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1.
The objective of this study was to optimise the temperature (25–50 °C), time (1–24 h) and the solvent ratio (ethanol/water, 0–100%) for the phenolic compounds extraction of Ghure marc (unripe grape) using response surface methodology. The central composite design (CCD) generated satisfactory models for the optimisation of process variables. The results revealed that the ratio (X3) was the most significant parameter on total phenolic content (TPC) and antioxidant activity [% 2‐diphenyl‐1‐picrylhydrazyl (DPPH)], and there was a significant correlation between TPC and antioxidant activity. The optimal conditions for temperature and time were 44.93 °C and 19.34 h, respectively, and the ratio of ethanol to water was 70.08, which verified with carrying out confirmatory experiments. Under this condition, TPC and %DPPH were 388.79 mg GAE per 100 g and 91.01, respectively. The results of this study revealed that the Ghure marc can be used as a low‐cost source of natural antioxidant in food.  相似文献   

2.
Murta (Ugni molinae T.) berries were air‐dried at five temperatures (40, 50, 60, 70 and 80 °C), and the changes in β‐carotene, phenolic acids, total phenolic and flavonoid contents and antioxidant capacities (DPPH and ORAC) were investigated. The berries showed a high content of β‐carotene, which decreased during drying temperature between 40 °C and 80 °C. Free and bound phenolic acids were also determined, showing gallic acid to be the prevalent phenolic acid. Total phenolic and flavonoid contents in the dried berries showed a higher decrease at lower temperature due to longer drying time. The radical‐scavenging activity also showed higher antioxidant activity at higher drying temperatures (70–80 °C) than at lower drying temperatures (40–50 °C). Total phenolic content (TPC) and flavonoids showed good correlation with antioxidant capacity. Murta berries proved to be an excellent source of antioxidants and bioactive compounds and are therefore a potential ingredient for new functional food products.  相似文献   

3.
Bioactive compounds from Brazilian hop (Humulus lupulus L.) cultivars were extracted by ultrasound and their phenolic profile compared with commercial hop from the USA. The most effective extraction conditions (solution of ethanol 49%, at 52 °C and a solid/liquid ratio of 1 g per 34 mL) for the total phenolic compounds (TPC) were determined using a Central Composite Rotatable Design. The Brazilian hop showed higher content of TPC (33.93 ± 0.67 mg GAE g−1), total flavonoids (54.47 ± 0.10 mg QE g−1) and higher antioxidant activity (ABTS: EC50 21.29 ± 1.36 μL mL−1; DPPH: EC50 3.91 ± 0.17 μL mL−1) when compared with the USA hop. The main phenolic compounds present in the extracts were the flavonoids isoquercitrin and quercetin. The antioxidant properties of the Brazilian hop extract had not been reported yet in the literature for this raw material, thus showing potential to be incorporated in polymeric films used as active packaging.  相似文献   

4.
The optimum extraction conditions for highest recovery of total phenolics content (TPC) and antioxidant capacities (AC) were analysed for Mangifera pajang peels (MPP), using response surface methodology. The effects of ethanol concentration (X1: 20–80%), extraction temperature (X2: 30–65 °C) and liquid-to-solid ratio (X3: 20–50 mL/g) on the recovery of total phenolics (Y1) and antioxidant capacity (Y2) were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolic content (R2 = 0.9966, p < 0.0001) and antioxidant capacity (R2 = 0.9953, p < 0.0001). The optimum extraction conditions for TPC were 68%, 55 °C and 32.7 mL/g, and for AC were 68%, 56 °C and 31.8 mL/g, respectively. Predicted values for extraction of TPC and AC agreed well with the experimental values. Liquid chromatography–mass spectrometry of the optimally obtained extracts from MPP revealed the major phytochemicals as mangiferin, gallic acid, catechin and epicatechin.  相似文献   

