hplc

Mycotoxins in food and feed are important risk factor for public health. There are many test methods for determination mycotoxins in food and feed and their products. The most common mycotoxins test method is based on high-performance liquid chromatography, but depend on the matrix, it is essential to develop validated methods of analysis and detection of them in food products. This study evaluated two different detection methods for the determination and confirmation of ochratoxin A (OTA) in liquorice extract powder. The detection of OTA was accomplished with high-performance liquid chromatography (HPLC) combined with fluorescence detector and Liquid Chromatography with tandem mass spectrometry (LC-MS/MS). The results indicate that the LC-MS/MS method was more specific and sensitive for the analysis and confirmation of OTA in liquorice extract than HPLC method because of false positive in HPLC method in some sample. So to comply with OTA legislation and consumer health protection, improvements in OTA analytical methodology is essential.

Lactic acid bacteria (LAB) play a critical role in food fermentation. Gamma Amino Butyric Acid (GABA) is one of bioactive metabolites produced by LAB that pose significant impact on human health. The objective of this research was isolation and identification of probiotic bacteria from traditional daires in Iran and evaluation of their potential in GABA production.

In this research, 30 isolates of bacteria from traditional dairies (yogurt, dough, cheese and butter) were studied. To diagnose probiotic species, initial tests including gram staining, oxidase and catalase were performed. Additional verification studies on the approved isolated bacteria in the last step were included to acid, bile and pepsin and trypsin resistance, hemolysis inactivity and L-arginine hydrolysis. Probiotic bacteria were charcterized by 16SrDNA PCR approach. In addition, GABA concentration was detected by HPLC equipped with C18 column (150 mm× 4.6 mm × 0.5 µm) at 25°C and UV-VIS detector (λ = 338 nm). The mobile phases of sodium dihydroxy phosphate and acetonitrile/ methanol/water were used in gradient mode.

Among all isolated bacteria, six strains were gram-positive, catalase-negative and oxidase-negative that initially known as LAB. Two out of six LAB isolates with acceptable probiotic characteristics were selecetd based on supplemantary tests. Accordingly, Lactobacillus lactis ssp. Lactis and Lactobacillusdelbrueckii ssp. Bulgaricus isolated from cheese and butter, respectively, showed the most significant probiotic properties. However, Lactobacillusdelbrueckii ssp. Bulgaricus produced higher GABA than another (377.54 vs. 301.09 mg l-1). As conclusion, traditional dairies in Iran are good reservoir of indigenious healthy microorganisms that can be used as starter or adjuvant culture with several helpful impacts on consumers.

Various types of alcohol for severalapplications are available worldwide, of which, disinfection is one of the most important. In Muslim nations, consumption of alcoholic beverages is prohibited even at low quantities in accordance to halal status. Therefore, denatonium benzoate (commercially known as Bitrex) that has sharp bitterness is added to alcohol to avoid its edible usage. In this regard, at least 10 mg l-1 of denatonium benzoate is added to industrial alcohol according to Iranian Ministry of Health regulation. In our study, we examined the concentration of denatonium benzoate and also purity of alcohol samples collected from capital city of Iran (Tehran).

In total, 62 samples of alcohol were collected and analyzed by HPLC for Bitrex and alcoholmeter for purity. For HPLC, C18 column (150×4.6 mm, 5 µm) as stationary phase and phosphate buffer/acetonitrile solution containing sodium lauryl sulfate (50:50 v v-1) as mobile phase with flow rate of 1.2 ml min-1 were used.

The results revealed that some companies (41 samples out of 62) did not use denatonium benzoate in their products and used fruit essences instead to improve the taste and smell of alcohol. These results were against the force of Ministry of Health in mandatory addition of denatonium benzoate to prevent the samples’ further abuse. In addition, purity of most alcohols was not compatible to the information provided by the labels. We concluded that more restriction and supervision is required to prevent adulteration.