Vitamin B12, only found naturally in animal-based foods, is essential for brain functions and various chemical reactions in the human body. Insufficient vitamin B12 leads to vitamin B12 deficiency, common among strict vegetarians due to their limited intake of animal-based foods. Nevertheless, extensive studies have demonstrated that macroalgae, specifically the Ulva lactuca species, are rich in vitamin B12 and could be further exploited in future dietary applications. In the current study, the ideal extraction method of vitamin B12 from dried U. lactuca was developed and optimised to achieve the maximum vitamin B12 yield. The effects of several extraction parameters, including the solvent-to-solvent, methanol:water (MeOH:H2O), and solute-to-solvent ratios, and pH on the total vitamin B12 content were analysed through a two-level factorial and central composite design. The highest vitamin B12 content, particularly cyanocobalamin (CN-Cbl), was recovered through the ultrasonic-assisted extraction (UAE) of oven-dried U. lactuca at 3 g:60 mL of solute-to-solvent and 25:75% of MeOH to H2O ratios at pH 4. The extraction of CN-Cbl from oven-dried U. lactuca that employed the UAE method has elevated CN-Cbl content recovery compared to other extraction methods.

at September 15 th , 2021. The seminar under the theme "Chemistry Resilience and Continuity in the Covid-19 Pandemic".The aim of the seminar is to explore and develop the concept of learning, innovation and competence building as a chemistry education framework. The objective of ISCE is to stimulate the establishment of knowledge based strategies or teaching development in Senior High School and College. The idea of the seminar is to bring together interesting issues about what is going on ASEAN countries, School, university and to share experience regarding methodology of design thinking in teaching area.Topic of interest to be covered in the conference includes, but not limited to: 1. Chemistry education curriculum and policy 2. Teacher learning and education (in-service and pre-service teachers) 3. Environmental and social issues in chemistry 4. Assessment and evaluation 5. Independence learning and digital learning 6. Skill oriented and instructional learning in 21st century 7. Classroom action research in sciences 8. Environmental chemistry and its aspects 9. Renewable and sustainable energy 10. Materials and advance materials 11. Green chemistry, chemical engineering and chemical process This program and abstracts book provides some information concerning the schedule, list of presenter and poster presenter. Hopefully, this book helps the participants for intensively listen and get valuable information in the conference.The scientific program of ISCE 2021 comprises the following: Keynote speakers 6 papers Invited speakers 5 papers Total papers for oral presentation 56 papers Total papers for poster presentation 25 papers Total papers 92 papers iii Chairperson's Foreword Dear Participants, Friends and Colleagues, Assalamu'alaikum Wr. Wb.It is a great pleasure for me to have your participation in an online 4th International Seminar on Chemistry Education, held by Chemistry Department, Universitas Islam Indonesia. This seminar is a kind of academic activity and tradition in our department which intended to bring opportunity to all lecturers, researchers and students from all around the world. The conference aims to stimulate our participants to explore the latest development and innovation including latest instrumentation, recent applications and assessment of future commercial trends and opportunities. As we know that science and technology including chemistry and chemical industries are developing fast at recent years, so it requires the highlights on chemistry research, and moreover, it will be closely related with chemistry education sector. In other side, pandemic covid-19 changes everything including how the education being delivered. Explorations on many adaptable teaching-learning modes as well as the updating recent progresses in chemistry, chemical and chemistry education research are important. This webinar is one of the efforts, and in addition, an energetic and dynamic scientific gathering especially with all participants respected presence.As similar with previous seminar, this webinar will compi...