Phenolic acids composition and antioxidant activity of canola extracts in cooked beef,chicken and pork

Crude polyphenol extracts (15 or 100 mg gallic acid equivalents (GAE)/kg meat) from canola meal reduced the formation of 2-thiobarbituric acid-reactive substances (TBARS) in pre-cooked beef (66–92%), pork (43–75%) and chicken (36–70%). The canola extract contained sinapic (99.7%), ferulic (0.28%) and p-hydroxybenzoic acids (0.07%).     

二丁基羟基甲苯对调理鸡肝贮藏过程中抗氧化效果的影响

研究调理肉制品在贮藏过程中的脂肪氧化情况以及不同添加水平的二丁基羟基甲苯(BHT)的抗氧化效果。以调理鸡肝为试材,BHT 添加量分别为0.05、0.10、0.15、0.20g/kg 处理鸡肝,然后在冻藏条件下贮藏,通过测定其在不同贮藏时期的酸价、过氧化值和硫代巴比妥酸值判定其脂肪氧化的程度及BHT 的抗氧化效果。结果表明：除BHT 添加量0.20g/kg 组外,其他各组脂肪氧化主要开始于贮藏第15 天,之后脂肪氧化产物发生不同程度的分解;4 个处理组中,BHT 添加量0.20g/kg 可有效抑制过氧化值增长,BHT 添加量0.15g/kg 可有效减少脂肪氧化产物的分解。BHT 在调理鸡肝贮藏过程中有较好的抗氧化效果。     

Effectiveness of synthetic and potential natural antioxidants in improving the stability of sheep's anhydrous butter fat during long-term storage

Sheep's anhydrous butter fat as prepared by including separately heat grits, turmeric, rosemary, sage, rue and fennel at a level of 75 g dry matter kg^?1 butter. The product as stored at room temperature in clear glass jars for a period of one year. The storage stabilities of the anhydrous butter fat samples ere compared ith a control and ith a sample treated ith a 1:1 mixture of BHA and BHT at a level of 0.25 g kg^?1. Both storage time and type of treatment had highly significant effects (P?0.01) on the peroxide value and free fatty acid content of the product. None of the treatments succeeded in keeping the peroxide value belo 5 mEq O₂ kg^?1 beyond the fourth month of storage. The BHA-BHT mixture and rosemary helped extend the peroxide induction period to 10 and 6 months respectively. Turmeric and heat grits ere as effective as BHA-BHT in controlling the oxidative rancidity during the first four months of storage. The rest of the herbs exhibited a pro-oxidant effect throughout the study hen they ere used separately. In a second experiment, some cases of positive synergistic interactions ere observed beteen turmeric and heat grits on one hand and the herbs used in the study on the other. This pattern as not regular as negative interactions ere also observed in some other cases. Free fatty acid content of all the samples remained belo 10 g kg^?1 as oleic acid; hoever, fennel had a significant (P?0.05) effect on controlling the evolution of free fatty acids.     

Simultaneous HPLC quantification of total cholesterol,tocopherols and β-carotene in Barrosã-PDO veal

A simple, rapid and sensitive procedure for the simultaneous determination of total cholesterol, tocopherols and β-carotene in meat is described. The method involves a direct saponification of the meat, a single n-hexane extraction and the analysis of the extracted compounds by normal-phase HPLC, using fluorescence (tocopherols) and UV–Vis photodiode array (cholesterol and β-carotene) detections in tandem. Rates of recovery of spiked meat samples were 93% for cholesterol, 83–86% for (α-, β- and -γ) tocopherols and 89% for β-carotene. Repeatabilities were high (CV < 6%) for all determined compounds, except for δ-tocopherol. This tocopherol, which is not usually present in meat, showed a much lower recovery percentage (73%) and repeatability (12.8%). This methodology was applied for the quantification of total cholesterol, tocopherols and β-carotene in three muscles (longissimus thoracis, longissimus lumborum and semitendinosus) of the Portuguese traditional Barrosã-PDO veal, obtained from autochthonous calves fed extensively during summer (with the least abundant green pastures) and slaughtered in early autumn (October). Barrosã-PDO veal showed median contents of total cholesterol (0.50–0.56 mg/g) and, depending on the analysed muscle, moderate to high contents of α-tocopherol (3.3–3.9 μg/g) and β-carotene (0.07–0.09 μg/g), suggesting an high sensorial and hygienic quality.     

二丁基羟基甲苯(BHT)微胶囊技术研究

为了降低BHT在食品中的使用量,利用喷雾干燥法和分子包埋法制得了BHT的微胶囊产品.优化了喷雾干燥法的工艺条件,在BHT与壁材之比为2080、阿拉伯胶与麦芽糊精之比为13、海藻酸钠含量0.6时包埋率最高,达98.98%.BHT与β-环糊精比例为1288,超声波处理时间为30～40min时,分子包埋法制得的BHT微胶囊包埋率可达90%.     

