Quality and Antioxidant Activity of Soybean Curd Supplemented with Codium fragile

한수지 53(6), 816-822, 2020

816

Copyright © 2020 The Korean Society of Fisheries and Aquatic Science pISSN:0374-8111, eISSN:2287-8815

Korean J Fish Aquat Sci 53(6),816-822,2020

Original Article

서 론

우리나라전통식품중의하나인두부

(soybean curd)

는대두 를물과함께마쇄하여그중의수용성단백질인

glycinin

과염 류인

Mg ²⁺

또는

Ca ²⁺

등의금속염과결합하거나산에의해등전 점

(pH 4.2-4.6)

^{에도달하면서단백질이이황화결합}

(disulfide bond)

및수소결합

(hydrogen bond)

등에응고시킨후탈수

,

성 형한겔

(gel)

상의식물성고단백질식품이다

(Kim et al., 2003).

두부는소화흡수율이

97%

로매우높고

,

곡류위주의식생활에

서부족하기쉬운라이신

(lysine)

등의필수아미노산의함량이

많아서신진대사와성장발육에꼭필요한아미노산공급에좋 은식품이다

(Kim et al., 2005).

국내두부시장은매년성장하고

있으며

,

^{특히상대적으로가격이높은포장두부의매출이늘고} 있다

. Ryu (2005)

의연구에따르면이는국민들이건강한삶에 대한관심이높아지면서안전한먹거리및웰빙에대한관심이 증가되었기때문이다

.

이추세에맞춰근래에는다양한생리활 성성분을함유하고있는천연소재를두부에첨가하여섬유소

,

칼슘및항산화활성이풍부한기능성두부개발을목표로하는 연구가활발하게진행되어왔다

(Lee et al., 2014).

그예로클로 렐라

(Kim et al., 2003),

파래분말

(Chung, 2010),

초석잠분말

(Lee et al., 2014),

홍삼추출물

(Lee et al., 2008),

쓰가루사과즙

(Kim et al., 2016)

등을첨가한기능성

,

기호성및항산화성등 을증진시킨두부에대한연구들이수행되었다

.

^청각

(Codium fragile)

^{은녹조식물문청각과에속하는다년생해조류로}

,

표면

청각(Codium fragile)을 첨가하여 제조한 두부의 품질특성 및 항산화 활성

최만석 ^1,2 ·전은비 ^1,2 ·김지윤 ^1,2 ·박신영 ^1,2 *

1경상대학교 해양산업연구소, ²경상대학교 해양식품생명의학과

Quality and Antioxidant Activity of Soybean Curd Supplemented with Codium fragile

Man-Seok Choi

^1,2

, Eun Bi Jeon

^1,2

, Ji Yoon Kim

^1,2

and Shin Young Park

^1,2

*

1

Institute of Marine Industry, Gyeongsang National University, Tongyeong 53064, Korea

2

Department of Seafood and Aquaculture Science, Gyeongsang National University, Tongyeong 53064, Korea

This study investigated the antioxidant activity and general and sensory properties of soybean curd supplemented with Codium fragile. The yield of soybean curd containing 0%, 20%, and 40% C. fragile was 113.62, 104.09, and 108.06, respectively. Antioxidant activities and pH were significantly increased (P<0.05) depending on the amount of C. fragile supplemented in soybean curd. Compared to that in additive-free soybean curd (control), the amount of crude ash and protein in soybean curd containing 40% C. fragile was significantly decreased (P<0.05) and increased (P<0.05), respectively. We observed a dose-dependent increase (P<0.05) in the hardness and chewiness of soybean curd concomitant with the amount of C. fragile supplemented. In contrast, we observed no significant difference (P>0.05) in soybean curd's cohesiveness between the groups. As determined by sensory evaluation based on seven- point hedonic scale, soybean curd supplemented with 20% C. fragile received an excellent score (6.55) for color.

As the same method, we observed that the flavor and overall acceptability significantly increased (P<0.05) in the C.

fragile content increased. Taken together, the antioxidant and sensory assays in our study make a compelling case for the practical development of soybean curd supplemented with C. fragile owing to its good antioxidant activities, general properties, and consumer acceptance.

