Antioxidant activity of lipid-soluble phenolic diterpenes from rosemary

A high-performance liquid chromatography method for analyzing the phenolic diterpenes present in rosemary (Rosmarinus officinalis L.) and commercial rosemary extracts is reported. Carnosic acid was the major phenolic diterpene present in rosemary leaves, with lesser amounts of 12-methoxycarnosic acid and carnosol. Several commercial rosemary extracts also were analyzed by this method, and in addition to these three compounds other phenolic diterpenes, such as 7-methoxyrosmanol, 7-methoxy-epirosmanol, and rosmanol, were found in some samples. These latter three compounds seem to be artifacts, produced from carnosic acid by oxidation and cyclization. The major phenolic diterpenes were isolated, and their relative antioxidatn activities in soybean oil were measured by the Rancimat. The potency of carnosic acid was more than twice that of any other compound. The antioxidant activity of pure carnosic acid was compared to butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tertiary butylhydroquinone (TBHQ) and was several times greater than BHT and BHA but less than TBHQ. Nuclear magnetic resonance data for several of the compounds that were incompletely characterized in previous literature are reported.     

Determination of carnosic acid and carnosol in Rosmarinus officinalis L. by high-performance capillary electrophoresis

Carnosol and carnosic acid in Rosmarinus officinalis L. were separated by high-performance capillary electrophoresis using a 50?cm capillary, a 12?mmol/L 80:20 pH 9.9 borax:methanol buffer using 25?kV of applied voltage at 30°C with detection at 280?nm. Rosmarinus officinalis L. was extracted with methanol with ultrasound at 170?W and 50?kHz for 20?min. The precision, repeatability, and recovery of the method were evaluated. The calibration relationships for carnosol and carnosic acid were y?=?2.331x?+?5.92 from 0.01 to 0.160?mg/mL and y?=?7.980x?+?4.32 from 0.005 to 0.080?mg/mL, respectively. The established method allows the separation and quantification of carnosic acid and carnosol in R. officinalis from various locations in China.     

迷迭香脂溶性抗氧化剂提取工艺的优化研究

以经不同方法预处理(蒸馏法去精油和水煮法去精油)后的迷迭香叶为原料,无添加食用油为提取剂,通过单因素试验考察提取温度、料液比、提取时间及提取次数对脂溶性抗氧化剂(鼠尾草酸+鼠尾草酚)得率的影响。在单因素试验的基础上,采用响应面法对提取工艺条件进一步优化。结果表明:水煮法去精油的原料迷迭香脂溶性抗氧化剂的最优提取条件为提取温度61℃、料液比1∶11、提取时间61 min、提取次数5次,在此条件下脂溶性抗氧化剂得率为2.860 1%;蒸馏法去精油的原料迷迭香脂溶性抗氧化剂的最优提取条件为提取温度71℃、料液比1∶11、提取时间81min、提取次数4次,在此条件下脂溶性抗氧化剂得率为3.801 3%。对比分析表明,蒸馏法去精油的迷迭香脂溶性抗氧化剂得率高于水煮法去精油的。     

Improving the Sensory and Oxidative Stability of Cooked and Chill‐Stored Lamb Using Dietary Rosemary Diterpenes

Two dietary rosemary extracts (DREs) containing diterpenes (carnosic acid and carnosol at 1:1 and 2:1 w:w) were tested in fattening lambs to stabilize the sensory quality of cooked and chill‐stored patties. A total of 63 lambs were fed freely for 80 ± 5 d with a basal diet supplemented or not with DRE. Minced leg meat from each lamb was used to make patty batches. The patties were cooked at 72 ºC for 2 min, aerobically packed, kept at 2 ºC for up to 4 d and then reheated. Sensory traits (color, odor, flavor, and texture), CIELab color, and lipid oxidation (assessed as TBARS) were determined. In a first experiment, the lamb diet was supplemented with 600 mg of 1:1‐DRE or 2:1‐DRE kg^?1 feed. The 1:1‐DRE diet delayed discoloration, flavor deterioration, and rancidity, while the 2:1‐DRE diet was ineffective in this respect. In a second experiment, 4 supplementation levels of 1:1‐DRE (0, 200, 400, and 600 mg kg^?1 feed) were compared. Flavor deterioration was delayed when the lamb diet was supplemented with at least 400 mg 1:1‐DRE kg^?1 feed. The effects of the diet on the odor, flavor, and color were corroborated by differences in TBARS and CIELab. The results obtained suggest that rosemary diterpenes and/or their active secondary compounds deposited in muscle can act as endogenous antioxidants in cooked lamb. The carnosol intake seems crucial in the antioxidant actions achieved through DRE. The use of rosemary antioxidants in animal feeding would allow meat‐based dishes to be preserved longer without adding preservatives.     