5.
Rice bran, the industry byproduct, contains high levels of phenolic compounds. Based on glycerol, a green recovery of phenolics from rice bran was proposed. Extraction temperature (X1), glycerol concentration (X2) and liquid-to-solid ratio (X3) were optimised by response surface methodology. Basic physical properties, that is, viscosity, conductivity, density were analysed and UPLC-Triple-TOF/MS method was applied for phenolic identification. Results showed the optimum conditions were X1 = 66.76 °C, X2 = 19.47% and X3 = 32.92 mL g−1. Under these conditions, the recovery yield in total polyphenols was 708.58 ± 12.36 mg GAE/100 g DW. Moreover, the recovery capacity of phenolic compounds was significantly correlated with viscosity, conductivity and density of glycerol solution. Under the optimal conditions, totals of thirteen phenolic compounds were identified and phenolic acids (4-hydroxybenzoic acid, vanillic acid, syringic acid, 4-coumaric acid, ferulic acid and salicylic acid) were quantified. These results demonstrate glycerol can serve as an ideal green solvent to recover phenolic compounds from rice bran.  相似文献   

6.
The nutrient profile and the phytochemical composition of the sapucaia nut cake milk (SNCM) were evaluated after applying five consecutive stages of block freeze concentration (C1, C2, C3, C4 and C5). The profile of phenolic compounds by LC-ESI-MS/MS and the antioxidant activity (ABTS and FRAP) of SNCM were also determined. The freeze concentration increased proteins, lipids, carbohydrates, ash, soluble solids (°Brix) and total phenolic compounds (TPC) in all stages and in the ice fractions obtained from C1, C2 and C3 stages. The antioxidant activity (ABTS) in C3, C4 and C5 fractions was highly significant (P < 0.05). The antioxidant activity (FRAP) and the phenolic compounds (gallic, vanillic, ferulic, sinapic and salicylic acids, catechin, taxifolin and sinapaldehyde) increased significantly (P < 0.05) for all five fractions. The freeze concentration was successfully used for enriching the SNCM, generating a promising ingredient for the food industry.  相似文献   

7.
The aim of this study was to evaluate the impact of ultrasound (US) at different frequencies (20, 370, and 583 kHz) and power levels (35 and 48 W) on the residual activity (RA) of peroxidase (POD) and polyphenol oxidase (PPO) in strawberry puree. Total anthocyanin content (TAC), total phenolic content (TPC), ferric ion reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) were also assessed. Results were compared with untreated, thermally treated at 40 °C (control) and pasteurized (90 °C) strawberry puree. POD and PPO RA were significantly (P < 0.05) reduced, whilst there was a significant (P < 0.05) increase in TAC (5%–19%) in all US-treated samples in comparison with the untreated samples and the controls. US at 20 kHz (35 W) increased significantly (P < 0.05) TPC (9%) and FRAP (6%) in strawberry puree, whereas the effect of 583 kHz (48 W) on these parameters was insignificant (P > 0.05). Pasteurization inactivated POD and PPO, however, decreased dramatically TAC (14%), TPC (17%) and FRAP (9.5%) in strawberry puree. These findings suggest that US is a promising novel non-thermal food technology that can be tailored to improve the quality of strawberry puree by inactivating enzymes responsible for food deterioration whilst maintaining the content of bioactive compounds.  相似文献   

8.
Effect of thermosonication on carrot juice containing peel (CJPL) and pulp (CJPP) extracts from orange at different concentration (0.5, 2.0 and 4.0 mg GAE per g extracts) of total phenolic contents (TPC) was evaluated for quality attributes. Thermosonication of juice was done at 52 °C, 6 min for CJPL and 60 °C, 5 min for CJPP (values based on our preliminary optimisation results of ultrasound process conditions of the juice) at 40 kHz and 110W. Effect of thermosonication and addition of peel and pulp extracts at highest concentration increased the TPC and antioxidant activity of the juice (P < 0.05). Highest inactivation of microorganisms and better sensory attributes was achieved in thermosonicated CJPP for 21 days. Titratable acidity, pH, browning index and viscosity were improved by thermosonication and at highest extract concentration. °Brix and total carotenoid were not significantly affected by treatments. Therefore, thermosonication at 60 °C and 4.0 mg GAE per g extract concentration of peel and pulp may be used in formulation of functional carrot juice with improved health properties.  相似文献   