Keywords: Antioxidant activity, Codium fragile , Protein, Soybean curd, Yield

*Corresponding author: Tel: +82. 55. 772. 9143 Fax: +82. 55. 772. 9149 E-mail address: [email protected]

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.

Received 26 October 2020; Revised 16 November 2020; Accepted 24 November 2020 저자 직위: 최만석(대학원생), 전은비(대학원생), 김지윤(대학원생), 박신영 (교수)

https://doi.org/10.5657/KFAS.2020.0816

Korean J Fish Aquat Sci 53(6), 816-822, December 2020

항산화 활성이 강화된 청각두부의 개발

817

은융처럼부드럽고감촉과미감

(味感)

^{이좋아오래전부터한} 국과일본

,

중국등의동아시아국가에서식용으로애용되어왔 다

.

청각을비롯한파래

,

미역

,

다시마등의해조류는육상생물 에비하여비타민및무기질성분함량이높은것으로알려져있 는데

,

청각은특히나장의운동에도움이되는식물성섬유질 과몸을구성하는나이아신이풍부하며다른녹조류에비해탄 수화물인당질과단백질함량이높은편이다

(Nagayama et al., 2002). Kim et al. (2018)

의청각추물물의항균활성및기능성 에대한연구에의하면청각추출물에는항생작용이있는아크 릴산

(acrylic acid)

이있어이는유해균만을억제하는항균작용 을가지고있으며

,

^{베타카로틴함량이풍부하여항암효과및면} 역기능에도활성을나타내는것으로보고되었다

.

최근에는청 각의항산화능이밝혀져청각에탄올추출물의항산화에관한 연구

(Lee and Kim, 2019),

청각을첨가한막걸리의항산화효 과에대한연구

(Jun et al., 2019),

발효한청각첨가물을활용한 화장품소재연구

(Lee et al., 2019)

^{등이진행되어왔지만}

,

^아직 까지청각을활용한식품가공학적측면의연구개발은매우미 진한편이다

.

따라서본연구에서는항산화효능이우수한청각을비율별 로첨가수준을달리하여고유한향이잘배합된두부를제조 하여

,

^{두부의항산화활성}

,

^{이화학적및관능적품질특성을평} 가하여청각의이용활성화와더불어이를이용한해조류의항 산화활성이강화된두부의개발을위한기초자료를제공하고 자하였다

.

재료 및 방법

두부의 제조

청각을첨가한두부의제조공정은

Fig. 1

과같다

.

본연구에서 사용된대두는경기김포에서수확한국내산대두

(

백태

)

를

,

청

각은경남통영에서수확한청각

(

^고형분

100%)

^{을사용하였으}

며

,

두부응고제로는염화마그네슘

(MgCl ₂ · 6H ₂ O)

를사용하였 다

.

건조대두

400 g

을수세한후실온에서

12

시간물에침지하 여불린다음

300 mL

의물을첨가하면서

30

초간마쇄하였다

.

이렇게얻은두미액을

80±3°C

에서

10

분간가열한후건조대 두중량대비

0, 20, 40% (w/v)

^{농도로마쇄한청각고형물을} 첨가하였고응고제로

40 mL MgCl ₂

을첨가하고

5

분간정치하 여응고시켰다

.

응고물은성형틀에넣어

75 psi

의압력으로

20

분압착성형한후일정규격

(13×13×3.5 cm)

으로절단하였

다

.

두부를폴리프로필렌용기에담고침지액인멸균증류수

50

mL

^를넣어

film

^{을용기에열접착방식으로부착시켜포장한다}

음

85°C

에서

15

분간열처리하고신속히냉각시켜

15°C

에서

10

일간저장하였다

. Lee et al. (2008)

의연구에의하면

,

두부를멸 균증류수에침지하는이유는두부를침지하지않고저장하면 표면에서부터수분함량이점차적으로감소하여두부의조직특 성에변화를일으킬수있기때문이다

.

