52 research outputs found
Employing Response Surface Methodology for the Optimization of Ultrasound Assisted Extraction of Lutein and β-Carotene from Spinach
Abstract: The extraction of lutein and β-carotene from spinach (Spinacia oleracea L.) leaves is important to the dietary supplement industry. A Box-Behnken design and response surface methodology (RSM) were used to investigate the effect of process variables on the ultrasound-assisted extraction (UAE) of lutein and β-carotene from spinach. Three independent variables, extraction temperature (°C), extraction power (%) and extraction time (min) were studied. Thin-layer chromatography (TLC) followed by UV visualization and densitometry was used as a simple and rapid method for both identification and quantification of lutein and β-carotene during UAE. Methanol extracts of leaves from spinach and authentic standards of lutein and β-carotene were separated by normal-phase TLC with ethyl acetate-acetone (5:4 (v/v)) as the mobile phase. In this study, the combination of TLC, densitometry, and Box–Behnken with RSM methods were effective for the quantitative analysis of lutein and β-carotene from spinach extracts. The resulting quadratic polynomial models for optimizing lutein and β-carotene from spinach had high coefficients of determination of 0.96 and 0.94, respectively. The optimal UAE settings for output of lutein and β-carotene simultaneously from spinach extracts were an extraction temperature of 40 °C, extraction power of 40% (28 W/cm3) and extraction time of 16 min. The identity and purity of each TLC spot was measured using time-of-flight mass spectrometry. Therefore, UAE assisted extraction of carotenes from spinach can provide a source of lutein and β-carotene for the dietary supplement industr
Effects of ultrasonic treatments on the polyphenol and antioxidant content of spinach extracts
The objective was to test ultrasound treatments on spinach leaves during extraction, and conventional extraction was used as a control. The effects of different combinations of the ultrasonic water bath factors tested on phenolic compound yields included frequency (37 and 80 kHz), exposure time (5, 10, 15, 20, 25 and 30 min), temperature (30, 40, and 50 C), and ultrasonic power (30%, 50%, and 70%). The best conditions for extraction yields were ultrasonic frequency of 37 kHz, extraction time of 30 min, reaction temperature of 40 C, and ultrasonic power of 50%. The mean yield (mg/100 g), total phenol (mg gallic acid/g DW), flavonoids (mg/g DW), % DPPH free-radical scavenging activity, and % ferric reducing antioxidant power were all high (64.88 ± 21.84, 33.96 ± 11.30, 27.37 ± 11.85, 64.18 ± 16.69 and 70.25 ± 9.68). Treatments were significantly different. The interaction among the ultrasonic parameters was significant. Temperature and power had significant effects on all other dependent variables
Simultaneous extraction, optimization, and analysis of flavonoids and polyphenols from peach and pumpkin extracts using a TLC-densitometric method
Background: The use of medicinal plants has been reported throughout human history. In the fight against illnesses, medicinal plants represent the primary health care system for 60 % of the world’s population. Flavonoids are polyphenolic compounds with active anti-microbial properties; they are produced in plants as pigments. Quercetin, myricetin, and rutin are among the most well-known and prevalent flavonoids in plants, with an antioxidant activity capable of decreasing the oxidation of low density lipoproteins [LDLs]. To date, this research is the first of its kind to employ a coupled thin-layer chromatography (TLC) and a densitometric quantification method with a Box-Behnken design (BBD) response surface methodology (RSM) for optimization of ultrasonic-assisted extraction and determination of rutin and quercetin from peach and ellagic acid and myricetin from pumpkin fruits.
Results: The effect of process variables (extraction temperature (°C), extraction power (%) and extraction time (min)) on ultrasound-assisted extraction (UAE) were examined by using BBD and RSM. TLC followed by Quantity-One™ (BioRad) image analysis as a simple and rapid method was used for identification and quantification of the compounds in complex mixtures. The results were consistent under optimal conditions among the experimental values and their predicted values. A mass spectrometry (MALDI-TOF MS) technique was also used to confirm the identity of the natural products in the TLC spots resolved.
