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1.
Thirty lambs were assigned to the following treatments: control diet (C) rich in omega-3 fatty acids; C plus 900 ppm red wine extract (RWE), or C plus 300 ppm vitamin E (VE). Oxidative stability and sensory properties of chops stored in MAP (70% O2/30% CO2) during 12 days were evaluated. Chops from the VE group showed lower lipid oxidation (p < 0.001) and protein carbonylation (p < 0.05), stable omega-3 fatty acids proportions and overall liking sensory scores (p < 0.05). Dietary RWE supplementation did not influence oxidative stability of chops, however levels of C20:5n-3 were greater (p < 0.05) and n-6/n-3 ratio (p < 0.01) was lower, relative to controls.  相似文献   

2.
The application of high hydrostatic pressure (HHP) in winemaking for substitution of the use of sulphur dioxide is still at a very early stage of development, since knowledge about the effect on physicochemical and sensorial characteristics of the wine during storage is very scarce. In this work, the evolution of colour, antioxidant activity and total phenolic compounds of SO2-free red wines treated by HHP and aged in bottles was followed for 12 months. The pressurised wines were compared with wine samples prepared with addition of 40 ppm of SO2 and without any of these two treatments. After 12 months, the pressurised wines presented higher values of CIELab parameters (a, b, and L) and a lower monomeric anthocyanin content (45–61%) when compared to the unpressurised ones. The pressurised wines showed also a better global sensorial assessment, with the pressure treatments imparting aged-like characteristics to the wines. The wine deposits of pressurised wines had higher total phenolic content, namely proanthocyanidins (3- to 10-fold). The results demonstrate that HHP can influence long term red wine physicochemical and sensorial characteristics, hypothesised to be due to an increase of condensation reactions of phenolic compounds, forming compounds with higher degree of polymerisation that became insoluble in wine along storage.  相似文献   

3.
Thirty-two lambs were fed with barley straw supplemented by a concentrate alone, or a concentrate enriched with either vitamin E (VITE006: 0.6 g kg−1 feed concentrate) or carnosic acid (CARN006: 0.6 g kg−1 feed concentrate; or CARN012: 1.2 g kg−1 feed concentrate). In order to elucidate the influence of the dietary supplementation of carnosic compared with a reference diet antioxidant (vitamin E), the animals were slaughtered and the longissimus thoracis were lyophilised to determine the FAs profile and the phenolic compounds. In addition, longissimus lumborum slices were stored in a modified atmosphere package for 3 days and then grilled to determine volatile compounds. Dietary carnosic acid did not modify the FAs profile, but had a clear effect on the production of volatile compounds, in a dose-dependent manner. These results have implications for the food industry, since dietary carnosic acid seems to extend the shelf life of lamb meat.  相似文献   

4.
The effect of supplementing PUFA-rich cull cow diets with vitamin E (2.8 g/animal/day) or vitamin E plus plant extracts rich in polyphenols (PERP) (126 g/animal/day), for 101 ± 3 days preceding slaughter, on the oxidative stability of longissimus thoracis (LT) and semitendinosus (ST) steaks was evaluated after ageing (for 12 d at 4 °C either in carcass or under-vacuum) and packaging (14 d under-vacuum (V), 4 d aerobic (A) and 7 d under modified atmosphere (70:30, O2/CO2) (MA)). The ageing method had no effect on a beef lipid oxidation intensity marker (malondialdehyde (MDA)), whereas packaging systems containing O2 (A and MA) significantly increased lipid oxidation intensity (5 and 13 times higher than under V, respectively). Adding antioxidants to diets of animals given a PUFA-rich diet significantly improved lipid stability in steaks; the combination of vitamin E and PERP was more efficient than vitamin E alone for the most deleterious beef packaging.  相似文献   

5.
Lipid oxidation mediated by haemoglobin from tilapia was monitored in washed Asian sea bass mince with and without added tannic acid (200 and 400 ppm) during 10 days of iced storage. Control samples (without tannic acid) had the highest peroxide value (PV) within the first 2 days and possessed the greater amount of thiobarbituric acid-reactive substances (TBARS) throughout the storage of 10 days (< 0.05). With addition of tannic acid, the lipid oxidation of washed Asian sea bass mince was retarded, especially when the higher level (400 ppm) was used, as evidenced by lowered PV and TBARS. The retarded formation of volatile lipid oxidation products in the samples with added 400 ppm tannic acid was found. Sensory analysis revealed that samples with added 400 ppm tannic acid possessed lower fishy odour score, compared with the control sample and that with added 200 ppm tannic acid (< 0.05).  相似文献   

