Mate (<Emphasis Type="Italic">Ilex paraguariensis</Emphasis>) as a source of water extractable antioxidant for use in chicken meat

Aqueous extract of mate, made from dried leaves of Ilex paraguariensis, St. Hilaire, was shown to be effective during chilled storage for up to 10 days in protecting lipids and vitamin E against oxidation in pre-cooked meat balls made from chicken breast added 0.5% salt and packed in atmospheric air. Extracts made with water, methanol, ethanol or 70% aqueous acetone were evaluated by comparing (1) total phenolic content, (2) radical scavenging capacity, (3) effect on lipid oxidation in a food emulsion model, and in liposomes. Based on the three-step evaluation, aqueous mate extract was preferred for food use. Dried leaves were further compared to dried rosemary leaves in chicken meat balls, and mate (0.05 and 0.10%) found to yield equal or better protection than rosemary at the same concentration against formation of secondary lipid oxidation products.     

Mate (<Emphasis Type="Italic">Ilex paraguariensis</Emphasis>) as dietary additive for broilers: performance and oxidative stability of meat

Aqueous extract of mate (dried leaves of Ilex paraguariensis) added to drinking water for broilers for the last 14 days prior to slaughter did not affect performance at 25 days of age, but improved oxidative stability of the chicken meat. Oxidative stability of precooked breast meat made from control meat (CON) and from meat of broilers raised on water with mate added was investigated during chill storage for up to 7 days. The use of mate showed no influence on the content of lipids in chicken breast meat; however, lipid oxidation measured as thiobarbituric acid–reactive substances (TBARS) was significantly lower for meat from broilers raised on water with mate extracts in different concentrations (MA0.1, MA0.5, and MA1.0 corresponding to 0.1, 0.5, and 1.0% of mate dried leaves). The relative effect was largest at 1 day of storage with more than 50% reduction on TBARS; the result was still significant after 3 days, but almost vanished after 7 days, when oxidative rancidity was very high in all samples. In meat from broilers raised on water with mate extract, vitamin E was protected during cooking, although in the very rancid meat balls at 7 days of storage, the protection almost disappeared. Nevertheless, mate can be an interesting natural alternative to be used in chicken diets to improve lipid stability of the meat.     

Antioxidant effect of dittany (<Emphasis Type="Italic">Origanum dictamnus</Emphasis>) in pre-cooked chicken meat balls during chill-storage in comparison to rosemary (<Emphasis Type="Italic">Rosmarinus officinalis</Emphasis>)

Dittany (Origanus dictamnus L.) has been compared with rosemary (Rosmarinus officinalis L.) as an antioxidant in pre-cooked meat balls made from chicken breast and added 0.50% salt during chill storage for up to ten days packed in atmospheric air. For an addition of 0.10% of dried leaves, dittany yielded protection of the product against oxidation a little less efficiently but comparable to dried rosemary added at the same concentration. For addition of 0.050%, dittany was less efficient than rosemary, while dittany at this concentration protected vitamin E against degradation in the product during storage even better than rosemary.     

肉松感官描述词汇的建立

通过对10种不同品牌的肉松进行感官评价,确定肉松的形态、颜色、气味、质地和滋味等感官描述词。经过招募、挑选和培训,构建由15人组成的感官评价小组,并进行感官描述词的征集、删减,建立各个感官描述词的定义和参照物。通过感官描述,建立了57个感官描述词,并对肉松的感官属性进行主成分分析,得到可有效区分样品间感官(形态、颜色、气味、质地、滋味)差异的描述词:小块状、蓬松、绒毛;橙褐色、浅棕色、金黄色;焦糖味、烘烤味、大料味;咸味、五香味、油炸味。由结果可知,肉松每一感官特征复杂多样,均需要多个描述词进行描述。肉松所呈现出的总体感官特征为:柔软蓬松和酥润浓郁的五香气味。     

Extracts of plant cell cultures of <Emphasis Type="Italic">Lavandula vera</Emphasis> and <Emphasis Type="Italic">Rosa damascena</Emphasis> as sources of phenolic antioxidants for use in foods

Ethanolic extracts of plant cell cultures of lavender (Lavandula vera) and rose (Rosa damascena) have been examined as potential food antioxidants. The L. vera cell extract quenched the radicals Fremy’s salt, DPPH (2,2-diphenyl-1-picrylhydrazyl radical), and ABTS^·+ (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic) radical) more efficiently than the R. damascena extract. Also the L. vera extract inhibited lipid oxidation in a methyl linoleate emulsion more efficiently than the R. damascena extract. However, the L. vera extract had a prooxidative effect on the iron-based Fenton reaction in an aqueous model system. A similar effect was observed for pure rosmarinic acid, but not for the R. damascena extract. The addition of L. vera extract to minced chicken meat reduced lipid oxidation (measured as thiobarbituric acid reactive species) and the loss of α-tocopherol during cold storage after the meat was cooked. This suggests the antioxidative properties of L. vera extracts dominate in a real food system.     

