Liquid-state NMR spectroscopy was used to follow the compositional changes in mango juice during ripening, whereas MAS and HR-MAS techniques enabled resolved (13)C and (1)H NMR spectra of mango pulps to be recorded. Spectral assignment enabled the identification of several organic acids, amino acids, and other minor components, and the compositional changes upon ripening were followed through the changes in the spectra. In pulps, sucrose was found to predominate over fructose and glucose at most ripening stages, and citric acid content decreased markedly after the initial ripening stages while alanine increased significantly. Other spectral changes reflect the complex biochemistry of mango ripening and enabled the role played by some compounds to be discussed. Some differences observed between the composition of juices and pulps are discussed. This work shows that NMR spectroscopy enables the direct characterization of intact mango pulps, thus allowing the noninvasive study of the overall biochemistry in the whole fruit.
High‐field (11.7 and 14 T) proton high‐resolution NMR spectra of apple juices obtained from a variety of cultivars are reported and partial spectral assignments are made. There are significant spectral differences between cultivars, which may be of value in identifying the origins of apple juices. The results also indicate that the method is likely to be of value in the authentication of fruit juices. Careful spectral analysis shows that some differences arise simply as a result of the differences in the pH of the juices and that microbiological and oxidative effects must be taken into account. Care must therefore be exercised in the application of multivariate methods to the data as spurious or trivial correlations may be obtained. It is concluded that the richness of the spectra and the ease with which they may be obtained indicate that high‐field proton NMR will prove valuable not only in speciation and authentication studies, but also in the analysis of biochemical changes occurring in fruits and their juices. © 1997 John Wiley & Sons, Ltd.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.