Earticle

환경문제에 대한 관심이 증가함에 따라 지속가능한 소재 에 대한 요구가 증가하고 있다. 전 세계적으로 커피는 가장 많이 소비되는 음료이며, 커피음료의 가공 및 소비로 발생 하는 커피 부산물에는 셀룰로오스, 헤미셀룰로오스, 리그닌, 지질 및 생리활성물질 등이 풍부하지만 대부분 폐기되는 실 정이다. 따라서, 많은 연구자들이 커피 부산물을 고부가가 치 소재로 개발하기 위하여 노력하고 있다. 본 총설에서는 고분자/커피 은피 복합화 연구, 커피 은피로부터 셀룰로오 스 추출 및 응용연구, 고분자/커피찌꺼기 복합화 연구, 커 피찌꺼기로부터 셀룰로오스 추출 및 이를 활용한 연구, 커 피찌꺼기로부터 지질 추출 및 이를 활용한 PHAs합성, 가 소제로써 커피찌꺼기로부터 추출한 지질의 응용가능성 연 구 등에 대하여 조사하였다. 선행 연구에서는 커피 부산물 인 커피 은피 및 커피찌꺼기 자체를 고분자와 혼합하여 복 합소재를 제조하고 물성을 평가하는 연구는 광범위하게 수 행되고 있는 것으로 확인되었다. 하지만, 커피 은피 및 커 피찌꺼기로부터 나노셀룰로오스를 추출하거나, 상대적으로 친수성인 커피 부산물과 소수성인 석유계 고분자 또는 생 분해성 고분자와 복합화 시 상용성 개선과 관련된 커피 부 산물의 표면 개질 및 상용화제 도입 등의 연구는 부족함을 확인하였다. 또한 커피 부산물로부터 추출한 지질을 활용하 여 PHAs를 합성하는 연구가 일부 진행되고 있지만 합성된 PHAs를 활용하여 포장소재로의 제조 및 응용에 관한 추가 적인 연구가 필요하다고 사료된다. 또한, 커피찌꺼기의 발 생량 대비 국내외 관리방안 마련 및 제품 적용 시 안전성 평가방법에 관한 연구는 거의 실시되지 않아 이에 대한 추 가적인 연구가 필요하다고 판단된다.

As awareness of environmental issues continues to grow, there is an escalating demand for recycling and repurposing byproducts of agricultural and food production processes and their conversion to high-value products. Coffee is the most widely consumed beverage globally; during coffee beverage processing and consumption, byproducts such as coffee silverskin (CS), spent coffee grounds (SCGs), and oil are generated. Despite containing beneficial materials such as cellulose, hemicellulose, lignin, lipids, and bioactive substances, these byproducts are typically discarded in landfills or incinerated. The utilization of CS, SCGs, and oil in the development of packaging materials holds significant potentials toward the realization of a sustainable society. To this end, considerable research efforts have been dedicated to the development of high-value materials derived from coffee byproducts, including functional fillers, polymer composites, and biodegradable polymers. Notably, CS and SCGs have been employed as functional fillers in polymer composites. Additionally, lipids extracted from SCGs have been used as plasticizers for polymers and cultured with microorganisms to produce biodegradable polymers. This review focuses on the research and development of polymer/CS and polymer/ SCG composites as well as cellulose extraction and utilization from CS and SCGs and its applications, oil extraction from SCGs, and cultivation with microorganisms using extracted oil for polyhydroxyalkanoates(PHA) production.

The edible coating system, consisting of gelatin and bacteriophages, has been developed to enhance the microbial safety of wild vegetables. Newly isolated Escherichia coli phage EP and Staphylococcus aureus phage SP were loaded into the gelatin coating solutions. The phages remained significantly stable for up to 3 days, respectively, and exhibited rapid antibacterial capacity within 2 h of coating application (p < 0.05). The developed coating was applied to bracken and exhibited antibacterial efficacy against E. coli and S. aureus within 6 h (1.9-log CFU/mL and 1.5-log CFU/ mL). Furthermore, the coated bracken significantly prevented weight loss and maintained firmness for 10 days (p < 0.05). Consequently, gelatin-based edible coatings containing phages have the potential as an antibacterial packaging strategy.

