• 한국식생활문화학회지
• /
• 제34권5호
• /
• pp.629-636
• /
• 2019

This study examined the quality characteristics of jelly prepared with green grape juice (GJ). The pH, $^{\circ}Brix$ value, color, texture, and sensory evaluation of the jelly were measured. The pH of the jelly significantly decreased with increasing amount of GJ over the range of 3.25-5.27. The $^{\circ}Brix$ value of the jelly showed a significantly higher result as the amount of GJ increased (p<0.001). Lightness (L) and redness (a) decreased with increasing amount of GJ, and yellowness (b) increased. In the texture measurement, the GJ-100 sample group with a high substitute rate of GJ showed high hardness, gumminess, and chewiness (p<0.001). The results of principal component analysis (PCA) showed that the sample groups with high GJ content were classified as having relatively strong yellowness, sweet aroma, metallic aroma, grassy aroma, sweetness, sourness, green grape skin taste, and astringency. In the acceptance test, the GJ-50 sample group was evaluated to be high in flavor (p<0.001) and overall acceptance (p<0.01). However, sample groups consisting of 50% or more GJ were evaluated to be significantly strong in terms of astringency. Therefore, further study needs to be conducted about improving astringency in the future.

• 한국식품영양학회지
• /
• 제31권2호
• /
• pp.272-277
• /
• 2018

This research was conducted to elucidate the optimum conditions for the antibacterial activity of konjak jelly using the evolutionary operation-factorial design technique. In the first set of experiments, concentration of a coagulation agent, soaking liquid, and temperature of water were set to 0.4%, $0.6{\times}10^{-2}N$, and $65^{\circ}C$ as a central point, respectively. The highest antibacterial activity was acquired at E21, in which the number of bacteria was 1.25 log cfu/g. Because the code of changes in the main effect was (-), it could be decided that the central point of the first set was not the optimum point. Although antibacterial activity in the second set was improved, the values of the main effect were higher than that of changes in the mean effect. The central point of third set was concentration of coagulation agent 0.8%, concentration of soaking liquid $1.0{\times}10^{-2}N$, and temperature of water $65^{\circ}C$. It was found that the antibacterial activity of central point in the third set was highest among all the tested set. Further, all the necessary conditions were appropriate to reach the optimum condition. The antibacterial activity of the central point in third set was more than 1,000 times higher than that of E11, in first set.

• 한국식품과학회지
• /
• 제53권4호
• /
• pp.446-453
• /
• 2021

본 연구에서는 에탄올 농도에 따른 노니주스 추출물의 총 페놀 및 총 플라보노이드 함량을 측정하고, DPPH radical 소거능, ABTS⁺ radical 소거능 및 환원력을 측정하여 노니주스의 항산화 활성을 확인하였다. 또한 노니주스를 물에 대하여 각각 0, 25, 50, 75, 100%로 대체한 곤약젤리를 제조하여 품질특성 및 관능평가를 실시하였다. 노니주스 추출물의 총 페놀 함량은 0% EtOH 추출물이 6.76 mg GAE/100 g으로 가장 높게 나타났고, 총 플라보노이드는 100% EtOH 추출물이 2.40 mg NE/100 g으로 가장 높은 함량을 나타냈다. DPPH radical 소거능은 50% EtOH 추출물이 72.27%로 가장 높았고, ABTS⁺ radical 소거능은 100% EtOH 추출물이 42.20%로 높게 나타났다. 환원력은 추출용매에 따른 유의적인 차이가 없었다. 노니 곤약젤리의 pH와 수분함량은 시료 첨가량이 증가함에 따라 유의적으로 감소하였고, 당도는 시료 첨가량이 증가할수록 높아지는 경향을 보였다. 조직감 측정 결과, 노니주스의 첨가량이 증가할수록 곤약젤리의 경도와 검성은 증가하였고, 탄력성과 응집성은 감소하는 경향을 나타냈다. 노니 곤약젤리의 색도 측정결과에서 시료 첨가량이 증가할수록 L값과 b값은 감소하고, a값은 시료 50% 첨가량까지 증가하다가 이후에는 감소하는 경향을 보였다. 관능검사 결과에서 색(color)과 향(flavor)의 기호도는 0%와 25% 첨가군이 높은 점수를 받았고, 나머지 평가항목에서는 시료 간의 유의적인 차이가 없었다. 노니 곤약젤리 제조 시 노니주스 25%의 첨가량이 곤약젤리의 항산화 활성을 증가시킬 수 있고 색과 향의 기호도도 높아 가장 적당할 것으로 판단된다.