Endocrine-Disrupting Chemicals from Synthetic Food-Contact Polymers as an Internal Medicine Concern: A Preliminary Assessment of Marine-Derived Sodium Alginate as a Potential Packaging Biomaterial

Petroleum-based polymers such as polyvinyl chloride, polyethylene terephthalate, polycarbonate and epoxy resins dominate the food-packaging sector, yet chemicals migrating from these materials represent a potentially important source of chronic human exposure with relevance to internal medicine. Bisphenol A (BPA), phthalates, oligomers, non-intentionally added substances and micro/nanoplastics have been detected in food-contact materials and human samples and have been associated with endocrine, metabolic, hepatic and cardiovascular outcomes. Reducing exposure at the packaging source is therefore an important preventive-medicine consideration. This study presents a preliminary materials assessment of sodium alginate extracted from the invasive brown macroalga Cystoseira barbata collected from the Şile coast of the Black Sea, with particular consideration of its potential as a marine-derived biomaterial for food-packaging applications. Alginate was recovered by formaldehyde pre-treatment, acid conditioning, sodium-carbonate extraction and double ethanol precipitation and was characterized by Fourier-transform infrared (FT-IR) spectroscopy. The FT-IR spectrum confirmed the characteristic hydroxyl, carboxylate and glycosidic bands of the alginate polysaccharide structure, with no evident structural degradation. The low mannuronic-to-guluronic (M/G) ratio reported for this species (~0.65) suggests potentially favourable material characteristics for film formation based on previously reported structure–property relationships. Sodium alginate is an established food-grade hydrocolloid (E 401) with a long history of food and pharmaceutical use. These characteristics support further investigation of C. barbata-derived alginate as a potential biomaterial for food-contact applications. However, the present study does not establish packaging safety, migration performance, mechanical or barrier properties, or a clinically meaningful reduction in exposure to endocrine-disrupting chemicals. Such claims require dedicated migration, mechanical, barrier, microbiological and toxicological studies.