9.
The purpose of this study was to investigate the enhancing effect of heat treatment (110 and 130 °C for 0.5, 1.0, 1.5 and 2.0 h, and 150 °C for 1.5 h) on antioxidant activity and phenolic compounds of immature calamondin (Citrus mitis Blanco). The results indicated that heat treatment could enhance the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) scavenging potency, oxygen radical absorbance capacity (ORAC) and total phenolic content. However, the major flavonoid, 3′,5′‐di‐C‐β‐glucopyranosylphloretin (DGPP), decreased drastically after being heated at ≥130 °C over 1.5 h. The increasing ratio of absorbance at UV420 nm coincided with the change of the antioxidant activity. Therefore, it was concluded that the browning products resulted in the increase of the antioxidant activity of immature calamondin heated at ≥130 °C over 1.5 h, while the increase of antioxidant activity at 110 and 130 °C ≤ 1.0 h heating was due to increased phenolic content.  相似文献   

10.
Germination has been proposed as an economic approach to improve the content of bioactive compounds in pseudocereals. In this work, response surface methodology (RSM) was employed to investigate the impact of germination conditions on the phytochemical content and antioxidant activity of quinoa. The use of desirability methodology showed that the optimum conditions to maximise the content of total phenolic content (TPC) and antioxidant activity in sprouted quinoa were 20 °C for 42 h. Sprouts produced under these conditions exhibited increases of 80% and 30% in TPC and antioxidant activity, respectively, compared to un‐germinated seeds, and contained high γ‐aminobutyric acid (GABA) concentration. The nonsignificant lack‐of‐fit and high determination coefficients obtained confirmed the suitability of the predictive models developed for TPC and antioxidant activity, whilst the one obtained for GABA was not significant (R2 < 0.75) within the conditions studied. Sprouting under optimum conditions enhanced the content of both flavonoid and nonflavonoid compounds, being the increase in flavonoids more pronounced. Kaempferol‐O‐dirhamnosyl‐galactopyranose and quercetin‐O‐glucuronide were the compounds that experienced the most noticeable increase in quinoa after germination. In conclusion, this study provides useful information on the optimum germination conditions to improve the levels of health‐promoting compounds in quinoa.  相似文献   

11.
In the present study Box–Behnken Design was employed to analyse the effects of fermentation parameters such as temperature (T F), pH, inoculum size (I S) and °Brix (BX) on total phenolic concentration (TPC), total flavonoid concentration (TFC), total anthocyanin concentration (TAC), ethanol concentration (ETHC), total higher alcohol concentration (THAC) and total ester concentration (TESC) for the development of a phytochemical‐rich wine using mulberry as a substrate. The results demonstrated that fermentation parameters significantly alter the wine characteristics. Hence, a wine with excellent consumer preference (overall acceptability of 8.51) and high concentration of phytochemicals (TPC = 6014.03 ± 27.80 mg L−1, TFC = 4791.35 ± 21.22 mg L−1, TAC = 1480.72 ± 5.33 mg L−1) as well as good aromatic properties (ETCH =82.85 ± 0.87 g L−1, THAC =249.91 ± 0.31 mg L−1 and TESC =52.55 ± 0.17 mg L−1) with high antioxidant activity (DPPH =220.18 mmol·l−1) was obtained at optimized fermentation conditions of T F = 25°C, pH = 4.00, I S = 10% (v /v) and BX = 26. The results from the present study might contribute to strengthening the development of wine containing high concentrations of phytochemical compounds with attractive olfactory attributes. Copyright © 2017 The Institute of Brewing & Distilling  相似文献   

