This study was performed to evaluate the quality characteristics and antioxidant activity of Nurungji by varying the purple sweet potato powder addition time (AR: added after rice cooking, BR: added before rice cooking) and powder ratio (0, 2, 4, 6, 8%) on the prepared rice during Nurungji’s manufacturing. In both AR and BR samples, water binding capacity, soluble solid content, reducing sugar, and hardness increased with an increasing proportion of purple sweet potato powder; however, the pH and moisture content decreased. The L value and b value decreased and increased with the influence of anthocyanin in purple sweet potato powder. The total polyphenol, flavonoid, anthocyanin contents, DPPH, and ABTS radical scavenging activity were highest in Nurungji with 8% of purple sweet potato powder. Moreover, AR samples showed higher antioxidant activity than BR samples. Based on the study results above, the preparation of Nurungji with 8% purple sweet potato powder by AR process was more favorable based on the content of antioxidants and antioxidant activity.

This study examined the quality characteristics of Jeung-pyeon made with wet non-glutinous rice flour and rice wine. The samples of Jeung-pyeon were prepared with different ratios of cooked purple sweet potato (0, 3, 6, 9, and 12%) to analyze the water content, sugar content, pH, chromaticity, texture characteristics, and sensory evaluation. No significant difference in water content, sugar content, and springiness was observed among the 5 samples. The pH and volume showed the highest level at 0%. The L-value and b-value decreased while the a-value increased. The hardness, chewiness, and gumminess were highest at 9% and lowest at 12%. The extent of violet chromaticity and pore size were optimal in 9%. In addition, 9%-added purple sweet potato showed the highest score of odor, taste, texture, and overall acceptability. In conclusion, the optimal addition for the highest acceptability of cooked purple sweet potato was 9%.

Anthocyanins, a class of flavonoids, are natural water-soluble pigments, which are mainly found in vegetables and fruits. Anthocyanins have attractive pharmacological activities, such as anti-oxidant, anti-inflammatory, anti-cancer, and anti-diabetic. The purpose of this study was to investigate the protective effects of anthocyanins-rich fraction (ANF) from Korean purple sweet potato variety, "Shinjami", against hydrogen peroxide (H2O2)-induced oxidative stress. In our results, pre-treatment of HepG2 cells with ANF (10μg/mL) significantly prevented cell death and maintained cell integrity, following exposure to 0.9 mM hydrogen peroxide. The H2O2-dependent production of intracellular ROS was also significantly decreased by pre-treatment with ANF (6 h, 10μg/mL). In addition, ANF increased the mRNA levels of antioxidant enzymes, catalase and glutathione level in H2O2-treated HepG2 cells. These results indicated that ANF protected HepG2 cells against H2O2-induced oxidative stress by inducing protective system.

The quality and characteristics of purple sweet potato sponge cake were studied with the addition of different proportions of purple sweet potato powder depending on storage period The pHs, heights, and weights of doughs were in the ranges of 6.3~6.5, 4.8~4.4 cm and 397~418 g, respectively. The sponge cake groups with the addition of different proportions of purple sweet potato powder showed significantly different characteristics in hardness, adhesiveness, cohesiveness, gumminess, and chewiness, according to texture profile analysis. The difference in colors of sponge cakes with addition with purple sweet potato revealed that L-value and b-value were significantly reduced but a-value especially increased according to the density. Using scanning electron microscopy (SEM), it was confirmed that the stoma size of purple sweet potato sponge cake become smaller and the stoma wall became thicker in proportion to the contents of purple sweet potato powder, which could result in an increased level of water content after a long period pf storage. According with the observations, water content remarkably increased after 4~6 days of storage and the ability to keep water content seemed to contribute to extention the shef-life of sponge cakes. In sensory evaluation, sponge cakes with high contents of purple sweet potato were preferred and cakes with the addition of 25% and 30% purple sweet potato powder was most preferred. It was expected that the shelf-life of purple sweet potato sponge cake was 4 days under the normal temperature.

