에굴패 Table 1. Changes of physicochemical and bacterial properties by addition of natural food additives in shucked and packed Pacific oyster Crassostrea gigasA) Packing water Storage
periods (day)
pH Viable cell counts
(log CFU/mL) Coliforms
(MPN/100 mL) Fecal Coliform (MPN/100 mL)
A B C D A B C D A B C D A B C D
0 6.32±0.3 6.40±0.6 6.38±0.3 6.55±0.6 2.5±0.4 2.6±0.2 1.6±0.2 1.3±0.3 <1.8 <1.8 <1.8 <1.8 <1.8 <1.8 <1.8 <1.8 1 6.16±0.3 6.23±0.6 6.19±0.3 6.28±0.6 2.5±0.4 2.3±0.2 2.1±0.2 2.4±0.3 2.0 <1.8 <1.8 <1.8 <1.8 <1.8 <1.8 <1.8 2 6.12±0.3 6.05±0.6 6.06±0.3 6.24±0.6 2.3±0.4 2.5±0.2 2.3±0.2 2.5±0.3 7.8 4.0 4.0 2.0 <1.8 <1.8 <1.8 <1.8 3 5.84±0.3 5.9±0.6 5.86±0.3 5.92±0.6 2.3±0.4 2.1±0.2 2.3±0.2 2.3±0.3 9.1 6.8 4.5 4.5 <1.8 <1.8 <1.8 <1.8 4 5.54±0.3 5.61±0.6 5.55±0.3 5.56±0.6 3.1±0.4 3.1±0.2 4.5±0.2 2.3±0.3 13 8.2 6.8 7.8 <1.8 <1.8 <1.8 <1.8 5 5.33±0.3 5.32±0.6 5.32±0.3 5.39±0.6 3.5±0.4 3.2±0.2 4.3±0.2 2.2±0.3 18 18 18 11 <1.8 <1.8 <1.8 <1.8
B) Oysters Storage
periods (day)
pH Viable cell counts
(log CFU/g) Coliforms
(MPN/100 g) Fecal Coliform (MPN/100 g)
A B C D A B C D A B C D A B C D
0 6.32±0.3 6.31±0.7 6.32±0.2 6.35±0.2 3.0±0.4 2.4±0.2 2.5±0.2 2.4±0.2 <18 <18 <18 <18 <18 <18 <18 <18 1 6.18±0.3 6.16±0.7 6.15±0.2 6.22±0.2 3.1±0.4 2.8±0.2 3.1±0.2 2.9±0.2 20 <18 20 18 <18 <18 <18 <18 2 6.10±0.3 6.17±0.7 6.06±0.2 6.18±0.2 3.0±0.4 3.1±0.2 3.0±0.2 2.6±0.2 20 20 <18 <18 <18 <18 <18 <18 3 5.92±0.3 6.03±0.7 5.96±0.2 6.05±0.2 3.0±0.4 3.1±0.2 3.1±0.2 2.5±0.2 <18 40 <18 <18 <18 <18 <18 <18 4 5.56±0.3 5.57±0.7 5.81±0.2 5.96±0.2 3.2±0.4 3.5±0.2 3.5±0.2 2.3±0.2 61 45 40 18 <18 <18 <18 <18 5 5.42±0.3 5.47±0.7 5.75±0.2 5.83±0.2 5.2±0.4 4.3±0.2 4.8±0.2 2.4±0.2 220 120 190 61 <18 <18 <18 <18 A, Blank; B, 1% ignited oyster shell powder (IOS); C, 0.5% lactic acid bacteria fermented powder (LBF); D, 0.1% IOS and 0.5% LBF.
각분말과유산균발효분말첨가는생굴의관능성에영향을미 치지않으면서뛰어난저장성연장효과를기대할수있는것으 로나타났다
.
위에서기술한것과같이초고압
,
유기산처리및방사선조 사등의비가열가공기술은병원성미생물이나부패성미생물 을효과적으로제어할수있어저장성연장에는효과적이지만 생굴의조직감외관및풍미등의관능적인품질저하를초래하 기때문에현장에서적용되지못하고있다.
이에본연구에서제 시한천연첨가물을이용한생굴의저장성연장및관능학적품 질향상에대한연구는생굴과같이조직이약한수산물의저장 성연장및관능성향상에관련된연구에실마리를제공할것으 로기대된다.
사 사
이논문은
2015
년해양수산부재원으로한국해양과학기술진흥원의지원을받아수행된수산실용화기술개발사업연구임
[
노로바이러스프리(free)
고부가가치굴및가공품개발].