12.
The standard static gravimetric method was used to determine moisture desorption isotherms (MDIs) of two onion varieties (Goudami and Galmi Violet) at 30 °C, 45 °C and 60 °C in the water activity ranging from 0.055 to 0.83. The combined effects of temperature and water activity on the antioxidant activities of the onion varieties were also studied. GAB, Oswin, Smith and BET equations were tested to fit the experimental data. The net isosteric heat of sorption was calculated. Equilibrium moisture content (EMC), total phenolic content (TPC) and antiradical activity were also measured. The isotherm and the EMC vary significantly with the onion variety and drying temperature, irrespective of water activity (aw). Desorption isotherms were best described by the GAB model. The maximum net isosteric heats for Galmi Violet (32.58 kJ mol?1) were greater than those of Goudami (23.50 kJ mol?1) at each EMC. The TPC and antiradical activity of the Galmi Violet were significantly (≤ 0.05) higher than that of the Goudami at all investigated temperatures and water activities.  相似文献   

13.
Abstract: The production of grape seed flour (GSF) from a waste product generated during winemaking, is of interest in product development applications due to its potential health benefits. However, before GSF can used in baking as a source of additional antioxidants, research on its heat stability is required. The overall objective of this study was to assess changes in phenolic content and antioxidant activity of GSF during heating. Merlot GSF was heated at 5 temperatures (120 to 240 °C) for 0 to 90 min. At each time/temperature combination, total phenolic content (TPC), total flavanoid content (TFC), Trolox equivalent antioxidant capacity (TEAC), 2,2 diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging, and ferric ion reducing antioxidant power (FRAP) of the extracts were determined. Specific polyphenolic compounds, including catechin, gallocatechin, epicatechin, and gallic acid were also measured. Results showed that when Merlot GSF was heated to ≥180 °C, significant decreases in the TPC and antioxidant activity, measured using FRAP, DPPH, and TEAC, were observed. Longer heating times also caused a reduction in antioxidant capability. Catechin and epicatechin content decreased with increasing heating temperature while gallocatechin and gallic acid content increased. Both catechin and epicatechin content had strong positive correlations (r > 0.91) with TPC and TFC, as well with FRAP and TEAC, suggesting that the GSF antioxidant activity is related to the presence of these particular compounds. Overall, while a decrease in antioxidant content was observed during heating, this occurred at higher baking temperatures. Thus GSF may be suitable for use as an ingredient in baked goods to bolster antioxidant content. Practical Application: In order for Merlot grape seed flour (GSF) to be used in baking as a source of additional antioxidant compounds, the impact of heating on the polyphenolic compounds in the GSF needed to be examined. Thermal treatment of Merlot GSF caused significant decreases in the TPC, antioxidant power, and specific polyphenolic compounds when heated ≥180 °C. Thus while antioxidant content decreased with higher heating temperatures, this occurred at higher baking temperatures. Thus, GSF may be suitable for use as an ingredient in baked goods to bolster antioxidant content.  相似文献   

14.
The total phenolic (TP) content, phenolic acid composition and in vitro antioxidant capacity of whole wheat doughnuts fried at 120–180 °C were determined to identify the effects of frying temperature. Significant differences (P < 0.05) in TP content were observed between doughnuts fried at different temperatures. The TP content of doughnuts decreased significantly when doughnuts were deep‐fat fried. The TP content of doughnuts increased with elevation with frying temperatures. These increases in TP content of doughnuts were also detected in the determination of individual phenolic compounds using HPLC. DPPH radical and iron‐chelating capacity of deep‐fat fried doughnuts exhibited increases with elevation of frying temperature from 120 to 180 °C. Deep‐fat frying at 120 °C lowered lipid peroxidation inhibition capacity of doughnuts prepared from both refined flour and whole‐grain meals and increased consistently with increased frying temperature from 120 to 180 °C. Moderate deep‐fat frying temperature would increase the content and activity of antioxidants of doughnuts.  相似文献   

