9 research outputs found
Identification of cheese rancidity-related lipases in Aspergillus oryzae AHU 7139
Full text linkThe adjunct product with enzymatic activity from Aspergillus oryzae is beneficial for flavor enrichment in the ripened cheese. However, an excessive lipolytic reaction leads to the release of volatile free fatty acids. Accordingly, a strong offflavor (i.e., rancidity) has been detected when A. oryzae AHU 7139 is used. To identify the rancidity -related lipase from this strain, we evaluated the substrate specificity and lipase distribution using five mutants cultured on a whey -based solid medium under different initial pH conditions. The results showed a higher diacylglycerol lipase activity than triacylglycerol lipase activity. Moreover, an initial pH of 6.5 for the culture resulted in higher lipolytic activity than a pH of 4.0, and most of the activity was found in the extracellular fraction. Based on the gene expression analysis by realtime polymerase chain reaction and location and substrate specificity, five genes (No. 1, No. 19, mdlB, tglA, and cutL) were selected among 25 annotated lipase genes to identify the respective knockout strains. Because DtglA and DmdlB showed an outstanding involvement in the release of free fatty acids, these strains were applied to in vitro cheese curd experiments. In conclusion, we posit that triacylglycerol lipase (TglA) plays a key role as the trigger of rancidity and the resulting diglycerides have to be exposed to diacylglycerol lipase (MdlB) to stimulate rancidity in cheese made with A. oryzae AHU 7139. This finding could help screen suitable A. oryzae strains as cheese adjuncts to prevent the generation of the rancid -off flavor. (c) 2024, The Society for Biotechnology, Japan. All rights reserved
sp. solid culture products on ripened semi‐hard cheese
Full text linkBACKGROUND Aspergillus sp. has been used in traditional Japanese fermented foods. Protease-containing culture products of A. oryzae have been applied as the adjunct enzyme source to enrich the flavor in ripened cheese. Although proteolysis was stimulated, the increase of free fatty acids (FFA) was recognized in some products. Since an excess amount of FFA accumulation can cause rancidity in cheese products, the assessment of lipase activity was considered to be essential for the cheese adjunct preparation. RESULTS Although an equal lipase activity from the adjunct materials of A. kawachii NBRC 4308, A. luchuensis RIB 2604 and A. oryzae AHU 7139 was applied to semi-hard cheese, the FFA level was significantly higher in A. oryzae cheese than in the others. Furthermore, the profiles of volatile components were different in experimental cheeses. An in vitro study with experimental curds demonstrated that the high FFA might not depend on the lipase retainability on curds. On the contrary, the pronounced activation of the lipases occurred in A. oryzae after incubation with the curds. Moreover, incubation of the insoluble lipase that had been attached to the cells with skim milk curd extracts allowed the release of lipases from the cells into the medium with remarkable activation. CONCLUSION A. oryzae AHU 7139 possessed a complex lipolytic system comprising extracellular and cell-binding lipases that were attributed to the increase in FFA in A. oryzae cheese
for semi‐hard cheese
Full text linkBACKGROUND Species belonging to the genusAspergillushave been used in traditional Japanese fermented foods.Aspergillus sojaeis a species responsible for strong proteolytic activity. Freeze-drying treatments followed by physical disruption enables the pulverization of the mycelia ofA. sojaeRIB 1045 grown in whey protein-base solid media. Intracellular proteases were extracted using this protocol to compare extracellular protease activity in terms of the reaction's pH dependence in the presence or absence of inhibitors. RESULT With different sensitivities to inhibitors, intracellular and extracellular proteases showed the strongest activity under acidic conditions, which were considered suitable for cheese application. The raw culture product (CP) and its freeze-dried product (FDP) were mixed with cheese curds, prepared according to Gouda-type cheese-making methods, and were allowed to ripen for 3 months. Chemical analysis of the products showed 13.3% water-soluble nitrogen (WSN) in the control, which had received noncultured media, whereas 20.0% and 21.1% WSN was found in the CP and FDP experimental cheeses, respectively. Although these adjuncts significantly increased WSN, an insignificant difference was found between CP and FDP. Free fatty acids in all experimental cheeses were similar, showing that CP and FDP caused no rancid defects. CONCLUSION The introduction of freeze-drying treatments accompanied by cell disruption resulted in a negligible effect in terms of WSN. However, the application ofA. sojaecan be beneficial when it comes to increasing the level of WSN compared withA. oryzae, as shown in our previous study. (c) 2020 Society of Chemical Industr
