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열처리에 의한 온주밀감의 산함량 감소 효과

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Alternative Title
Study on Reducton of Acidity of Satsuma Mandarin by Heat Treatment
Abstract
Heat treatment was conducted to reduce acidity of satusma mandarin grown in Jeju island, Korea. In an effort to maintaining fruit freshness and internal qualities, other conditions such as humidity, film, temperature and time were examined.
To set up the humidity(RH) condition during heat treatment, fruits were held at 35℃ at low(65±2%) or high(100±2%) RH for 72 hours. The rate of titratible acidity(TA) reduction was not affected by RH condition. However, weight loss was higher and firmness was significantly lower in fruit treated under low RH compared with that under high RH. In addition, fruits under low RH developed more ethanol and acetaldehyde content which induced more off-flavors. Therefore, high RH gave better effect on fruit appearance and internal qualities during heat treatment.
To select proper plastic film for maintaining humidity, fruits were sealed with 3 types of films and held at 30℃ for 55 hours. The concentration of O2 and CO2 within film was 20.4 and 0.3% with 18㎛ HDPE punched film, 16.8 and 4.2% with 30㎛ LDPE film, 13.7 and 7.9% with 100㎛ LDPE film respectively. The higher CO2 concentration in film was, the more ethanol and acetaldehyde content increased. Hence fruits with 18㎛ HDPE punched film accumulated the lowest volatiles and were not much affected in developing off-flavors.
The effect of temperatures(25, 30, 35℃) and treatment time(48, 72hr for 25℃, 72, 96hr for 30℃, 96, 144hr for 35℃) on fruit qualities was examined. TA showed about 0.13 to 0.24% decrease whereas temperature control showed 0.09% for 6 days in low ambient temperature. Soluble solids content(SSC) remained without any significant differences before and after heat treatment. Consequently, SSC:TA ratio increased from 11.2 on harvest day to 12.1~13.6 after treatment while control was 11.6. Decay rate was considerably high in 25℃ which was not a proper temperature for treatment, while temperatures higher than 30℃ seemed to delay the decay. Firmness and off-flavors did not show much differences between control and all other treatment. Thus, the combination of temperature and time applied to this experiment did not affect fruit freshness besides the reduction of acidity.
In conclusion, heat treatment at 30℃ within 96 hours and 35℃ within 72hr, with high humidity and unchanged gas composition, can effectively reduce acidity of satsuma mandarins while maintaining soluble solid content and fruit freshness.
Author(s)
이지현
Issued Date
2011
Awarded Date
2011. 8
Type
Dissertation
URI
http://dcoll.jejunu.ac.kr/jsp/common/DcLoOrgPer.jsp?sItemId=000000005563
Alternative Author(s)
Lee, Ji-Hyun
Affiliation
제주대학교
Department
대학원 식품공학과
Advisor
강영주
Table Of Contents
Summary 1
Ⅰ. 서 론 3
Ⅱ. 재료 및 방법 6
1. 재료 6
2. 실험방법 7
1) 열처리 시 습도조건이 과실품질에 미치는 영향 7
2) 열처리 시 과실포장용 필름종류가 과실품질에 미치는 영향 7
3) 열처리 시 온도와 시간 조합이 과실품질에 미치는 영향 8
4) 호흡량 및 과실 내부 CO2측정 8
5) 필름 내 가스조성 측정 9
6) 산, 가용성고형물 함량, 및 당산비 9
7) 유리당 및 유기산 정량 10
8) 경도, 감모율 및 부패과율 11
9) 에탄올 및 아세트알데하이드 정량 11
10) 이취(off-flavor)정도 관능평가 및 선호도 조사 12
11) 통계분석 12
Ⅲ. 결과 및 고찰 13
1. 열처리가 감귤과실의 호흡에 미치는 영향 13
2. 열처리 시 습도조건이 과실품질에 미치는 영향 16
3. 열처리 시 과실포장용 필름종류가 과실품질에 미치는 영향 19
4. 열처리 중 용기 위치 및 밀봉처리 시점에 따른 과실 품온 변화 25
5. 열처리 시 온도와 시간 조합이 과실품질에 미치는 영향 27
1) 온도별 산 및 가용성고형물 함량 27
2) 온도별 유리당 및 유기산 함량 30
3) 감모율, 부패과율 및 경도 32
4) 에탄올 및 아세트알데하이드 함량 34
5) 관능평가 37
6) 온도처리 후 시간경과에 따른 품질변화 39
Ⅳ. 요 약 43
Ⅴ. 참고문헌 45
Degree
Master
Publisher
제주대학교 대학원
Citation
이지현. (2011). 열처리에 의한 온주밀감의 산함량 감소 효과
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General Graduate School > Food science and Engineering
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