Quantification, Correlation and Hierarchical Cluster Analysis of the Mineral Content Data of Citrus Fruit Varieties

Abstract

Citrus fruits are widely grown and consumed all over the world. Their health benefits are highly cherished as well. However, how varied and similar are the varieties of citrus fruits remain a contentious issue in quality control of processed citrus fruits drinks. Triplicates of twelve samples containing six citrus fruits varieties were collected. The varieties were peeled and prepared as both juice and whole edible portion. The samples were digested with nitric acid and hydrogen peroxide. Flame Emission Photometer and Atomic Absorption Spectrometer were used to determine the mineral elements. Physical, sensory and physicochemical studies were also conducted. The result shows that all the varieties recorded the presence of the mineral elements in the following ranges: Na (1.09-15.30); K(9.87-37.28); Ca(1.83-3.65); Mg(2.14-4.41); Fe(4.98-13.60); Mn(1.84-3.72); Cu(1.82-3.70); Zn(2.06-4.63 mg/100g). The dendrogram of the hierarchical cluster analysis derived from 2 principal components with cumulative variance of 92.36%, classifies citrus into three groups based on elements signatures. The grapefruit pair of Duncan (edible portion) and Pumelo (juice) is found to be closest substitute. There are prominent mutual correlations between density and colourimetry as well as sensory taste and conductivity. The hierarchical cluster analysis characterized the parameters that are peculiar to citrus species. This characterization is invaluable in quality control and authenticity monitor in processed fruit drinks.