Strengthening the Bank's population work in the nineties
Full text linkThis paper argues that the Bank should give renewed priority to population matters and accelerate the current upward trend in lending for family planning programs in the 1990s. It is timely for two reasons. First, the need for bank action in population will increase in the 1990s as a result of growing unmet demand for family planning and stagnant bilateral assistance levels. Second, there is evidence that the initial effects of the 1987 World Bank reorganization have been to strengthening the potential for population work by integrating it more fully with economic analysis and overall country programming, but some further adjustments would assure that the potential could be realized. As the largest and most influential international development organization, there is an important leadership role for the Bank in promoting population policy analysis, dialogue, and in financing family planning programs.Adolescent Health,Health Monitoring&Evaluation,Agricultural Research,Reproductive Health,Early Child and Children's Health
Seroprevalence and preventive practices of dengue and chikungunya among school children in Bangkok: Gaps in prevention and vaccination strategies
No full textAbstract Background Dengue and chikungunya, both transmitted by Aedes mosquitoes, continue to pose significant public health concerns in Thailand, particularly during the rainy season. Despite ongoing vector control efforts, the incidence of infection remains high, with an increasing trend observed in chikungunya. This underscores the need for additional control measures, including vaccination, to reduce disease burden and morbidity. This study aims to assess the seroprevalence of dengue and chikungunya infections among children aged 10-15 years in Bangkok and to evaluate the knowledge, attitudes, and practices (KAP) related to mosquito-borne disease prevention. Methodology A cross-sectional descriptive study was conducted across 12 schools in Bangkok. Children aged 10 to 15 years were included. Seroprevalence was determined using rapid diagnostic tests (Abbott DENGUE IgG/IgM and Citest Chikungunya IgG/IgM) based on the immunochromatography technique, using fingertip blood samples. Parents completed KAP questionnaires, including factors influencing vaccination decisions. Principal findings From June to August 2024, 937 participants were enrolled, with a mean (SD) age of 11 (1.6) years; 67% were aged 10–12 years, and 33% were aged 13–15 years. The seroprevalence of dengue was 28.1% (95% CI 25.2-31.0), while that of chikungunya was 6.3% (95% CI 4.7-7.9). KAP assessments revealed a high level of awareness regarding symptoms and transmission; however, notable deficiencies in preventive behaviors were identified. Only 14.8% of respondents reported consistent use of mosquito repellent, and 17.5% routinely inspected and removed mosquito larvae from their homes. Conclusion The substantial seroprevalence of dengue and the emerging trend of chikungunya among children in Bangkok highlights the urgent need to enhance community education and strengthen vector control interventions. Expanding dengue vaccination coverage and raising awareness about chikungunya prevention, including consideration for future vaccine implementation, are essential to mitigating future outbreaks and reducing the disease burden. Author summary Mosquito-borne diseases, including dengue and chikungunya, are significant health problems in Southeast Asia. In our study, we evaluate the seroprevalence of these diseases using rapid blood tests in a school-based setting among children in Bangkok. The seroprevalence data highlight the risk of exposure, particularly among children, and can guide preventive practices, including vaccination. Despite the widespread recognition of these diseases, preventive practices remain limited. Therefore, implementing effective preventive measures and vaccination strategies could significantly reduce the severity of infections and improve public health outcomes
