Antioxidant properties of tuna-skin and bovine-hide gelatin films induced by the addition of oregano and rosemary extracts

We have investigated the antioxidant properties (FRAP ferric-reducing ability and ABTS radical-scavenging capacity) as well as the light barrier properties of gelatin-based edible films containing oregano or rosemary aqueous extracts. For comparative purposes both bovine-hide and tuna-skin gelatins were studied. The oregano and rosemary extracts were first characterised by both their total phenolic content and antioxidant activity, with the oregano extract showing the higher values. HPLC and confocal laser scanning microscopy revealed qualitative differences between extracts although rosmarinic acid was the most abundant phenolic compound in both. After determining the total quantities of phenolics on films, the polyphenol–protein interaction was found to be more extensive when tuna-skin gelatin was employed. However, this did not clearly affect the antioxidant properties of the films, although it could affect the phenol diffusion from film to food. The light barrier properties were improved by the addition of oregano or rosemary extracts, irrespective of the type of gelatin employed.     

In vitro antioxidant analysis of supercritical fluid extracts from rosemary (Rosmarinus officinalis L.)

Different supercritical fluid extraction conditions were tested on rosemary leaves using a pilot-plant-scale extractor. Each of them provided two separated fractions which were characterized chemically by liquid chromatography–diode-array detection–mass spectrometry using electrospray in the positive mode. Twelve compounds were identified, including phenolic diterpenes and flavonoids. Owing to the lack of available standards, only carnosic acid could be quantified. The antioxidant activity of the extracts was determined by the 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH) test and the -carotene bleaching test was used to study the differences in behavior of antioxidants in an emulsified medium for some of the extracts obtained. The results of the correlation studies to examine the relationship between the antioxidant activity (EC₅₀), obtained by using the DPPH test, and the concentration of all the compounds detected in the extracts showed that carnosic acid was the more correlated compound, with a coefficient of correlation of –0.87. Using forward stepwise multiple linear regression, carnosic acid, methyl carnosate and carnosol were the compounds selected to predict the mentioned activity, with a value of 0.95 for the coefficient of determination.Área de Tecnología de Alimentos, Facultad de Ciencias, Universidad Autónoma de Madrid is an associated unit of IFI-CSIC.     

Thermoxidative stability of soybean oil by natural extracted antioxidants from rosemary (Rosmarinus officinalis L.)

This study aimed to evaluate the effects of rosemary extract, grown in Iran, on thermoxidative stability of soybean oil. Rosemary extract was added to soybean oil at a concentration of 3000 mg/kg and then heated at 180°C for 20 h. The oxidative stability index, total polar compounds, tocopherol content, and fatty acid profile were measured at intervals of 0, 10, and 20 h. The results compared with synthetic antioxidant tert-butyl hydroquinone at a concentration of 50 mg/kg. Rosemary extract could lead to higher oxidative stability index, lower polar compounds, more retention of tocopherols and the greatest amount of polyunsaturated fatty acids in soybean oil after 20 h of thermoxidation process. The tert-butyl hydroquinone showed weaker antioxidant activity than rosemary extract and there was no synergistic effect between them.     

Thiol oxidation and protein cross-link formation during chill storage of pork patties added essential oil of oregano,rosemary, or garlic

The effect of two levels (0.05% and 0.4%) of essential oil of rosemary, oregano, or garlic on protein oxidation in pork patties was studied during storage under modified atmosphere (MAP: 70% O₂: 20% CO₂: 10% N₂) or under aerobic conditions (AE) at 4 °C. The oxidative stability of the meat proteins was evaluated as loss of thiols for up to 9 days of storage, and as formation of myosin cross-links analyzed by SDS-PAGE after 12 days of storage. Protein thiols were lost during storage to yield myosin disulfide cross-links. Essential oils of rosemary and oregano were found to retard the loss of thiols otherwise resulting in myosin cross-links. Garlic essential oil, on the contrary, was found to promote protein oxidation, as seen by an extreme loss in thiol groups, and elevated myosin cross-link formation compared to control.     