두부의 수율(%)

청각두부의수율은

Kim et al. (2003)

의방법을적용하여제 조된두부의무게를원료대두의무게로나누어백분율로나 타내었다

.

Yield (%)=[Weight of tofu (g)/Weight of soybean(g)]×100

ABTS 라디칼 소거활성능

청각두부의

2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)

라디칼소거능분석은

Kim et al. (2018)

과

Lee et al. (2014)

의방법을참고하여수행하였다

. 7 mM

의

ABTS (Sigma-Aldrich Co., St. Louis, MO, USA)

와

2.45 mM

의

K ₂ S ₂ O ₈ (potassium persulfate)

를혼합하여

12-16

시간동안암 실에방치하여

ABTS cation radical (ABTS ⁺ )

^{을형성시킨후}

, 734 nm

에서흡광도값이

0.70±0.02

가되도록

99.99%

에탄 올로희석하여사용하였다

.

그리고두부시료

0.05 g

를희석된

ABTS ⁺

용액

1 mL

에가하여

60

분간반응시키고

734 nm

에서 흡광도를측정하였다

. ABTS ^.

라디칼소거활성능

(%)

은시료무 첨가군대비흡광도감소율로나타냈다

.

^또한

,

^{양성대조구실} 험으로시료대신에

L-ascorbic acid

를동량첨가하여

ABTS

라 디칼소거활성능

(%)

에대해분석하였다

.

ABTS

라디칼소거활성

(%)=[1-(

시료첨가군

/

무첨가군

)]×100

DPPH 라디칼 소거활성능

청각두부의

1,1-diphenyl-2-picrylhydrazyl (DPPH) (Sigma-

Fig 1. The preparation procedure of soybean curd containing Codium fragile.

Soybean Washing and soaking (at room temperature for 12 h)

Grinding (addition of water) Filtering and collecting soymilk

Heating soymilk (80±3°Cfor 10 min)

Coagulation (addition of MgCl

₂

·6H

₂

O)

Moulding

(13×13×3 cm, at 75 psi for 20 min) Cooling

Codium fragile soybean curd

Codium fragile Washing and soaking (at room temperature for 12 h)

Grinding (addition of water)

Addition of grinded Codium fragile

(a) (b) (c)

0 20 40 60 80 100

Ascorbic

acid 0 20 40

DPPH free radical scavenging activity (%)

Codium fragile (%)

b a

c d

0 20 40 60 80 100

Ascorbic

acid 0 20 40

ABTS free radical scavenging activity (%)

Codium fragile (%)

b a

c

d

최만석

ㆍ

전은비

ㆍ

김지윤

ㆍ

박신영

818

Aldrich Co., St. Louis, MO, USA)

^{라디칼 소거능은}

Blois (1958)

의방법에따라먼저

DPPH

용액을

0.005 g/100 mL

로

99.9%

에탄올에희석한후

2

시간이상암소에서방치하고

, 517 nm

에서흡광도값이

1.5-1.7

로보정하여준비하였다

.

그리고 두부시료

0.2 g

에

DPPH

용액

0.8 mL

를넣어교반한다음실 온에서

30

^{분간방치한후}

517 nm

^{에서흡광도를측정하였다}

.

DPPH

라디칼소거활성능

(%)

은시료무첨가군대비흡광도감

소율로나타냈다

.

또한

,

양성대조구실험으로시료대신에

L- ascorbic acid

를동량첨가하여

DPPH

라디칼소거활성능

(%)

에대해분석하였다

.

DPPH

^{라디칼소거활성}

(%)

=[1-(

시료첨가군

/

무첨가군

)]×100 일반성분(조회분, 조단백질) 및 pH

일반성분분석은

AOAC (2000)

법에의거하여조회분은건식

회화법

,

조단백질은

micro Kjeldahl

법으로분석하였다

.

청각두 부의

pH

^는

YSI 63 pH meter (Orion star A211, Thermo Scien- tific, MI, USA)

를이용하여측정하였다

.

