Microbiological hazards and control in the roasted seasoned laver manufacturing processes

최은숙 Graduate School, Korea University 2013 국내석사

The aim of this study was to investigate microbial contaminations of roasted seasoned laver throughout the manufacturing process and to find a critical control point for sanitary management. Raw materials and semi- or final products were collected from 6 steps (raw materials, primary roasting, seasoning, secondary roasting, counting and distribution, and final products) of total 6 manufacturers (A-F) and microbiological analyses were performed (quantitative: aerobic plate counts (APC), coliforms, Bacillus cereus, Staphylococcus aureus, Vibrio parahaemolyticus; qualitative: B. cereus, Escherichia coli, Listeria monocytogenes, Salmonella spp., S. aureus, V. parahaemolyticus). Samples from working environments were also collected and assessed (APC and coliform counts) except manufacturer F. The dried laver initially indicated high level of APC (average: 6.85 log CFU/g), and it gradually decreased during the process: primary roasting (6.30) > seasoning (6.15) > secondary roasting (4.30) > counting and distribution (3.56) > final products (3.21). Coliforms or B. cereus was not detected from all the final products but some raw materials and semi-products. E. coli and the tested foodborne pathogens were not detected except B. cereus. Microbiological quality of semi-products varied depending on manufacturing process (especially for secondary roasting) and processing quality level of each plant. The critical point to control microbiological hazards was ‘secondary roasting’ (at 260-400°C for 2-10 seconds) which reduced APC by 1.28-4.18 log CFU/g except manufacturer F of which rather increased (1.55 log CFU/g). As secondary roasting was more severe and managed properly, microbial contamination was more successfully controlled. Microbiological quality of working environment was rather clean except manufacturer F. APC on workbench surfaces and food worker’s hands (ND to 2.11 and 2.15 log CFU/cm2, respectively) were not high and microbiological quality of the air was less than 90 CFU/m3 (international recommendation). Coliform was not detected from any samples. It is required to develop adequate roasting technique for totally eliminating microbiological hazards. Further, good practice of proper processing and sanitation control in working environments were also important to ensure microbiological quality of roasted seasoned laver manufacturing. These results provide the comprehensive database for microbiological changes in the roasted seasoned laver manufacturing and may contribute to establish strategic sanitation management plan for the roasted seasoned laver industry.

Development of polymeric films impregnated with moisture-absorbers and effectiveness of their applications on the quality improvement of seasoned laver

최홍열 연세대학교 대학원 2012 국내석사

The objective of the study is to develop the effective moisture absorbing films and evaluate their effectiveness in improving the quality of seasoned laver during storage. To develop these functional films, four experiments were carried out as follows: (1) to screen the high moisture ansorbent materials; (2) to form the moisture absorbing materials impregnated films by the extrusion process; (3) to determine the mechanical, thermal, morphological properties of the developed film structures; (4) to evaluate the quality of seasoned laver packaged in the developed films. Moisture sorption-isotherms of the selected moisture absorbing materials were performed at 20, 30 and 40℃ with 30, 40, 50, 60, 70, 80, and 90% RH. PAPSS and ATPGAA materials had higher moisture absorbency values than other materials. The best fit of the experimental sorption data was obtained by the comparison with the mathematical expression models.. Isosteric energy values for moisture on absorbing agents are determined by differential scanning calorimetry (DSC) analysis. PAPSS and ATPGAA had lower isosteric heat values of sorption than other materials. Studies of physical and thermal properties were conducted on the developed films containing PAPSS and ATPGAA levels of 0.5, 1, 2, and 4%, respectively. The tensile strength and the elongation at break of each film were measured using a universal testing machine (UTM). Values of the tensile strength and elongation at the break were decreased by incorporating the moisture absorbing materials with LLDPE. Films impregnated with PAPAA and ATPGAA of 4% showed the lowest elongation at break compared to the other films containing PAPSS and ATPGAA of different concentrations. The crystallization temperatures (Tc) of developed films were ranged from 106 to 107℃. The melting temperature was also increased the rate of 1℃ by increasing PAPSS and ATPGAA levels. Values of WVTR and OTR for developed films were decreased by an increase of PAPSS and ATPGAA levels. The effects of developed films for keeping quality of seasoned laver were investigated at storage temperatures of 23, 40, and 60℃. As the quality factors of seasoned laver, changes in weight, color, texture, and peroxide value were monitored as a function of storage time. The quality attribute of packaged seasoned laver was also determined using sensory evaluation. The seasoned laver packaged with ATPGAA impregnated films showed the good stability and high sensory attributes. PAPSS and ATPGAA impregnated films would be helpful in improving the quality of seasoned laver during storage. The objective of the study is to develop the effective moisture absorbing films and evaluate their effectiveness in improving the quality of seasoned laver during storage. To develop these functional films, four experiments were carried out as follows: (1) to screen the high moisture ansorbent materials; (2) to form the moisture absorbing materials impregnated films by the extrusion process; (3) to determine the mechanical, thermal, morphological properties of the developed film structures; (4) to evaluate the quality of seasoned laver packaged in the developed films. Moisture sorption-isotherms of the selected moisture absorbing materials were performed at 20, 30 and 40℃ with 30, 40, 50, 60, 70, 80, and 90% RH. PAPSS and ATPGAA materials had higher moisture absorbency values than other materials. The best fit of the experimental sorption data was obtained by the comparison with the mathematical expression models.. Isosteric energy values for moisture on absorbing agents are determined by differential scanning calorimetry (DSC) analysis. PAPSS and ATPGAA had lower isosteric heat values of sorption than other materials. Studies of physical and thermal properties were conducted on the developed films containing PAPSS and ATPGAA levels of 0.5, 1, 2, and 4%, respectively. The tensile strength and the elongation at break of each film were measured using a universal testing machine (UTM). Values of the tensile strength and elongation at the break were decreased by incorporating the moisture absorbing materials with LLDPE. Films impregnated with PAPAA and ATPGAA of 4% showed the lowest elongation at break compared to the other films containing PAPSS and ATPGAA of different concentrations. The crystallization temperatures (Tc) of developed films were ranged from 106 to 107℃. The melting temperature was also increased the rate of 1℃ by increasing PAPSS and ATPGAA levels. Values of WVTR and OTR for developed films were decreased by an increase of PAPSS and ATPGAA levels. The effects of developed films for keeping quality of seasoned laver were investigated at storage temperatures of 23, 40, and 60℃. As the quality factors of seasoned laver, changes in weight, color, texture, and peroxide value were monitored as a function of storage time. The quality attribute of packaged seasoned laver was also determined using sensory evaluation. The seasoned laver packaged with ATPGAA impregnated films showed the good stability and high sensory attributes. PAPSS and ATPGAA impregnated films would be helpful in improving the quality of seasoned laver during storage.

