Open Access

We present a new method for investigating the oxidation and emission behavior of air-permeable materials. Employing this method, a differentiated statement can be made about the extent to which critical volatile organic compounds (VOCs) such as formaldehyde, acetaldehyde, and acrolein are contained in the material as impurities or formed by thermo-oxidative degradation of the polymer matrix in the use phase. The parameters affecting methods of VOC analysis are reviewed and considered for the developed method. The molecular mechanisms of VOC formation are discussed. Toxicological implications of the reaction kinetics are put into context with international guidelines and threshold levels. This new method enables manufacturers of cellular materials not only to determine the oxidative stability of their products but also to optimize them specifically for higher durability. Environmental Implication: Cellular materials are ubiquitous in the technosphere. They play a crucial role in various microenvironments such as automotive interiors, building insulation, and cushioning. These materials are susceptible to oxidative breakdown, leading to the release of formaldehyde, acetaldehyde, and acrolein. The ecotoxicological profiles of these compounds necessitate monitoring and regulation. The absence of reproducible and reliable analytical methods restricts research and development aimed at risk assessment and mitigation. This work significantly enhances the toolbox for optimizing the oxidative stability of any open-cell cellular material and evaluating these materials in terms of their temperature-dependent oxidation and emission behavior.

Investigations into volatile organic compound (VOC) emissions from polymer fleeces used in particle filtering half masks were conducted and evaluated against the German hygienic guide value for total volatile organic com- pounds and the “Lowest Concentration of Interest” for construction products. All masks showed emission of Xy- lene. In 94 % of samples, up to 24 additional aromatic compounds were found. 17 % of samples showed terpenes, 53 % emitted aldehydes, 77 % exhibited caprolactam and 98 % released siloxanes. All masks exceeded the TVOC hygienic guidance value level 5 of 10 mg/m³. Emission levels were investigated for masks immediately after their packages were opened and for masks that were “vented” for two weeks. Further, the emissions were repeatedly measured to investigate the decrease of emissions. An exponential decline was observed and a fitting function was calculated. The influence of the two commonly gas chromatograph (GC) hyphenated detectors, mass spectrometer (MS) and flame ionization detector (FID) on the VOC quantification, as well as the influence of temperature on the emission of VOCs were investigated. A statistical analysis of emission value differences for Notified Bodies was conducted and CE 2163 and 2020-1XG proved to be outliers.

This systematic review critically examines existing literature on the effects of spontaneous fermentation on the nutritional and antinutritional properties of the aforementioned food staples, focusing on the changes in nutrients, digestibility, and antinutrients. The literature search flow was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRiSMA-2020) approach. Only peer-reviewed journal articles published in English between 2002 and 2024 were sourced from Scopus, Web of Science, and PubMed. A total of 67 articles were considered eligible after the title, abstract, full text, and quality assessment. It was evident from the various studies consulted in this review that traditional fermentation, though being an ancient food processing practice, remains an important approach for increasing the level of nutrients, reducing antinutritional factors, and enhancing the nutrient digestibility of cereals, legumes, roots, tuber, and plantain. This has made fermented foods an important part of diet and nutrition in many cultures around the world, especially in the global south, with limited access to sophisticated food processing techniques and infrastructure. Overall, the findings suggest that incorporating spontaneous fermentation into the preparation of cereals, legumes, roots, and tuber crops can be a valuable strategy for enhancing the nutritional value and health-promoting properties of these dietary staples.