6.
The effects of addition of vitamin D3 and vitamin E to pig diets on blood plasma calcium concentration, meat quality (longissimus muscle) and antioxidative capacity were investigated. Two treatments consisted of supplementation with vitamin D3 (500,000 IU/d) for 5 days separately (group D) and a combination of vitamin E (500 mg α-tocopheryl acetate/kg diet) for 30 days and vitamin D3 (500,000 IU/d) for 5 days (group D + E) to growing-finishing pigs before slaughter. Pigs fed with vitamin D3 had higher (P < 0.01) plasma calcium concentration compared with control pigs. Dietary supplementation of vitamin E significantly (P < 0.05) increased the concentration of α-tocopherol in meat (longissimus muscle). Vitamin D3 supplementation resulted in higher (P = 0.07) a values of loin chops at 5 days of storage. Vitamin D3 and vitamin E supplementation did not affect other meat quality characteristics or tenderness (quantified by Warner–Bratzler shear force). Antioxidative capacity (measured as MDA production after incubation of longissimus muscle homogenates with Fe2+/ascorbate) was improved by vitamin E and partly by vitamin D3 supplementation.  相似文献   

7.
The effects of different initial in-package O2 and CO2 concentrations (2.5 kPa O2 + 7 kPa CO2, 10 kPa O2 + 7 kPa CO2, 21 kPa O2, 30 kPa O2 and 70 kPa O2) on peroxidase activity, vitamin C content, total phenolics and antioxidant capacity of fresh-cut ‘Piel de Sapo’ melon have been investigated for 14 days at 4 °C. The radical scavenging activity of fresh-cut melon strongly increased after 9 days storage related to a synthesis of phenolic compounds, especially under 2.5 kPa O2 + 7 kPa CO2 atmospheres. Low O2 levels best maintained vitamin C and phenolic content during the storage. However, stressful too-low O2 and high CO2 levels induced an important increase of peroxidase activity under 2.5 kPa O2 + 7 kPa CO2 atmosphere, which was directly related to changes of vitamin C throughout storage. Therefore, 70 kPa O2 atmospheres are proposed to prevent anaerobic conditions during storage of fresh-cut melon and thus, reduce wounding stress and deteriorative changes related to high peroxidase activity in tissue.  相似文献   

8.
Three levels (0%, 1% and 2%) of a conjugated linoleic acid enriched oil (CLA) were combined with two levels of monounsaturated fatty acids (MUFA) (19% and 39% average) for pig feeding. Changes in instrumental colour, lipid oxidation (thiobarbituric acid reactive substances, TBARS) and volatile profile of fresh loin chops, as affected by dietary CLA, MUFA and CLA × MUFA, were studied throughout 7 days of refrigerated storage. Lightness (L∗) evolution was conditioned by dietary CLA, whereas changes in redness (a∗) and yellowness (b∗) were unaffected by dietary supplements. Dietary CLA at 2% led to higher TBARS values of loin chops at day 7 of refrigerated storage (p < 0.05), while MUFA supplementation and CLA × MUFA interaction did not affect lipid oxidation. Dietary CLA, MUFA or CLA × MUFA did not affect most volatile compounds of loin chops after 7 days of storage.  相似文献   

9.
The feasibility of minimal processing and modified atmosphere packaging (5%O2+5%CO2) to preserve color attributes and bioactive compounds of fresh-cut tomato from different cultivars (Rambo, Durinta, Bodar, Pitenza, Cencara and Bola) was evaluated through storage under refrigeration. The phenolic compounds and vitamin C content of the six cultivars varied between 187.4 and 335.9 mg/kg fw and from 69.6 and to 212.3 mg/kg fw, respectively. The highest content of lycopene was found in Bodar tomatoes (80.5 mg/kg fw) while the concentration in the other cultivars ranged between 20.0 and 43.1 mg/kg fw. Antioxidant capacity, measured on the basis of the DPPH stable radical, was higher than 9.8% of DPPH inhibition. Neither the content of health-related compounds (lycopene, vitamin C and phenolic compounds) nor the antioxidant capacity changed significantly between whole and just-processed fresh-cut tomatoes. Furthermore the initial colors of fresh-cut tomatoes as well as vitamin C were maintained for 3 weeks under cold storage. The antioxidant capacity was well correlated with vitamin C and phenolic content, whereas lycopene was directly related to color measurements (a*, L* and H*). Minimal processing maintains the main antioxidant compounds and color parameters of slices tomatoes for 21 days at 4 °C, thus preserving their initial nutritional value.  相似文献   

