ABSTRACT
A novel and fast salting out liquid-liquid extraction method was developed for simultaneous determination of food additives with different polarities in juices. Chromatographic separation was achieved in less than 6â¯min using Acquity UPLC BEH C 18 (100â¯mmâ¯×â¯2.1â¯mm d.i.â¯×â¯1.7⯵m) column with ammonium acetate with 0.01% of trifluoroacetic acid as eluent A and acetonitrile as eluent B at a flow rate of 0.2â¯mLâ¯min-1. The main factors affecting the extraction efficiency were optimized. The method was validated applying accuracy profile based on total error. The extraction recoveries ranged from 84.97 to 122%. Relative standard deviation ranged from 1.24 to 7.99% for intraday assay and from 1.69 to 9.16% for intermediate precision. The limits of detection for five food additives were from 0.3 to 1.42⯵gâ¯mL-1. The method was successfully applied to 47 samples of juices from nine brands.
Subject(s)
Food Additives/analysis , Fruit and Vegetable Juices/analysis , Sweetening Agents/analysis , Ammonium Sulfate/chemistry , Chromatography, High Pressure Liquid , Chromatography, Reverse-Phase , Food Additives/isolation & purification , Hydrogen-Ion Concentration , Liquid-Liquid Extraction , Sweetening Agents/isolation & purificationABSTRACT
L-Asparaginase is an enzyme that hydrolyses the amino acid L-Asparagine into aspartic acid and ammonia. As a medication, L-Asparaginase is used in chemotherapy to treat acute lymphoblastic leukaemia by depleting circulating Asparagine and depriving tumor cells. Interest in Actinomycetes as potential producers of antibiotics and enzymes encouraged us to investigate an isolated strain (CA01) from soft wheat bran.The Actinomycete strain was characterized based on its morphological and biochemical characteristics and selected due to a proved promising ability to produce L-Asparaginase optimized in both solid and liquid media cultures.The conditions of enzyme production were standardized according to a one-factor-at-a-time (OFAT) experimental design.To obtain optimal medium combination, a Box-Behnken Response Surface Methodology (RSM) has been adopted by choosing the most influential factors. The optimal conditions for the enzyme production were (g/l): L-Asparagine 10.7; Glucose 2.7; starch 7, in based medium containing (g/l): K2HPO4 0.5; MgSO4, 7H2O 0.1, corresponding to an optimal enzymatic activity of 8.03 IU/ml at 27.83°C. The maximum production of enzyme was reached on the sixth day of experiment. The ANOVA test (P value Ë 0.05) and adjusted R2 values close to the experimental R2 show that the obtained model of the active L-Asparaginase of CA01 strain production is significant with the following linear terms: temperature, substrate concentration, Glucose concentration and there squared.
Subject(s)
Actinobacteria/enzymology , Actinobacteria/isolation & purification , Asparaginase/biosynthesis , Dietary Fiber/microbiology , Extracellular Space/enzymology , Analysis of Variance , Carbon/pharmacology , Kinetics , Nitrogen/pharmacology , Reference Standards , Time FactorsABSTRACT
>Background: Food additives are widely used in industries. Overall, these additives have a beneficial role, but if their concentration exceeds certain limits, they may have an adverse effect on human health. Objective: This study outlines the determination of benzoic acid (BA), sorbic acid (SA), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in juices using dispersive liquid-liquid microextraction and HPLC-diode-array detection. Methods: Different parameters that significantly affect the extraction efficiency were optimized. The disperser and extraction solvents were acetone and chloroform, respectively. The other parameters were selected and optimized using two-level (2k) factorial and central composite designs, respectively. A full method validation using an accuracy profile for the total measurement error was carried out. Results: The optimized conditions were 625 µL acetone, 350 µL chloroform, 0.85 g NaCl, and pH 2. The validated method demonstrated good linearity with R² ≥ 0.99 and good precision with the RSD of repeatability and intermediate precision at 1.97-10.7% and 2.31-11.9%, respectively. The relative recoveries were 96.2-105.4%, and the LODs were around 0.03 µg/mL for all compounds. The analysis of 41 samples revealed that BA and SA were quantified in 25 and 20 samples, respectively. BHA and BHT were not detected. Conclusions: The proposed methodology is an appropriate tool to determine important food additives in juices to ensure their compliance with the food additives legislation. Highlights: The work has demonstrated that the method can be successfully used in the simultaneous determination of four food additives in fruit juices.
ABSTRACT
This paper presents the validation of a method for the quantification of benzoic acid and its salt preservatives, which are extensively used in the preservation of foodstuffs. The Joint Expert Committee on Food Additives at the Food Agricultural Organization and World Health Organization has established maximum permitted limits for these compounds in different foodstuffs because of the harmful effects of benzoic acid and its salt preservatives when they exceed certain limits. Therefore, a reliable and simple method to quantify these preservatives was validated. The developed method used a combination of extracted external calibration standards, a simple extraction procedure, and reversed-phase HPLC. This method was validated by applying a new approach in which the total error was based on the ß-expectation tolerance interval developed by the Society of Pharmaceutical Science and Techniques Commission with an acceptability limit fixed at a λ of ±15%. The results demonstrated that the method is accurate, with repeatability between 1.096 and 1.986% and intermediate precision between 1.133 and 2.005% in the considered concentration range. The LOD was 0.1597 µg/mL.