Quantitative Determination of Acrolein in Cider by 1H NMR Spectrometry

Abstract

Acrolein occasionally appears in cider, completely spoiling its quality due to its bitter taste. It is crucial to detect it in the early steps, before the taste is severely affected, to apply the appropriate treatment. A simple and rapid analytical method to determine this compound in cider is therefore desirable. In this work, a quantitative determination method of acrolein in cider is proposed using the proton nuclear magnetic resonance technique (1H NMR). Acrolein produces a doublet signal in the spectrum at 9.49 ppm, whose area is used to determine the concentration of this compound. 3-(trimethylsilyl)-2,2,3,3-d4-propionic acid sodium salt is added to the cider as a reference for 0.00 ppm and 1,3,5-benzenetricarboxylic acid as an internal standard for acrolein determination. The method is validated by gas chromatography (GC). There is a good correlation between the acrolein concentrations obtained by 1H NMR and by gas chromatography in different commercial ciders (Pearson coefficient 0.9994). The 95% confidence interval for the intercept is 0.15 ± 0.49 (includes 0) and for the slope is 0.98 ± 0.03 (includes 1). When applying the paired t test, no significant difference is observed. The proposed method is direct, and no prior derivatization is needed.

Inhibitory Effect on Acrolein by Cyanidin-3-O-glucoside and Its Acrolein Adducts from the Pigment of Mynica Red

“…Likewise, compared with the C3G data, we found that the 1 H NMR spectrum of C3G−2ACR was similar to that of C3G, except that the two proton signals at δ H 6.64 (H-6) and 6.87 (H-5′) in the 1 H NMR spectrum of C3G had disappeared, suggesting that ACR groups linked with C3G at the positions of C-6 in the A-ring and C-5′ in the B-ring. We also discovered that there was one additional set of proton signals (δ H 2.71 m, 2H; δ H 2.16 m, 2H; δ H 5.86 m, 1H) for the ACR group in the 1 H NMR spectrum and one additional set of carbon signals (δ C 14.90, δ C 25.77, and δ C 93.39) for the ACR group in the 13 C NMR spectrum, and the data were similar to C3G−ACR in which one ACR group was attached at C-7 in the A-ring of C3G. In addition, another additional set of proton signals (δ H 2.81 m, 2H; δ H 2.03 m, 2H; δ H 5.80 m, 1H) for the ACR group in the 1 H NMR spectrum and another additional set of carbon signals (δ C 14.64, δ C 25.63, δ C 93.59) in the 13 C NMR spectrum for the ACR group were also observed.…”

“…We also discovered that there was one additional set of proton signals (δ H 2.71 m, 2H; δ H 2.16 m, 2H; δ H 5.86 m, 1H) for the ACR group in the 1 H NMR spectrum and one additional set of carbon signals (δ C 14.90, δ C 25.77, and δ C 93.39) for the ACR group in the 13 C NMR spectrum, and the data were similar to C3G−ACR in which one ACR group was attached at C-7 in the A-ring of C3G. In addition, another additional set of proton signals (δ H 2.81 m, 2H; δ H 2.03 m, 2H; δ H 5.80 m, 1H) for the ACR group in the 1 H NMR spectrum and another additional set of carbon signals (δ C 14.64, δ C 25.63, δ C 93.59) in the 13 C NMR spectrum for the ACR group were also observed. The key HMBC showed that the proton at δ H 2.81 was correlated with δ C 93.59 (C-16), δ C 25.63 (C-15), and δ C 112.62 (C-5′), implying that another ACR group was linked to the C-5′ position in the B-ring of C3G.…”

“…C3G and its adducts were analyzed in d 4 -methanol. 1 H and 13 C NMR data of C3G, C3G− ACR, and C3G−2ACR are listed in Table 1.…”

“…High-resolution mass spectrum (MS 1 ) of C3G−ACR, high-resolution mass spectrum (MS 2 ) of C3G−ACR, 1 H NMR spectrum of C3G−ACR, 13 C NMR spectrum of C3G−ACR, HSQC-NMR spectrum of C3G−ACR, HMBC-NMR spectrum of C3G−ACR, high-resolution mass spectrum of (MS 1 ) C3G−2ACR, high-resolution mass spectrum (MS 2 ) of C3G−2ACR, 1 H NMR spectrum of C3G−2ACR, 13…”

“…Its harm to human health is directly reflected in a variety of common chronic diseases, such as Alzheimer’s disease, Parkinson’s disease, diabetes, and cardiovascular diseases . An increasing number of studies have reported that ACR exists in alcohol, wine, beer, and alcoholic beverages that mainly come from microbial fermentation. − In the brewing process, lactobacillus strains with glycerol dehydrase convert glycerol, the third largest product of yeast in the process of alcohol fermentation, second only to ethanol and carbon dioxide, through anaerobic fermentation to 3-hydroxypropanal, which is then dehydrated to produce ACR . Ferreira found that ACR existed in all four stages of wine-making (grape, must, fermentation, and wine), and the advancement of the degree of ripeness and increasing the grape maceration time seemed to result in higher concentrations of ACR .…”