10.
In the present paper, a method for the determination of trans-resveratrol in red wine samples, by adsorptive stripping square-wave voltammetry (Ad-SSWV) in a glassy carbon electrode, is presented. In 0.10 M perchloric medium, trans-resveratrol experiments an adsorptive–oxidative process, which promotes the appearance of a peak at 0.72 V. Calibration graph have been constructed from 5.0 to 35 ng/mL. Detection limit of 4.2 ng/mL has been calculated, according to Clayton criterion. Extraction of trans-resveratrol from red wine with diethylether and posterior clean-up with C18 cartridges is carried out. Recovery percentages close to 100% have been calculated with different red wine samples. The accumulation of analyte in the electrode is carried out at +0.60 V for 60 s, in the presence of 0.10 M HClO4 and 10% of ethanol; the measurement stage is performed after a medium exchange, in 0.10 M HClO4 and 30% of ethanol. The standard addition method was employed for the analysis of real samples, since a matrix effect is observed in red wine extract. The method has been applied to several commercial red wines samples, and the results have been satisfactorily validated by HPLC.  相似文献   

11.
Effects of lyophilized Urtica dioica L. water extract (LUWE) and modified atmosphere packaging (MAP) on the quality and shelf life of ground beef were investigated. Ground beef was stored as aerobic control, MAP (80%O2 + 20% CO2), MAP + 250 ppm LUWE and MAP and 500 ppm LUWE at 2 ± 0.5 °C for 14 days. MAP and LUWE had significant effects on mesophilic, psychrotrophic and lactic acid bacteria and Pseudomonas counts. Depending on the level of LUWE, Pseudomonas and psychrotrophic counts decreased. Treatment with 500 ppm LUWE + MAP showed the lowest TBARS values compared to other groups during storage. 80% O2-MAP increased TBARS values. Treatment had no significant effect on L* and b* values of the exterior of the ground beef, but had significant effects on the color of interior sections.  相似文献   

12.
HS-SPME–GC–MS analysis of Aglianico del Vulture red wine from Southern Italy showed the presence of ethyl acetate, 3-methyl-1-butanol, 3-methylbutyl acetate, ethyl hexanoate, diethyl butanedioate, ethyl octanoate, and ethyl decanoate. Thermal treatment for 24 h in the 20–60 °C range showed that for most of the compounds analysed the simple transition from 20 to 30 °C induces a significant modification on the composition of volatile compounds. A sharp decrease was observed for ethyl acetate, diethyl butanedioate, and 3-methylbutyl acetate; a moderate decrease was observed for ethyl hexanoate, while an increase was observed for 3-methyl-1-butanol, ethyl octanoate, and ethyl decanoate. The temperature of 40 °C induces the maximum evolution of this type of compound. Higher temperatures induce a reduction of volatile compounds in wine. Irradiation of Barolo (red wine, Northern Italy), Amarone (red wine, Northern Italy), and Brunello di Montalcino (red wine, Central Italy), at 20 °C was performed with a 13 W neon lamp. 3-Methyl-1-butanol was affected by the irradiation. In the case of Barolo and Amarone, we observed a moderate increase, while, for Brunello di Montalcino, a decrease was observed. In the same way, esters were degraded during irradiation. In the red wine one or more components (phenols?) are able to protect esters from photodegradation. In diethyl butanedioate and ethyl hexanoate, octanoate, and decanoate we observed an initial increase of the concentration of the esters in some cases.  相似文献   

13.
As part of the ongoing research into the chemical composition of the uniquely South African wine cultivar Pinotage, the volatile composition of nine young wines of this cultivar was investigated using comprehensive two-dimensional gas chromatography (GC × GC) in combination with time-of-flight mass spectrometry (TOFMS). Headspace solid phase micro-extraction (HS-SPME) using a carboxen/polydimethylsiloxane (CAR/PDMS) fibre was used to extract the volatile compounds from the wine matrix. Extracts were analysed using an in-house developed GC × GC system equipped with a single jet, liquid nitrogen-based cryogenic modulator. In the current study, 206 compounds previously reported in wine and related matrices have been detected in nine Pinotage wines. Positive identification for 48 compounds was performed using authentic standards, while tentative identification of 158 compounds was based on deconvoluted mass spectra and comparison of linear retention indices (LRI) with literature values. Identified compounds included esters, alcohols, aldehydes, ketones, acids, acetals, furans and lactones, sulphur compounds, nitrogen compounds, terpenes, hydrocarbons, volatile phenols and pyrans. Volatile compounds potentially capable of influencing wine aroma are highlighted. Many of the compounds were common to all 9 wines, although volatile components unique to specific samples were also observed. The results represent the most detailed characterisation of volatile constituents of this cultivar reported to date.  相似文献   