곤드레의 이용과 김치의 다양성을 모색하기 위해 강원도 의 특산물인 곤드레를 김치제조에 이용하고자 하였다. 곤드레는 당과 단백질이 풍부한 식품으로 김치제조에 생 또는 삶은 형태로 이용을 검토한 결과 일반 성분은 비슷하였지만 항산화성이 생 곤드레가 삶은 곤드레보다 1.2배 많은 것으 로 나타나 김치제조에 생 곤드레를 첨가하기로 하였다. 생 곤드레를 배추김치에 20, 40 및 50 (w/w) 첨가하여 저장실 험한 결과 pH, 산도 및 미생물의 변화는 곤드레의 첨가량 과 관계없이 유사한 경향을 보였고 관능검사를 한 결과 곤 드레를 20% (w/w) 첨가한 김치가 맛, 향, 색 및 전체적인 기호도에서 우수한 것으로 나타나 향후 김치 제조에 곤드레 의 이용이 가능할 것으로 사료되었다.

In this study, we investigated the use of Gondre, a special product from Gangwon-do, as an ingredient in Kimchi. Kimchi added with Gondre was manufactured for further analysis. The antioxidative properties of Kimchi with uncooked Gondre were found to be 1.2 times higher than those of Kimchi with boiled Gondre, suggesting that uncooked Gondre is the preferred additive. To assess the effect of Gondre over a 30-day period at 5°C, Kimchi was prepared with Gondre at mixed ratios of 20%, 40%, and 50% (w/w). No significant effects of Gondre on pH, titrated acidity, or microorganism growth were observed. However, sensory evaluation results indicated that Kimchi with 20% (w/w) Gondre was preferred over other ratios.

This review paper provides a detailed analysis of PET (polyethylene terephthalate) bottle recycling in Japan. Japan is a global leader in PET bottle recycling due to its advanced regulatory framework and proactive industry initiatives. Japan's success attributes to the widespread adoption of bottle-to-bottle recycling, driven by the beverage industry's commitment to sustainability. By utilizing post-consumer PET bottle recovery and food-grade mechanical recycling technologies, Japan has achieved significant milestones in PET bottle recycling. This paper examines regulatory frameworks, collection systems, reprocessing facilities, and food safety assessments to highlight Japan's innovative approaches to PET bottle recycling and their impact on global sustainability efforts. Drawing parallels with Korea's early stages of PET recycling, it suggests involving major beverage companies and re-evaluating regulations to promote bottle-to-bottle recycling. The focus is on the implications for Korea to promote circular economy principles in plastic recycling.

The addition of oxygen scavengers to food products helps to reduce oxygen exposure, thereby mitigating deterioration, including changes in taste, odor, and color, as well as inhibiting microbial growth. Despite the advantages of the existing non-metallic oxygen removal materials in terms of safety for the human body and suitability for use in microwave ovens, their utilization has been limited due to their slow reaction initiation speed. Therefore, in the current study, sodium metabisulfite was impregnated into various porous media, including halloysite nanoclay, activated carbon, montmorillonite, and silica gel. The oxygen scavenger, produced by impregnating silica gel with sodium metabisulfite, demonstrated a 425% improvement in the initial oxygen removal rate compared to pure sodium metabisulfite. Additionally, sachets containing an oxygen-removing composition with an enhanced oxygen removal rate effectively decreased the oxygen concentration to less than 0.5% on the third day of storage in apple packaging, without elevating carbon dioxide levels. Moreover, it proved effective in preventing the browning of the apple surface. Therefore, the SM/SG oxygen-removal composition can be effectively applied to active food packaging by controlling the oxygen concentration within the packaging.

Molded pulp products has become more attractive than traditional materials such as expanded polystyrene foam (EPS) owing to low-priced recycled paper, environmental benefits such as biodegradability, and low production cost. In this study, various design factors regarding compression and cushioning characteristics of the molded pulp cushion with truncated pyramid-shaped structural units were analyzed using a test specimen with multiple structural units. The adopted structural factors were the geometric shape, wall thickness, and depth of the structural unit. The relative humidity was set at two levels. We derived the cushion curve model of the target molded pulp cushion using the stress-energy methodology. The coefficient of determination was approximately 0.8, which was lower than that for EPS (0.98). The cushioning performance of the molded pulp cushion was affected more by the structural factors of the structural unit than by the material characteristics. Repeated impacts, higher static stress, and drop height decreased the cushioning performance. Its compression behavior was investigated in four stages: elastic, first buckling, sub-buckling, and densification. It had greater rigidity during initial deformation stages; then, during plastic deformation, the rigidity was greatly reduced. The compression behavior was influenced by structural factors such as the geometric shape and depth of the structural unit and environmental conditions, rather than material properties. The biggest difference in the compression and cushioning characteristics of molded pulp cushion compared to EPS is that it is greatly affected by structural factors, and in addition, strength and resilience are expected to decrease due to humidity and repetitive loads, so future research is needed

