초록 ▼

Ⅳ. 연구개발결과
나노 기술을 이용하여 과일 coating에 적합한 coating제를 개발하였다. 개발된 coating제가 자두, 포도, 그리고 사과의 미생물 저해, 항갈변, 항산화, 색도, 그리고 관능에 대하여 미치는 영향을 연구하였고, 이를 통해 현장 적용에 적합한 coating제와 과일을 선정하였다. 신선 과실 가공장 현장 적용을 위한 주요 장비 필요사항과 coating parameter를 결정하였으며, 현장 적용 형태를 결정하고 coating 라인의 도면을 제작하였다. 개발된 coating제를 포도와 사과에 적용한 결과

Ⅳ. 연구개발결과
나노 기술을 이용하여 과일 coating에 적합한 coating제를 개발하였다. 개발된 coating제가 자두, 포도, 그리고 사과의 미생물 저해, 항갈변, 항산화, 색도, 그리고 관능에 대하여 미치는 영향을 연구하였고, 이를 통해 현장 적용에 적합한 coating제와 과일을 선정하였다. 신선 과실 가공장 현장 적용을 위한 주요 장비 필요사항과 coating parameter를 결정하였으며, 현장 적용 형태를 결정하고 coating 라인의 도면을 제작하였다. 개발된 coating제를 포도와 사과에 적용한 결과, 과일의 미생물 안전성을 향상시키고 물리화학적인 품질을 유지시켜 과일의 안전 기간과 선도유지 기간을 효과적으로 연장시켰다. Coating 기술을 적용한 과일의 저장 연구 데이터와 수학적 modeling을 이용하여 포도의 선도 및 안전 기간을 예측한 결과, coating이 포도의 선도 유지 및 안전 기간을 연장시켜주는 것을 알 수 있었다. Coating제의 경제성을 분석한 결과, 저렴한 가격으로 저장 중 부패로 인한 과일의 손실을 막을 수 있어 coating 적용이 경제적이라는 결론을 얻을 수 있었다.

Abstract ▼

Nanoemulsion coatings incorporating essential oils or an anti-browning agent have been developed and their effects on microbial safety and storage stability of plums, grape berries, and whole and fresh-cut apples have been investigated. Carnauba wax (CW)-based nanoemulsions incorporating lemongrass