14.
In this study, 10 young steers received no beta agonist (C), 50 animals all received zilpaterol hydrochloride (Z), with 1 group receiving Z while the other 4 groups received Z and vitamin D3 at the following levels (IU/animal /day) and durations before slaughter: 7 million for 3 days (3D7M) or 6 days (6D7M), 7 million for 6 days with 7 days no supplementation (6D7M7N) and 1 million for 9 days (9D1M). LD samples were vacuum-aged 14 days post mortem, and repacked in high-oxygen modified atmosphere (70% O2/30% CO2) for a further 7 days. Parameters included Warner Bratzler shear force (WBSF), myofibril fragment length, thiobarbituric acid reactive substances, free thiol levels, muscle fat, and instrumental colour parameters. When allowing for a conversion period of vitamin D3 to its active metabolites, supplementing the zilpaterol treated steers with a high dosage of vitamin D3 (6D7M7N) resulted in improved colour stability, higher stability towards protein oxidation and lower stability towards lipid oxidation.  相似文献   

15.
The objective of this study was to investigate the effect of vitamin E supplementation on oxidative status in blood, liver, milk, and ovarian follicular fluid in periparturient heifers. Vitamin E supplementation started 8 wk before calving and continued until 8 wk postpartum. Grass silage was the main forage fed during the experiment. In addition, supplemented heifers (n = 9) received 3,000 IU of vitamin E daily on a carrier food; control heifers (n = 9) consumed only the carrier food. Blood samples and liver biopsies were taken frequently throughout the study and ovarian follicular fluid was sampled at 8 wk postpartum. Body condition score was scored weekly and milk yield was measured daily. A marker of oxidative damage, determinable reactive oxygen metabolites (d-ROM), and a set of antioxidants were measured in blood, liver, milk, and ovarian follicular fluid. Control heifers had a low vitamin E status, and selenium status was marginal in control and supplemented heifers. Vitamin E supplementation increased vitamin E concentrations in blood, liver, and ovarian follicular fluid and increased triacylglycerol in liver. Serum d-ROM were not reduced by vitamin E supplementation. Superoxide dismutase and glutathione peroxidase activity in red blood cells and liver and glutathione peroxidase activity in ovarian follicular fluid were not affected by vitamin E supplementation and they were not increased around calving. Protein thiol groups and ratio of reduced glutathione to oxidized glutathione were also not increased around calving. These results suggest that heifers around calving experience a low level of oxidative processes. This might be caused by lower than expected milk production attributed to a low forage intake. Serum d-ROM were negatively correlated with protein thiol groups and positively correlated with the activity of glutathione peroxidase in red blood cells, oxidized glutathione, and the ratio of reduced glutathione and oxidized glutathione in serum. The lack of treatment effects allowed estimation of the effects of body condition 4 wk before calving and the loss of body condition on markers of lipid peroxidation and antioxidants. A trend that a body condition of ≥3 might result in more oxidative damage measured by serum d-ROM was observed, but fatter heifers had a significantly higher ratio of reduced glutathione to oxidized glutathione.  相似文献   

16.
Colorifico is a spice consisting essentially of a mixture of annatto (Bixa orellana) and corn flour. The effects of colorifico addition (0.4 g/100 g) to chicken meat on the development of lipid oxidation, colour stability, and degradation of bixin and vitamin E was investigated in raw and grilled patties during storage at −18 °C for 120 days. Colorifico was able to provide a more stable and intense red and yellow colour in both raw and grilled chicken patties when compared to the meat without spice. Lipid oxidation was delayed by colorifico in the grilled patties until 30 days of storage; however, no effect was observed in the raw patties. Vitamin E content was significantly higher in raw meat with colorifico and heat treatment resulted in relatively less loss when compared to the meat without spice; however, during storage both presented the same degradation pattern. Bixin content was stable during storage but not after grilling. The observed antioxidant mechanism suggests that vitamin E, probably the tocotrienols, is acting along with bixin to protect the unsaturated lipids from oxidation.  相似文献   

