A simple visual ethanol biosensor based on alcohol oxidase (AOX) immobilised onto polyaniline (PANI) film for halal verification of fermented beverage samples is described. This biosensor responds to ethanol via a colour change from green to blue, due to the enzymatic reaction of ethanol that produces acetaldehyde and hydrogen peroxide, when the latter oxidizes the PANI film. The procedure to obtain this biosensor consists of the immobilization of AOX onto PANI film by adsorption. For the immobilisation, an AOX solution is deposited on the PANI film and left at room temperature until dried (30 min). The biosensor was constructed as a dip stick for visual and simple use. The colour changes of the films have been scanned and analysed using image analysis software (i.e., ImageJ) to study the characteristics of the biosensor's response toward ethanol. The biosensor has a linear response in an ethanol concentration range of 0.01%-0.8%, with a correlation coefficient (r) of 0.996. The limit detection of the biosensor was 0.001%, with reproducibility (RSD) of 1.6% and a life time up to seven weeks when stored at 4 degrees C. The biosensor provides accurate results for ethanol determination in fermented drinks and was in good agreement with the standard method (gas chromatography) results. Thus, the biosensor could be used as a simple visual method for ethanol determination in fermented beverage samples that can be useful for Muslim community for halal verification.

The use of chemometrics to analyse infrared spectra to predict pork adulteration in the beef jerky (dendeng) was explored. In the first step, the analysis of pork in the beef jerky formulation was conducted by blending the beef jerky with pork at 5-80 % levels. Then, they were powdered and classified into training set and test set. The second step, the spectra of the two sets was recorded by Fourier Transform Infrared (FTIR) spectroscopy using atenuated total reflection (ATR) cell on the basis of spectral data at frequency region 4000-700 cm(-1). The spectra was categorised into four data sets, i.e. (a) spectra in the whole region as data set 1; (b) spectra in the fingerprint region (1500-600 cm(-1)) as data set 2; (c) spectra in the whole region with treatment as data set 3; and (d) spectra in the fingerprint region with treatment as data set 4. The third step, the chemometric analysis were employed using three class-modelling techniques (i.e. LDA, SIMCA, and SVM) toward the data sets. Finally, the best result of the models towards the data sets on the adulteration analysis of the samples were selected and the best model was compared with the ELISA method. From the chemometric results, the LDA model on the data set 1 was found to be the best model, since it could classify and predict 100 % accuracy of the sample tested. The LDA model was applied toward the real samples of the beef jerky marketed in Jember, and the results showed that the LDA model developed was in good agreement with the ELISA method.

A rapid immuno strip test was developed to provide visual detection of pork adulteration in processed meats. Gold nanoparticles was prepared and conjugated with anti-Swine IgG polyclonal antibody. A lateral flow immunosensor was developed, and then were used to test pork adulterated in processed meats, i.e. beef meatball samples. The simulated samples consisted of pork-in-beef meatball at the ratio of 0-100 (%w/w) adulteration levels that were extracted in phosphate-buffered solution. Pure beef meatball without pork was included as controls. The response time was completed in 5 min, after incubation time. Detection limit of the immunosensor strip was 0.1% (w/w). This immunosensor tests can be applied to detect low levels of pork adulteration in beef meatballs. The reliability of the assay was further investigated by comparing the results to those of commercially available ELISA kits. It was obtained that the correlation of two methods was excellent. Thus, the strip could provide a simple approach to detect pork adulteration in processed meats samples with high reliability.

Determination of Al(III) from aqueous samples using Chrome Azurol S (CAS) as reagent immobilized in polymer inclusion membranes (PIMs) was discussed. The PIMs was prepared using poly (vinyl chloride) (PVC), 2-nitrophenyl octyl ether (2-NPOE) and Aliquat 336 as polymer matrix, solvent and ion carriers respectively. Experimental designs for four factors (weight of PVC, Aliquat 336, 2-NPOE, and the concentration of CAS) were used for the optimization of the membrane fabrication. For this purpose, a two level half factorial design, which involves eight experiments, was adopted. The combination of 200 mg of PVC, 50 mg of Aliquat 336, 50 mg of 2-NPOE and 1 x 10(-3) mol/L CAS was found to be the optimum formulation for the preparation of PIMs. Wide dynamic range of Al(III) determination (0.2-50 ppm), better reproducibility within the same batch, good repeatability and photostability with RSD 1.21% and 0.93%, respectively. The calculated t values indicated that there is no significant difference between the two methods at the 95% confidence level and thus there is no bias in the method. (C) 2014 Elsevier B.V. All rights reserved.

The use of chemometrics to analyse near infrared (NIR) spectra to determine pork adulteration in beef meatball was developed. Since, the adulteration of pork in beef meatball is frequently occurring. This study was aimed to develop a fast and simple technique for the determination and quantification of pork adulteration in beef meatball using NIR spectra and chemometrics. Both partial least-squares (PLS) calibration and linear discriminant analysis (LDA) model were developed to determine pork adulteration in beef meatballs. The models using the first derivative spectra, accurately classified 100 % of the pork adulterated beef meatballs samples using training set and test set. The PLS and LDA models were subsequently used for the determination of pork adulteration in real beef meatball samples. The results showed that the PLS and LDA models developed were in good agreement with the immunochromatographic method. Therefore, the potential of NIR spectra and chemometrics as a rapid method for halal authentication and identification of pork adulteration in beef meatball have been successfully developed.