Hadi K. Purwadaria

Near Infrared Reflectance Testing to Predict Sucrose and Malic Acid Concentrations of Mangoes

Abstract Mangoes classification (Mangifera indica, var. gedong) into their tastes, sweet, sweet-sour and sour, commonly judged by aroma and experiences, is becoming increasingly difficult due to consumer demands on a prime quality guarantee. The near infrared diffuse reflectance system was developed and applied to 200 mango samples at the wavelength ranged from 1 400 to 1 975 nm. The Stepwise method was utilized in selecting the optimal NIR wavelengths for the sucrose and the malic acid of the samples measured by the HPLC analysis. The parameters were integrated to the calibration equations expressing the relationship between the NIR prediction and the measured sucrose and malic acid displaying agreeable correlation.

Ultrasonic system for automation of internal quality evaluation of durian

Abstract An investigation has been carried out to determine the relationship of the physico-chemical properties of durian meat ( Durio zibethinus Murr): the firmness and the sugar content with its ultrasonic properties. For this purpose, a measurement system based on the ultrasonic method was developed and controlled by a PC computer. The objective of the research is to develop a nondestructive method for the quality evaluation of whole intact durian by the ultrasonic method. Three kinds of ultrasonic transducer (1 MHz, 500 kHz, and 50 kHz) were tested for measuring the transmission characteristics of the durian meat. The test results revealed that the ultrasonic wave capable to be transmitted into the durian meat was the one with 50 kHz. There was a significant relationship between the ultrasonic wave transmission at 50 kHz with the meat firmness, as well as with the meat sugar content.

Infrared and Raman studies on polylactide acid and polyethylene glycol-400 blend

As a biodegradableplastic, polylactideacid (PLA) can be blended with polyethylene glycol (PEG) to form a polymer blend because PEG has a good miscibility with PLA. Furthermore, this paper study the functional groups of PLA-PEG400 blend using direct casting to produce matrix film. Fourier Transform Infrared (FTIR) and Raman spectroscopy was used to identify alteration of functional group PLA-PEG400 blend. Absorbance and frequency wavenumber were used to observe any changing among functional group. In general, PLA-PEG blend did not produce a new configuration or chemical properties although some functional groups tended to decrease. PLA-PEG400 film spectra showed a similaritycompared to those of neat PLA because of each pristine polymer. However, FTIR and Raman investigated reducing carbonyl group of PLA with PEG400 addition and followed improving CH-COC bonding. Methyl group represented CH3symmetricchanged both the shift and absorbance.FTIR and Raman spectroscopy observed increasing hydrogen bonding with i...

Model for Predicting and Classifying Durian Fruit Based on Maturity and Ripeness Using Neural Network

Abstract This study was aimed to develop the model to predict the maturity, ripeness and defects of durian based on its physical and chemical characteristics by using the neural network. The density and acoustic characteristics measurement was fed into the model as the inputs, which provided the levels of maturity and ripeness as the output. Data training were tested to models of neural network with various nodes in the hidden layer, i.e., 4, 6, 8, and 10 nodes. The results recommended the use of 6 nodes in the hidden layer that would provide the highest accuration of 100 % in classifying the durian based on its maturity and ripeness.

Determination of Acoustic Properties of Durian Fruit

Abstract The objective of the research is to determine acoustic properties of durian ( Durio zibethinus Murr.) cv Sunan by ultrasonic method. Twelve mature durians of (95±3) days after fullbloom and 12 immature durians of (70±3) days after fullbloom were used to determine the velocity and the attenuation. For this proposes, a measurement system based on ultrasonic method was developed and controlled by a PC computer. The experimental apparatus for measuring the transmission of the ultrasonic wave was developed consist of 1) an ultrasonic tester, 2) a transmitter and receiver transducer (50 kHz), 3) an analog oscilloscope, 4) a digital oscilloscope, 5) an A/D converter and 6) a personal computer. A low frequency (50 kHz) ultrasonic was used and placed underwater to transmit and receive ultrasound signal. The ultrasonic signal transmitted through the durian fruit sampled and displayed on the digital oscilloscope. An interface PC Lab Card was used to transfer the signal stored in the digital oscilloscope to the PC computer. The power spectra were obtained by means of Fast Fourier Transfonn (FFT) techniques. The attenuation calculated with formula A x = A 0 e -αx and the velocity calculated by formula V = (Δt - L/V water )/L . The result shows that mature durian had attenuation of 0.521 dB/cm and the immature one was 0.311 dB/cm. The velocity of mature durian was 423.49 m/sec and the immature one was 538.64 m/sec. The relationship between velocity and quality indices were linear (r 2 = 0.82 for firmness and r 2 = 0.73 for sugar content). The relationship between attenuation, and quality indices seems to be exponential with r 2 = 0.83 for firmness and r 2 = 0.73 for sugar content.

Classification of Mango by Near Infrared Diffuse Reflectance: Comparison of Methods Used in Predicting the Sugar and Acid of Mango

Abstract The classification of mango (Mangifera indica var. gedong) into their taste, sweet, sweet-sour, and sour which were traditionally judged by aroma and experiences is becoming increasingly more difficult due to the cross breeding and to the Internationals consumer demand. The NIR system was developed and applied to 200 mango samples at the wavelength range from 1400 - 2000 nm. The samples were separated into two main group i.e. calibration data and validation data. The stepwise method was used to select the best wavelength for calibration equation. This calibration equation was then validated using the second data and also compared with the Principal Componen Analysis (PCA)of the selected samples. It was found that the standard error of prediction (SEP) of the validation data either using the multiple regression or PCA shows an agreeable correlation.

Neural Network Application on Non-Destructive Evaluation of Lanzone Using Visible Light

Abstract A neural network model using 4 nodes in the hidden layer and 6000 iterations was applied to predict the weight of lanzone seeds in the fruit, thus, classifying the seedless from the seed ones. Inputs fed to the model were the wholefruit weight, the diameter and the transmittance intensity ratio of visible light passing through the fruits. The output was the weight of lanzone seeds inside the pulp. The model successfully predict the weight of the lanzone seeds with a determinant coefficient of 0.86.

Computer controlled on-line system for mango grading using image and NIR measurement

Abstract The objective of this study is to develop an on-line system, run by a computer controlled input, to classify the mangoes based on their size, colour and taste by implementing the image processing and NIR sensors The on-line system to classify mangoes on their size, colour and taste by applying non-destructive methods has been developed. The system is integrally constructed from various components computer control subsystem, electro-optical sensors, transportation device of fruits, and sorting mechanism. The electro-optical sensors consist of image processing to grade the size and colour of mangoes and the NIR to select mangoes based on their taste. The results indicate that the system has above 90% accuracy in sorting out mangoes by size and colour, and above 70% accuracy in classifying mangoes into four different tastes sweet-sour, sweet, sour and bland