M. N. Uddin*
BCSIR Laboratories Dhaka, Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka-1205, Bangladesh
R. Ara
Department of Food Engineering and Tea Technology, Shahjalal University of Science and Technology, Sylhet-3114, Bangladesh
M. Motalab
Institute of Food Science and Technology (IFST), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka-1205, Bangladesh
A. N. M Fakhruddin
Department of Environment Science, Jahangirnagar University, Dhaka-1342, Bangladesh
B. K. Saha
Institute of Food Science and Technology (IFST), Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka-1205, Bangladesh
Mango varieties; Artificial neural network; Linear discriminant analysis
BCSIR Laboratories Dhaka, Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka-1205, Bangladesh
Postharvest and Agro-processing
Sample collection Nine popular varieties of mango available in Bangladesh such as, Gopalbhog, Langra, Fazlee, Tosha, Khersapat, Aamrupali, Mollika, Kohitor and Himsagor were collected from local markets of Dhaka City during pick days of their seasons. Nine samples from each variety were taken and thus 81 samples were used finally in the study. Measuring parameters The collected mangoes were washed with de-ionized water, pilled and pulps were taken. Nutritional properties of these mango pulps were determined at Fruit Technology Research Laboratory of Institute of Food Science and Technology (IFST) under Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka by using suitable instruments for measuring different parameters. Finally, 18 physico-chemical properties of the mango pulp samples were measured, and they are Edible portion, Moisture content, pH, Titratable acidity, Total Soluble Solids (TSS), Total sugar, Reducing sugar, Ash, Vitamin C, Total Protein, Total Fat, Crude fibre, Total energy, Total carbohydrate, Sodium (Na), Potassium (K), Calcium (Ca) and Magnesium (Mg). Dimension reduction by Factor Analysis (FA) All parameters are not equally important for classification of mango to their varieties. So dimension of the data could be reduced by selecting comparatively more important parameters of mango pulps. In order to reduce the dimensionality of a dataset, FA is very popular and powerful technique. In most of the scientific research variable are large in number and are correlated. It is very often necessary to reduce the dimensionality of the dataset retaining the variability presented in it as much as possible and with a minimum loss of information (Hair et al,1998). This reduction is achieved by transforming the dataset into a new set of variables-factors, which are orthogonal (non-correlated) and are arranged in decreasing order of importance. FA can be expressed as Fi=a1xij+a2x2j+...+amxm Where Fi= factor, a= loading, x= measured value of variable, i= factor number,j = sample number, m= total number of variables Before dimension reduction by FA, it is necessary to test sample adequacy by Kaiser-Mayer-Olkin (KMO) test and Sphericity test for assess eligibility of using FA. Then factors are extracted. Next, rotation of the extracted factors are performed to choose comparatively more important variable and thereby dimensionality of dataset is reduced. Finally, these selected variables are used for further application of chemometric techniques. Artificial neural network (ANN) ANN is a mathematical representation inspired by the human brain, and has an ability to adapt on the basis of the inflow of new information. Mathematically, ANN is a non-linear optimization tool. The ANN is especially suitable for classification and is widely used in practice. The network consists of one input layer, one or more hidden layers and one output layer, each consisting of several neurons. Each neuron processes its inputs and generates one output value that is transmitted to the neurons in the subsequent layer. Initially, a weighted sum of inputs is calculated at each neuron: the out put value of each neuron in the proceeding network layer times the respective weight of the connection with that neuron.
Bangladesh J. Sci. Ind. Res.51(4), 253-260, 201
Journal