Increasing public awareness of food quality and safety has prompted a rapid increase in food authentication of halal food, which covers the production method, technical processing, identification of undeclared components, and species substitution in halal food products. This urges for extensive research into analytical methods to obtain accurate and reliable results for monitoring and controlling the authenticity of halal food. Nonetheless, authentication of halal food is often challenging because of the complex nature of food and the increasing number of food adulterants that cause detection difficulties. This review provides a comprehensive and impartial overview of recent studies on the analytical techniques used in the analysis of halal food authenticity (from 1980 to the present, but there has been no significant trend in the choice of techniques for authentication of halal food during this period). Additionally, this review highlights the classification of different methodologies based on validity measures that provide valuable information for future developments in advanced technology. In addition, methodological developments, and novel emerging techniques as well as their implementations have been explored in the evaluation of halal food authentication. This includes food categories that require halal authentication, illustrating the advantages and disadvantages as well as shortcomings during the use of all approaches in the halal food industry.

Abstract:In this work we have examined the use of plasticiser-free polymeric films incorporating a proton selective chromoionophore for optical pH sensor. Four types of methacrylic-acrylic copolymers containing different compositions of n-butyl acrylate (nBA) and methyl methacrylate (MMA) were synthesised for use as optical sensor films. The copolymers were mixed with appropriate amounts of chromoionophore (ETH5294) and a lipophilic salt before spin coated on glass slides to form films for the evaluation of pH response using spectrophotometry. Co-polymer films with high nBA content gave good response and the response time depended on the film thickness. A preliminary evaluation of the optical films of high nBA content with pHs from 2 -14 showed distinguishable responses from pH 5 -9. However, the adhesion of the pH sensitive film was good for copolymers with higher content of MMA but not for films with high nBA.

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This research focus on transforming the traditional design of reference electrode into all-solid-state reference electrode front-end using Ag/AgCl screen-printed electrodes. By replacing the internal reference solution of a traditional reference electrode by a solid photocurable membrane, an all-solid-state reference electrode can be achieved. The solid-state screen-printed reference electrode was designed using a photocurable acrylic film containing immobilized sodium tetrakis [3,5-bis(trifluoromethyl)phenyl] borate (NaTFPB) and trimethylocthylammonium chloride (TOMA-Cl). An optimum ratio of NaTFPB:TOMA-Cl = 1:1 produced a stable reference electrode. In the anions interference studies, all anions i.e. NO 3 -, Cl -, Br -and SO 4 2-does not give effect to the SPRE except perchlorate anions. The all-solid-state reference electrodes was applied to the detection of potassium ions and ammonium ions. Validation of the all-screen-printed reference electrode was performed with reference electrode standard gel type. The validation results showed that all-solid-state screenprinted reference electrode demonstrated performance that was comparable to standard reference electrode.

In this study, the effect of poly(vinyl pyrrolidone) (PVP) additive on the fabrication of asymmetric nanofiltration (NF) membranes was investigated in terms of performance, structural details and key properties. On addition of PVP ranging from 2 to 10 wt% into the dope solution, the fabricated NF membranes exhibited significantly different in properties and improved performance. In particular, the membranes made from 2 wt% PVP had the highest water flux and salt rejection of about 3.61 × 10–6 m3/m2s and 44.49 %, respectively. Modeling results revealed that small amount of PVP (2–4 wt%) produced finer structural properties. Moreover, the key properties (rp, ∆x/Ak and ζ) of the fabricated NF membranes were found to be within the range of that of commercial NF membranes.