15.
Passion fruit seeds are currently discarded on the pulp processing but are known for their high piceatannol and scirpusin B contents. Using pressurized liquid extraction (PLE), these highly valuable phenolic compounds were efficiently extracted from defatted passion fruit bagasse (DPFB). PLE was performed using mixtures of ethanol and water (50 to 100% ethanol, w/w) as solvent, temperatures from 50 to 70 °C and pressure at 10 MPa. The extraction methods were compared in terms of the global yield, total phenolic content (TPC), piceatannol content and the antioxidant capacity of the extracts. The DPFB extracts were also compared with those from non-defatted passion fruit bagasse (nDPFB). Identification and quantification of piceatannol were performed using UHPLC–MS/MS. The results showed that high TPC and piceatannol content were achieved for the extracts obtained from DPFB through PLE at 70 °C and using 50 and 75% ethanol as the solvent. The best PLE conditions for TPC (70 °C, 75% ethanol) resulted in 55.237 mg GAE/g dried and defatted bagasse, whereas PLE at 70 °C and 50% ethanol achieved 18.590 mg of piceatannol/g dried and defatted bagasse, and such yields were significantly higher than those obtained using conventional extraction techniques. The antioxidant capacity assays showed high correlation with the TPC (r > 0.886) and piceatannol (r > 0.772). The passion fruit bagasse has therefore proved to be a rich source of piceatannol and PLE showed high efficiency to recover phenolic compounds from defatted passion fruit bagasse.  相似文献   

16.
Brassicaceae oilseeds provide feedstocks for the biofuels industry, but value‐added coproducts are necessary to supply financial incentives for increased production. Our objective was to use high‐intensity ultrasound to optimize extraction of antioxidants from mustard (Brassica juncea) seed meal. The ultrasound‐assisted extraction (UAE) variables included temperature, solvent‐to‐material ratio, sonication duration, and EtOH concentration. Extracts were analyzed for total phenolics content (TPC), antioxidant activity, and sinapine content. Conventional extraction using water and 70% EtOH (v/v) at 80 °C for 3×30 min yielded 7.83 ± 0.07 and 8.81 ± 0.17 mg sinapic acid equivalents (SAE)/g meal, respectively. UAE extraction at 40 °C for 30 min yielded similar phenolics content (8.85 ± 0.33 mg SAE/g meal) as conventional hot ethanolic extraction, but required less time and lower temperature. The highest TPC (13.79 ± 0.38 mg SAE/g meal) was in the 7‐d aqueous extracts. Sonicated solutions of pure sinapine and sinapic acid showed 1st‐order reaction kinetics with greater degradation of isolated compounds than those present in extracts. Sinapine contained in extracts showed insignificant (P < 0.05) degradation after 30 min of sonication. Our research indicates that ultrasound treatment can assist the extraction of antioxidants from B. juncea meal by reducing both the temperature and time requirement without significant degradation of the primary antioxidants present.  相似文献   

17.
The impact of noodle processing, storage and cooking on the total phenol content (TPC) and total flavonoid content (TFC) was assessed. Total phenol content (TPC) and total flavonoid content (TFC) of mixed flour were 77.50 and 39.56 mg per 100 g, respectively, and it decreased to 71.80 and 36.30 mg per 100 g after noodle processing. For the fresh Qingke barley noodles (FQBNs), stored at 25 °C, both TPC and TFC decreased significantly during storage. After cooking the fresh noodles, the TPC of the noodles stored for 0 and 4 h increased, while it decreased for the noodles stored for 8, 16 and 24 h; the TFC of all cooked Qingke barley noodles (CQBNs) decreased. Compared with the flour, the DPPH, ABTS•+, HO and scavenging ability and ferric reducing antioxidant power (FRAP) decreased significantly (P < 0.05) after noodle processing. For FQBN, increased storage time led to a reduction in antioxidant ability. After cooking, the DPPH and HO scavenging ability and FRAP of noodles stored at 25 °C for 0 and 4 h, and the ABTS•+ and scavenging ability of noodles stored at 25 °C for 0, 4 and 8 h increased. Overall, noodle processing, storage and cooking will affect the phenolic compound content and antioxidant activities of barley noodles. Although the shelf life of FQBN is 17 h at 25 °C, from the perspective of nutrition, it is not suitable for long-term storage, and it is best choice to consume it within the first 4 h.  相似文献   