조미김의 제조공정 및 보관에 따른 세균의 모니터링에 대한 연구

노소연 성균관대학교 일반대학원 2017 국내석사

일부 연구자들에 의해 김의 섭취는 당뇨, 비만, 고혈압, 심장질환 및 암과 같은 다양한 반성질환의 위험을 감소시킬 수 있다는 보고된 바 있다. 이러한 김의 효능에 힘입어 국내산 김은 다양한 형태(김밥김, 조미김 등)로 일본, 중국 등의 수출 시장을 넓히고 국내에서도 소비가 급증되고 있다. 따라서, 본 연구는 수출 시장 경쟁력 및 국내의 안정적인 소비시장을 위해 향후 위생관리 계획 수립에 기여할 수 있도록 조미김(김자반)의 전 제조공정 및 보관에 따른 세균의 모니터링을 도출하여 기초자료를 제시하고자 한다. 김자반은 제조공정별 4가지의 성상(물김, 마른김자반, 로스팅김자반, 조미김자반)을 나타내며, 이를 세부적으로 나누어 10개의 시료를 채취하였고 각 시료별 미생물 분석(일반세균, 대장균, 황색포도상구균, 장염비브리오, 바실러스 세레우스, 클로스트리디움 퍼프린젠스, 살모넬라, 리스테리아 모노사이토제네스)을 수행하였다. 모든 공정에서 일반세균 외의 식중독세균은 검출되지 않았으며, 일반세균의 경우 물김의 2.47 log CFU/g 수준을 시점으로 건조과정을 거친 후 마른김자반에서의 6.46 log CFU/g로 최대로 증가 하였고, 1차 가공공정인 로스팅 과정(5.17 log CFU/g)과 2차 가공공정인 조미 과정(4.81 log CFU/g)을 통해 점차 감소하였으며, 최종 제품(조미김자반)에서의 일반세균은 4.59 log CFU/g로 나타났다. 보관기간에 따른 균 모니터링을 위해 최종제품(조미김자반)을 보관온도 25℃ 및 35℃에서 63일간 저장하면서 7~10일 간격으로 일반세균(식중독세균은 제조공정에 따른 모니터링 실험 결과 모두 불검출로 보관기간에 따른 실험에서는 생략함)실험을 수행하였다. 25℃의 보관되었던 조미김자반은 5.22 log CFU/g, 35℃의 보관되었던 조미김자반은 5.15 log CFU/g로 온도별 보관기간 중에는 큰 차이가 없는 것으로 나타났다. 마른김자반의 제조는 물김의 생산시기에 따라 보통 1월~4월로 한정된다. 선행연구를 통해 제조시기에 따른 마른김의 제조공정별 미생물 모니터링연구가 진행되었으며, 그 결과는 3~4월에 제조된 마른김은 1월에 제조된 마른김 보다 일반세균수가 다소 높다는 결과가 보고되었다.(Kang, 2016) 이를 통해 본 연구에서는 원료(물김)의 균수가 최종제품(조미김자반)까지 영향을 미치는지 알아보기 위해 제조공정 및 로스팅시간별 비교실험을 진행하였고, 그 결과 일반세균수가 높은 원료의 경우, 최종 제품까지 높은 수준의 결과가 나타났다. 선행연구자에 의하여 일부 조미김 업체의 관리 소홀로 원물 및 반제품에서 식중독세균이 검출되었다고 밝혀진 바가 있다.(Choi, 2012) 본 연구에서 식중독세균(대장균, 바실러스 세레우스, 황색포도상구균, 리스테리아 모노사이토제네스)를 마른김에 접종하여 제조공정별 검출여부를 진행하여 접종균의 생존성 여부를 살펴보았으며, 그 결과 최종제품에서 모두 불검출로 제조공정상의 안정성을 나타냈다.