Conclusion: The results show that the coupled TLC-densitometric methods & BBD can be a very powerful approach to qualitative and quantitative analysis of; rutin and quercetin from peach extracts; and ellagic acid and myricetin contents from pumpkin extracts
Phytochemicals: Extraction, Isolation, and Identification of Bioactive Compounds from Plant Extracts
There are concerns about using synthetic phenolic antioxidants such as butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA) as food additives because of the reported negative effects on human health. Thus, a replacement of these synthetics by antioxidant extractions from various foods has been proposed. More than 8000 different phenolic compounds have been characterized; fruits and vegetables are the prime sources of natural antioxidants. In order to extract, measure, and identify bioactive compounds from a wide variety of fruits and vegetables, researchers use multiple techniques and methods. This review includes a brief description of a wide range of different assays. The antioxidant, antimicrobial, and anticancer properties of phenolic natural products from fruits and vegetables are also discussed
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A difficult diagnosis - constrictive pericarditis and its treatment: a case report
RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are.Abstract The diagnosis of constrictive pericarditis requires a high degree of clinical suspicion, for the signs and symptoms of this disease can be falsely attributed to other causes. Herein, we present a case of a 70-year old retired farmer whose symptoms of right heart failure were initially attributed to co-existing pneumonia and pulmonary embolism. He was discharged. Three weeks later he presented with worsening breathlessness and ascites. Echocardiography, computed tomography and cardiac catheterization revealed the diagnosis of constrictive pericarditis. He underwent complete pericardectomy and to date has made a good recovery. This case exemplifies the difficulty in diagnosing this condition, the investigation required, and provides a discussion of the benefit and outcomes of prompt treatment.Peer Reviewe
Biscuit contaminants, their sources and mitigation strategies: A review
The scientific literature is rich in investigations on the presence of various contaminants in biscuits, and of articles aimed at proposing innovative solutions for their control and prevention. However, the relevant information remains fragmented. Therefore, the objective of this work was to review the current state of the scientific literature on the possible contaminants of biscuits, considering physical, chemical, and biological hazards, and making a critical analysis of the solutions to reduce such contaminations. The raw materials are primary contributors of a wide series of contaminants. The successive processing steps and machinery must be monitored as well, because if they cannot improve the initial safety condition, they could worsen it. The most effective mitigation strategies involve product reformulation, and the use of alternative baking technologies to minimize the thermal load. Low oxygen permeable packaging materials (avoiding direct contact with recycled ones), and reformulation are effective for limiting the increase of contaminations during biscuit storage. Continuous monitoring of raw materials, intermediates, finished products, and processing conditions are therefore essential not only to meet current regulatory restrictions but also to achieve the aim of banning dietary contaminants and coping with related diseases
Evaluation of meat and meat product oxidation and off-flavor formation: Managing oxidative changes
One of the primary issues with processed foods during heat treatment and freezing storage is fat oxidation, which causes significant changes in fats due to their interaction with reactive oxygen species (ROS). This interaction leads to the creation of various aldehydes that have a high affinity for large molecules, such as proteins, leading to the formation of final products of advanced oxidation processes that contribute to food spoilage. Co-oxidation can also result in extensive damage. Another problem affecting the quality and nutritional value of meat products is protein oxidation, which can occur during storage via freezing and thawing or as a result of heat treatment. Heat treatment can cause physical and chemical changes, such as the loss of some essential amino acids and the transformation of certain amino acids into carbonyl compounds via various mechanisms. Protein oxidation is indicated by the accumulation of these carbonyl compounds, and the heat treatment can lead to the denaturation of myoglobin, which is responsible for the brown color of cooked meat and is influenced by several factors. Active protein aggregates can interact with the oxidation products of polyunsaturated fatty acids and with carbohydrate glycation or glycoxidation to produce Maillard products. It is critical to understand the oxidative changes that occur in fats and proteins in food, particularly in meat products, since these components are among the primary constituents of food.One of the primary issues with processed foods during heat treatment and freezing storage is fat oxidation, which causes significant changes in fats due to their interaction with reactive oxygen species (ROS). This interaction leads to the creation of various aldehydes that have a high affinity for large molecules, such as proteins, leading to the formation of final