Texture 측정

성형된두부의

texture

측정은두부를일정크기

(1.5×1.5×1.5 cm)

로절단한다음

CT3 texture analyzer (Brookfield Engi- neering Laboratories Inc., Middleboro, MA, USA)

^를사용하 여

texture profile analysis (TPA) mode

에서경도

(hardness),

씹힘성

(chewiness),

응집성

(cohesiveness)

를측정하였다

.

측정 조건은

probe, stainless steel probe-type TA18 12.7 mm; test speed, 1.0 mm/s; force threshold, 20 g; distance threshold, 0.50 mm; Compression limit, 50% deformation

^이었다

. 관능평가

관능검사는경상대학교해양식품생명의학과대학생과 대학 원생으로구성된

20

대성인

30

명

(

남

15

명

,

여

15

명

)

을선정하여 평가를실시하였다

.

두부는일정한크기

(2×2×1 cm)

로흰색 접시에담아제공하였으며외관

(appearance),

^색상

(color),

^풍 미

(flavor),

조직감

(texture),

전반적인 기호도

(overall accept- ability)

이며이에대한결과를

7

점척도법

(7

점

,

매우좋음

; 1

점

,

매우나쁨

)

으로평가하였다

.

통계분석

청각첨가두부의수율

,

^{항산화활성}

(ABTS radical

^소거활성 능

, DPPH radical

소거활성능

), pH,

일반성분

(

조회분

,

조단백 질

), texture

는모든실험에대해각시료당

3

회반복을통하여 얻은평균값과표준편차를이용하여진행하였다

.

또한

,

관능검 사결과는

30

명의패널의각제품에대한평균점수와표준편차 를이용하여통계처리하였다

.

^{통계프로그램은}

SPSS version 12.0 software program (SPSS Inc., Chicago, IL, USA)

중일원

배치분산분석

(one-way ANOVA)

^및

Duncan’s

^{다중범위검정}

(multiple range test)

을이용하였으며유의성차를

5% (P<0.05)

수준에서검증하였다

.

결과 및 고찰

청각두부의 수율

청각을첨가한두부의수율을측정한결과는

Table 1

에 나

타내었다

.

두부의 수율은 대조군

(

청각 무첨가 두부

)

의 경우

113.62±2.31%

으로가장높았으며

, 20%

및

40%

청각을첨 가한두부의수율은각각

104.09±3.17, 108.06±7.02%

^이였 다

.

일반적으로두부의수율은두부의수분과콩의수용성단백 질함량에직접적인영향이보고되고있다

(Smith et al., 1960).

Chung (2010)

과

Park and Jeon (2008)

은각각파래분말과노 랑파프리카즙을첨가하여제조한두부의첨가물함량이커질 수록수율이감소하는경향을나타냈는데

,

^{이는각첨가물이두} 부의보수력을감소시켜대두단백질의응고성에변화를가져 온것으로보고하였다

.

유사하게

, Choi et al. (2000)

은천연물 의첨가가대두단백질의결합을방해하여수율이낮아질수있 다고보고하였다

. Ko et al. (2013)

은두부의다양한간수

(

응고 제

)

^{를이용하여제조된두부의수율이첨가된응고제}

(

^간수및

MgCl ₂ )

의농도에따른유의적인차이가없었으며

(P>0.05),

두 부를압착하는방법혹은응고제의용해도가두부의수율에더 큰 영향을미쳤을것으로판단하였다

. Rekha and Vijayalak-

shmi (2013)

은두부제조시에콩을충분히마쇄시키지못하였

을때

,

^{지나친마쇄에의한대두단백질의열변성}

,

^{올바르지못} 한증자

(

끓임

),

응고과정

(coagulation)

의과도한교반등이수 율의감소에직접적인영향이있다고보고하였다

.

본연구에서 는두부의수율이청각함량에따라유의적인차이는없었지만

(P>0.05),

청각함량이높아질수록수율의평균이감소하는결 과를나타냈다

.