17.
Hen’s egg lysozyme (LYZ) is added to red wine for preventing malolactic activity. Sulphur dioxide and polyphenolic compounds can depress LYZ solubility and effectiveness, likely by sulphonation of enzyme disulphide bonds or protein binding, respectively. These phenomena were evaluated in either young red wine or model wine systems. A reliable and validated HPLC method was first developed in order to quantify soluble LYZ in wine (r95% = 10.7 mg l−1). The amount of insolubilized LYZ in red wine was related to the content of non-anthocyan flavonoids of low molecular weight and enzyme precipitation occurred in few minutes when flavonoid concentration exceeded 50 mg l−1. Interaction between sulphur dioxide and LYZ occurred in polyphenol-free model wine systems and for the first time the formation of mono-thiosulphonated LYZ was demonstrated. This reaction was favoured by increasing pH value and sulphur dioxide concentration. Nevertheless, sulphonation alone did not fully explain LYZ instability in model wine systems.  相似文献   

18.
Eighteen Barbarine lambs (3 months of age), were assigned for 95 days to 3 treatments: six lambs were fed a barley-based concentrate plus oat hay ad libitum (control group, C); other lambs received the control diet plus essential oil (400 ppm DM) either of Rosmarinus officinalis (R400 group; n = 6) or of Artemisia herba alba (A400 group; n = 6). At slaughter the muscle longissimus dorsi was sampled and subjected to fatty acid and volatile organic compounds (VOC) analyses. The A400 lambs presented a greater amount of vaccenic, rumenic and linolenic acids and of polyunsaturated fatty acids (PUFA) in meat than the C and R400 animals. Essential oils supplementation did not affect meat VOC profile though the sesquiterpenes copaene and β-caryophyllene were detected only in the meat of R400 and A400 lambs. It is concluded that the supplementation of rosemary or artemisia essential oils does not produce detrimental effects on lamb meat VOC profile. The supplementation of artemisia can improve meat healthy properties.  相似文献   

19.
The objectives were to compare the effects of packaging methods on color stability, metmyoglobin-reducing-activity (MRA), total-reducing-activity and NADH concentration of different bovine muscles and to explore potential mechanisms in the enhanced color stability by carbon monoxide modified atmosphere packaging (CO-MAP, 0.4% CO/30% CO2/69.6% N2). Steaks from longissimus lumborum (LL), psoas major (PM) and longissimus thoracis (LT) packaged in CO-MAP, high-oxygen modified atmosphere packaging (HiOx-MAP, 80% O2/20% CO2) or vacuum packaging were stored for 0 day, 4 days, 9 days, and 14 days or stored for 9 days then displayed in air for 0 day, 1 day, or 3 days. The CO-MAP significantly increased red color stability of all muscles, and especially for PM. The PM and LT were more red than LL in CO-MAP, whereas PM had lowest redness in HiOx-MAP. The content of MetMb in CO-MAP was lower than in HiOx-MAP. Steaks in CO-MAP maintained a higher MRA compared with those in HiOx-MAP during storage. After opening packages, the red color of steaks in CO-MAP deteriorated more slowly compared with that of steaks in HiOx-MAP.  相似文献   

20.
Brazilian dry fermented sausages with different salt contents were manufactured: control (2.5% NaCl), 50% salt reduced (1.25% NaCl, F1), 50% replaced by KCl (1.25% NaCl and 1.25% KCl, F2), 50% replaced by CaCl2 (1.25% NaCl and 1.25% CaCl2, F3), and 50% replaced by KCl and CaCl2 (1.25% NaCl, 0.625% KCl and 0.625% CaCl2, F4). Changes in the composition of volatile compounds were studied during processing (0, 7, and 19 days) and storage (30, 60, and 90 days). Neither reduction nor replacement of NaCl by KCI affected the volatile compounds produced during the manufacturing process, and both increased the volatile compounds from carbohydrate fermentation and amino acid degradation during storage. The addition of CaCl2 improved the generation of hexanal and (E)-hept-2-enal and other volatiles from lipid oxidation during processing and storage. After 90 days of storage, the control sample showed an increase in the generation of volatile compounds from lipid oxidation.  相似文献   

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