NMR investigations for a quality assessment of Italian PDO saffron (<i>Crocus sativus</i> L.)

High-resolution NMR spectroscopy was employed to analyze Italian Protected Designation of Origin (PDO) saffron from L'Aquila, S. Gimignano and Sardinia and commercial saffron samples available on the Italian market. An extensive resonance assignment of DMSO saffron extract was reported, including glucose and gentiobiose in bound and unbound form for the first time. A multivariate statistical analysis of NMR data led to a clustering of samples by performing unsupervised PCA. OPLS-DA model was successively performed to highlight the markers responsible for this discrimination. An analysis of the corresponding S-plot indicated that picrocrocin and crocins were the most relevant compounds for characterizing Italian PDO saffron. By contrast, commercial saffron barely contained these characteristic compounds, and they were primarily enriched in fatty acids

NMR-based metabolic profiling of different yeast fermented apple juices

NMR based metabolic profiling was used to investigate metabolic changes in ciders fermented by yeast species as valuable tool for the identification of metabolites responsible for yeast activities. 1H NMR spectra of apple ciders produced by Saccharomyces cerevisiae EC1118, Torulaspora delbrueckii TD291, Starmerella bacillaris YR21, Hanseniaspora osmophila HO16, Hanseniaspora uvarum Y4M, and Saccharomyces uvarum SU3, revealed to be dominated by glycerol and organic acids signals. The aromatic region showed the presence of low intense signals referred to epicatechin, catechin, chlorogenate, xanthine, uracil, tyrosol, fumarate, histamine, and histidine. The anomeric region showed signals related to xylose, arabinose, glucose, fructose and sucrose. Finally, in the aliphatic region, signals due to amino acids like alanine, aspartate, asparagine, isoleucine and threonine, organic acids like acetate, lactate, malate, pyruvate, quinate, succinate, and alcohols like 2,3 butanediol, ethanol, and glycerol and sterol were detected. Principal component analysis performed considering NMR data from either all spectral regions and only aromatic region revealed the potentiality to discriminate the yeast action. Signals due to glucose, fructose, glycerol, malate, fumarate, tyrosol, histidine, and histamine resulted discriminant for sample differentiation. This study, the first one by NMR, provides preliminary insights on the metabolic differences among yeast species involved in cider production

NMR-Based Metabolomic Study on <i>Phaseolus vulgaris</i> Flour Fermented by Lactic Acid Bacteria and Yeasts

In recent years, fermented foods have attracted increasing attention due to their important role in the human diet, since they supply beneficial health effects, providing important sources of nutrients. In this respect, a comprehensive characterization of the metabolite content in fermented foods is required to achieve a complete vision of physiological, microbiological, and functional traits. In the present preliminary study, the NMR-based metabolomic approach combined with chemometrics has been applied, for the first time, to investigate the metabolite content of Phaseolus vulgaris flour fermented by different lactic acid bacteria (LAB) and yeasts. A differentiation of microorganisms (LAB and yeasts), LAB metabolism (homo- and heterofermentative hexose fermentation), LAB genus (Lactobacillus, Leuconostoc, and Pediococcus), and novel genera (Lacticaseibacillus, Lactiplantibacillus, and Lentilactobacillus) was achieved. Moreover, our findings showed an increase of free amino acids and bioactive molecules, such as GABA, and a degradation of anti-nutritional compounds, such as raffinose and stachyose, confirming the beneficial effects of fermentation processes and the potential use of fermented flours in the production of healthy baking foods. Finally, among all microorganisms considered, the Lactiplantibacillus plantarum species was found to be the most effective in fermenting bean flour, as a larger amount of free amino acids were assessed in their analysis, denoting more intensive proteolytic activity

GC-MS based metabolomics and NMR investigations of formula milk

Breast milk (BM) is the gold standard in neonatal nutrition. When BM is not available, it can be substituted or integrated with commercial infant formulas, sold under different brands and formulations. The low-molecular-weight hydrophilic compounds in various formula milk (FM) brands and BM samples were analyzed by GC-MS and multivariate statistical data analysis. Results highlighted that FM formulations, besides being strongly different from BM, are diverse especially in regard to the addition of oligosaccharides and other nutrients. Moreover, the 1H NMR spectra of the aqueous and of the lipid fractions of FM samples exhibited differences due to the diverse formulations. Strengths and weaknesses of the two analytical approaches will be discussed also in the light of the nutritional reports

NMR Methodologies in Food Analysis

Nuclear Magnetic Resonance (NMR) methodologies offer a comprehensive characterization of foodstuffs owing to the possibility to study a sample from different points of view including structural, compositional, functional, morphological etc. aspects. High resolution NMR spectroscopy applied to semi-solid food samples or to extracts in solution is used to determine the foodstuff composition. Here, some features of high resolution NMR methodologies related to food analysis such as quantitative analysis, chemometrics, and use of databases are included. Other NMR methodologies such as relaxometry and imaging described in this chapter give precious information regarding morphology and texture of intact food samples

NMR Applications in Food Analysis: Part B

Applications of low-field NMR relaxometry and NMR-imaging in the analysis of food samples are described using examples of different food matrices and different problems related to food processing, maturation and ageing, authenticity, shelf-life, perishability, etc

Chapter 5. NMR methodologies in food analysis

Nuclear Magnetic Resonance (NMR) methodologies offer a comprehensive characterization of foodstuffs owing to the possibility to study a sample from different points of view including structural, compositional, functional, morphological etc. aspects. High resolution NMR spectroscopy applied to semi-solid food samples or to extracts in solution is used to determine the foodstuff composition. Here, some features of high resolution NMR methodologies related to food analysis such as quantitative analysis, chemometrics, and use of databases are included. Other NMR methodologies such as relaxometry and imaging described in this chapter give precious information regarding morphology and texture of intact food samples

NMR applications in food analysis. Part B

Applications of low-field NMR relaxometry and NMR-imaging in the analysis of food samples are described using examples of different food matrices and different problems related to food processing, maturation and ageing, authenticity, shelf-life, perishability etc