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1.
Pomegranate (Punica granatum) peel extracts have been shown to possess significant antioxidant activity in various in vitro models. Dried pomegranate peels were powdered and extracted with methanol for 4 h. The dried methanolic extract was fed to albino rats of the Wistar strain, followed by carbon tetrachloride (CCl4), and the levels of various enzymes, such as catalase, peroxidase, and superoxide dismutase (SOD), and lipid peroxidation were studied. Treatment of rats with a single dose of CCl4 at 2.0 g/kg of body weight decreases the levels of catalase, SOD, and peroxidase by 81, 49, and 89% respectively, whereas the lipid peroxidation value increased nearly 3-fold. Pretreatment of the rats with a methanolic extract of pomegranate peel at 50 mg/kg (in terms of catechin equivalents) followed by CCl4 treatment causes preservation of catalase, peroxidase, and SOD to values comparable with control values, wheres lipid peroxidation was brought back by 54% as compared to control. Histopathological studies of the liver were also carried out to determine the hepatoprotection effect exhibited by the pomegranate peel extract against the toxic effects of CCl4. Histopathological studies of the liver of different groups also support the protective effects exhibited by the MeOH extract of pomegranate peel by restoring the normal hepatic architecture.  相似文献   

2.
六种果皮原料果胶的理化及凝胶特性比较   总被引：4，自引：2，他引：2  
为了解不同品种水果的果皮(柚子皮、西番莲皮、脐橙皮、石榴皮、榴莲皮)以及向日葵盘所提取果胶的理化和质构特性,研究了不同原料果胶的得率、色泽、果胶酸含量、甲氧基含量、酯化度、黏度及质构特性,特别是采用高效液相色谱准确测定了各类果胶的分子量。结果表明:柚子皮、向日葵盘和脐橙皮果胶质量分数较高,分别为18.06%、14.61%和14.43%;西番莲皮果胶质量分数为8.76%;而石榴皮及榴莲皮果胶质量分数较低(均<3%)。从分子量看,石榴皮、脐橙皮果胶分子量较大(>1000kDa),向日葵盘果胶分子量最小(483kDa)。此外,几种果胶的溶胶均属低黏度值果胶(<25厘泊),且在pH值为7.0时黏度最大、在pH值为5.0时黏度最小。结合凝胶质构分析表明:石榴皮果胶分子量最大,凝胶强度最大,但为高甲氧基果胶,且得率较低;而向日葵盘果胶分子量最小,但得率较高,且为低甲基果胶,在非糖及含糖体系中均可形成性能优良的凝胶,因此是生产果胶的良好原料。该文为果胶的生产及应用提供参考。  相似文献   

3.
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4.
Abstract

We investigated the effect of foliar application of potassium nitrate (KNO3) and zinc sulfate (ZnSO4) on the fruit quality of pomegranate (Punica granatum L. cv. Malas-E–Torsh in Saveh). Potassium was applied as KNO3 at concentrations of 0%, 0.25%, and 0.5% and zinc was applied as ZnSO4 at concentrations of 0%, 0.5%, and 1% in a completely randomized block design. To determine the effect of the treatments on fruit quality, we measured fruit weight, peel thickness, aril diameter, phenol content of the juice, pH, total soluble solids (TSS), titratable acidity (TA), and antioxidant capacity. Foliar application of KNO3 significantly increased fruit weight, 100 aril weight, peel weight, peel thickness, TTS, and antioxidant capacity. In contrast, pH, TA, TSS/TA, and phenol content of the juice were not influenced by foliar application of KNO3. ZnSO4 significantly increased fruit weight, aril diameter, and phenol content of the juice. KNO3 1% and ZnSO4 0.5% were identified as the most appropriate treatments in improving quality and quantity of pomegranate. The fatty acid profile of the pomegranate oil was primarily composed of punicic acid, linoleic acid, oleic acid, palmitic acid, and stearic acid.  相似文献   