헤미셀룰레이즈를 0.005%, 0.010%, 0.015%, 0.020%를 첨가한 자색고구마 제조한 식빵의 품질 특성과 관능검사를 실시하였다. 반죽의 pH와 총 산도는 시료들 간에 유의적인 차이가 없었다(p<0.05). 발효 시간에 따른 발효 팽창력은 발효시간이 길어질수록 유의적으로 증가하였고(p<0.05), 헤미셀룰레이즈 첨가량에 따른 발효 팽창력은 45분과 60분에서는 헤미셀룰레이즈 0.015% 첨가군이 가장 높았으며, 대조군이 가장 낮게 나타났다(p<0.05). 식빵의 pH는 대조군보다 헤미셀룰레이즈 첨가군들이 유의적인 차이가 없었으며(p<0.05), 총 산도는 헤미셀룰레이즈 첨가군들이 대조군보다 유의적으로 높았다(p<0.05). 비용적과 굽기 손실률은 헤미셀룰레이즈 첨가군들이 대조군보다 유의적으로 높았다(p<0.05). 수분 함량은 시료들 간에 유의적인 차이가 없었다(p<0.05). 명도는 대조군보다 헤미셀룰레이즈 첨가군들이 유의적으로 낮았고(p<0.05), 적색도는 0.005% 첨가군을 제외하고, 대조군보다 헤미셀룰레이즈 첨가군들이 유의적으로 낮았다(p<0.05). 황색도는 헤미셀룰레이즈 첨가군들이 대조군보다 다소 높았다(p<0.05). 견고성과 부서짐성은 헤미셀룰레이즈 첨가량이 증가할수록 유의적으로 감소하였으며(p<0.05), 복원성은 0.005% 첨가군을 제외하고, 헤미셀룰레이즈 첨가군들이 대조군보다 유의적으로 높았다(p<0.05). 소비자 기호도 검사는 색과 부드러움은 실험군들 간에 유의적인 차이를 나타내지 않았고(p<0.05), 향미는 헤미셀룰레이즈 첨가군들이 대조군보다 유의적으로 높았다(p<0.05). 종합적인 기호도는 헤미셀룰레이즈 0.010% 첨가군이 5.67로 가장 높은 값을 나타냈다. 이상의 실험에서 헤미셀룰레이즈 0.010% 첨가가 자색고구마 식빵의 부피를 개선하는데 최적 첨가량으로 확인되었다.

This study was performed to investigate the qualities of jelly supplemented with purple sweet potato (C:0 g, P1:1 g, P3:3 g, P5:5 g, P7:7 g). The pH decreased (acidity increased) with the addition of purple sweet potato powder (p<0.01). The sugar content of the jelly also significantly increased when purple sweet potato was added. The DPPH radical scavenging activities of jelly increased as the addition of purple sweet potato increased. As the content of purple sweet potato increased, the L and b values decreased and the "a value" increased. In terms of textural characteristics, the addition of purple sweet potato increased hardness and springiness, while it decreased the cohesiveness. The results of the sensory evaluation showed that the appearance, flavor, taste, texture, and overall acceptability gave the highest score for jelly containing 5 g of purple sweet potato (P5).

The effects of pH and temperature on degradation of anthocyanin in purple-fleshed sweet potato cultivars(Mokpo No.62, Borami, Jami, Sinjami and Ayamurasaki) were determined at pH ranges of 1 to 5 and temperature ranges of 20 to 80℃. The anthocyanin contents of five sweet potato varieties were 3.9, 3.8, 4.7, 4.1, 4.2 ㎎/g of dried sweet potato, respectively. Degradations of anthocyanins at different pHs and temperatures followed the first-order reaction. Our results clearly showed that the anthocyanin stability of purple-fleshed sweet potato was dependent on the source of the sweet potato cultivars. Anthocyanin obtained from Borami showed the highest stability. The half-life of antocyanin degradation of purple sweet potato cultivars(Mokpo No.62, Borami, Jami, Sinjami and Ayamurasaki) at pH 3 were 22.2, 28.3, 26.3, 23.4, 22.7 days at 60℃, respectively. A significant decrease in anthocyanin stability was observed at temperatures above 40℃. Activation energies of purple-fleshed sweet potato cultivars at different temperatures were 54.67, 60.93, 71.73, 59.35, 62.28 kJ/mol, respectively.

