Sodium quantitation in soft drinks: A rapid methodology by qNMR.

High sodium dietary intake has a positive association with an increase in blood pressure and can be correlated with risk factors of disease. Considering that the World Health Organization recommends a sodium intake lower than 2 g day-1 for adults, the hidden sodium content in processed foods is an important factor that compromises the assessment of a healthy diet. Accordingly, the present paper aimed to quantitate the sodium content of conventional soft drinks and their diet versions using nuclear magnetic resonance spectroscopy as a quantitative analytical technique (23 Na qNMR). The results show one free sodium signal (Na+ ) displayed as a singlet at 0 ppm in the 23 Na NMR spectrum, making its quantitation highly specific. This signal alone was used to directly determine the concentration of sodium in soft drinks. Flame photometry analysis was used to validate the method, and an excellent linearity was found in qNMR analysis (r = 0.9994) in comparison with flame photometry (r = 0.9958). In addition, a good correlation was found between sodium concentrations obtained by 23 Na NMR and flame photometry in the evaluated commercial soft drinks. Since the intensity of the resonance line is directly proportional to the number of nuclei (spins), the concentration of sodium in soft drinks can be determined via this straightforward method without the need for external calibration. The experimental acquisitions are fast (approximately 15 min), allowing the analysis of several samples in a short period of time. This is a novel alternative for sodium quantitation using an efficient NMR methodology.

NMR-based and chemometric approaches applicable to adulteration studies for assessment of the botanical origin of edible oils.

The health benefits of edible oils, especially promoted by ω3 and ω9 fatty acids, have been associated with their botanical origin. In order to investigate fatty acid profiles, we assessed Brazil nut, chia, linseed, sesame (toasted and raw), and soybean oils by 1H nuclear magnetic resonance (1H NMR) and chemometrics. PCA plots revealed important relationships between chemical composition and botanical origin for reference and commercial samples. Strong evidence of commercial Brazil nut oil adulteration was confirmed using a spiking procedure. Our findings show that NMR and chemometrics are successful tools for correlating fatty acid profile with botanical origin, which can be suitable for detecting sample adulteration.

Linseed, Baru, and Coconut Oils: NMR-Based Metabolomics, Leukocyte Infiltration Potential In Vivo, and Their Oil Characterization. Are There Still Controversies?

Different fatty acid proportions produce potential inflammatory and metabolic changes in organisms. However, the evidence for how each fatty acid mediates the metabolic pathway, and its lipid stability remains controversial. To resolve this controversy, the present study investigated the metabolic effects of cold-pressed linseed (LG), coconut (CG), and baru (BG) oils in comparison to those of soybean oil (SG) in mice, in terms of their oil characterization and stability. The quality analysis showed less oxidative behavior among PUFA-rich oils (SO, BO, and LO, with induction periods lower than 2 h compared to 39.8 h for CG), besides the high contents of tocopherols and carotenoids in SG and LG. In the experimental study, CG presented higher triglyceride (257.93 ± 72.30) and VLDL-cholesterol levels (51.59 ± 14.46, p < 0.05), while LG reduced LDL levels (59.29 ± 7.56, p < 0.05) when compared to SG (183.14 ± 22.06, 36.63 ± 4.41 and 131.63 ± 29.0, respectively). For visceral fats, the adiposity index was lower for BG (7.32 ± 3.13) and CG (9.58 ± 1.02, p < 0.05) in relation to SG (12.53 ± 2.80), and for leukocyte recruitment, CG presented lower polymorphonuclear (PMN) (p < 0.0001) and mononuclear (MN) (p < 0.05) cell infiltration, demonstrating anti-inflammatory potential. In NMR-based metabolomics, although CG presented higher values for the glucose, lactate, and LDL/VLDL ratio, this group also evidenced high levels of choline, a lipotropic metabolite. Our study emphasized the controversies of saturated fatty acids, which impair serum lipids, while alfa-linolenic acid presented cardioprotective effects. However, coconut oil also has a positive immunomodulatory pathway and was found to reduce visceral bodyfat in mice. Therefore, for future applications, we suggest a combination of lauric and al-fa-linolenic acid sources, which are present in coconut and linseed oil, respectively. This combination could be less obesogenic and inflammatory and exert cardioprotective action.