Farideh Sharifi; Latifeh Pourakbar
Abstract
Introduction: Numerous biochemical reactions in human body produce active oxygen which is able to destroy biomolecules. This destructive effect of free radicals can be blocked by antiradicals. The role of free radicals in causing a noticeable number of disease has been proved. Anti-oxidants defend against ...
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Introduction: Numerous biochemical reactions in human body produce active oxygen which is able to destroy biomolecules. This destructive effect of free radicals can be blocked by antiradicals. The role of free radicals in causing a noticeable number of disease has been proved. Anti-oxidants defend against these oxidative destructions. One of the best natural resources of oxidants are phenolic compounds in plants. Phenolic compounds by giving electrons to free radicals, restrain lipid oxidative reactions. Chemical antioxidants have been using a lot in food industrysuch as BHT, BMA, TBHQ and propyl gallate that their destructive and carcinogenesis effects on human body have been proved. Therefore, nowadays, the consumption of medicinal plants and their phenolic compounds as natural resources of antioxidants has been highly recommended. Different solvents and a variety of extraction methods can be used for extracting anti-oxidative compounds from plant tissues. Polarization degree of different solvents will effect on the amount of extracted phenolic compounds. Berberidacease family has a significant use in medicine and industry. There are biological activities in Barberry and it's highly used in food and medical industries. The main alkaloid of barberry is Barberine which has the anti-oxidative and anti-inflammatory properties and decreases blood pressure, hypoglycemia and lipid. Phenolic compounds and anthocyanins are the most important secondary active nutrients in Barberry. Barberry's extract and its bark root are rich in anti-oxidative and phenolic compounds. Berberis Integerrima × vulgaris has been studied in this research. The aim of this study was to determine the best solvent for extraction, the amount of phenolic compounds, anti-radical activity and anti-oxidative capacity in different extracts of fresh barberry which is gathered from Qamchoqai zone, Bijar, kordestan province.Materials and method: For this study, Barberries were collected from Qamchoqai zone located in Bijar, Kurdistan, Iran. They had been maintained in freezer till we started to examine them. Then, we prepared the ethanol, methanol and water extracts of these frozen Berberis. The total Phenol and Flavonoid contents of extracts according to the method of UV-VIS, Total antioxidant activity content of extracts by using three different methods including scavenging activity of DPPH , NO, reducing power assay and the capacity of inhibit lipid peroxidation by thiobarbituric acid were determined.Results and Discussion: In conclusion, this investigation demonstrates that Barberry is a rich source of phenolic compounds and antioxidant capacity. The aqueous extract showed the highest total phenol content (48/98±0/49 mg/g (wet weight)) and scavenging power of Nitric Oxide radical activity(%723/6±64/56) and the methanol extract showed the highest flavonoid content (1/93±0/033 mg/g(wet weight)), DPPH scavenging effect (%44/62±0/99), reducing power (5/89±0/42 mmol/g(wet weight)) and MDA content (37/12±0/79 mmol/g(wet weight). The type of solvent used for extraction has significant effect on phenolic compounds and flavonoids. Methanol extract has the minimum amount of phenol in fresh barberry, but methanol is a good solvent for flavonoids in barberry. The result of anti-oxidative effects in different extracts of barberry according to MDA scale shows that the water extract has the maximum amount of anti-oxidative activity. These activities in extracts are because of the existence of phenols which prevent lipid oxidation by removing free radicals and stop the increase of Malondialdehyde. In this study, Methanol extract has the maximum amount of anti-radical activity. These different results in extracts are due to the different phenolic compounds and flavonoids in them. Among extracts, water exract has the maximum capacity in trapping nitric oxide radical. Anti-radical activity against NO radicals probably is done by anti-oxidative compounds in barberry which competes with O2 over NO. In term of reduce power, extracts didn’t have significant difference with each other. FRAP and DPPH method was the same result. This means that the methanol extract than other extracts showed higher antioxidant activity. In the extraction of phenolic compounds, Organic solvents especially methanol, was more effective than water and possibly "phenolic compounds derived regenerative better by methanol extract. Results showed that aqueous and alcohol extracts of Berberis Integerrima×Vulgaris can act as a natural antioxidant and after complimentary expriments, it can be used in food and medecine industry
Latifeh Pourakbar
Abstract
Introduction: Lipid oxidation is a major cause of food quality deterioration during storage of oils, fats and other fat-containing foods. Oxidation of lipids results in changes that may affect the nutritional quality, wholesomeness, colour, flavour and texture of food. Moreover, the products of lipid ...