^따라서

,

^{수율의감소는두부제조의정확도}

(ac- curacy)

혹은정밀도

(precision)

측면의오차이거나

,

청각의첨 가가두부의응고성에변화를준것으로사료된다

.

Table 1. Yield, pH, and proximate composition of the soybean curd supplemented with Codium fragile

Codium fragile contents (%) 0 (w/v) 20 (w/v) 40 (w/v) Yield (%) 113.62±2.3^1NS 104.09±3.17 108.06±7.02

pH 5.02±0.16^b 5.26±0.22^ab 5.49±0.06^a

Crude ash (%) 1.74±0.02^a 1.68±0.01^a 1.48±0.10^b Crude protein (%) 7.35±0.16^b 7.51±0.05^b 9.26±0.64^a NS means within the same row did not different (P>0.05) by Dun- can’s multiple range test. ^a-bMeans represented by different super- scripts in the same row are significantly different (P<0.05) by Dun- can’s multiple range test.

항산화 활성이 강화된 청각두부의 개발

819

청각두부의 pH

청각을첨가한두부의

pH

^{를측정한결과는}

Table 1

^에나타 내었다

.

두부의

pH

는 청각 첨가군이

5.26-5.49

로 대조군의

pH 5.02

에비해유의적으로더증가하여 알칼리성이되었다

(P<0.05).

이는해조류천연물에존재하는

Mg, K, Na, Mn

등 의양이온성분이두부의

pH

에관여하여두부를알칼리화한 것으로사료된다

(Kim et al., 2003).

^{본연구와유사하게}

Kim et

al. (2016)

의쓰가루사과즙을첨가한두부의연구에서는사과

즙무첨가군두부의

pH

는

5.41-5.64

이였으나

, 20% (w/v)

쓰가 루사과즙을첨가하였을때에는

6.23

으로두부가알칼리화한 것으로나타났다

.

그러나

,

본연구와는다르게사과즙농도를

30-40%

^{로더높였을경우에는}

pH

^{가오히려감소하였다}

.

^이는 등전점보다낮은

pH

에서는단백질이산과반응하여단백질

-

산 염복합체를형성하여불용성으로응고되어침전하여

pH

를높 이지만

,

단백질

-

산반응이완전히종결되고나면여분의유기산 이생겨

pH

가낮아질수있기때문이다

(Setyono, 1994).

본연 구에서도청각에존재하는아크릴산

(acrylic acid)

^{등의유기산} 이두유의단백질과반응하면서소모되어청각두부의

pH

가청 각의함량에따라높아진것으로사료된다

.

청각두부의 일반성분(조회분, 조단백질)

청각첨가량을달리하여제조한두부의조회분과조단백질을 분석한결과는

Table 1

^{에나타내었다}

.

^{조회분은청각무첨가군} 두부가

1.74%

으로가장높았으며

, 20%

청각두부

(1.68%)

과는 유의적인차이가없었지만

(P>0.05), 40%

청각두부

(1.48%)

보 다는유의적으로높았다

(P<0.05).

반면

,

조단백질은

40%

청각 두부가

9.26%

으로가장높았으며

,

무첨가군두부

(7.35%)

및

20%

^청각두부

(7.51%)

^{보다유의적으로높았다}

(P<0.05).

Lee et al. (2014)

의초석잠분말을첨가한두부는

0.6%

이상 초석잠분말을첨가하였을때부터조회분및조단백질의유의 적인감소를보였는데

(P<0.05),

그원인으로두부순물의탁도 가증가한것으로보아초석잠분말의성분이두부의단백질에 흡착되지못하고순물로빠져나간것으로보고하였다

. Hwang et al. (2011)

의청양고추착즙액을첨가한두부에관한연구에 서도청양고추착즙액을첨가할수록무첨가군두부에비해조 회분과조단백질이 낮아지는경향을나타냈다

. Hwang et al.

(2011)

은청양고추즙의식이섬유와색소성분등이단백질과응

고제와의결합강도등에영향을주어두부의보수력에영향을 준것을원인으로보고하였다

.

