Journal•ISSN: 1936-9751
Food Analytical Methods
Springer Science+Business Media
About: Food Analytical Methods is an academic journal published by Springer Science+Business Media. The journal publishes majorly in the area(s): Detection limit & Extraction (chemistry). It has an ISSN identifier of 1936-9751. Over the lifetime, 3466 publications have been published receiving 55090 citations.
Topics: Detection limit, Extraction (chemistry), Chemistry, Solid phase extraction, High-performance liquid chromatography
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TL;DR: A review of the methods most widely used for the determination of antioxidant capacity are evaluated, presenting the general principals, recent applications, and their strengths and limitations as discussed by the authors, with regards to both lipophilic and hydrophilic antioxidants with regards the similarity and differences of both hydrogen atom transfer and electron transfer mechanism.
Abstract: Antioxidant capacity is related with compounds capable of protecting a biological system against the potentially harmful effect of processes or reactions involving reactive oxygen and nitrogen species (ROS and RNS). These protective effects of antioxidants have received increasing attention within biological, medical, nutritional, and agrochemical fields and resulted in the requirement of simple, convenient, and reliable antioxidant capacity determination methods. Many methods which differ from each other in terms of reaction mechanisms, oxidant and target/probe species, reaction conditions, and expression of results have been developed and tested in the literature. In this review, the methods most widely used for the determination of antioxidant capacity are evaluated, presenting the general principals, recent applications, and their strengths and limitations. Analysis conditions, substrate, and antioxidant concentration should simulate real food or biological systems as much as possible when selecting the antioxidant capacity method. The total antioxidant capacity value should include methods applicable to both lipophilic and hydrophilic antioxidants, with regards the similarity and differences of both hydrogen atom transfer and electron transfer mechanism. The methods including various ROS/RNS also have to be designed to comprehensively evaluate the antioxidant capacity of a sample.
569 citations
TL;DR: In this article, two widely applied spectrophotometric assays based on aluminium complex formation used for determination of total flavonoid content in food or medicinal plant samples were examined for several compounds from different classes of flavonoids family.
Abstract: Two widely applied spectrophotometric assays based on aluminium complex formation used for determination of total flavonoid content in food or medicinal plant samples were examined for several compounds from different classes of flavonoid family. The method which involves the measurement at 410–430 nm after addition of AlCl3 solution is selective only for flavonols and flavones luteolin. The procedure in the presence of NaNO2 in alkaline medium seems to be specific for rutin, luteolin and catechins, but also phenolic acids exhibit considerable absorbance at 510 nm. Application of both procedures to natural samples gave different order in terms of their flavonoid content. Thus, the expression “total flavonoid” content is not adequate as the results of both methods are dependent on the structure of the individual flavonoids present.
489 citations
TL;DR: In this article, the biochemical characteristics of Moringa oleifera are compared with those of other plants. And the results show that the three most abundant amino acids were glutamic acid, arginine, and aspartic acid, while the fatty acids present at the highest content were linolenic acid (C18:3ω3).
Abstract: This study was carried out in order to compare the biochemical characteristics from three edible parts of the multipurpose tree Moringa oleifera such as the leaves, flowers, and immature pods. On average, the three most abundant amino acids were glutamic acid, arginine, and aspartic acid. The fatty acids present at the highest content were linolenic acid (C18:3ω3), palmitic acid (C16:0), linoleic acid (C18:2ω6), and oleic acid (C18:1ω9). The chemical composition (of dry weight) ranged from 19.34% to 22.42% for protein, 1.28% to 4.96% for lipids, 7.62% to 14.60% for ash, and 30.97% to 46.78% for dietary fiber. M. oleifera is a nonconventional plant with substantial nutritional value.
201 citations
TL;DR: In this article, the effect of commonly used techniques and solvents in the antioxidant activities of pink-flesh guava fruit were studied, and the results showed that the homogenization technique was the most convenient exhaustive and time-saving extraction technique.
Abstract: The effect of commonly used techniques and solvents in the antioxidant activities of pink-flesh guava fruit were studied. The extraction techniques compared were homogenization, shaking, sonication, magnetic stirring, and maceration for 1, 2, and 3 days. The solvent systems used were methanol, ethanol, and acetone at three different concentrations (50%, 70%, and 100%) and with 100% distilled water. The antioxidant activity of the fruit was evaluated using Folin–Ciocalteu index, ferric-reducing antioxidant power assay, and 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging capacity. Ultrasonic and homogenization were the best techniques to extract the antioxidant from guava fruit. Homogenization technique was found to be the most convenient exhaustive and time-saving extraction technique. Results showed that the extracting solvent significantly (P < 0.05) altered the antioxidant property estimations of pink-flesh guava fruit. Pure solvents were inefficient extraction media for antioxidant. Enhanced extraction yields were obtained from solvent containing higher water concentrations and 50% acetone is a recommended solvent for extracting antioxidants compounds from pink-flesh guava fruit. High correlations between phenolic compositions and antioxidant activities of pink-flesh guava extracts were observed. High levels of antioxidant activities were detected in pink-flesh guava, indicating that the fruit may serve as an excellent dietary source of natural antioxidants.
185 citations
TL;DR: In this paper, the results showed that microwave assisted extraction was the most suitable method for the extraction of flavonoids from P. oleracea L. because of its high effect and short extraction time.
Abstract: Portulaca oleracea L. is a traditional edible and medicinal plant in China. Flavonoids are one of the main active ingredients of this plant. Five extraction technologies of flavonoids from P. oleracea L. were investigated and compared, including microwave-assisted extraction, ultrasonic extraction, reflux extraction, Soxhlet extraction, and marinated extraction. The results showed that microwave-assisted extraction was most suitable for the extraction of flavonoids from P. oleracea L. because of its high effect and short extraction time. The found optimum extraction conditions were that the ethanol concentration was 70% (v/v), solid–liquid ratio was 1:50, extracting temperature was 50 °C and irradiation time was 9 min. Quantification was performed by means of UV–Vis spectrophotometry with chromogenic system of NaNO2–Al (NO3)3–NaOH. Under the optimum conditions, the calibration curve for the analyte was linear with the correlation coefficients greater than 0.9999. The average recovery was 102.6%, and its RSD was 1.13%(n = 5). Eight types of P. oleracea L. according to different habits were investigated. The total content of flavonoids was 7.16, 7.10, 9.38, 6.82, 6.78, 11.36, 5.12, and 1.76 mg g−1, respectively.
178 citations