Determination of five alcohol compounds in fermented Korean foods via simple liquid extraction with dimethyl-sulfoxide followed by gas chromatography-mass spectrometry for Halal food certification

Determination of alcohols in various fermented food matrices using gas chromatography-flame ionization detector for halal certification

In this study, an analytical method for the determination of alcohols by gas chromatography-flame ionization detection was applied to fermented foods. The limit of detection and limit of quantitation were 0.79 and 2.40 mg/kg for methanol, 0.55 and 1.66 mg/kg for ethanol, 0.51 and 1.56 mg/kg for n-propanol, 0.35 and 1.05 mg/kg for n-butanol, and 0.38 and 1.16 mg/kg for n-pentanol, respectively. The recoveries from the matrices of gochujang, soy sauce, and kimchi were 93.80-102.03%, 93.27-99.69% and 89.06-102.17%, respectively, and the corresponding intra- and inter-day relative standard deviations were below 5.33%, 5.35% and 4.10%. In 95 fermented foods, ethanol showed the highest mean, median and maximum values among the five alcohols. The detection rate of ethanol was 86.3% among all samples and 100% in gochujang and gochujang-based sauces. A total of 22 samples had an alcohol content above 0.5%, of which 16 were gochujang.

Adoption of analytical technologies for verification of authenticity of halal foods - a review

Halal authentication has become essential in the food industry to ensure food is free from any prohibited ingredients according to Islamic law. Diversification of food origin and adulteration issues have raised concerns among Muslim consumers. Therefore, verification of food constituents and their quality is paramount. From conventional methods based on physical and chemical properties, various diagnostic methods have emerged relying on protein or DNA measurements. Protein-based methods that have been used in halal detection including electrophoresis, chromatographic-based methods, molecular spectroscopy and immunoassays. Polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) are DNA-based techniques that possess better accuracy and sensitivity. Biosensors are miniatured devices that operate by converting biochemical signals into a measurable quantity. CRISPR-Cas is one of the latest novel emerging nucleic acid detection tools in halal food analysis as well as quantification of stable isotopes method for identification of animal species. Within this context, this review provides an overview of the various techniques in halal detection along with their advantages and limitations. The future trend and growth of detection technologies are also discussed in this review.

A novel colorimetric indicator for ethanol detection in preserved baby mangoes

A colorimetric indicator cube for use in smart packaging was designed and fabricated to detect ethanol produced by microbial fermentation in preserved baby mangoes. The presence and level of ethanol was indicated by color variations of the indicator cube, which consists of porous melamine foam (MF) that entraps an indicator solution of potassium dichromate and sulfuric acid. Within the packaging, the cube sits behind a gas-permeable membrane. The morphological structure of MF was studied by digital microscope and X-ray fluorescence analysis. In the optimal condition, the indicator cube exhibited distinct color changes from yellow to brown, green and blue over an ethanol concentration range from 0.25% to 5.0%. Color changes were clearly visible to the naked eye. The repeatability of the ethanol indicator cube was good and storage stability was maintained for up to 19 and 74 days at room and refrigeration temperatures, respectively. The smart packaging was applied to detect ethanol in preserved baby mangoes at different storage times.

Recent advances in halal food authentication: Challenges and strategies

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.

Effect of Alternative Preservatives on the Quality of Rice Cakes as Halal Food

The halal food market is steadily increasing. The use of alcohol for any reason is strictly prohibited in halal foods; however, ethanol is widely used as a preservative for commercial rice cakes (tteok). The purpose of this study was to investigate the use of natural substances as alternative preservatives for rice cakes. Four different solutions were tested: distilled water (control), ethanol, grapefruit seed extract (GSE), and a mixture of citric extracts and organic acids (MCO). We investigated the total plate count (TPC), yeast and mold counts, color, texture profile assays (TPA), and sensory evaluation. Significant reductions of 3.65 log CFU were observed in TPC in rice cake treated with MCO solution after 28 days of storage. However, mold and yeast counts were only reduced by ethanol treatment. Among the physical texture properties analysis, hardness was maintained for the 28 days in all samples. The total color difference values (ΔE) revealed no significant color changes in any rice cake compared to the controls. The ethanol-treated rice cake scored the lowest for overall preference and desired hardness.

Determination of ethanol in foods and beverages by magnetic stirring-assisted aqueous extraction coupled with GC-FID: A validated method for halal verification

An in-house method, employing magnetic stirring-assisted aqueous extraction combined with gas chromatography-flame ionization detector, for determination of ethanol in different foods and beverages was validated according to the ISO/IEC 17025 standard. Validation parameters, including selectivity, method limits of detection (approx. 0.006 mg/g) and quantification (approx. 0.02 mg/g), linearity (R² of >0.999), trueness (relative biases of <3%), accuracy (recoveries of 96-105%), and precision (relative standard deviations of <5%), were satisfactory. The proposed method was as accurate and precise as and more sensitive than the AOAC method 2016.12, with estimated relative expanded uncertainties of around 8% for all samples. The validated method was successfully applied for determination of ethanol in 108 commercially processed foods and beverages, and it could be used for halal verification. Accordingly, this study provided a reliable method for routine quantitative analysis of ethanol in processed foods and beverages to ensure their halal integrity prior to halal certification.