The colored sweet potato, particularly purple sweet potato, has been well known to contain anthocyanins abundantly. This study was conducted to examine the antioxidant properties of purple sweet potato. The chopped purple sweet potato was extracted 2 times with water or acetone for 18 hours at . The antioxidative potential of each solvent extract was assessed by DPPH free radical scavenging activity assay, FRAP assay, and total phenolic contents. The results showed that both extracts had not only high DPPH free radical scavenging activity but had high level of total phenolic compounds. Furthermore, both solvent extracts were found to have antioxidative effects in human colon cancer cells (HCT 116, HT 29) in DCFDA assay. The notable antioxidant activity of purple sweet potato suggests its significant health benefit and deserves further study to develop into functional food ingredient.

자색고구마 추출물의 항산화 효과와 산화적 스트레스로 유도된 PC12 신경세포에 대한 보호효과에 대하여 연구하 였다. 자색고구마 추출물의 총 페놀함량은 44.25 mg/g, monomeric anthocyanin 함량은 2,394 mg/L로 나타났 다. 자색고구마 추출물의 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-(3-ethylben-zthiazoline- 6-sulfonic acid) (ABTS) radical 소거활성, ferric reducing/antioxidant power (FRAP) 및 환원력은 농도 의존 적으로 항산화 활성이 증가하였다. MTT {3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyl-tetrazoliumbromide} reduction assay를 이용하여 자색고구마 추출물의 신경세포 보호효과를 측정한 결과, 세포 생존율이 두드러지게 증가하는 것으로 나타났다. 산화적 스트레스는 신경세포막 손상 정도를 증가시키기 때문에 lactate dehydrogenase (LDH) release assay와 neutral red uptake assay를 이용하여 세포막 손상 보호효과를 조사한 결과 자색고구마 추출물 처리구는 대조구에 비하여 산화적 스트레스로 유도된 세포막 손상 보호효과가 농도 의존적으로 나타났다. 따라서 자색고구마 추출물은 천연 항산화 소재 및 알츠하이머성 치매와 같은 신경퇴행성 질환의 예방 소재로서의 활용 가능성이 기대된다.

Pigment concentrates with violet-red color and sweet taste were obtained from purple-fleshed sweet potato(PFSP) using ethyl alcohol and water. Extract from general potato(GP) were used as a control. The relative stability of PFSP pigment concentrate(PFSPPC) in a storage test over 15 days was confirmed in the order of dark > fluorescence > sun-light irradiation. The relative stability of GP pigment concentrate(GPPC) in a storage test over 15 days was confirmed in the order of sun-light > fluorescence > dark storage. The RRP of PFSPPC was higher than that of GPPC, but the color strength of GPPC was 1/2 that of PFSPPC. Treatment of PFSPPC with aluminum potassium sulfate(0.2～0.3%, w/w) best improved its stability. The improved RRPs of PFSPPC were 45.16～47.31% in sun light irradiation, 55.91～60.22% in fluorescence irradiation, and 76.34～75.97% in dark storage conditions. In substituting aluminum potassium sulfate for chitosan, an amount of 0.2～0.3%(w/w) was suitable, giving similar results in improving pigment stability for all concentrates tested. Also, freeze-dried PFSPPC powder was manufactured as a substitute for dextrin, and also as a substitute for chitosan to the extent of 0.25%(w/w). The results of storage stabilite for freeze-dried PFSPPC and GPPC powder over 15 days, irradiation were, PRRs of 74.47～89.36% and 61.54～76.92%, respectively. The stability improving effect of freeze dried PFSPPC powder was confirmed by the results of storage experiments at various conditions. The use of freeze-dried PFSPPC powder was therefore confirmed to be an effective treatment for general foods.

The objective of this study was to assess the quality characteristics of almond Dasik prepared with the addition of purple sweet potato powder (PSPP). Five different levels (0, 5, 10, 15, and 20%) of PSPP were added and the physicochemical properties of the Dasik were examined. Crude protein and crude fat contents decreased as the level of PSPP increased (p<0.05). The Hunter L-value decreased while the a-value increased as the PSPP level increased. Texture measurements showed that the addition of PSPP increased hardness, cohesiveness, and brittleness. Total polyphenol content and antioxidant activity were assessed in terms of estimating the functionality of the Dasik. The results showed that incorporating PSPP into the Dasik provided higher polyphenol content and antioxidant activity compared to the control Dasik (p<0.05). The results of a consumer acceptance test revealed that the Dasik sample made with 15% PSPP was most preferred and the 20% sample was the least preferred. Therefore, it is suggested that purple sweet potato powder can be incorporated into Dasik up to 15% without reducing its quality.