5.
The antioxidant activities of three parts (peel, juice, and seed) and extracts of three pomegranate varieties in China were investigated by using a chemiluminescence (CL) method in vitro. The scavenging ability of pomegranate extracts (PEs) on superoxide anion, hydroxide radical, and hydrogen peroxide was determined by the pyrogallol-luminol system, the CuSO4-Phen-Vc-H2O2 system, and the luminol-H2O2 system, respectively. DNA damage preventing the effect of PE was determined by the CuSO4-Phen-Vc-H2O2-DNA CL system. The results showed that the peel extract of red pomegranate had the best effect on the scavenging ability of superoxide anion because its IC50 value (4.01 +/- 0.09 microg/mL) was the lowest in all PEs. The seed extract of white pomegranate could scavenge hydroxide radical most effectively of the nine extracts (the IC50 value was 1.69 +/- 0.03 microg/mL). The peel extract of white pomegranate had the best scavenging ability on hydrogen peroxide, which had the lowest IC50 value (0.032 +/- 0.003 microg/mL) in the nine extracts. The seed extract of white pomegranate (the IC50 value was 3.67 +/- 0.03 microg/mL) was the most powerful on the DNA damage-preventing effect in all of the PEs. Also, the statistical analysis indicated that there were significant differences (at P < 0.05) among the extracts of the different varieties and parts in each system.  相似文献   

6.
石榴果实发育期果皮褐变及相关酶活性变化   总被引：1，自引：0，他引：1  
为探明石榴果实发育期果皮褐变及其相关酶活性、总酚和抗氧化能力的变化规律及相互关系,以泰山红和泰山三白甜石榴为试材,研究各发育期果皮褐变度、多酚氧化酶(PPO)活性、过氧化物酶(POD)活性、苯丙氨酸解氨酶(PAL)活性、总酚含量和DPPH自由基清除率的变化。结果表明,2个品种果皮褐变度、PPO活性、POD活性、总酚含量和DPPH自由基清除率随着发育天数的增加逐渐降低,均在7月15日达到最高。2个品种果实发育期果皮PAL活性呈先降低后升高再降低的变化趋势,分别在7月15日和9月13日出现峰值。泰山红抗褐变能力高于泰山三白甜,二者分别在9月23日和9月13日采收能减轻褐变的发生。相关性分析表明,PAL、PPO、POD、总酚和DPPH自由基清除率均与石榴果实酶促褐变密切相关,石榴果实酚类物质含量高低与其抗氧化能力极显著正相关。本研究结果为深入揭示石榴果实褐变机理提供了理论依据。  相似文献   

7.
石榴皮提取液对草莓的保鲜效果   总被引：11，自引：7，他引：4  
为了发展草莓贮藏保鲜的新技术和有效利用石榴皮资源,以新鲜草莓为材料,在贮藏前分别经过1.25%壳聚糖溶液（T1）、1%石榴皮提取液（T2）、1.25%壳聚糖石榴皮提取物复合溶液（T3）浸泡处理,以蒸馏水浸泡作为对照（CK）,通过对其在贮藏期相关品质指标（质量损失率、软化腐烂率、可溶性固形物质量分数、可滴定酸质量分数、Vc质量分数、丙二醛（MDA）含量）的测定,比较了3种处理溶液的保鲜效果。结果显示,T1、T2、T3处理均降低了草莓果实质量损失率、软化腐烂率和MDA含量,延缓了果实可滴定酸、可溶性固形物和Vc质量分数的下降,其中T3处理效果明显好于T1和T2处理,T3处理可使在室温下放置的草莓保鲜期延长1～2 d。结果表明石榴皮提取液用于草莓保鲜可行,与一定浓度的壳聚糖配制的复合保鲜液保鲜效果更理想。  相似文献   

8.
冯尚坤  陈浩  邵志勇  汪俏梅 《核农学报》2021,35(6):1340-1346
为探究红光处理对萝卜芽菜采后营养品质的影响,本试验对采收后的萝卜芽菜进行8 h红光处理,之后置于4℃条件下贮藏,于贮藏0、1、2和3 d对其芥子油苷,叶绿素、花青素等抗氧化物质含量,以及总抗氧化能力进行分析。结果表明,与对照相比,红光处理使萝卜芽菜中的脂肪类芥子油苷(4-甲硫基-3-丁烯基芥子油苷等)和吲哚类芥子油苷(4-甲氧基-吲哚-3-甲基芥子油苷等)含量分别提高9.5%和20.6%,并且延缓了贮藏过程中具有抗癌活性的4-甲硫基-3-丁烯基芥子油苷含量的下降。此外,红光处理提高了萝卜芽菜中叶绿素和花青素的含量,以及贮藏早期的抗氧化能力。本研究结果为通过光照处理维持萝卜芽菜采后品质提供了理论依据,具有潜在的应用价值。  相似文献   