Antioxidative activity of summer savory (Satureja hortensis L.) and rosemary (Rosmarinus officinalis L.) in minced,cooked pork meat

The sensory intensity measured as theabsolute threshold value of spice andrecognition of spice was evaluated for summer savory and rosemary in meat balls. The values forabsolute threshold value of spice were found to be significantly lower for rosemary than for summer savory. The antioxidative activity of the spices was analysed in two accelerated model systems and in a storage experiment. In one of the model systems, oxidation was accelerated by heat and by an elevated pressure of oxygen. Both spices significantly improved the oxidative stability of the meat balls in this model system. In the second model system metal catalyst oxidation in a meat slurry was used and a reduction in the oxidative processes in samples containing the spices was again shown. In both model systems a slightly higher antioxidative activity was seen for rosemary compared to summer savory. In the storage experiment, the spices were added at a sensorially acceptable level and the heat-treated meat balls were stored at 5°C. A significant reduction in the development of warmed-over flavour (WOF) caused by the addition of spices was measured by a reduction in 2-thiobarbituricacid-reactivesubstances (TBARS) and in hexanal. A reduction in TBARS of approximately 30% in meat balls containing added spices was seen independently of packaging in 1% oxygen or in atmospheric air and the reduction (30%) was constant throughout the storage period.     

The pre- and post-grinding application of rosemary and its effects on lipid oxidation and color during storage of ground beef

The timing of the application of rosemary extract was evaluated as one-way of minimizing myoglobin and lipid oxidation in ground beef. In experiment 1, rosemary extract was added to beef at four different stages namely trim, cube, coarse, and fine ground beef. The beef was evaluated for color and TBARS values during 144 h of storage (4 °C). Results showed that when rosemary was added to the pre-grinding treatments of trim and cube, ground beef had the highest a^∗ values (redness), oxymyoglobin content, and lowest TBARS values at 144 h. In experiment 2, the effect of rosemary extract was evaluated on the color quality of case ready ground beef inoculated with 10⁷ CFU/g Escherichia coli. Microbial counts, color, and TBARS values were measured during 144 h of simulated storage. The results showed that both the rosemary treated samples that were inoculated and uninoculated remained redder longer and had lower TBARS values than the untreated inoculated and uninoculated controls. There was no significant inhibition of E. coli by the rosemary extract.     

A multivariate approach to optimise the synergistic blend of oleoresin rosemary (Rosmarinus officinalis L.) and ascorbyl palmitate added into sunflower oil

The simultaneous optimisation of a synergistic blend of oleoresin rosemary (ROS) and ascorbyl palmitate (AP) in sunflower oil (SO) was performed using central composite and rotatable design coupled with principal component analysis (PCA) and response surface methodology (RSM). The physicochemical parameters, viz. peroxide value, anisidine value, induction period, total polar matter, UV absorbances (232 and 270 nm) and antioxidant capacity were considered as response variables. PCA reduced the original set of correlated responses to few uncorrelated principal components (PC). The PC1 (eigenvalue, 6.08; data variance explained, 86.97%) was selected for optimisation using RSM. The quadratic model described the data (R² = 0. 93, P < 0.05), and lack of fit was insignificant (P > 0.05). The contour plot of PC 1 score indicated the optimal synergistic combination of 1309.62 and 129.29 ppm for ROS and AP, respectively. In conclusion, the versatility of PCA–RSM approach has resulted in an easy interpretation in multiple response optimisations.     

The combined effect of rosemary (Rosmarinus officinalis L.) and modified atmosphere packaging as protection against warmed over flavour in cooked minced pork meat

Rosemary (dried leaves ofRosmarinus officinalis L.) added to cooked meat balls (minced pork) was found to retard the formation of warmed over flavour (WOF) during chill storage. The spice was added to pork meat (Longissimus dorsi) balls in an amount acceptable for the product, as evaluated by a sensory panel (0.05% of total weight). After cooking (water bath, internal temperature 80°C), the meat balls were packed using five atmosphere packaging conditions: (i) air; (ii) 5% O₂/95% N₂; (iii) 3% O₂/97% N₂; (iv) 1% O₂/99% N₂; and (v) 100% N₂. During chill storage (5°C), the sensory quality of the reheated meat balls was evaluated by a trained sensory panel, and lipid oxidation was followed by measurement of thiobarbituric acid reactive substances (TBARS). The combination of decreased O₂ atmosphere in the packages and addition of rosemary resulted in a significantly (p<0.05) lower amount of TBARS and a significantly (p<0.05) better sensory score.     