18.
This study aimed to optimise aqueous extraction conditions for total phenolic compounds (TPC) from Davidson's plum (Davidsonia pruriens F. Muell) and to assess the physicochemical and antioxidant properties of the phenolic‐enriched extract. The results showed that temperature, time and ratio significantly affected the extraction of TPC. Optimization of extraction conditions was performed using response surface methodology (RSM) utilising a Box–Behnken design. Optimal extraction conditions were determined to be temperature: 90 °C, extraction time: 30 min and solvent to mass ratio: 20:1 mL g?1. The extracted solid obtained under these conditions had low‐moisture content, high water solubility and contained 45 mg GAE g?1 of TPC, 22 mg RUE g?1 of flavonoids, 3.2 mg CAE g?1 of proanthocyanidins, 2 mg CGE g?1 of anthocyanidins and 56 mg ACE g?1 vitamin C. The extract possessed potent antioxidant capacity, but was comparatively lower than those of vitamin E and BHT. Thus, Davidson's plum should be further investigated for its potential health promoting benefits and utilisation in the nutraceutical and food industries.  相似文献   

19.
The impact of heat treatment using hot air (HT 45 °C and 55 °C for 1 h) and two active modified atmosphere packaging (MAP) conditions of high oxygen atmosphere (HOA: 80 kPa O2, 20 kPa N2) and high CO2 atmosphere (HCA: 20 kPa CO2, 80 kPa N2), individually or combined, on the antioxidant capacity, polyphenols, vitamin C content, total anthocyanins, polyphenoloxydase (PPO) activity and shelf life of fresh‐cut (FC) pomegranate arils stored for 14 days at 4 °C was studied. The results indicate that HT 45 °C along with HOA inhibited PPO activity and prevented loss of antioxidant capacity, vitamin C and phenolic compounds in arils, in comparison with control and HT 55 °C. All treatments reduced the accumulation of anthocyanins, but HCA‐treated arils lost more anthocyanins besides having worse a* colour parameter values. No significant differences in titrable acidity (TA) and total soluble solids (TSS) were observed between treatments. The combination of HOA and HT 45 °C enhanced the benefits of applying each treatment separately and could be useful to improve and extend postharvest life of pomegranate FC arils.  相似文献   

20.
Pressurised liquid extraction (PLE) of antioxidant compounds from bitter gourd fruits (Momordica charantia) in aqueous ethanolic solvent was investigated using response surface methodology at laboratory scale to understand key impact of extraction variables. Extraction efficiency was optimised by measuring the yield of extraction, total phenolic content (TPC), total flavonoid content (TFC), ferric reducing/antioxidant power assay (FRAP) and radical scavenging activity (RSA). The optimal extraction conditions were reached at 80% ethanol concentration, 10‐min extraction time and at 160 °C. Under these extraction conditions, values of TPC (5.40 ± 0.30 g GAE per 100 g), TFC (1.50 ± 0.10 g QE per 100 g), FRAP (778.55 ± 10 μmol eq Fe (II) g?1), yield (178.50 ± 5.50 mg g?1 dc) and RSA (75.50 ± 4.50%) were achieved. Furthermore, statistical analysis revealed that antioxidative attributes of bitter gourd extract were strongly and positively correlated with extraction temperature and ethanol concentration rather than processing time. This study illustrated that PLE has the potential to extract antioxidant compounds from tropical fruit vegetables in an accelerated manner. Furthermore, influential parameters affecting the process could be optimised for further industrial intake.  相似文献   

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