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Introduction: Lipid oxidation is a major cause of food quality deterioration during storage of oils, fats and other fat-containing foods. Oxidation of lipids results in changes that may affect the nutritional quality, wholesomeness, colour, flavour and texture of food. Moreover, the products of lipid oxidation may be potentially toxic and may lead to adverse effects such as the production of carcinogens, mutagenesis and aging. Autoxidation occurs when molecular oxygen reacts with unsaturated lipids. The process involves a free radical chain reaction that is most frequently initiated by exposure of unsaturated lipids to light, heat, ionizing radiation, metal ions or metalloprotein catalysts. Free radicals are defined as any chemical species having one or more unpaired electrons. Antioxidants are a group of chemicals capable of extending the shelf life of food that contain lipids. They are used to retard the development of unpleasant flavour caused by the oxidation of unsaturated fatty acids. They retard oxidation of lipids by reacting with free radicals, chelating free catalytic metals and also by acting as oxygen scavengers. Currently the food industry uses synthetic antioxidants such as BHA, BHT and TBHQ to retard lipid oxidation. However, there is concern about the safety and toxicity of synthetic antioxidants in relation to their metabolism and accumulation in body organs and tissues. Synthetic antioxidants are known among other things to cause impairment of blood clotting, lung damage and to act as tumor promoters. As a result of this, consumers have a preference for natural ingredients and there is a growing interest in the potential use of antioxidants from natural sources. Phenolic extracts from herbs and spices, cereals and legumes have been reported to effectively retard lipid oxidation in oils and fatty foods. As a result of concern for the safety of synthetic antioxidants, there is a growing interest in the potential use of phenolic extracts from plant sources as antioxidants in lipids. The potential use of phenolic extracts from different plant sources such as sorghum, herbs and spices have been studied extensively. Extracts of spices such as rosemary and sage are now available commercially for use as natural antioxidants. Phenolic compounds are defined as substances possessing a benzene ring bearing one or more hydroxyl substituents, including their functional derivatives. There are different sources of phenols such as grapes, olive oil, sorghum, beans, spices and herbs. Phenols have many favourable effects on human health. They decrease the risk of heart diseases by inhibiting the oxidation of low-density lipoproteins (LDL). A large range of low and high molecular weight phenols exhibiting antioxidant properties have been studied and proposed to be used as antioxidants against lipid oxidation. This is particularly true for those phenolics with multiple hydroxyl groups that are generally the most efficient for preventing lipid oxidation. Phenolic compounds are also known to possess antibacterial, antiviral, antimutagenic and anticarcinogenic properties. Generally the efficacy of phenolic compounds as antioxidants depends on a number of factors such as the number of hydroxyl groups bonded to the aromatic ring, the site of bonding, mutual position of hydroxyls in the aromatic ring and their ability to act as hydrogen or electron donating agents and free radical scavengers. All polyphenols are capable of scavenging singlet oxygen and alkyl radical through electron donating properties, thus generating a relatively stable phenoxyl radical. The goals of this study were to investigate the effect of incorporation of different apple cultivars’ phenolicextracts onformation of primary oxidation products in buttercomparing tosome of thesynthetic antioxidants such as BHA and BHT Material and methods: Different apple cultivars from different places of West Azerbaijan province had been collected and their total phenol content, flavonids and antioxidant properties were measured according to Folin-Ciocalteu, Colorimetry and Diphenylpicrylhydrazyl (DPPH) methods respectively. The measurement of peroxide value and thiobarbituric acid of local butter oil samples consisting of different concentrations of extract and synthetic antioxidants was performed as well. Discussion & Results: In conclusion, this investigation demonstrates that apple is a rich source of phenolic compounds and antioxidant capacity.Fuji and Sheikh Ahmad cultivars showed the maximum and minimum content of total phenol content, flavonoids and antioxidant activity which are 2940.24 and 1350.22 microgram equivalent gallic acid/ gram of dry extract; 2530.32 and 1200.74 microgram equivalent quercetin/ gram of dry extract and 91.87 and 32%. The maximum and minimum amount of peroxide value and thiobarbituric acid was reported for control and 400 ppm apple extract samples respectively. The results of this study showed that "Fuji" cultivar contained the highest antioxidant activity.The Fuji apple extract are able to reducethe formation of hydroperoxides in butter oil during storage at 6ooC. The phenolic extracts from Fuji apple to be more effective than BHA in stabilising butter oil at 60ºC. Apple phenolic extracts inhibited oxidation of butter oil. Theextracts were able to retard oxidation because of the ability of phenolic compounds toscavenge and stabilise lipid radicals by donating hydrogen atoms.Also the concentration of the extract was an effective factor in the inhibition of oxidation; that is, as we increased the concentration, the inhibition of oxidation also increased. Conclusion:: Due to their ability to act as reducing agents, phenolic compounds in apple phenolic extracts from Fujivarieties can be used as antioxidants in butter oil toretard formation of primary oxidation products, specifically hydroperoxides.