The purpose of this study was to investigate the effects of dietary purple sweet potato(Ipomoea batatas) powder on serum lipid levels and antioxidative enzymes in normal and pretective effect on hepatotoxicity rats induced by carbon tetrachlolide. Four groups of rats (3-week-old inbred Sprague-Dawley male rats) were normal rats fed control diet(C), induced hepatotoxicity rats fed control diet(EC), normal rats fed purple sweet potato diet(P), and induced hepatotoxicity rats fed purple potato sweet diet(EP). Rats were induced by single injection of 50% carbon tetrachlolide(0.1 mL/100 g B.W., i.p.). The rats were fed ad libitum each of the experimental diet for 5 weeks. After 5 weeks the rats were sacrificed and activities of antioxidant enzymes and lipid peroxidation products were determined in their liver homogenates. But serum concentrations of lipid was not significant in all groups. Serum alanine aminotransferase(ALT/GPT) and aspartate aminotransferase(AST/GOT) of the EC and EP groups were heigher than the C and P groups. The hepatic glucose 6-phosphatase(G6Pase) activity of the group fed purple potato diet(P) was lower than the other groups(p<0.05). However, The glutathione peroxidase(GPx) activities was not statistically different between the groups. Renal glutathione S-transferase(GST) activity of the EC and EP groups were lower than the C and P groups(p<0.05). In conclusion, these results suggest that purple sweet potato is believed to be possible protective effect on hepatotoxicity rats induced by carbon tetrachlolide.

요구르트 제조시 고형분 함량을 증가시키기 위해 첨가하는 탈지분유의 일부를 자색고구마로 대체(고형물비로 22.7, 38.6, 63.6%)하여 요구르트를 만들고, 탈지분유만 첨가한 대조구와 비교하여 젖산균의 생육과 산생성, 점도, 관능성, 유기산 및 색도를 조사하였다. 자색고구마의 첨가로 젖산균의 산생성은 감소되어 발효 24시간 후 자색고구마 첨가 요구르트가 1.114∼1.228%로 탈지분유만 첨가한 대조구의 1.268%보다 상당히 낮은 것으로 나타났다. 젖산균의 생육은 자색고구마의 첨가로 감소되어 24시간 발효 후 9.08∼9.33 log cfu/ml였으나 탈지분유만 첨가한 대조구는 9.62 log cfu/ml로 가장 높았다. 자색고구마 첨가 요구르트의 점도는 고형물비로 63.6% 첨가한 구에서 46, 000 cps로 대조구의 32, 200 cps보다 상당히 높은 것으로 나타났다. 전체적인 기호도는 자색고구마 첨가구가 대조구에 비해 우수하였으며, 그 중 고형물비가 38.6% 첨가된 요구르트가 가장 높았으나, 조직감에서는 오히려 대조구가 더 우수하였다. 유기산 중 젖산 함량은 자색고구마 첨가로 감소되었으며, oxalic acid, fumaric acid, succinic acid 그리고 mailc acid도 소량 검출되었다.

자색고구마 분말을 0∼5%를 첨가하여 호상 요구르트를 제조하여 요구르트의 품질 및 기호성에 미치는 영향을 검토한 결과는 다음과 같다. 자색고구마첨가에 의해 산도, 당도, 유산균수가 대조구에 비해 높게 나타났으며 요구르트의 색택은 자색고구마 첨가량이 많을수록 lightness와 yellowness는 감소되고 redness는 증가하면서 점도는 크게 상승하였다. 요구르트의 관능성을 보면 조직감과 색은 대조구보다 첨가구에서 양호했으며 맛에서는 차이가 없었고 전체적인 기호도는 자색고구마 3∼4% 첨가구에서 가장 우수하였다.

