Diffraction is a phenomenon that exists commonly in everyday activities, but is often disregarded and taken for granted. Most of the techniques used for this purpose are based on theoretical studies. The simplest definition of diffraction is the irregularities caused when waves encounter an object. These results demonstrated that powder X-ray diffraction can be used as a diagnostic tool to quickly identify different forms of calcium lactate pentahydrate that may occur in Cheddar cheese. X-ray diffraction analysis is essential in studying stacking faults. Powder X-ray diffraction results were validated using enzymatic assays for lactate enantiomers. Furthermore, we collected crystals from the exteriors and interiors of Cheddar cheeses to demonstrate the ability of powder X-ray diffraction to differentiate between the 2 forms of calcium lactate pentahydrate crystals in Cheddar cheeses. Therefore, this report presents detailed data from the 2 diffraction patterns, which may be used to prepare 2 reference diffraction cards that differentiate calcium l-lactate pentahydrate from calcium dl-lactate pentahydrate. From the resulting diffraction patterns we determined that the existing reference diffraction card corresponds to calcium dl-lactate pentahydrate and that the other form of calcium lactate pentahydrate observed in cheese crystals corresponds to calcium l-lactate pentahydrate. However, the powder X-ray diffraction database currently contains only one reference diffraction card under the title “calcium lactate pentahydrate.” To resolve this apparent gap in the powder X-ray diffraction database, we generated diffraction patterns from reagent-grade calcium l-lactate pentahydrate and laboratory-synthesized calcium dl-lactate pentahydrate. We hypothesized that the 2 diffraction patterns corresponded to 2 enantiomeric forms of calcium lactate pentahydrate (L- and DL-) that are believed to occur in Cheddar cheese, based on previous studies involving enzymatic analyses of the lactate enantiomers in crystals obtained from Cheddar cheeses. During a preliminary study of crystals harvested from various Cheddar cheese samples, we observed 2 slightly different but distinct diffraction patterns that suggested that calcium lactate pentahydrate may be present in 2 different crystalline forms. According to this method, diffraction patterns are generated from a powdered sample of the crystals and compared with reference cards within a database that contains the diffraction patterns of known crystals. Recall incoming X-rays diffract from crystal planes: reflections must be in phase for a detectable signal spacing between hkl planes d q l q extra distance traveled by wave 2 i.e., for diffraction to occur, x-rays scattered off adjacent crystal planes must be in phase: 2 (Bragg’s Law is not satisfied) X-ray intensity (from detector) q. X-ray powder diffraction analysis of a silicon carbide-based ceramic - ScienceDirect Materials Letters Volume 49, Issue 2, June 2001, Pages 137-145 X-ray powder diffraction analysis of a silicon carbide-based ceramic A.LOrtizab FSnchez-Bajob F. Powder X-ray diffraction has been used for decades to identify crystals of calcium lactate pentahydrate in Cheddar cheese.
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