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The carbon stable isotope ratio (δ13C) has become an important tool to determine the composition and quality of various beverages, indicating the amount of C3- and C4-sources used in brewing. Accordingly, we assessed the isotopic composition of beers produced in Brazil and abroad, in order to quantify the use of C4-sources as adjuncts. We also related the presence of such adjuncts to beer price, and compared the current results to similar studies, in order to assess any differences regarding beer composition over time. The mean δ13C value for Brazilian beers was around −22.0‰, indicating a high addition of C4-adjuncts during the brewing process. A dichotomy of beer isotopic signatures was observed: beers from large breweries had higher δ13C values (around −20.0‰) than beer from artisanal breweries (−25.0‰). Beer price per L was directly related to δ13C values in Brazil and abroad. This significant relationship, in addition to the 13C-enrichment observed in this study, may reflect a change in the Brazilian beer market, in which a greater variety of beverages are produced and marketed following traditional recipes regarding their purity.

Based on the fact that streamwater quality reflects landscape conditions, the objectives of this study were: to investigate nitrogen (N), carbon (C), and major ion concentrations in six streams crossing minimally disturbed Atlantic Forest areas, with similar geomorphological characteristics; to determine N and C fluxes in one of these pristine streams (Indaia); and assess the impact of human activity on the biogeochemistry of two other streams in the same region, crossing urbanized areas. The distribution pattern of carbon and inorganic nitrogen dissolved forms, as well as the major ion and biogenic gas concentrations in the streamwater, was similar in pristine streams, indicating that the C and N dynamics were determined by influence of some factors, such as climate, atmospheric deposition, geology, soil type, and land covering, which were analogous in the forested watersheds. The urban streams were significantly different from the pristine streams, showing low dissolved oxygen concentrations, high respiration rates, and high concentrations of carbon dioxide, dissolved inorganic nitrogen, dissolved inorganic carbon, and major ion. These differences were attributed to anthropogenic impact on water quality, especially domestic sewage discharge. Additionally, in the Indaia stream, it was possible to observe the importance of rainfall over temporal dynamics of dissolved carbon forms, and also, the obtained specific flux of dissolved inorganic nitrogen was relatively elevated (approximately 11 kg ha−1 year−1). These results reveal the influence of human activity over the biogeochemistry of coastal streams and also indicate the importance N export of Atlantic Forest to the ocean.