검색 상세

Physicochemical quality characteristics of rice nurungji added with Raphanus sativus powder

무 분말을 첨가한 쌀누룽지의 이화학적 품질 특성

초록/요약 도움말

본 연구는 쌀과 무 건조부각 분말 (DRBP)로 제조한 누룽지의 물리화학적 품질, 항산화활성, 감각특성(전자혀와 전자코)을 조사하였다. DRBP는 무 건조부각 (DRB)을 분말화 한 것이며, DRB는 초미세 쌀가루인 찹쌀가루 80%, 멥쌀가루 20%로 코팅하여 제조하였다. 누룽지는 80%의 멥쌀과, 20%의 찹쌀로 하였으며, 무 건조부각 분말은 각각 2, 4, 6, 8, 10% 수준으로 첨가하여 제조하였다 (NR-2, NR-4, NR-6, NR-8, NR-10). 총 폴리페놀과 플라보노이드 함량은 무 건조부각 분말의 양이 증가함에 따라 21.34에서 27.87 mgGAE/mL, 7.46에서 20.05 mgNE/mL로 증가하였다. 무 건조부각 분말을 10% 함유한 누룽지 (NR-10)는 각각 27.87 mgGAE/mL 및 20.05 mgNE/mL로 모든 누룽지 샘플보다 총 폴리페놀 및 총 플라보노이드 함량이 더 높았다. 그러나 무 건조부각 분말 8%를 함유한 누룽지 (NR-8) 와는 유의한 차이가 없었다. 누룽지의 항산화 활성는 무 건조부각 분말의 첨가량이 증가할수록 증가하였다. 또한, 무 건조부각 분말의 비율이 증가함에 따라 누룽지 시료간 유의적인 차이가 없이 경도는 증가했다. b Hunter 값, 총 가용성 고형물 (°Brix), 수화특성 (WAI) 및 수분함량은 증가하였다. 반면에 제조한 누룽지의 품질 특성 중 L Hunter 값, pH, 팽윤능 및 수용성 지수는 무 건조부각 분말의 비율이 증가함에 따라 감소하였다. 누룽지 NR-0의 전단응력 특성은 다른 시료에 비해 더 높은 전단응력과 더 높은 전단희석 유체 특성을 보인 반면, NR-8과 NR-10은 큰 유의적의 차이를 나타내지 않았다. 따라서 무 건조부각 분말의 비율이 증가할수록 안정적인 전단특성은 감소하는 것으로 나타났다, 겉보기 점도의 크기는 NR-0가 다른 누룽지에 비해 높았으며, 무 건조부각 분말이 증가함에 따라 점도가 감소하는 것으로 나타났다. NR-0는 다른 누룽지 처리구에 비해 짠맛, 단맛, 쓴맛 등에서 높은 값을 나타내었다. 동시에 NR-6는 감칠맛과 신맛이 높았다. 전자혀의 주성분분석 (PCA) 결과 누룽지 제조시 무 건조부각 분말을 첨가한 것이 미각특성에 영향을 준 것으로 나타났다. NR-8과 NR-10 누룽지 간에는 유의적인 차이가 나타나지 않았다. 전자코를 사용한 PCA 결과 NR-0, NR-2, NR-4 간의 불쾌취 특성에 있어서 차이가 없는 것으로 나타났다, 그러나 NR-8과 NR-10 누룽지는 냄새 특성이 유사한 반면 NR-6 는 유사하지 않은 냄새 특성을 나타내었다. 또한, 누룽지의 미세구조 (SEM)에 있어서 NR-0와 기타 누룽지 간에 다른 형태를 나타내었지만, 무 건조 부각 분말을 처리한 누룽지 간에는 차이가 없었다. 따라서 본 연구의 결과는 초미세 쌀가루인 찹쌀과 멥쌀가루를 코팅한 무 건조부각이 누룽지 제조 원료로 활용될 수 있을 것으로 생각된다. 또한 무 건조부각 분말 6%를 첨가한 쌀누룽지 (NR-6) 제조가 이화학적 품질 및 감각적 특성 측면에서 우수한 것으로 생각된다.