迷迭香的综合提取工艺研究

介绍了一种新的溶剂提取迷迭香的工艺和方法,通过乙醇直接提取迷迭香,采用逐级溶剂分离的方法对迷迭香油、水溶性成分、脂溶性成分进行综合提取。该方法工艺简单,成本低,并已实现工业化。     

Phenolic diterpene and α‐tocopherol contents in leaf extracts of 60 Salvia species

BACKGROUND: Carnosic acid and carnosol, the two major phenolic diterpenes present in rosemary and sage extracts, have received attention in food science and biomedicine because of their potent antioxidant properties. In plants, these compounds have been identified as being present in some species of the family Lamiaceae, but there is still little information about their distribution within the plant kingdom. The aim of the present study was to gain a better understanding of the occurrence of these compounds within leaf extracts of the genus Salvia and also to examine to what extent leaf senescence may influence their accumulation in relation to that of α‐tocopherol (vitamin E). RESULTS: Methanolic leaf extracts of 60 species of the genus Salvia were tested for the presence of carnosic acid and carnosol. These two diterpenes were detected in 48 and 27 species respectively. In contrast, α‐tocopherol was present in all species examined. Leaf senescence in Salvia officinalis resulted in α‐tocopherol increases by up to 5.5‐fold, while carnosic acid and carnosol increased by up to 18 and 290% respectively. Isorosmanol, an oxidation product of carnosic acid, increased by up to 2.1‐fold in senescing leaves. CONCLUSION: It was found that, while α‐tocopherol is ubiquitous in the genus Salvia, phenolic diterpenes are present in several but not all species. It was also shown that leaf senescence may increase the yield of both phenolic diterpenes and α‐tocopherol in sage extracts. Copyright © 2008 Society of Chemical Industry     

Thermal recovery of antioxidant activity from carnosol quinone,the main antioxidation product of carnosol

The antioxidant reaction of carnosol, a phenolic diterpene of sage and rosemary, produced ortho‐ and para‐quinone derivatives. Although the orthoquinone derivative of carnosol (CARQ) is stable in a lipophilic solution and has a very weak antioxidant activity, the thermal treatment of CARQ in lipid restored strong antioxidant activity. HPLC analysis of the thermal recovery reaction clarified that the strong activity was mainly due to the reproduced carnosol. A possible mechanism for the production of carnosol from CARQ is the self‐redox reaction of CARQ. Two of the oxidation products from CARQ in the thermal recovery reaction were identified to be rosmariquinone and dehydrorosmariquinone. Copyright © 2004 Society of Chemical Industry     

Enhancing Lipid Oxidative Stability of Cooked‐Chilled Lamb Meat through Dietary Rosemary Diterpenes

A dietary rosemary extract (DRE) containing carnosic acid and carnosol at 1:1 (w/w) for enhancing the lipid oxidative stability in cooked‐chilled lamb meat, is evaluated. Three diets for fattening lambs are tested: i) a cereal‐based concentrate (C‐diet); ii) the C‐diet plus 600 mg vitamin E per kg feed (E‐diet); and iii) the C‐diet plus 600 mg rosemary diterpenes per kg feed (R‐diet). Griddled‐chilled lamb patties are kept at 4 °C and lighting for 2 days, simulating catering conditions. Diterpenes have a lower deposition rate than vitamin E in lamb muscle and are completely degraded during cooking. DRE is thus less effective than dietary vitamin E in enhancing the oxidative stability of the patties. After 2‐day storage, the R‐diet shows lower (p < 0.01) peroxide values and thiobarbituric acid reactive substances than the C‐diet, while, in contrast to the E‐diet, it does not inhibit (p > 0.05) the formation of cholesterol oxidation products. The R‐diet increases (p < 0.05) the proportion of polyunsaturated fatty acids and decreases (p < 0.05) the n‐6/n‐3 ratio. These findings suggest antioxidant protection by dietary bioactive compounds beyond the direct radical scavenging activity that is able to stabilize lipids during the meat shelf‐life. Practical Applications: Cooked‐chilled meat lipids strongly oxidize in ready‐to‐eat dishes kept in retailing conditions, which may negatively affect their levels of polyunsaturated fatty acids (PUFA), cholesterol oxidation products (COP), and other lipid oxidation products. Dietary rosemary diterpenes can be used as a clean alternative to feed additives to enhance the oxidative stability of cooked‐chilled meat. Improved health and antioxidant status of the animal might be able to reduce oxidative spoilage during meat shelf‐life. Diterpenes provide lesser antioxidant protection than dietary vitamin E but may improve the PUFA content, with positive implications for the nutritional quality of lamb fat. The use of dietary antioxidants with different properties may contribute to improving the efficacy of animal feeds to improve meat quality.