Natural Occurrence of Nitrite-Related Compounds in Malt and Beer

Abstract

Despite sufficient control of volatile N-nitrosamines in foods and beverages, little attention remained on nonvolatile nitroso compounds, which are mostly unknown and relative to nitrite reactions. In a recent study, new compounds related to reactions of nitrite in beer were pyruvic acid oxime, 4-nitrosophenol, 4-cyanophenol, N-nitrosoproline ethyl ester, nitrosoguaiacol, and 2-methoxy-5-nitrophenol, as well as the already known N-nitrosoproline. The present study is intended to observe their natural occurrence in commercial beers and malts. All 22 nitrite-related products (N-products) were monitored in almost 200 samples of beers and malts. As many as 17 N-products were detected in malts, and all 22 N-products were found in beers. The hierarchical clustering grouped samples based on similarities of detected N-products by frequency of their appearance and level of response. Between N-products and N-nitrosodimethylamine concentrations in malts, only moderate Pearson correlations were found. The same applied to N-product correlations with the apparent total nitroso compound determination in beers.

Use of Residual Malt from an Artisanal Beer Brewing Process in the Biosynthesis of Silver Nanoparticles Mediated by Nucleating and Structure-Directing Agents

“…Figure 4 shows the FTIR spectra of No NA/SDA, NaCl, GA, and T samples of ME-AgNPs (Figures 4a, 4b, 4c and 4d, respectively). Figure 4a peaks correspond to main peaks around 2926, 1646, 1456, 1338, 1240, 1206, 1152, 1077, and 993 cm −1 and a prominent peak area between 925 and 400 cm −1 previously described for ME (Figure 3), which indicates the presence of ME biomolecules acting as stabilizing agents on the surface of these AgNPs [48,49]. In the case of NaCl/ME-AgNPs (Figure 4b), besides the peaks corresponding to Figure 4 shows the FTIR spectra of No NA/SDA, NaCl, GA, and T samples of ME-AgNPs (Figures 4a, 4b, 4c and 4d, respectively).…”

“…Considering that it has been reported that malt has around 5042 compounds which include amines, alcohols, carboxylic acids, terpenes, etc. [48], and also nitroso compounds such as N-nitrosodimethylamine have been found in malt [49], the detection of the signals of these functional groups on the surface of ME-AgNPs was expected. Figure 4 shows the FTIR spectra of No NA/SDA, NaCl, GA, and T samples of ME-AgNPs (Figures 4a, 4b, 4c and 4d, respectively).…”