Nanoemulsion coatings incorporating essential oils or an anti-browning agent have been developed and their effects on microbial safety and storage stability of plums, grape berries, and whole and fresh-cut apples have been investigated. Carnauba wax (CW)-based nanoemulsions incorporating lemongrass oil (LO) were applied to plums, ' Campbell early' grape (CG) berries, and whole apples. A LO-incorporating-chitosan-based coating emulsion was applied to ' Kyoho' grape (KG) berries. Edible coatings prepared from Aloe vera gel containing anti-browning agents, including cysteine, citric acid, ascorbic acid were applied to fresh-cut apples.
Uniform and continuous coatings on plums, formed with stable emulsions, initially inhibited Salmonella Typhimurium and Escherichia coli O157:H7 by 0.2 to 2.8 and 0.8 to 2.7 log CFU/g, respectively, depending on the concentration of LO and the sequence of coating. The coatings did not significantly alter the flavor, fracturability, or glossiness of the plums. The antimicrobial effects of the coatings against S. Typhimurium and E. coli O157:H7 were demonstrated during storage at 4 and 25 ℃. The coatings reduced weight loss and ethylene production by approximately 2 to 3 and 1.4 to 4.0 fold, respectively, and also retarded the changes in lightness and the concentration of phenolic compounds in plums during storage. The firmness of coated plums was generally higher than uncoated plums when stored at 4 ℃ and plum respiration rates were reduced during storage.
The coating solutions produced by dynamic high pressure (DHP) demonstrated the highest emulsion stability and resulted in uniform and continuous coatings on grape berries. The coating on the berries with 3.0 g LO/100 g initially inhibited S. Typhimurium and E. coli O157:H7 inoculated on the berries by more than 3.2 and 2.6 log CFU/g, respectively. The coatings did not significantly alter the flavor of the berries and improved their glossiness. Antimicrobial effects against S. Typhimurium and E. coli O157:H7 were exhibited during storage at 4 and 25 ℃ for 28 days. The coatings were also effective at reducing loss of weight, firmness, total anthocyanin, and antioxidant activity and preventing degradation of the phenolic compounds in the grape berries.
Both LO-incorporating-chitosan-based coatings with conventional emulsion and nanoemulsion effectively inhibited the growth of S. Typhimurium, Botrytise cinerea, total mesophilic aerobes, and yeasts and molds and retarded the changes in weight, firmness, total soluble solids, and titratable acidity in grape berries during storage. The emulsion coatings did not significantly affect the sensory properties of color, odor, and overall preference. Glossiness of the berries coated at 1.0% LO was preferred to uncoated berries. The coating with nanoemulsion resulted in higher retention of total polyphenols, anthocyanin, and antioxidant activities, rating in color in sensory evaluation, and inhibition on the growth of mesophilic aerobes during storage at 25 ℃ than the coating with conventional emulsion.
During storage, the hardness of the uncoated whole apples decreased by 3.3 N, and the weight loss was 7.7%. In contrast, the hardness of the coated whole apples did not change, and the weight loss was 5.2%. Titratable acidity and total soluble solids were not significantly different between coated and uncoated whole apples. The whole apples coated with the CW/LO solution had the best sensory appreciations. After 5 months of storage, the population of total aerobic bacteria on the coated apples was decreased by 1.4 log CFU/g compared with the uncoated apples. In addition, the population of yeast and molds on the uncoated apples was 2.2 log CFU/g after 5 months of storage, whereas yeast and molds were not detected on the coated apples.
Fresh-cut apples coated with the Aloe vera gel showed delayed browning and reduced weight loss and softening compared to the control. The A. vera gel coating was also effective in reducing the populations of the total aerobic bacteria and yeast and molds. In particular, A. vera gel containing 0.5% cysteine was most effective in delaying browning and the reduction of microbial populations among the treatments.
Highly stable nanoemulsions were developed for coating plums, grape berries, and whole and fresh-cut apples by DHP. Coatings containing nanoemulsions of LO have the potential to inhibit S. Typhimurium and E. coli O157:H7 contamination of plums, grape berries, and whole apples and extend shelf life of the products. The coating with the A. vera gel containing a 0.5% cysteine resulted in a better fresh-cut apple quality of color, microbial load, weight loss, firmness, and sensory properties during storage. Overall, the results of the study indicate that a nanoemulsion coating containing LO or cysteine solution is an effective postharvest technology that can be applied to commercial ready-to-eat plums, grape berries, and whole and fresh-cut apples to increase their microbial safety and shelf life.

목차 Contents

• 표지 ... 1
• 제출문 ... 2
• 요약문 ... 3
• SUMMARY ... 5
• 목차 ... 7
• 제 1 장 서 론 ... 8
• 제 2 장 국내외 기술개발 현황 ... 10
• 제1절 연구개발대상 기술의 국·내외 연구 현황 ... 10
• 제2절 국·내외 연구현황 비교 및 필요 연구 분야 ... 12
• 제 3 장 연구개발수행 내용 및 결과 ... 13
• 제1절 나노 기술이 이용된 포도와 자두용 edible coating제 개발 및 효과검증 ... 13
• 제2절 나노 기술이 이용된 사과 edible coating제 개발 및 효과 검증 ... 89
• 제 4 장 연구개발목표 달성도 및 대외기여도 ... 136
• 제1절 목표대비 달성도 ... 136
• 제2절 정량적 성과(논문게재, 특허출원, 기타) ... 137
• 제 5 장 연구개발결과의 활용계획 ... 138
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 139
• 제 7 장 기타 중요 변동사항 ... 141
• 제 8 장 국가과학기술종합정보시스템에 등록한 연구장비 현황 ... 142
• 제 9 장 참고문헌 ... 143
• 끝페이지 ... 151