Foods and Raw Materials Foods and Raw Materials Foods and Raw Materials 2308-4057 2310-9599 121009 10.21603/2308-4057-2027-1-704 XDFJZD Research Article Research Article Research Article Cellulase enzyme and citric acid in producing iodine-enriched agar powder from Gracilaria tenuistipitata Cellulase enzyme and citric acid in producing iodine-enriched agar powder from Gracilaria tenuistipitata https://orcid.org/0000-0002-8146-758X Hien Bui Thi Thu Hien Bui Thi Thu btthien@mae.gov.vn Trung Do Minh Trung Do Minh https://orcid.org/0000-0003-0130-077X Diem Pham Thi Diem Pham Thi Nguyet Bui Thi Minh Nguyet Bui Thi Minh Quyen Vu Thi Quyen Vu Thi Nguyen Nguyen Van Nguyen Nguyen Van Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Вьетнам Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Vietnam Institute of Biomedicine and Pharmacy, Vietnam Military Medical University Ha Noi Вьетнам Institute of Biomedicine and Pharmacy, Vietnam Military Medical University Ha Noi Vietnam Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Вьетнам Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Vietnam Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Вьетнам Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Vietnam Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Вьетнам Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Vietnam Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Вьетнам Northern Research Center for Marine Fisheries, Vietnam Academy for Fishery Siences Hai Phong Vietnam 22 04 2026 22 04 2026 15 1 207 221 27 04 2025 13 01 2026 https://jfrm.ru/en/issues/24071/24378/

Seaweed is a valuable source of iodine, an essential micronutrient critical for thyroid function. However, conventional iodine fortification methods often result in nutrient loss and environmental issues, necessitating more sustainable alternatives. This study established an environmentally sustainable process to produce iodine-enriched agar powder from Gracilaria tenuistipitata C.F. Chang & B.-M. Xia, 1976, a red seaweed commonly cultivated in Vietnam. The production involved pretreatment, agar extraction, blending of functional ingredients, and organic iodine enrichment. Response Surface Methodology optimized critical factors, including enzyme concentration, citric acid usage, and iodine supplementation. The developed agar-based powder had a stable iodine content (7.42 mg/100 g), protein level (8.51%), and a firm, elastic gel texture. Utilizing MPB cellulase enzyme and citric acid improved the agar yield by ~ 20%, minimized the environmental impact, preserved bioactive compounds, and stabilized iodine. Optimal extraction conditions included cellulase (0.4–0.6%), temperature (45–50°C), and duration (36–48 h). The final optimal formulation combined agar, carrageenan, and gelatin (60:30:10). It was supplemented with 0.2% of sea grapes and 2.5% fermented red algae to significantly enhance iodine retention and sensory quality. Analytical tests (HPLC, UV-Vis) and sensory evaluation verified the product’s quality. The agar powder demonstrated excellent iodine stability and maintained sensory acceptability after six months of refrigeration storage. Integrating cellulase enzymatic treatment, citric acid refinement, and organic iodine enrichment effectively enhanced the nutritional value and addresses iodine deficiency in health-oriented functional foods.

Seaweed is a valuable source of iodine, an essential micronutrient critical for thyroid function. However, conventional iodine fortification methods often result in nutrient loss and environmental issues, necessitating more sustainable alternatives. This study established an environmentally sustainable process to produce iodine-enriched agar powder from Gracilaria tenuistipitata C.F. Chang & B.-M. Xia, 1976, a red seaweed commonly cultivated in Vietnam. The production involved pretreatment, agar extraction, blending of functional ingredients, and organic iodine enrichment. Response Surface Methodology optimized critical factors, including enzyme concentration, citric acid usage, and iodine supplementation. The developed agar-based powder had a stable iodine content (7.42 mg/100 g), protein level (8.51%), and a firm, elastic gel texture. Utilizing MPB cellulase enzyme and citric acid improved the agar yield by ~ 20%, minimized the environmental impact, preserved bioactive compounds, and stabilized iodine. Optimal extraction conditions included cellulase (0.4–0.6%), temperature (45–50°C), and duration (36–48 h). The final optimal formulation combined agar, carrageenan, and gelatin (60:30:10). It was supplemented with 0.2% of sea grapes and 2.5% fermented red algae to significantly enhance iodine retention and sensory quality. Analytical tests (HPLC, UV-Vis) and sensory evaluation verified the product’s quality. The agar powder demonstrated excellent iodine stability and maintained sensory acceptability after six months of refrigeration storage. Integrating cellulase enzymatic treatment, citric acid refinement, and organic iodine enrichment effectively enhanced the nutritional value and addresses iodine deficiency in health-oriented functional foods.

 Seaweed agar powder iodine Gracilaria tenuistipitata processing technology enrichment enzymatic treatment Seaweed agar powder iodine Gracilaria tenuistipitata processing technology enrichment enzymatic treatment This research was financially supported by the Ministry of Agriculture and Environment as part of the project “Research and Development of Commercial Cultivation and Processing Technologies for Economically Valuable Seaweed Species in Vietnam (No. 101/2022/HĐ-KHCN-TS)”. This research was financially supported by the Ministry of Agriculture and Environment as part of the project “Research and Development of Commercial Cultivation and Processing Technologies for Economically Valuable Seaweed Species in Vietnam (No. 101/2022/HĐ-KHCN-TS)”.

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