Nuclear Magnetie Resonance Spectroscopy in Dairy Science Ankit GoYal*, Neelam UPadhYaY *Dairy Chemistry Division, National Dairy Research Institute Karnal- 132001, Haryana, India *E-mail: ankit'ndri@gmail'com Abstract Nuclear magnetic resonance (NMR) spectroscopf is a powerful analytical techniquewith a wide varietyof applications. lt may be used for complexstructural studies, for protocol or process development, or as a simple q u a l i t y assay for which structural informationis imoortant. lt is nondestructive, non-invasive and high- quality data may be obtained from milligram, even microgram, quantities of sample. lt is based upon the principle of resonance by atomsnuclei and mostcommon n u c l e i u s e d are r H, r rC and r1P. Whereas other spectroscopy techniques may be usedto determine the nature of the functional groups present in a sample, only NMR spectroscopy can provide the data necessary to determine the complete structure of a molecule.NMR techniouecan be used to determine moistureand fat content in dairy products, cheese and fruits etc. lt also can be used to monitor process on-line, various metabolic changes duringrigormoftis, ripening of fruits and cheese, fermentations and other unit operations like dehydration etc. Major applications of NMR spectroscopy are in clinicaland pharmaceutical companies for drugs and diagnostic purpose; but now in food industries alsoit has various applications in food analysis, authentication and quality control of food stuff. lntroduction Laboratory analysis of food quality involves extensive Preparation procedures, during which foods are severely disturbed by sizereducing, Deforming or dilution steps, Unlike the way in which food consumers evaluate the food produces(Consumed while their integrity is generally intact)One may therefore ask:Are the current chemical and physical methods for food quality measurement reliable ? Naturally it would be desirable to analyze food quality in a completelynondestructive and noninvasive way by the nuclear magnetlc resonance technioue. NuclearMagnetic Resonance (NMR) Technique Include NMR Spectroscopy and NMR imagingor more frequentlytermed magnetic resonance lmaSlng (MRl).Can be used to nondestructively and noninvasively s t u d y the chem ical and physical properties and phenomena, anatomical structure, and dynamic processes of food materials and products. Measures the absorption of eleclromagnetic radiation in the radiofrequency region of roughly 4MHz to Z50MHz. Nuclei of the atom is involved ratherthan outer electrons as in case of UV, Visibleand lR Spectroscopy. ln orderto cause nucleito absorb radiationit is necessary to expose the sample containing nuclei of interest to a magnetic field. The magnetic field has the effect of developing the energy slates required for alltorplionto occur. Basic Principles of NMR Spectroscopy Basedon the Principle of Resonance. Certain Nuclei posses the property called spin is considered as spinning about an axis, this Spinning generates .l mag,netic field, known as magnetic moment' Like magnet bar,this magnetic moment hasa north and a southpole calleda nuclear magnetic dipole. Spin quantum number | + 0 : Net spin associated with the protons and neutrons (odd mass) Nuclei Unpaired UnPaired sPin I Protons neutrons I 2H , '* I :l;r :,, , " :_ lndian Food lndustry r 31(1),Jan-Feb 20.2@1