청각은채취시기마다그일반성 분이달라져

,

조회분은

53.1-56.8%,

조단백질은

5.0-6.5%

으로 알려져있는데

(Jung et al., 2005),

본연구에서개발된청각두부 의조회분은청각원재료보다낮으므로두부의제조과정에서 청각의무기질이두부의단백질에잘흡착하지못하여순물등 으로빠져나간것으로사료된다

.

결과적으로

,

청각을첨가한두 부를제조함으로써조회분은낮추고조단백질은증가시킨영양 학적으로우수한두부를개발할수있었다

.

청각두부의 항산화력 활성

청각은항암및항산화억제의생리활성물질이라고알려진 사포닌

(saponin),

플라보노이드

(flavonoid),

이소플라본

(isofla- vone),

토코페롤

(tocopherol),

안토시아닌

(anthocyanin),

탄닌

(tannin)

등의성분이다량함유되어있어항산화활성능이있는

것으로알려져있다

(Jung et al., 2005; Kim et al., 2006).

^항산 화활성능에대한측정은세포손상의원인이되는자유라디칼

(free radical)

을소거하는것이핵심이다

(Kim et al., 2018).

청 각두부의

ABTS

라디컬소거활성능은

Fig. 2

에나타내었다

.

청

각두부의

ABTS

라디칼소거활성능은대조군에서

48.16%

로

가장낮았으며

,

^{청각의첨가량이증가함에따라}

20, 40%

^첨가 군에서각각

59.97%, 76.17%

로그활성능이유의적으로증가 하였다

(P<0.05). DPPH

는질소중심의라디칼로서짙은자주색 을나타내며

,

라디칼전자의비편재화에의해분자내에서안정 화상태로존재한다

(Kim et al., 2007).

청각두부의

DPPH

라디 컬소거활성능은

Fig. 3

^{에나타내었다}

.

^{청각두부의}

DPPH

^라디 칼소거활성능은대조군에서

52.56%

로가장낮았으며

,

청각의 첨가량이증가함에따라

20%, 40%

첨가군에서각각

64.97%, 80.88%

로그활성능이유의적으로증가하였다

(P<0.05).

Jun et al. (2019)

의청각막걸리의항산화활성연구결과

,

청 각무첨가군의

ABTS

^{라디칼소거활성}

(21.21%), DPPH

^라디 칼 소거활성

(30.97%)

에비해

10%, 20%, 30%

청각첨가막 걸리에서 더 높은

ABTS

라디칼소거활성

(51.01%, 54.24%, 64.79%), DPPH

라디칼소거활성

(74.63%, 79.36%, 84.64%)

Fig 2. ABTS free radical scavenging activity in the soybean curd supplemented with Codium fragile. ABTS, 2-2'-Azino-bis (3-eth- yl-benzothiazoline-6-sulfonic acid) diammouium. ^a-dMeans repre- sented by different superscripts in the same row are significantly different (P<0.05) by Duncan’s multiple range test.

Soybean Washing and soaking (at room temperature for 12 h)

Grinding (addition of water) Filtering and collecting soymilk

Heating soymilk (80±3°Cfor 10 min)

Coagulation (addition of MgCl

₂

·6H

₂

O)

Moulding

(13×13×3 cm, at 75 psi for 20 min) Cooling

Codium fragile soybean curd

Codium fragile Washing and soaking (at room temperature for 12 h)

Grinding (addition of water)

Addition of grinded Codium fragile

(a) (b) (c)

0 20 40 60 80 100

Ascorbic

acid 0 20 40

DPPH free radical scavenging activity (%)

Codium fragile (%)

b a

c d

0 20 40 60 80 100

Ascorbic

acid 0 20 40

ABTS free radical scavenging activity (%)

Codium fragile (%)

b a

c

d

최만석

ㆍ

전은비

ㆍ

김지윤

ㆍ

박신영

820

을나타냈다

.

^따라서

,

^{청각첨가함량이높아질수록청각첨가식}

품의

ABTS

라디칼소거활성능과

DPPH

라디칼소거활성능이

증가하는것을확인할수있었다

.