products of advanced oxidation processes that contribute to food spoilage. Co-oxidation can also result in extensive damage. Another problem affecting the quality and nutritional value of meat products is protein oxidation, which can occur during storage via freezing and thawing or as a result of heat treatment. Heat treatment can cause physical and chemical changes, such as the loss of some essential amino acids and the transformation of certain amino acids into carbonyl compounds via various mechanisms. Protein oxidation is indicated by the accumulation of these carbonyl compounds, and the heat treatment can lead to the denaturation of myoglobin, which is responsible for the brown color of cooked meat and is influenced by several factors. Active protein aggregates can interact with the oxidation products of polyunsaturated fatty acids and with carbohydrate glycation or glycoxidation to produce Maillard products. It is critical to understand the oxidative changes that occur in fats and proteins in food, particularly in meat products, since these components are among the primary constituents of food
Anti-Hyperglycaemic properties of an ethanolic extract from Costus spicatus (jacq) on Streptozotocin-induced diabetic male albino Wistar rats
In this contribution, for the first time an ethanolic extract of Costus spicatus, was screened for evaluating its composition followed by its in vitro antidiabetic activity. Both spectrometric and gas chromatography techniques were employed along with the antidiabetic activity on (STZ)-Streptozotocin-induced male albino Wistar rats. A rich phytochemical content, made up of tannins, saponins, flavonoids, steroids, etc, was attained together with a high amount of ash content (11.3%) and moisture content (1.27%); further, a total of 25 compounds were positively identified by GC-MS analysis. For antidiabetic activity, different treatment period of 0th day, 21th days, 45th days were taken into consideration. Histopathological studies, considering high blood glucose levels, Serum Glutamic oxaloacetic Transaminase (SGOT), Serum Glutamic Pyruvic Transaminase (SGPT), and Alkaline Phosphatase (ALP) levels highlighted no damage in the pancreas tissue cells. Based on the findings of this study, such an insulin plant might be considered a potential source and therapeutic agent for diabetic patients
Функциональное печенье, обогащенное порошком картофельной кожуры: физические, химические, реологические и антиоксидантные свойства
This research aimed to replace wheat flour with potato peel powder (PPP) at different levels (3, 5, 7, 10, 30, and 50%). An effect of PPP on physical, chemical, rheological, and antioxidant properties of biscuit samples was investigated. The results show that the PPP sample had a significantly higher content of total sugar, protein and ash, and a lower content of moisture (15.68g/100g dry weight, 15.32 g/100g dry weight, 9.11%, 8.35%, respectively) compared with the wheat flour sample. Also, a higher total phenolic content and antioxidant activity (71.12 mg Gallic acid equivalent / 100g dry weight and 68.39%, respectively) was observed in the PPP sample. The highest percentage of PPP addition (50%) exerted the greatest significant effect on the content of total sugar, protein, moisture, ash, total phenols, and antioxidant activity compared with the control sample and other biscuit samples leading to their increase to 50.90 g/100g dry weight, 12.74 g/100g dry weight, 5.56%, 2.39%, 41.71 mg Gallic acid equivalent / 100g dry weight, 59.72%, respectively. A decrease in the L*, a*, b*, C*, h and BI values, and an increase in ∆E values were observed with replacing wheat flour with PPP. The 3% and 5% replacement rates contributed to improving most organoleptic characteristics (general acceptability, color, taste) compared to the samples with the highest studied percentages (30% and 50%). Although the highest percentages of PPP addition led to lower scores for sensory characteristics, all studied samples were acceptable from the sensory point of view, except the samples with the 50% replacement rate in terms of their taste and color.Цель этой работы состоит в описании и исследовании ранее неизвестного явления самосегментации молочного сгустка в сыродельной ванне открытого типа. На основе анализа кинетики гелеобразования определено, что самосегметация геля начинается вблизи гель-точки, развивается в течение нескольких десятков секунд и закрепляется по мере уплотнения геля. Сегменты в молочном сгустке не имеют определённой правильной формы, их средний размер вариабелен в пределах от 5 до 50 см. Форма и размеры сегментов не повторяются и не коррелируют с видом вырабатываемого сыра. Смещение сегментов молочного сгустка в сыродельной ванне относительно друг друга по высоте составляет от 0,5 до 2 мм. Ширина граничного слоя между сегментами сгустка увеличивается в процессе вторичной фазы гелеобразования от 3 до 10 мм. В результате проведенных экспериментальных исследований показано, что самосегментация молочного геля вызывается термогравитационной конвекцией, образующей циркуляционные ячейки Бенара. Предложено описание возможного механизма самосегментации молочного геля в сыродельных ваннах открытого типа. Отмечена действенная роль жировых шариков в механизме самосегментации молочного сгустка. Высказано предположение, что самосегментация молочного сгустка в сыродельной ванне может вызвать некоторые органолептические дефекты в готовом сыре, в частности неравномерность текстуры и неравномерность цвета
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