또한 이논문은수산과학발전에깊은관심을가지고계셨던고강영 환님을기리기위해미국시애틀소재SKS Trading Co.
의지원 에의해조성된부경대학교발전기금의장학금지원에의해이 루어진연구로이에감사드립니다.
References
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Storage periods
(day) Appearance Flavor Taste Texture Salty Fishy off-flavor Total
preference
0
A 9.5±0.3 7.6±0.8 7.6±0.5 8.1±0.3 4.4±0.3 4.9±0.6 1.6±0.1 7.9±0.4
B 9.1±0.3 7.4±0.8 7.0±0.5 8.1±0.3 3.9±0.3 4.3±0.6 1.6±0.1 7.5±0.4
C 9.6±0.3 9.0±0.8 8.1±0.5 8.5±0.3 4.0±0.3 3.5±0.6 1.7±0.1 8.0±0.4
D 9.8±0.3 8.9±0.8 7.9±0.5 8.6±0.3 4.5±0.3 4.3±0.6 1.6±0.1 7.1±0.4
1
A 8.1±0.4 8.0±0.3 7.4±0.4 7.6±0.1 4.6±0.3 5.0±0.4 2.7±0.2 7.0±0.6
B 8.9±0.4 8.6±0.3 7.9±0.4 7.9±0.1 4.3±0.3 4.4±0.4 2.3±0.2 6.1±0.6
C 8.9±0.4 8.7±0.3 8.0±0.4 7.7±0.1 5.0±0.3 4.1±0.4 2.4±0.2 7.6±0.6
D 8.4±0.4 8.3±0.3 7.1±0.4 7.7±0.1 4.3±0.3 4.7±0.4 2.4±0.2 6.7±0.6
2
A 7.7±0.5 7.3±0.3 6.1±0.5 7.1±0.1 5.0±0.4 6.9±0.5 2.9±0.1 5.7±0.3
B 6.7±0.5 7.4±0.3 6.3±0.5 7.0±0.1 4.4±0.4 5.9±0.5 2.9±0.1 6.3±0.3
C 7.3±0.5 6.9±0.3 6.7±0.5 7.3±0.1 4.3±0.4 6.0±0.5 3.1±0.1 6.3±0.3
D 6.6±0.5 6.9±0.3 5.4±0.5 7.0±0.1 4.1±0.4 6.4±0.5 2.9±0.1 6.1±0.3
3
A 6.6±0.2 6.3±0.4 5.1±0.1 5.7±0.3 4.3±0.6 4.4±0.2 2.4±0.2 5.4±0.2
B 6.5±0.2 7.0±0.4 5.2±0.1 5.6±0.3 5.3±0.6 4.4±0.2 2.7±0.2 5.9±0.2
C 6.7±0.2 6.0±0.4 5.0±0.1 5.3±0.3 4.1±0.6 4.2±0.2 2.7±0.2 5.7±0.2
D 6.3±0.2 6.6±0.4 5.1±0.1 5.1±0.3 5.1±0.6 4.7±0.2 2.4±0.2 5.9±0.2
4
A 5.4±0.4 5.1±0.3 5.0±0.3 5.8±0.6 3.3±0.2 5.0±0.5 3.1±0.3 4.8±0.3
B 5.8±0.4 5.4±0.3 5.0±0.3 6.3±0.6 3.5±0.2 4.6±0.5 2.8±0.3 5.0±0.3
C 4.9±0.4 4.8±0.3 4.5±0.3 5.3±0.6 3.1±0.2 5.5±0.5 3.5±0.3 4.4±0.3
D 5.4±0.4 5.0±0.3 4.5±0.3 5.0±0.6 3.3±0.2 4.5±0.5 3.0±0.3 4.4±0.3
5
A 3.7±0.3 4.0±0.2 4.1±0.3 3.9±0.4 3.9±0.4 5.3±0.3 3.7±0.4 3.9±0.3
B 3.3±0.3 4.0±0.2 4.0±0.3 3.4±0.4 3.6±0.4 5.4±0.3 3.4±0.4 3.4±0.3
C 3.1±0.3 3.7±0.2 4.6±0.3 4.0±0.4 3.6±0.4 5.1±0.3 3.4±0.4 3.9±0.3
D 3.4±0.3 4.1±0.2 4.1±0.3 4.3±0.4 3.0±0.4 4.7±0.3 2.7±0.4 3.9±0.3
A, Blank; B, 1% ignited oyster shell powder (IOS); C, 0.5% lactic acid bacteria fermented powder (LBF); D, 0.1% IOS and 0.5% LBF.
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