본 연구에서는 국내산 자색고구마(Ipomoea batatas L. Lam.) 추출물을 제조하고 이들 추출물에 대하여 항산화 활성을 측정하였다. 자색고구마 추출물은 70% 에탄올 추출물과 그 추출물로부터 에틸아세테이트 분획으로 제조하였다. 추출물 및 분획의 수율은 건조 분말 당 각각 39.2% 및 3.49%이었다. 이들 추출물/분획에 대한 항산화 활성을 확인하기 위해 자유 라디칼(1,1-phenyl-2-picrylhydrazyl, DPPH) 소거활성과 루미놀 발광법을 이용한 총항산화능 그리고 세포손상에 대한 보호효과를 측정하였다. 자유 라디칼 소거활성(FSC50)은 70%에탄올 추출물과 에틸아세테이트 분획이 각각 90.16μg/mL와 7.69μg/mL를 나타내었다. 비교 대조군으로 사용한 (+)-α-tocopherol의 라디칼 소거활성은 8.98μg/mL로, 에틸아세테이트 분획의 라디칼 소거활성이 보다 큼을 알 수 있었다. 루미놀 발광법을 이용한 70% 에탄올 추출물과 에틸아세테이트 분획의 총 항산화능(OSC50)은 각각 5.75μg/mL와 1.92μg/mL이었다. 비교 대조군으로 사용한 항산화 효능이 매우 우수한 L-ascorbic acid의 항산화능은 1.50μg/mL로 추출물의 에틸아세테이트 분획과 유사한 활성을 나타내었다. 1O2로 유도된 사람 적혈구의 세포손상에 대한 보호 효과 실험에서 에틸아세테이트 분획은 농도 의존적(5∼50μg/mL)으로 세포보호 효과를 나타내었다. 에틸아세테이트 분획의 세포보호활성(τ50)은 5μg/mL에서 45.6 min으로 모든 농도에서 비교 대조군인 (+)-α-tocopherol 보다 더 높은 세포보호 효과를 나타내었다. 이상의 결과들로부터 자색고구마의 에틸아세테이트 분획은 뛰어난 항산화능을 나타내며, 이는 피부노화 억제를 위한 항노화 기능성 화장품원료로 응용될 수 있는 가능성을 시사하였다.

In this study, purple sweet potato muffins were made with the addition of 0, 25, 50, 75, and 100% rice flour, and their quality characteristics were determined. The weight and height increased with the increase in the amount of rice flour added. The moisture contents decreased significantly. As the amount of rice flour added increased, the pH and acidity decreased. The lightness and yellowness of the rice flour decreased significantly, but the redness increased with increasing purple sweet potato content. The textural properties, such as the cohesiveness, chewiness, and brittleness, were significantly lower in the groups with added rice flour. The DPPH radical scavenging activity was significantly higher in the purple sweet potato muffins to which 50 and 75% rice flour were added compared to those in the control. The results of the sensory evaluation showed that there was no significant difference in flavor among the samples. The chewiness was higher with 50, 75, and 100% rice flour than with 0 and 25% rice flour. The groups with 50 and 75% rice flour had significantly higher scores for overall acceptability compared to the control group.

Purple sweet potato (PSP, Ipomoea batatas) has various biological effects including antidiabetic, anti-inflammatory, and antioxidant activities. In this study, the antioxidant activity of PSP after roasting were compared using DPPH, ABTS, and FRAP assays. In addition, the total phenolics and flavonoid contents, Maillard reaction products, and phenolic acid contents were measured to identify the factors that changed PSP,s antioxidant activity due to roasting. The roasted PSP exhibited significantly higher antioxidant activity than unroasted PSP. In particular, the PSP roasted at 200℃ for 10 min showed the highest antioxidant activity among all the PSPs that were roasted under different conditions. The total phenolic and flavonoid contents, Maillard reaction products and phenolic acid contents markedly increased, corresponding to the general increase in antioxidant activities after roasting. These results suggest that roasted PSP extracts are potential source of natural antioxidants that may be used in certain food applications.

자색 고구마로부터 페놀성 화합물 추출 최적 조건은 50% 에탄올로 12시간 추출하였을 때 최대 용출량을 나타내었다. 불과 50% 에탄올을 용매로 하여 제조한 자색 고구마 종류별 추출물의 항산화 활성 측정 결과 전자공여능, ABTS, PF 측정에서 일반 고구마에 비하여 자색 고구마 자미, 신자미, 연자미 품종 모두 높게 나타났으며, TBARs 측정결과 모든 추출물에서 30% 이하로 낮은 TBARs 생성 억제활성을 나타내었다. 피부상재균에 대한 최소