또한

,

청각두부의항산화활성 정도를비교하기위하여항산화제인

L-ascorbic acid

를양성대 조군으로사용하여청각두부와같은농도로측정한결과각각

ABTS

^{라디칼소거활성능}

86.09%, DPPH

^{라디칼소거활성능}

92.06%

으로확인되었다

.

초석잠분말첨가두부의항산화활성

연구결과

(Lee et al., 2014),

본연구와유사하게초석잠분말함 량이높아질수록

ABTS

라디칼소거활성과

DPPH

라디칼소거 활성이유의적으로높아졌으며

(P<0.05),

최대

0.8%

의초석잠 분말첨가시

45.16% ABTS

^{라디칼소거활성}

, 88.95% DPPH

라디칼소거활성을나타냈다

.

청각두부

,

초석잠분말첨가두부 모두항산화제인

L-ascorbic acid

의항산화능보다는낮았지만

,

상당히높은항산화능을보여주었다

.

청각두부의 Texture 및 관능검사

청각첨가두부의물성특성을알아보기위하여

texture

^를측

정한결과는

Table 2

와같다

.

응집성

(cohesiveness)

는청각첨 가에따른유의적인차이를확인할수없었지만

(P>0.05),

경도

(hardness)

와씹힘성

(chewiness)

는청각첨가함량이

20%

혹은

40%

일때무첨가두부보다유의하게증가하였다

(P<0.05).

본 연구결과와유사하게

,

^{파래분말을첨가한두부의연구결과에} 서는

(Chung, 2010),

파래분말을

0.2%

까지첨가하였을때응 집성

(cohesiveness)

은유의적인변화가없었으며

(P>0.05),

반 대로경도

(hardness)

와씹힘성

(chewiness)

은유의적으로증가 하였다

(P<0.05).

그러나

,

파래분말을

0.3%

및

0.4%

첨가시에 는무첨가두부보다응집성

(cohesiveness)

^{이낮아지는것을보} 고하였다

(Chung, 2010).

이러한물성의차이는두부를제조시 사용한천연물과물질상태

(

예

,

액체

,

고체

),

고형분함량

,

응고 제첨가량

,

단백질함량과조성등에의한차이라고사료된다

.

청각을

0, 20%, 40%

첨가하여제조한두부는

Fig. 4

에나타냈 으며

,

^{관능검사결과는}

Table 3

^{에나타냈다}

.

^{청각첨가함량에} 따른두부의외관

(appearance)

는유의적인차이가없었지만

,

색 상

(color)

는

20%

청각두부가가장유의적으로높은결과를보 였다

(P<0.05).

이에대한관능평가조사결과

,

청각첨가량을증 가시킬수록연두빛색상이짙어지면서

,

청각을

40%

첨가할시

에는두부의색상이어두운연두빛을 띄었기때문에

20%

^청

각을첨가한두부의밝은연두빛의색상

(color)

에대한선호도

가가장높은것으로나타났다

.

조직감

(texture)

결과는기계적 인물성에서는경도

(hardness)

와씹힘성

(chewiness)

이청각함

Table 2. Texture analysis of the soybean curd supplemented with Codium fragile

Codium fragile contents (%)

0 (w/v) 20 (w/v) 40 (w/v)

Texture

Hardness (g) 225.71±14.44^b 240.86±26.13^b 295.43±35.94 ^a

Cohesiveness (g) 0.60±0.08^NS 0.59±0.08 0.63±0.05

Chewiness (g) 156.00±34.31^b 212.29±25.75^ab 251.86±42.39^a

a-bMeans represented by different superscripts in the same row are significantly different (P<0.05) by Duncan’s multiple range test. NS means within the same row did not different (P>0.05) by Duncan’s multiple range test.

Fig 3. DPPH free radical scavenging activity in the soybean curd supplemented with Codium fragile. DPPH, 1,1-diphenyl-2-picryl- hydrazyl. ^a-dMeans represented by different superscripts in the same row are significantly different (P<0.05) by Duncan’s mul- tiple range test.

