Food Analytical Methods最新文献

Natural Deep Eutectic Solvents (NADESs) are a form of green solvents used to extract phenolic compounds and are considered a more environmentally friendly alternative to traditional solvents. The study aimed to explore a more eco-friendly and effective approach to extracting anthocyanins from Prunus domestica by utilizing NADESs. Four NADESs were created by making combinations of choline chloride with citric acid, lactic acid, glycerol, and ethylene glycol. The study investigated the anthocyanins profile, antioxidant, and anti-sickling properties of fruit extracts that were obtained using NADESs. The examination of NADESs revealed that the hydrogen bond acceptors and donors had a substantial impact on the viscosity, pH, density, and chemical structure of the NADESs. The resulting extracts demonstrated the highest recovery rates, resulting in the greatest total phenolic content (35.05 ± 0.15 mg GAE/100 g) and total anthocyanin content (17.22 ± 0.296 mg CGE/100 g). This extract from the Prunus domestica fruit, which contains anthocyanin, has anti-sickling effects on sickle cell erythrocytes. The Emmel test was used to assess the in vitro anti-sickling effects of the NADES extract. The percent sickling of negative control was found to be 40.88%. And it was discovered that the NADES extract of CHCL: ETHGly was 14.71% at an effective concentration of 0.2% (v/v), and the NADES extract of CHCl: GLY was discovered to be 20.94% at an effective concentration of 0.2% (v/v). The phenolic (anthocyanin) impact on percent sickling revealed a significant difference between the control and test.

Graphical Abstract

Heiyai (Elaeagnus latifolia L.) is an underutilized semi-wild berry which is found in Manipur during the mid of March and April. In the present study, Heiyai fruit was explored for the extraction of lycopene using supercritical fluid extraction (SFE) using CO₂ and the conventional solvent extraction (CSE) method. An experimental design based on response surface methodology was used for SFE with independent variables (pressure, temperature, and time) and CSE (temperature, time, and solid-to-liquid ratio) to investigate the effect on the extraction yield (%) and lycopene content (mg/100 g) from Heiyai. An empirical model was developed for correlating independent and response variable with a good fit which was obtained. The optimum conditions for SFE were pressure (20 MPa), extraction time (90 min), and temperature (40 °C) resulting into extraction yield of 3.35% and 69.78 mg/100 g of lycopene content. The optimum conditions for CSE were temperature (30 °C), time (15 min), and solid-to-liquid ratio (70 g/mL) resulting into extraction yield of 1.318% and lycopene content of 29.983 mg/100 g. Furthermore, lycopene was isolated and purified using the column chromatography method, and its chemical structure was studied using FT-IR and a visible spectrophotometer.

This work describes the optimization and validation of sample preparation methods for determining major and minor elements in artisanal Brazilian cheese samples by inductively coupled plasma optical emission spectrometry. Three sample preparation methods were optimized and compared: microwave-assisted digestion, ultrasound-assisted extraction, and alkaline solubilization using tetramethylammonium hydroxide. A central composite design was used for the optimization using the R software. The optimal experimental conditions were achieved at 1.58 mL of HNO₃ 14 mol L⁻¹ and 0.570 g of sample mass for the microwave-assisted digestion (capable of determining Ca, Fe, K, Mg, Na, and P); 3.4 mol L⁻¹ of HNO₃, 0.91 mol L⁻¹ of HCl, and 2.5 min for the ultrasound-assisted extraction (capable of determining Ca, K, Na, and Zn); and 21.8% (w/w) of tetramethylammonium hydroxide, 50 °C, and 103 min for the AS method (capable of determining K, Na, and Zn). The optimized methods were validated and applied for the analysis of four kinds of artisanal Brazilian cheeses and compared with the dry-ashing method, using a paired t-test, where the means agreed with the dry-ashing method at a 95% confidence interval.

A methodology with rapidity and specificity is of great significance for the effective control and management of outbreaks caused by Salmonella enterica as it has presented an obvious threat to food safety and public health worldwide. In this study, we aimed to develop a tube-closed and real time cross-priming amplification assay for the rapid and sensitive detection of S.enterica and decrease the possibility of detecting false-positive signals derived from aerosol contamination or non-specific amplification caused by traditional CPA assay. The reaction system was optimized and the results showed that molecular beacon CPA (MB-CPA) method was highly specific for detection of S. enterica. The sensitivity of established assay was found to be 10 CFU/mL, 100 CFU/25 g, 10 CFU/25 g in pure culture, chicken sample without and with 6 h enrichment, respectively. And the sensitivity of MB-CPA was 10 times higher than that of real-time PCR. An application of MB-CPA assay was conducted with 78 naturally contaminated food samples to test its practicality. After an enrichment step at 37℃ for 6 h, the results showed 100% sensitivity and 100% specificity compared with standard culture-based method. Considering its rapidity, user-friendliness, cost-effectiveness, this MB-CPA assay will aid in the broader application in food industry for the detection of S. enterica in small or resource-limited food testing laboratories.