9.
In the present study, free amino acids and seed protein contents of pomegranate germplasm from Tunisia and China were conducted using Hitachi L8800 amino acid analyzer, Bradford and Kjeldahl methods. The work offers more consideration to protein pomegranate seeds which can be with great importance regarding the nutritive seed value of this crop. In other hand, the protein and amino acids contents were used to compare the Tunisian and Chinese pomegranate cultivars based on multivariate analyses (principal component and clustering analyses). Results show that the Tunisian and Chinese pomegranate seeds were rich in storage proteins independently of organoleptic taste as sweet, sour sweet or sour. Qualitatively, the storage protein and free amino acids of pomegranate seeds were identical. Besides, the segregation of Chinese and Tunisian pomegranate cultivars into three groups was reveled based on high, low or moderate amino acids contents. Statistically, the differences between organoleptic groups (sweet, sour sweet and sour) were not significant (P?<?0.05). However, the differences between pomegranate cultivars were statistically significant within groups. The separation of cultivars is independent to the organoleptic taste neither the geographical origin.  相似文献   

10.
The consumption of pomegranate juice (PJ), a rich source of antioxidant polyphenols, has grown tremendously due to its reported health benefits. Pomegranate extracts, which incorporate the major antioxidants found in pomegranates, namely, ellagitannins, have been developed as botanical dietary supplements to provide an alternative convenient form for consuming the bioactive polyphenols found in PJ. Despite the commercial availability of pomegranate extract dietary supplements, there have been no studies evaluating their safety in human subjects. A pomegranate ellagitannin-enriched polyphenol extract (POMx) was prepared for dietary supplement use and evaluated in two pilot clinical studies. Study 1 was designed for safety assessment in 64 overweight individuals with increased waist size. The subjects consumed either one or two POMx capsules per day providing 710 mg (435 mg of gallic acid equivalents, GAEs) or 1420 mg (870 mg of GAEs) of extracts, respectively, and placebo (0 mg of GAEs). Safety laboratory determinations, including complete blood count (CBC), chemistry, and urinalysis, were made at each of three visits. Study 2 was designed for antioxidant activity assessment in 22 overweight subjects by administration of two POMx capsules per day providing 1000 mg (610 mg of GAEs) of extract versus baseline measurements. Measurement of antioxidant activity as evidenced by thiobarbituric acid reactive substances (TBARS) in plasma were measured before and after POMx supplementation. There was evidence of antioxidant activity through a significant reduction in TBARS linked with cardiovascular disease risk. There were no serious adverse events in any subject studied at either site. These studies demonstrate the safety of a pomegranate ellagitannin-enriched polyphenol dietary supplement in humans and provide evidence of antioxidant activity in humans.  相似文献   

11.
两段式冷却对牛肉食用品质的影响   总被引：2，自引：1，他引：1  
为探讨两段式冷却对牛肉食用品质的影响,以20头杂交牛胴体（延边牛×西门塔尔牛）按试验设计进行两段式冷却（温度-13～-15℃、时间2 h,风速3 m/s,随后转入常规冷却间至24 h）和常规冷却处理（温度0～4℃、时间24 h）相比较,研究不同处理对牛肉食用品质的影响。表明：两段式冷却处理加快胴体温度下降速率,减缓pH值下降速率,显著降低胴体冷却质量损失,使肉的色泽鲜红,提高肉的剪切力,对背最长肌的保水性无影响。可以认为在肉牛屠宰加工流程中,单独采用两段式冷却处理能降低肉的嫩度,但随时间的增加,剪切力值会有所降低,建议应用时结合电刺激处理来同时改善肉的食用品质。  相似文献   

12.
Antioxidant-rich fractions were extracted from pomegranate (Punica granatum) peels and seeds using ethyl acetate, methanol, and water. The extracts were screened for their potential as antioxidants using various in vitro models, such as beta-carotene-linoleate and 1,1-diphenyl-2-picryl hydrazyl (DPPH) model systems. The methanol extract of peels showed 83 and 81% antioxidant activity at 50 ppm using the beta-carotene-linoleate and DPPH model systems, respectively. Similarly, the methanol extract of seeds showed 22.6 and 23.2% antioxidant activity at 100 ppm using the beta-carotene-linoleate and DPPH model systems, respectively. As the methanol extract of pomegranate peel showed the highest antioxidant activity among all of the extracts, it was selected for testing of its effect on lipid peroxidation, hydroxyl radical scavenging activity, and human low-density lipoprotein (LDL) oxidation. The methanol extract showed 56, 58, and 93.7% inhibition using the thiobarbituric acid method, hydroxyl radical scavenging activity, and LDL oxidation, respectively, at 100 ppm. This is the first report on the antioxidant properties of the extracts from pomegranate peel and seeds. Owing to this property, the studies can be further extended to exploit them for their possible application for the preservation of food products as well as their use as health supplements and neutraceuticals.  相似文献   