热风微波联合干燥过程中南美白对虾滋味物质变化研究

为研究热风微波联合干燥过程中南美白对虾滋味物质的变化,测定了其呈味核苷酸与游离氨基酸含量,同时根据干燥过程中虾肉水分含量计算两者的干基含量变化,并计算虾肉味精当量.研究结果表明:虾肉干燥过程中,呈味核苷酸中肌苷酸含量最高,干制虾肉肌苷酸含量为405.96 mg/100 g,且始终高于阈值,对干制虾肉的鲜味形成有显著贡献;相比鲜样,干制南美白对虾中肌苷酸与单磷酸腺苷干基含量均显著下降;在虾肉中谷氨酸对鲜味形成有显著贡献,甘氨酸、丙氨酸与精氨酸对甜味形成有贡献,苯丙氨酸、赖氨酸与组氨酸能产生苦味;而在干燥过程中鲜、甜味氨基酸相对含量不断上升,分别从3.77％和17.03％上升到4.29％和35.84％;游离氨基酸总干基含量始终下降,但甘氨酸、丙氨酸、精氨酸与脯氨酸4种可以形成良好滋味的游离氨基酸干基含量上升;虾肉中肌原纤维蛋白与肌浆蛋白的干基含量均不断下降,部分分解为游离氨基酸;虾肉味精当量整体呈显著上升趋势,但在微波干燥初期(前40 s)显著下降,干制南美白对虾味精当量为3.50 g/100 g,远高于鲜虾(0.53 g/100 g),且虾肉味精当量始终远高于阈值.研究结果表明,由热风微波联合干燥引起的水分挥发与物质变化能够促进南美白对虾滋味形成.     

白茶散茶与茶饼在色泽、滋味及香气组分上的差异研究

为探明压饼工艺对白茶品质的影响,本文以白牡丹散茶为原料制成白牡丹茶饼,比较了压饼工艺前后白茶散茶与茶饼之间在干茶色泽、滋味及香气组分上的差异。结果表明,散茶色泽鲜绿、滋味浓、香气以嫩香为主,而茶饼色泽黄、滋味浓醇、香气以果香与甜香为主。与散茶相比,茶饼色泽的红绿度(a*)极显著(p<0.01)增加,干茶色泽变红;总叶绿素、叶绿素a和b含量均极显著(p<0.01)降低;水浸出物、茶多酚、黄酮与"茶三素"含量显著(p<0.05)降低,而氨基酸、可溶性糖含量显著(p<0.05)提高,引起酚氨比极显著(p<0.01)降低。与散茶相比,茶饼中醇类香气总量和香叶醇组分相对含量降低9%左右,而芳樟醇氧化物、烯类、酮类、酯类和杂氧化合物香气平均相对总量分别增加1.86%、1.89%、1.87%、3.42%和0.83%;香气组分主成分分析得出,茶饼香气质量综合得分比散茶高4~7分。     

Enhancement of bioactive compounds content and antioxidant activity of aqueous extract of mate (Ilex paraguariensis A. St. Hil.) through freeze concentration technology

The purpose of this study was to evaluate the effects of freeze concentration of aqueous extract of mate leaves on the content of bioactive components and antioxidant activity of the concentrated fluid and the ice obtained. Five stages of freeze concentration were studied. In relation to the total dry matter content, the concentration factor increased eightfold by the end of the process. The concentrated fluid showed increasing values of phenolic compounds in all the freeze concentration stages. Although process efficiency reduced significantly in comparison with the first stage due to the retention of phenolic compounds in ice, it remained about 75% in all the stages. The isolated phenolic compounds detected by HPLC, such as chlorogenic acid, 3,5-dicaffeoylquinic acid, caffeic acid, p-coumaric acid, 3,4-dihidroxibenzoic acid and gallic acid, improved substantially in all freeze concentration stages. The methylxanthines caffeine and theobromine contents also increased significantly with the application of the freeze concentration procedure. The antioxidant activity of the concentrated fluid of each freeze concentration stage, measured by FRAP and DPPH assay, was significantly higher in comparison to that of the feed extract. Moreover, the values of both antioxidant assays were significantly correlated with the content of phenolic compounds and methylxanthines of the aqueous extract of mate. Freeze concentration is an effective technique to raise the content of bioactive components and enhance the antioxidant activity of aqueous extract of mate leaves.     