In vitro antioxidant and antiproliferative activity of three rosemary (Rosmarinus officinalis L.) extract formulations

Antioxidant and antiproliferative activities of three rosemary extract formulations (VivOX 20, VivOX 40 and Inolens 50) with different contents of carnosic acid, carnosol and methylcarnosol were tested in vitro. Electron spin resonance measurements revealed that Inolens 50 extract that contained highest amount of carnosic acid was the most potent scavenger of hydroxyl (concentration of extract where 50% of its maximal scavenging activity is observed, that is, EC₅₀, 109.54 μg mL^?1), superoxide anion (EC₅₀ = 7.94 μg mL^?1) and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) (EC₅₀ = 27.4 μg mL^?1)‐free radicals. Comparison of the radar charts of standard antioxidants and rosemary extracts showed similarity between antioxidant characteristics of Inolens 50 and chlorogenic and caffeic acids. Tested rosemary extracts exhibited significant (P ≤ 0.01) antiproliferative effect in cervix epitheloid carcinoma (HeLa), breast adenocarcinoma (MCF7) and colon adenocarcinoma (HT‐29) cell lines. In both MCF7 and HeLa cell lines, the extracts yielded very low IC₅₀ values (concentration of extract needed to inhibit cell growth by 50%), the most pronounced being for Inolens 50 in MCF7 (IC₅₀ = 9.95 μg mL^?1) and VivOX 20 in HeLa cell line (IC₅₀ = 10.02 μg mL^?1). The obtained results may provide support for the use of tested rosemary extracts as nutraceuticals and phytopharmaceuticals.     

Antioxidative activity of summer savory (Satureja hortensis L.) and rosemary (Rosmarinus officinalis L.) in minced, cooked pork meat

The sensory intensity measured as theabsolute threshold value of spice andrecognition of spice was evaluated for summer savory and rosemary in meat balls. The values forabsolute threshold value of spice were found to be significantly lower for rosemary than for summer savory. The antioxidative activity of the spices was analysed in two accelerated model systems and in a storage experiment. In one of the model systems, oxidation was accelerated by heat and by an elevated pressure of oxygen. Both spices significantly improved the oxidative stability of the meat balls in this model system. In the second model system metal catalyst oxidation in a meat slurry was used and a reduction in the oxidative processes in samples containing the spices was again shown. In both model systems a slightly higher antioxidative activity was seen for rosemary compared to summer savory. In the storage experiment, the spices were added at a sensorially acceptable level and the heat-treated meat balls were stored at 5°C. A significant reduction in the development of warmed-over flavour (WOF) caused by the addition of spices was measured by a reduction in 2-thiobarbituricacid-reactivesubstances (TBARS) and in hexanal. A reduction in TBARS of approximately 30% in meat balls containing added spices was seen independently of packaging in 1% oxygen or in atmospheric air and the reduction (30%) was constant throughout the storage period.     

Evaluation of the Antioxidant Potential of Hyssop (Hyssopus officinalis L.) and Rosemary (Rosmarinus officinalis L.) Extracts in Cooked Pork Meat

ABSTRACT: The objective of this work was to study the ability of rosemary and hyssop extracts to inhibit lipid oxidation and metmyoglobin formation in pork meat, thereby stabilizing meat color. We also evaluated their effects on iron release from the heme moiety of pork meat. Meat samples were blended with hyssop and rosemary extracts and cooked. The cooked meat was chopped into pieces and stored for 8 d at 4 °C. Heme iron, TBA values, metmyoglobin percentage, and meat color were calculated. Hyssop and rosemary were seen to inhibit lipid oxidation and degradation of heme pigments caused by cooking and storage. Both spices delayed metmyoglobin formation and stabilized the red meat color during storage of the cooked meat.     

Influence of rosemary (Rosmarinus officinalis, L.) on plant sterol oxidation in extra virgin olive oil

The objective of this study was to investigate the potential role of rosemary compounds in inhibiting the plant sterol oxidation in extra virgin olive oil during heating. The stability of plant sterols was measured by quantification of plant sterol and sterol oxide formation upon 6 h of heating in both the extra virgin olive oil and its respective oil at 10% rosemary concentration (ROE). The total sterol and sitosterol oxide contents were determined by GC-flame ionization detection (GC-FID) and GC-MS techniques, respectively. Heating experiments were carried out at 180 degrees C for 0, 1, 3 and 6 h. The total sterol content in the extra virgin olive oil was 255 mg/100 g and that in the ROE 270 mg/100 g. Sitosterol was the most abundant sterol in both samples (50% of total sterol). The ROE showed a lower content of sitosterol oxides with respect to the extra virgin olive oil during heating: after 6 h of heating only 6.1% of sitosterol oxides were formed, while up to 11.5% of sitosterol oxidized in the extra virgin olive oil. Our findings suggested that rosemary compounds were able to counteract the oxidation of plant sterols in the extra virgin olive oil during heating, preventing formation of potentially harmful compounds to human health.     

