Polyurethane (PU) is a unique polymer that has versatile processing methods and mechanical properties upon the inclusion of selected additives. In this study, a freestanding bio-based polyurethane film the screen-printed electrode (SPE) was prepared by the solution casting technique, using acetone as solvent. It was a one-pot synthesis between major reactants, namely, palm kernel oil-based polyol and 4,4-methylene diisocyanate. The PU has strong adhesion on the SPE surface. The synthesized bio-based polyurethane was characterized using thermogravimetry analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy (FTIR), surface area analysis by field emission scanning electron microscope, and cyclic voltammetry. Cyclic voltammetry was employed to study electrocatalytic properties of SPE-polyurethane towards oxidation of PU. Remarkably, SPE-PU exhibited improved anodic peak current as compared to SPE itself using the differential pulse voltammetry method. Furthermore, the formation of urethane linkages (-NHC(O) backbone) after polymerization was analyzed using FTIR and confirmed by the absence of peak at 2241 cm-1 attributed to the sp-hydridized carbons atoms of C≡C bonds. The glass transition temperature of the polyurethane was detected at 78.1°C.

Histamine is an important substance that can be applied as a parameter for allergic reactions and food freshness. This study develops a method to produce a histamine sensor based on electrodes modified using polyurethane-LiClO4. A sensor method was developed where this sensor was produced from polyurethane. The application of 4,4′-diphenylmethane diisocyanate (hard compound) and palm kernel oil-based monoester polyol (soft compound) to produce polyurethane (PU) based on bio-polyol. The addition of lithium perchlorate (LiClO4) was done in order to increase the conductivity of PU. The oxidation process was detected using cyclic voltammetry, whereas the electrochemical impedance spectroscopy was used to analyze the conductivity of the polymer. The polyurethane-LiClO4 was attached on a screen-printed electrode (SPE) within 45 min. Moreover, the 1% LiClO4-PU-SPE presented satisfactory selectivity for the detection of histamine in the pH 7.5 solution. The LiClO4-PU-SPE presented a good correlation coefficient (R = 0.9991) in the range 0.015–1 mmol·L–1. The detection limit was 0.17 mmol·L–1. Moreover, the histamine concentration of mackerel samples was detected by the PU-SEP-LiClO4. Several amine compounds were chosen to study the selectivity of histamine detection using SPE-PU-LiClO4. The interference was from several major interfering compounds such as aniline, cadaverine, hexamine, putrescine, and xanthine. The technique showed a satisfactory selective analysis compared to the other amines. A satisfactory recovery performance toward varying concentrations of histamine was obtained at 94 and 103% for histamine at 0.01 and 0.1 mmol·L–1, respectively. The application of PU-SEP-LiClO4 as an electrochemical sensor has a great prospect to analyze histamine content in fish mackerel as a consequence of PU-SEP-LiClO4 having good selectivity and simplicity.

Biogenic amines generally can be found in fish due to amines in fish undergoing a degradation process. According to the United States Food and Drug Administration (FDA), biogenic amines in fish and fish products can cause harm to consumers if consumed more than 50 µg/mL. Thus, it is important to analyze them. Five biogenic amines such as heptylamine, histamine, tyramine, cadaverine and spermidine were extracted using soaking method with methanol 50% (v/v), afterward they were detected in fish and fish products using gas chromatography – flame ionisation detector (GC-FID) and the biogenic amines structures were confirmed using mass spectrometry (MS). The detection limits (DLs) were range at 1.20 – 2.90 µg/mL. Histamine was detected in fish and fish products such as sardine (Sardinella gibosa) and mackerel (Scomberomorus guttatus) at concentration of 5.96 and 2.69 µg/mL, respectively, whereas cadaverine was found in sardine (Sardinella gibosa) at concentration of 4.96 µg/mL. Histamine concentrations in this study were detected below 50 µg/mL which is below the permissible threshold associated with scombroid poisoing.

Bovine and porcine are poultry meat that consumed worldwide particularly in Southeast Asia.Both of them are prone to food counterfeit owing to several factors such as price, appetite and Halal status. Sensitive and selective analytical methods are required to control meat products that distributed to markets. This paper studied the sensitivity between real – time and conventional PCR or known as qPCR and cPCR, respectively. Bovine and porcine were samples used to verify the sensitivity of them. Nevertheless, those instruments did not show a specific difference during DNA analysis of bovine and porcine. In conventional PCR, two pairs of DNA primers targeted cytochrome b (Cyt b) was analyzed, resulting of 120 and 131 amplicons, respectively. While qPCR applied to analyze porcine and bovine DNA. The detection limit of qPCR after porcine and bovine analysis were at 0.004 and 0.007 µg/µL, respectively. Results demonstrated the qPCR was reliable for verifying porcine and bovine DNA compared to conventional PCR. Furthermore, the study concluded that the developed assay can be easily employed for the identification of porcine and bovine tissue in food products in low resource areas.

Weaning food is given as a complement to breast milk which is helpful for babies in the process of baby led weaning. At six months, the baby's digestive tract is able to digest some  food such as flour so baby can be introduced to solid food. Purple sweet potato has good nutrition such as carbohydrates, protein, fat, vitamins, minerals, and water. Ultrasound modification is considered easier, simpler, and safer because it does not use chemical additives. This research used a non-factorial completely randomized design (CRD) with one variable treatment and three replication. The variable was  the ratio of sweet potato ultrasound modified starch and rice flour (0%:100%; 20%:80%; 40%:60%; 60%:40%; 80%:20%; 100%:0%).  The result showed the ratio of sweet potato ultrasound modified starch and rice flour had significant effect on the chemical properties of instant weaning food.  The significant result was shown by formulation of sweet potato ultrasound modified starch 100%  and rice flour 0%  with moisture content 3.88%, ash 0.69%, protein 16.87%, fat 1.66%, and carbohydrates 76.88%.