Soybean Washing and soaking (at room temperature for 12 h)

Grinding (addition of water) Filtering and collecting soymilk

Heating soymilk (80±3°Cfor 10 min)

Coagulation (addition of MgCl

₂

·6H

₂

O)

Moulding

(13×13×3 cm, at 75 psi for 20 min) Cooling

Codium fragile soybean curd

Codium fragile Washing and soaking (at room temperature for 12 h)

Grinding (addition of water)

Addition of grinded Codium fragile

(a) (b) (c)

0 20 40 60 80 100

Ascorbic

acid 0 20 40

DPPH free radical scavenging activity (%)

Codium fragile (%)

b a

c d

0 20 40 60 80 100

Ascorbic

acid 0 20 40

ABTS free radical scavenging activity (%)

Codium fragile (%)

b a

c d

Fig. 4. Images of soybean curd coagulated with various coagulants such as (a) 0% (w/v) Codium fragile, (b) 20% (w/v) Codium frag- ile, (c) 40% (w/v) Codium fragile.

Soybean Washing and soaking (at room temperature for 12 h)

Grinding (addition of water) Filtering and collecting soymilk

Heating soymilk (80±3°Cfor 10 min)

Coagulation (addition of MgCl

₂

·6H

₂

O)

Moulding

(13×13×3 cm, at 75 psi for 20 min) Cooling

Codium fragile soybean curd

Codium fragile Washing and soaking (at room temperature for 12 h)

Grinding (addition of water)

Addition of grinded Codium fragile

(a) (b) (c)

0 20 40 60 80 100

Ascorbic

acid 0 20 40

DPPH free radical scavenging activity (%)

Codium fragile (%)

b a

c d

0 20 40 60 80 100

Ascorbic

acid 0 20 40

ABTS free radical scavenging activity (%)

Codium fragile (%)

b a

c

d

항산화 활성이 강화된 청각두부의 개발

821

량에따른유의적인차이가있었지만

(P<0.05),

관능검사에서는 유의적인차이를보이지않았다

(P>0.05). “

조직감에대한차이 를느꼈는지

”

에대한관능평가조사결과

,

^{차이를느꼈다는패널} 은한명도없었다

.

향미

(flavor)

의평가에서는청각이첨가된 두부에서고소함과청각특유의신선한향을느낄수있어서첨 가량이증가할수록향미

(flavor)

의유의적인상승을확인할수 있었다

(P<0.05).

청각의향기에대해서는정약전의

「

자산어보

」

에서도

“

^{젓갈의비린내와마늘냄새를중화시켜식품의뒷맛을} 개운하게한다

”

고언급되어있다

(Kim et al., 2018).

청각함량

의증가에따른두부에대한향미

(flavor)

의상승효과가전반적

인기호도

(overall acceptability)

의유의적인상승에도영향을 미쳤다

(P<0.05).

따라서

,

^{본연구에서는대두 두부}

(

^{청각무첨가군}

)

^{와 청각을}

20-40%

첨가하여 제조한두부의항산화성

,

물리화학적 품질

및관능적특성을확인함으로써청각을첨가한두부의상품성 과청각을이용한다양한수산물가공식품개발의가능성을제 시하였다

.

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Table 3. Sensory evaluation of the soybean curd supplemented with Codium fragile

Sensory attributes Codium fragile contents (%) 0 (w/v) 20 (w/v) 40 (w/v) Appearance 5.82±1.13^NS 5.55±1.39 5.36±0.70 Color 5.97±0.51^ab 6.55±0.51^a 5.10±0.55^b Flavor 4.36±1.08^b 5.73±1.07^ab 6.39±0.66^a Texture 5.73±1.3^NS 5.82±1.36 5.42±1.03 Overall acceptability 4.48±0.72^b 5.97±0.85^ab 6.26±0.76^a Values are given as mean±SD (n=30). NS means within the same row did not different (P>0.05) by Duncan’s multiple range test.

a-bMeans represented by different superscripts in the same row are significantly different (P<0.05) by Duncan’s multiple range test.

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