Addition of different rosemary preparations (Rosmarinus officinalis L.) to chicken meatballs improves their quality profile

Effect of rosemary (Rosmarinus officinalis L.) preparations in baked, vacuum-packed meatballs from chicken meat during 14 days of storage at +4 °C was assessed. The meatballs were divided into the following groups: RD−with 1.0% of dried spice, REE40 and REE70−with 2.0% of ethanol extracts: 40% (v/v) and 70% (v/v), respectively, and REO−with 0.1% of essential oil. The CONTROL product did not contain added rosemary. In chicken meatballs, the antioxidant stability was determined, microbiological analyses as well as sensory evaluation were performed. After 14 days of storage, the strongest antioxidant activity in the chicken meatballs exhibited rosemary ethanol extracts. Compared with the CONTROL, the REE70 and REO had the best microbiological quality at the end of the storage period. All products with rosemary were sensory acceptable; however, the highest scores in the evaluation of all sensory attributes were obtained by the RD treatment.     

Classification of Sunflower Oil Blends Stabilized by Oleoresin Rosemary (Rosmarinus officinalis L.) Using Multivariate Kinetic Approach

The sunflower oil–oleoresin rosemary (Rosmarinus officinalis L.) blends (SORB) at 9 different concentrations (200 to 2000 mg/kg), sunflower oil–tertiary butyl hydroquinone (SO_TBHQ) at 200 mg/kg and control (without preservatives) (SO_control) were oxidized using Rancimat (temperature: 100 to 130 °C; airflow rate: 20 L/h). The oxidative stability of blends was expressed using induction period (IP), oil stability index and photochemiluminescence assay. The linear regression models were generated by plotting ln IP with temperature to estimate the shelf life at 20 °C (SL₂₀; R² > 0.90). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) was used to classify the oil blends depending upon the oxidative stability and kinetic parameters. The Arrhenius equation adequately described the temperature‐dependent kinetics (R² > 0.90, P < 0.05) and kinetic parameters viz. activation energies, activation enthalpies, and entropies were calculated in the range of 92.07 to 100.50 kJ/mol, 88.85 to 97.28 kJ/mol, ?33.33 to ?1.13 J/mol K, respectively. Using PCA, a satisfactory discrimination was noted among SORB, SO_TBHQ, and SO_control samples. HCA classified the oil blends into 3 different clusters (I, II, and III) where SORB₁₂₀₀ and SORB₁₅₀₀ were grouped together in close proximity with SO_TBHQ indicating the comparable oxidative stability. The SL₂₀ was estimated to be 3790, 6974, and 4179 h for SO_control, SO_TBHQ, and SORB₁₅₀₀, respectively. The multivariate kinetic approach effectively screened SORB₁₅₀₀ as the best blend conferring the highest oxidative stability to sunflower oil. This approach can be adopted for quick and reliable estimation of the oxidative stability of oil samples.     

Radiation-induced enhancement of antioxidant activity in extracts of rosemary (Rosmarinus officinalis L.)

Dry rosemary leaf powder was subjected to 30 kGy of gamma ray irradiation, followed by solvent extraction with methanol, ethanol or water. The antioxidant activity of the extracts was assessed using the DPPH radical-scavenging method and the reducing power test. EC₅₀ values, using the radical-scavenging method, indicate a 22% increase in the antioxidant activity of ethanol and water extracts as a result of irradiation treatment. EC₅₀ values in the reducing power test show an increase of 45% and 28% for the ethanol and water extracts, respectively. The antioxidant activity of methanol extracts of irradiated rosemary remained the same as in the controls in both types of test. A high correlation was found between the EC₅₀ values obtained in the DPPH radical test and those from the reducing power test. Total phenolic content (Folin–Denis test) increased by 35% in the water extracts as a result of irradiation but remained the same in the methanol and ethanol extracts. The methanol extract showed the highest antioxidant activity and the highest amount of total phenolic compounds. Radiation reduced the good correlation between antioxidant activity and total phenolic content.     

Processing of marjoram (Majorana hortensis Moench.) and rosemary (Rosmarinus officinalis L.). Effect of blanching methods on quality

Marjoram and rosemary are herbs which are valued for their flavour and colour. The use of microwave in blanching and drying is becoming more and more popular in recent years. This paper reports the effect of microwave blanching as compared to water and steam blanching on the volatile oil, colour, texture (by compression), chlorophyll and ascorbic acid contents of these herbs. There was maximum retention of ascorbic acid in microwave blanched marjoram and rosemary (21.5, 33.0 mg/100 g) i.e. 79.4% and 49.9% compared to fresh herbs. Blanching resulted in better retention of the original green colour of the fresh herb compared to direct drying of the herbs. Texture of microwave blanched herbs improved as revealed by higher compression force values (109.3, 157.8 N). However, there was greater loss of volatile oil in all the blanched samples.