3种脂溶性酚类对紫苏籽油的抗氧化作用研究

采用Schaal烘箱法,以过氧化值和α-亚麻酸含量为指标,比较了3种脂溶性酚类及人工合成抗氧化剂对紫苏籽油的抗氧化效果。结果表明,当抗氧化剂添加量为100 mg/kg时,基于过氧化值的抗氧化效果为香芹酚百里香酚、丁香酚BHT、BHA。低添加量抗氧化剂(1~100 mg/kg)紫苏籽油中α-亚麻酸含量均高于不添加抗氧化剂的处理组。香芹酚的最适添加量为5 mg/kg,α-亚麻酸含量为6.399 mg/g,与4℃保存的紫苏籽油含量相近;BHT的最适添加量为50 mg/kg,α-亚麻酸含量为6.987 mg/g,高于4℃保存的紫苏籽油;分别添加100 mg/kg的香芹酚与100 mg/kg的BHT的紫苏籽油中α-亚麻酸含量相近,说明二者抗氧化能力相当。研究结果证实了香芹酚、百里香酚、丁香酚对紫苏籽油具有较好的抗氧化作用,为安全高效的天然酚类抗氧化剂的筛选及其在油脂食品中的应用提供理论参考。     

Antioxidant and antimicrobial activities of crude sorghum extract

Here, we report the antioxidant and antimicrobial activities of sorghum (Sorghum bicolor Moench) extracts prepared from 25 cultivars from South Korea. Four cultivars of sorghum were extracted with methanol, then further fractioned with n-hexane, ethyl acetate, n-butanol, and water. The RC₅₀ (the concentration of antioxidant required to achieve absorbance equal to 50% that of a control containing no antioxidants) value of the DPPH method and reducing power showed higher efficiency in the BuOH layer of all selected cultivars except Neulsusu. The various fractions were then examined for antimicrobial activity by a serial two fold dilution assays using the paper disc method. The methanol extracts showed higher levels of antimicrobial activity than the other fractions. Our results indicate that sorghum extracts could be used as a source of antioxidant and antimicrobial ingredients in the food industry.     

高效液相色谱测定植物油中BHA、BHT

文章根据植物油中BHA.BHT的作用机理,用高效液相色谱法测定其含量,实验结果证明,该方法快速简便安全,分析结果准确,工作效率高.     

Antioxidant activity of stem and root extracts of Rhubarb (Rheum ribes): An edible medicinal plant

The antioxidant activity of chloroform and methanol extract of roots and stems of Rhubarb (Rheum ribes L.), which are used for medicinal purposes and also its fresh stems and petioles are consumed as vegetable, was studied. The antioxidant potential of both extracts of roots and stems were evaluated using different antioxidant tests, namely total antioxidant (lipid peroxidation inhibition activity), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, superoxide anion radical scavenging, ferric reducing power, and cupric reducing power (CUPRAC), and metal chelating activities. Total antioxidant activity was also measured according to the β-carotene bleaching method, and all four extracts exhibited stronger activity than known standards, namely butylated hydroxytoluene (BHT) and α-tocopherol. Particularly, higher activity was exhibited by roots with 93.1% and 84.1% inhibitions of chloroform and methanol extracts, while 82.2% and 82.0% inhibitions by stem extracts, respectively. However, both methanol extracts exhibited higher DPPH radical scavenging activity than the corresponding chloroform extracts, moreover, methanol extract of the stems showed better activity than BHT. In addition, both root extracts showed more potent superoxide anion radical scavenging activity than BHT, and comparable with well known radical scavenger l-ascorbic acid. Except chloroform extract of the roots, the other three extracts exhibited better metal chelating activity than quercetin. Also, total phenolic and flavonoid contents in both extracts of the roots and stems of R. ribes were determined as pyrocatechol and quercetin equivalents, respectively.     

A fourier transform infrared spectroscopic method for determining butylated hydroxytoluene in palm olein and palm oil

A simple, rapid, and direct FTIR spectroscopic method was developed for the determination of BHT content in refined, bleached, and deodorized (RBD) palm olein and RBD palm oil. The method used sodium chloride windows with a 50-mm transmission path. Fifty stripped oil samples of both RBD palm olein and RBD palm oil were spiked with known amounts of BHT concentrations up to 300 mg/kg (ppm). The data were separated into two sets for calibration and validation using partial least squares models. FTIR results for both oils correlated well with results obtained by the IUPAC HPLC-based method. For RBD palm olein, the coefficient of determination (R ²) was 0.9907 and the SE of calibration (SEC) was 8.47 ppm. For RBD palm oil, an R ² of 0.9848 and an SEC of 10.73 ppm were achieved. Because of the significant decrease in analysis time and reduction in solvent usage, this FTIR method for BHT is especially well suited for routine quality control applications in the palm oil industry.