more

초록/요약 도움말

This study investigated the physicochemical quality, antioxidant activity, and sensory properties (electronic tongue and nose) of nurungji prepared from rice and dried-radish root bugak powder (DRBP). DRBP was made from dried-radish root bugak (DRB) coated with superfine 80% glutinous and 20% non-glutinous rice powders. The nurungji food products were processed from 80% non-glutinous rice, 20% glutinous rice, and DRBP was added at different levels 2, 4, 6, 8, and 10% respectively (NR-2, NR-4, NR-6, NR-8, and NR-10). The total polyphenol and flavonoid contents increased from 21.34 to 27.87 mgGAE/mL and 7.46 to 20.05 mgNE/mL respectively as DRBP increased. Nurungji sample (NR-10) containing 10% of dried-radish bugak powder had a higher value of total polyphenol and total flavonoids contents than all tested nurungji samples with 27.87 mgGAE/mL and 20.05 mgNE/mL respectively but no significant difference with nurungji sample containing 8% DRBP (NR-8). The antioxidant activity (DPPH radical scavenging activity) of the nurungji samples increased as the proportion of DRBP increased. In addition, the increasing proportion of DRBP also increased texture (hardness) without significant differences among all treatment samples, b hunter value, total soluble solids (°Brix), hydrations properties (WAI), and water content in nurungji sample treatments were increased. In contrast, L Hunter value, pH, swelling capacity, and water solubility index were decreased with the increase of amounts of DRBP of prepared nurungji food products. Steady shear properties of control sample (NR-0) showed highly shear-thinning fluids with high shear stress compared to other samples however NR-8 and NR-10 showed no significant difference. Hence, as the proportion of DRBP increased, the steady shear properties decreased. The magnitude of apparent viscosity was higher in NR-0 compared to other treatment samples, with an increase of DRBP, a significant decrease in viscosity was found. The electronic tongue results showed that the control sample (NR-0) had higher saltiness, sweetness, and bitterness taste scores than other sample treatments. At the same time, umami and sourness were high in the NR-6 sample treatment. E-tongue PCA discriminant function analysis indicated that adding DRBP to nurungji preparation affected the taste characteristics among treatment samples however, there were no significant differences between NR-8 and NR-10. Electronic nose PCA (Principal component analysis) results indicated no difference in odor characteristics between NR-0, NR-2, and NR-4 however difference from other sample treatments was detected. NR-8 and NR-10 samples were similar in odor features while NR-6 samples exhibited unsimilarity odor characteristics with all sample treatments. Furthermore, SEM images indicated different shapes between the control sample (NR-0) and other sample treatments however no differences among nurungji treated with DRBP. Therefore, this study's results suggest the utilization of DRBP as ingredient for the preparation of nurungji. Based on the study results, the preparation of rice nurungji (NR-6) with 6% DRBP was more favorable based on physicochemical quality and sensory characteristics.

more

목차 도움말

Abstract i
요약 iv
List of figures x
List of tables xi
1. Introduction 1
1.1. Background 1
1.2. Korean traditional food production 5
1.2.1. Bugak production 5
1.2.2. Nurungji production 6
1.3. Objectives of the study 8
1.3.1. General objective 8
1.3.2. Specific objectives 8
1.4. Scope of the study 10
2. Materials and Methods 11
2.1. Materials preparation 11
2.2. Sample preparation 11
2.2.1. Biometrical characteristics, pH, and total soluble solids of raw radish root 11
2.2.2. Dried-radish root bugak (DRB) and its powder (DRBP) preparation 12
2.2.3. Processing of nurungji added with dried-radish bugak root powder (DRBP) 14
2.3. Physicochemical and flavor properties analysis for nurungji samples 17
2.3.1. Color measurement 17
2.3.2. pH and total soluble solids (TSS) determination 17
2.3.3. Texture characteristics evaluation 17
2.3.4. Water hydration feature and water content determination 18
2.3.5. Determination of rheological characteristics 19
2.3.6. Electronic tongue 19
2.3.7. Electronic nose 20
2.3.8. Scanning electron microscope (SEM) 20
2.4. Antioxidant property analysis 21
2.4.1. Total polyphenols (TPC) and flavonoids contents (TFC) analysis 21
2.4.2. Determination of DPPH radical scavenging activity 22
2.5. Statistical analysis 22
3. Results and discussion 23
3.1. Color 23
3. 2. Texture 26
3. 3. pH and total soluble solids (TSS) 26
3.4. Water hydration properties (SC, WAI, WSI) and water content (WC) 29
3.5. Rheological characteristics 31
3.6. Electronic tongue and nose 34
3.7. Scanning electron microscope (SEM) 41
3.8. Total polyphenols (TPC) and flavonoids contents (TFC) analysis 43
3.9. DPPH radical scavenging activity 43
4. Conclusions 48
References 49
Acknowledgement 54

more