The book composed of importance of calcium citrate and its percentage yield from different varieties of citrus fruits. The comparison between the percentage yield of calcium citrate and volatile is present in it. Hydrodistillation method has been opted for the extraction of volatile oil from the citrus lemon, orange and sweet orange. Further, the importance of plants and their extract as an antimicrobial has also been reported. The book in future is mean to help for researcher to work on such projects.