13.
不同氮肥用量对石榴果实产量和品质的影响   总被引：2，自引：1，他引：1       下载免费PDF全文
以‘秋艳’石榴为试验材料,研究了不同氮肥用量对其果实产量和品质的影响。结果表明,施用氮肥可显著提高石榴果实产量,适量施用氮肥可增加石榴果实可溶性固形物、Vc、糖含量,降低石榴果实酸含量,提高石榴果实糖酸比,改善石榴果实的风味;施用氮肥对石榴百粒重、籽粒硬度无显著影响;石榴籽氮元素含量高于石榴皮,石榴汁中氮含量很低,中高氮处理的石榴汁中氮元素含量显著降低,石榴皮和石榴籽中氮元素含量变化不显著;本试验5年生石榴树纯氮施肥用量宜以0.4 kg·株~(-1)为宜。  相似文献   

14.
Caseinophosphopeptides (CPP) and casein hydrolysates have been shown to bind prooxidant metals such as iron, but their effectiveness as metal chelators to inhibit lipid oxidation in foods has still not been fully investigated. Thus, the antioxidant activity of CPP and casein hydrolysates was studied in phosphatidylcholine liposome model systems. CPP (< 1.0 mg/mL) and casein hydrolysates (0.3-1.7 mg/mL) were effective inhibitors of TBARS development when oxidation was promoted by ferric/ascorbate. High amounts of CPP (> 1.0 mg/mL) were prooxidant, whereas casein hydrolysates were observed to be only antioxidative. In the presence of peroxyl radicals, casein hydrolysates were more effective scavengers than enriched CPP (3-15 mM). In cooked ground beef, TBARS formation was inhibited 75, 39, and 17% by 0.5% enriched CPP, casein hydrolysates, and low molecular weight casein hydrolysates, respectively, after 4 days of storage. The results show that CPP and casein hydrolysates are promising sources of natural antioxidants for foods.  相似文献   

15.
This paper reports the effects of heat treatment on huyou (Citrus paradisi Changshanhuyou) peel in terms of phenolic compounds and antioxidant capacity. High-performance liquid chromatography (HPLC) coupled with a photodiode array (PDA) detector was used in this study for the analysis of phenolic acids (divided into four fractions: free, ester, glycoside, and ester-bound) and flavanone glycosides (FGs) in huyou peel (HP) before and after heat treatment. The results showed that after heat treatment, the free fraction of phenolic acids increased, whereas ester, glycoside, and ester-bound fractions decreased and the content of total FGs declined (P < 0.05). Furthermore, the antioxidant activity of methanol extract of HP increased (P < 0.05), which was evaluated by total phenolics contents (TPC) assay, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) (ABTS*+) method, and ferric reducing antioxidant power (FRAP) assay. The correlation coefficients among TPC, ABTS, FRAP assay, and total cinnamics and benzoics (TCB) in the free fraction were significantly high (P < 0.05), which meant that the increase of total antioxidant capacity (TAC) of HP extract was due at least in part to the increase of TCB in free fraction. In addition, FGs may be destroyed when heated at higher temperature for a long time (for example, 120 degrees C for 90 min or 150 degrees C for 30 min). Therefore, it is suggested that a proper and reasonable heat treatment could be used to enhance the antioxidant capacity of citrus peel.  相似文献   

16.
The intake of polyphenols has been demonstrated to have health-promoting and disease-preventive effects. The pomegranate (Punica granatum L.), which is rich in several polyphenols, has been used for centuries in ancient cultures for its medicinal purposes. The potential health benefits of pomegranate polyphenols have been demonstrated in numerous in vitro studies and in vivo experiments. This study investigated the absorption and antioxidant effects of a standardized extract from pomegranate in healthy human volunteers after the acute consumption of 800 mg of extract. Results indicate that ellagic acid (EA) from the extract is bioavailable, with an observed C(max) of 33 ng/mL at t(max) of 1 h. The plasma metabolites urolithin A, urolithin B, hydroxyl-urolithin A, urolithin A-glucuronide, and dimethyl ellagic acid-glucuronide were identified by HPLC-MS. The antioxidant capacity measured with the oxygen radical absorbance capacity (ORAC) assay was increased with a maximum effect of 32% after 0.5 h, whereas the generation of reactive oxygen species (ROS) was not affected. The inflammation marker interleukin-6 (IL-6) was not significantly affected after 4 h after the consumption of the extract. Overall, this study demonstrated the absorbability of EA from a pomegranate extract high in ellagitannin content and its ex vivo antioxidant effects.  相似文献   