Purple yam (Dioscorea trifida) has high agricultural productivity in the Amazon region but has not been much investigated. Multivariate strategies were employed to optimize the method to obtain a food extract rich in functional compounds. The optimal conditions showed that the combination of 0.2 g of dried purple yam with 15 mL of citric acid (1%) under agitation in a water bath at 36 °C for 4 min yields an extract with a high content of peonidin-3-O-glucoside-5-O-glucoside, peonidin-3-O-feruloylglycosideum-5-O-glycosideum, peonidin-3-Op-coumaroylglycosideum-5-O-glycoside, quinic acid, apigenin 8-C-xyloside-6-C-glycoside (vicenin 3), quinic acid, apigenin 6-C-xyloside-8-C-glycoside (vicenin 1), and isorhamnetin-O-dihexoside. Our extract also presented 56.91 ± 0.76 mg 100 g⁻¹ of total anthocyanins, 417.05 ± 11.37 mg 100 g⁻¹ total carotenoids, and 493.09 ± 6.38 mg GAE 100 g⁻¹ of total phenolic compounds. In a Galleria mellonella, in vivo model consumption safety was for up to 150 g by 70 kg of body weight. In addition, it inhibited the growth of Gram-negative bacteria (Salmonella typhimurium and Escherichia coli). The simple, fast, and ecofriendly extraction conditions, combined with the biological effects of our extract, gives us a great potential for its application in food or packaging technologies.

Stenocereus stellatus is one of the 10 species of cactus of greatest economic importance in Mexico, although its fruits contain bioactive components such betalains and phenolic compounds, which in turn cause multiple positive pharmacological effects on health, very little has been explored. This study aimed to employ a response surface methodology (RSM) approach to optimize the extraction conditions for maximizing the concentration of betalains (betacyanins and betaxanthins), total phenolic compounds (TPC), and antioxidant capacity (AC). To optimize the extraction of betalains, pH (W), extraction temperature (X), extraction time (Y), and water:ethanol solvent ratio (Z) were evaluated. For TPC and AC, the same factors were evaluated, except Z. All these factors influenced on the concentration of betalains. The optimal extraction conditions were found to be pH 4.2, extraction temperature of 10 °C, extraction time of 60 min, and a water:ethanol solvent ratio of 55%, and under these conditions, 0.51 mg per g total betalains (BT) were obtained, of which 0.25 mg per g corresponded to BC and 0.26 mg per g to BX. In TPC and AC, only pH and temperature affected these determinations. The optimal conditions for both variables were pH of 4 and extraction temperature of 60 °C, and under these conditions, 2.34 mg of gallic acid equivalents per g and 18.60 µmol of Trolox equivalents per g were obtained. The results suggest that Stenocereus stellatus could be a promising source for these compounds, which have potential applications in the food and pharmaceutical industries due to their excellent stability under these conditions.

Gluten proteins may cause adverse reactions when consumed by predisposed individuals. In dietary gluten-free products, its content must not exceed the threshold value of 20 mg/kg. Compliance with labeling is to be controlled via quantification methods. Some methods use flour as a reference material for quantification. The composition and content of gluten proteins in foods may vary depending on the origin of the gluten source. Because of these variations, the use of a limited number of marker peptides found in flour may lead to false results when quantifying gluten. In this study, a UHPLC-MS/MS method was developed that mitigates the influence of variations in gluten protein content and composition on the quantification result. The general limit of quantification of the method was 10 mg gluten proteins/kg food product. Increasing the number of marker peptides taken into account improves the robustness of the method against varying composition of gluten proteins in commercially available food products.

In this study, we developed a column-switching high-performance liquid chromatography (HPLC) method with fluorescence detection for the analysis of vitamin K. Column-switching is accomplished by changing the direction of flow using a switching valve with a set time program. Using this method, three vitamin K, phylloquinone (PK), menaquinone-4 (MK-4), and menaquinone-7 (MK-7), were separated and identified with high sensitivity, and impurities were eliminated. This method was used to determine the vitamin K content in meat, fish meat, snails, bivalves, sea urchins, seaweeds, vegetables, tea, soy products, milk products, and supplements. The results showed that chicken showed the highest content of MK-4 (15.35 ± 0.35 μg/100 g), matcha showed the highest content of PK (3069.66±80.10 μg/100 g), and dried natto showed the highest content of MK-7 (3997.57±79.42 μg/100 g). This method can also be used to analyze vitamin K in supplements and pharmaceuticals. The results of this study revealed that different manufacturers add different types of vitamin K to their commercial supplements and infant formulas. The developed method provides highly reproducible and quantitative results and allows for the rapid analysis of the three vitamin K types. Thus, the method developed in this study may aid the sequential analysis of vitamin K in different samples to assess food nutrients.

A method for the determination of tebuconazole, triadimefon, triadimenol, propiconazole, and diniconazole fungicide in vegetables, fruits, and sprouts of wheat and corn by high-performance liquid chromatography coupled to mass detection with cloud point extraction by phases of nonionic surfactant Triton X-114 was developed. The factors influencing the concentration of nonionic surfactant, medium acidity, equilibrium temperature, holding time of solutions in a water bath, and time and speed of centrifugation on extraction parameters were optimized. The complete extraction of analytes into the 0.2% (w/v) Triton X-114 phase occurs in the 2.0–9.0 pH range, provided that the analytes exist in hydrophobic electroneutral molecular forms that effectively transfer to the surfactant-rich phase of the nonionic surfactant at a temperature of 50 °C. The required time for the complete formation of the surfactant-rich phase is more than 15 min when centrifuging solutions at 4000 rpm for 12 min. The developed fungicide determination method is characterized by the limit of detection (3σ) of 0.4–0.8 ng∙mL⁻¹, the limit of quantitation (10σ) of 1.4–2.5 ng∙mL⁻¹, and a working range of 1.4–200 ng∙mL⁻¹. The developed method was applied to the determination of tebuconazole and triadimenol in beets, grapes, and sprouts of wheat and corn after their treatment with industrial fungicide preparations.

Graphical Abstract