본 연구에서는 PBAT의 가교 개질을 위해 DCP를 도입 하였고 화학발포제인 ADC를 PBAT에 분산시킨 후 압축성형 공정으로 발포제의 분해를 통해 셀을 형성하여 시트 형태의 PBAT 발포체를 제작하였다. FT-IR 분석을 통해 DCP의 분해를 확인하였으며 DCP 함량에 따른 PBAT의 용융 흐름 지수를 비교하여 가교로 인한 용융 점도의 향상 을 확인할 수 있었다. DSC 분석을 통해 열적 특성을 비교 한 결과 Tc의 변화를 확인할 수 있었고 이를 통해 DCP 첨가로 인한 가교 반응의 결과를 확인할 수 있었다. TGA 분석 결과를 통해 DCP의 첨가가 열 안정성의 유의미한 차 이를 야기시키지 않는 것을 확인하였다. 발포 시트의 DCP 함량 별 기계적 물성은 유의미한 차이를 보이지 않았으나 PB_D3에서 다소 낮은 인장강도를 보였으며 PB_D3의 큰 셀 사이즈로 인해 응력 전달에 부정적으로 작용하여 인장 강도 및 연신율이 감소하였을 것으로 판단하였다. DCP 함 량 증가에 따라 발포 셀의 개수는 감소하였으나 평균 셀 사이즈는 증가하였고 가장 큰 PB_D3의 평균 셀 사이즈로 인해 발포 시트의 밀도가 가장 낮게 나타났다. 반면 이러한 큰 셀의 사이즈와 낮은 밀도는 열전도도를 감소시키는 요 인으로 작용하여 PB_D3 발포 시트의 경우 최대 0.066W/ mk 까지 감소시킬 수 있었기에, 단열 특성을 지닌 생분해 성 발포 시트로의 활용에 대한 가능성을 확인할 수 있었다.

Poly (butylene adipate-co-terephthalate) (PBAT) is one of the representative biodegradable polymers with high ductility and processability to replace petroleum-based polymers. Many investigations have been conducted to broaden the applications of PBAT in a variety of industries, including the food packaging, agricultural mulching film, and logistics and distribution fields. Foaming process is widely known technique to generate the cell structure within the polymer matrix, offering the insulation and light weight properties. However, there was no commercially feasible foam product based on biodegradable polymers, especially PBAT, and maintaining a proper melt viscosity of the polymer would be a key parameter for the foaming process. In this study, chemical foaming agent and cross-linking agent were introduced to PBAT, and a compression molding process was applied to prepare a foam sheet. The correlation between cell morphological structures and mechanical and physical properties was evaluated. It was found that PBAT with foam structures effectively reduced the density and thermal conductivity, allowing them to be suitable for applications such as insulation and lightweight packaging or cushion materials.

In this study, environmental evaluation of high barrier coated paper (coating layer/paper) packaging is conducted in comparison with conventional aluminum laminated (PET/VMPET/LLDPE) plastic packaging. The target product for this packaging is a KF94 mask, which requires a high barrier of water and oxygen to maintain the filtration ability of the mask filter. The functional unit of this study is 10,000 mask packaging materials based on a material capable of blocking oxygen (<1 g/m2day) and moisture (<3 g/m2day) for the preservation of KF94 masks. In order to understand the results easily, paper-based mask packaging system divided into 6 stages (pulp, pulping & paper making, calendaring & coating, printing, packing and waste management), while plastic-based mask packaging consists of 5 stages (material production, processing, printing, packing, waste management) In case of paper-based mask packaging, most contributing stage is calendaring & coating, resulting from heat and electricity production. On the other hand, plastic-based mask packaging is contributed more than 30% by material production, specifically due to linear low density polyethylene and purified terephthalic acid production. The comparison results show that global warming potential of paper-based mask packaging has 32% lower than that of plastic-based mask packaging. Most of other impact indicators revealed in similar trend.