This study was conducted to determine seafood product quality change in the fresh food cold chain logistics. Salmon was stored in three different simulated refrigerated distribution environments according to door opening time (0, 20, and 60 s) every 10 min before the samples’ qualities were evaluated. The temperature inside the refrigerator generally rose from the bottom to the top, and it was possible to confirm the rapid change in temperature in the order of A, B, and C as the door opening time increased. It was observed that the freshness of salmon decreased as the door opening time increased through the evaluation of various food qualities of salmon, such as its appearance, color, pH, VBN, moisture content, hardness, general bacteria, and E. coli bacteria. It was confirmed that fresh food quality is strongly associated with delivery temperature, while cold-chain delivery vehicles must reduce heat exposure time during delivery.

In this study, effect of mixing ratio of -carrageenan and glucomannan on quality characteristics of jelly incorporated with omija concentrate were analyzed. Through previous studies, the concentration of the gelling agent was fixed at 1.5% of the weight of the jelly. As a control, omija concentrate jelly using a single gelling agent was prepared. The texture of the jelly using glucomannan alone could not be measured because it was difficult to maintain its shape. The texture was changed according to the mixing ratio of -carrageenan and glucomannan. When -carrageenan was mixed with glucomannan, the water holding capacity was increased. Jelly prepared in mixing 2:1 ratio of -carrageenan and glucomannan was observed to have the highest hardness, springiness, gumminess, cohesiveness, and chewiness. Also, in order to manufacture omija jelly that maintains high water retention for a long period of time, it is optimal to mix -carrageenan and glucomannan at a ratio of 1:2.

Various jellies were produced depending on the type and concentration of gelling agent (nine types), which added a single or double agent in jelly production. Firstly, jelly was manufactured using nine different single gelling agents and characterized. Secondly, six suitable gelling agents were selected to combine double gelling agents among nine gelling agents. To find the optimum gelling agent condition, jelly was intentionally made around 3.6-3.7 pH and 4- 5 N fracturability. A total of 1.2% gelling agent (both single and double agents) was suitable for making jelly (3.6- 3.7 pH, 4-5 N fracturability). According to the analytical result, the optimum single gelling agent was κ-carrageenan and gellan gum, while a suitable combination of double gelling agents was κ-carrageenan and gellan gum at ratios of 1.0:0.2, 0.8:0.4, and 0.6:0.6 and agar and locust bean gum at ratios of 0.8:0.4, 0.6:0.6.

This study compared and analyzed the quality characteristics and antioxidant activity of the commercial stick-type jelly of pomegranate (P1-P3), green apple (G1-G3), and red ginseng (R1-R3). The pomegranate group's pH showed a relatively low range (3.38-3.61), and the red ginseng group showed a relatively high range (4.14-4.96). The total acidity of commercial stick-type jelly was in the range of 0.31-4.60, and this value satisfied the total acidity standard of candy prescribed in the Ministry of Food and Drug Safety. Water content in the commercial stick-type jelly was lowest in P1 (45.99%) and highest in R3 (83.16%). The pomegranate group was significantly higher than the other samples for sugar content and turbidity (p<0.05). Fracturability was measured only in G2 and G3 with significantly lower hardness values (p<0.05), while the pomegranate group showed significantly higher values for hardness, adhesiveness, cohesiveness, gumminess, and chewiness compared to other samples (p<0.05). In DPPH free radical scavenging activity and total phenolic content results, the pomegranate group tended to have a high value, especially P3, which showed significantly the highest DPPH free radical scavenging activity (p<0.05). These results show that various commercial stick-type jelly products have different characteristics according to such factors like raw material and manufacturer.

본 연구에서는 낙동강 수계 8개의 보 구간에서 퇴적물의 변화에 대하여 알아보았다. 보 구간의 퇴적물을 채취하여 유기물, 영양염류, 금속류 항목을 분석하였으며, 시간의 흐름에 따른 변화를 알아보았다. 보를 기준으로 상류부에는 퇴적물이 세립해지거나 세립한 퇴적물이 증가와 감소를 반복하는 것으로 나타났으며, 하류부에서 조립한 퇴적물을 유지하는 것으로 나타났다. 퇴적물의 유기물 및 영양염류는 입도와 강한 상관성을 보이고 있으며, 조립한 상태를 유지하는 지점보다 퇴적물이 세립해지는 지점에서 증가하였다. 유기물과 영양염류의 농도가 증가하는 지점이 있었으나 하천·호소 퇴적물 오염평가 기준의 기준치를 넘는 지점이 없어 유기물, 영 양염류에 대하여 오염 정도가 미약한 상태로 보인다. 금속류의 경우 전반적으로 농도가 증가하는 것으로 나타났으며, 입도 및 유기물, 영양염류와 상관성이 미약하였다. 일부 금속이 독성이 나타날 가능성이 있는 II등급에 속하는 지점이 있으나 I등급과 농도 차이가 많지 않으며 대부분의 금속이 I등급 을 유지하여 금속류에 대한 오염정도는 미약한 것으로 판단 된다. 본 연구결과가 낙동강 수계의 퇴적물 변화를 모두 대표 할 수는 없지만 보 구간의 퇴적물 변화 특성을 이해하는 자료로 활용이 가능할 것으로 생각되며, 향후 독성평가를 진행 하거나 보 구간에서 입도와 금속류의 분포 및 상관관계에 대한 지속적인 연구가 진행되어야 할 것으로 보인다.

To evaluate the geochemical characteristics and assess the pollution in surface sediments of the Nakdong River estuary, two sites adjacent to the estuary bank (Hh1 and Hh2) and one site at the upper part of the estuary bank (Hh3) were investigated. The surface sediments were analyzed for their contents of metals (Cu, Pb, Ni, Cr, Zn, and Al), organic matter (IL, COD, TOC, and TN), and grain size from 2018 to 2020. As a result of the pollution assessment, there was little anthropogenic contamination by most of the metals. The surface sediments in Hh2 had comparatively abundant silt and clay, whereas the other sites were mainly composed of sand. The organic index and contents of organic matter were highest at Hh2. Multivariate statistical analyses (cluster analysis and Pearson correlation analysis) showed that the contents of organic matter and pollution were associated with fine sediment. These results suggest that the geochemical characteristics were changed by the estuary bank built in the research area and that the increase in fine sediment attributable to the low-energy environment resulted in an increase in organic matter pollution.