17.
Apple and pear fruits are important sources of secondary plant metabolites and one of the major sources of dietary phenolics consumed all year round. The aim of this work was to identify the main variables influencing phenolic content and antioxidant capacity in apples. Higher phenolic and antioxidant contents were observed in some varieties (such as the Delbar Estival apple and Durondeau pear). Storage conditions were important. Our results also showed that fruits should be consumed rapidly after purchase and with their peel. After one week of domestic storage, the ascorbic acid content was found to decrease by 75%. Peeling led to a more than 25% decrease in total phenolics and ascorbic acid. The harvest time (at normal ripeness) had only a limited impact, but significant year-to-year variations were observed. In conclusion, well-chosen and well-stored apples and pears may contribute to an antioxidant-rich diet if consumed rapidly and with their peel.  相似文献   

18.
(1-->3),(1-->6)-Beta-D-Glucan, a cell wall polysaccharide in many microorganisms, fungi and algae, is a well-known biological response modifier. Recently, it was found that (1-->3)-beta-D-glucan from Saccharomyces cerevisiae also exhibits antioxidative capabilities. In this study the antioxidative activity of the cell wall fractions of brewer's yeast was investigated. Particular emphasis was put on the question to which extent glucan is responsible for the antioxidative activity of the cell walls and how the other cell wall components might contribute. For the experiments yeast cell walls from brewery fermentations were used. Glucan was isolated by a three-step extraction procedure including a combination of hot water and enzymatic treatment. The level of (1-->3),(1-->6)-beta-D-glucan in the cell walls was analyzed enzymatically. The antioxidant activity was determined by electron paramagnetic resonance spectrometry and Trolox equivalent antioxidant capacity assay. The results show that the antioxidative activity of yeast cell wall proteins exceeds that of beta-glucan greatly. Especially aromatic side chains and free thiols from denatured proteins seem to work as antioxidants.  相似文献   

19.
Heat treatments have been used to extend storability of several fruits, although no information is available about their effects on nutritive and functional properties in pomegranates, which was the objective of this research. Thus, pomegranate fruits were heat treated (dips at 45 degrees C for 4 min) and stored at 2 degrees C for 90 days. Every 15 days, samples were taken and further stored 2 days at 20 degrees C for shelf life study. Arils from heat-treated pomegranates exhibited higher total antioxidant activity than controls, which was correlated primarily to the high levels of total phenolics and to lesser extent to ascorbic acid and anthocyanin contents. Additionally, the levels of sugars (glucose and fructose) and organic acids (malic, citric, and oxalic acids) remained also at higher concentrations in arils from treated fruits. With this simple and non-contaminant technology, the functional and nutritive properties, after long periods of storage, could then be even greater than in recently harvested fruits, thus providing a high content in health-beneficial compounds to consumers after the intake of these fruits.  相似文献   

20.
Four cultivars of strawberries (Senga Sengana, BFr77111, Elsanta, and Honeoye) were studied for their content of antioxidants, total antioxidant capacity, and low molecular weight carbohydrates in relation to harvest year, ripening stage, and cold storage. For ascorbic acid, chlorogenic acid, ellagic acid, and total antioxidative capacity, measured in both water-soluble and water-insoluble extracts, there was a 2-5-fold variation among cultivars. Unripe berries contained lower concentrations of chlorogenic acid and p-coumaric acid and also quercetin and kaempferol compared with riper berries. During cold storage for up to 3 days, relatively few changes in the concentration of the different antioxidants occurred. The concentrations of several investigated parameters were interrelated, for example, for ascorbic acid and water-soluble antioxidant capacity and for ellagic acid and water-insoluble antioxidant capacity. The dominating sugars in strawberries were fructose and glucose, but considerable amounts of sucrose were also present, and their contents varied among cultivars, giving a predicted glycemic index of approximately 81. Verbascose, raffinose, and stachyose were found in only minor amounts. The study shows that the concentration of a number of bioactive compounds in strawberries varied according to cultivar, ripening stage, and storage. This information should make it possible to select strawberries with an optimal content of bioactive compounds.  相似文献   

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