Methylxanthines,phenolic composition,and antioxidant activity of bark from residues from mate tree harvesting (Ilex paraguariensis A. St. Hil.)

Leaves and products made from them are the major focus of research on bioactive compounds of mate (Ilex paraguariensis). However, studies on other parts of the plant, are scarce. The aim of this study was to determine the methylxanthines, phenolic compounds, and antioxidant activity of mate bark (residual biomass) and compare with those of mate leaves. The high antioxidant activity of mate bark and its high concentration of total polyphenols were apparent in both the aqueous and the methanolic extracts, the values of which were greater than those detected in the leaves. Of the phenolic acids identified, the levels of chlorogenic acid and 4,5-dicaffeoylquinic acid in the samples were significantly higher in the methanolic bark extract. With regard to methylxanthines, considerable concentrations were detected in the samples. The results obtained contribute to the viability of exploiting this residue, broadening the use of the mate plant.     

保湿剂对鸭肉干品质改良的研究

针对肉干经常出现干硬、口感差、出品率低等问题,通过添加保湿剂对鸭肉干的品质进行了改良研究,结果表明:改善鸭肉干品质的最佳保湿剂组合为山梨醇0.20%,甘露醇0.20%,蔗糖0.15%.此配比具有良好的保湿性,它使肉干在不改变水分活度的条件下,能使水分含量提高将近7%,使肉干质地、口感、持香性均得到了很好的改善.     

Muscle traits for long matured dried meats

The distinctive flavour of aged pork products is a complex mix of taste, smell and even touch. To meet increasing consumer's preference for ethnic foods or foods addressing linkage with specified geographic origin or complying with traditional manufacturing and breeding guidelines, efforts should be made to encourage selection of processing techniques and raw materials targeting desired end product qualities. Thanks to research carried out with sensory analysis and chemical and physical characterisation of raw and matured pork, as well as breeding and genetics, improved knowledge is now available relating dried meat properties to raw matter or manufacturing. The achievement of the distinctive taste and texture properties of aged products through genetics (animal selection for the enhancement or the removal of some muscle traits), breeding (effect of diet and slaughtering age on pork properties) with reference to current findings about this type of products is discussed.     

肉制品添加剂的现状和研究进展

<正>当前,我国食品加工业使用非食品原料加工食品、滥用添加剂甚至非法使用工业原料生产加工食品的问题较为严重,同时,农兽药残留、重金属超标等化学污染问题也很较严重。为尽量避免由滥用添加剂引发食品安全隐患,我国将对食品添加剂实行市场准入, 同时要求食品加工企业必须建立购买和使用食品添加剂的台账,并定期向质检部门备案。从今年7月1日起,我国将对肉制品等10种食品开展取证查处。     

桑叶饲料添加剂对鸡蛋黄品质的影响

分析在蛋鸡饲料中分别添加2.5%、5.0%、7.5%、10.0%桑叶对鸡蛋黄品质的影响,结果表明：随桑叶添加量增加,蛋黄颜色加深;添加桑叶对蛋黄胆固醇含量影响不大;5.0%和7.5%桑叶组的蛋黄磷含量显著高于对照组(P＜0.05);添加桑叶各组的饱和脂肪酸含量比对照组显著降低(P＜0.05),单不饱和脂肪酸与多不饱和脂肪酸含量比对照组极显著提高(P＜0.01);5.0%和7.5%桑叶组的7种必需氨基酸总量显著高于对照组(P＜0.05);蛋黄VE含量随桑叶添加量增加而极显著增加(P＜0.01),其中10.0%桑叶组比对照组提高了近3倍。桑叶组蛋黄在气味和口感上都优于对照组,其中5.0%、7.5%桑叶组较其他桑叶组好(P＜0.05)。总之,饲料中添加桑叶能改善鸡蛋黄的品质,添加量在5.0%～7.5%比较合适。     

Extractive components of boiled–dried scallop adductor muscle and effect on the taste of soup after mixing with chicken leg meat

The extractive components of raw and boiled–dried scallop adductor muscle were examined. On a dry weight basis the levels of total free amino acids, total adenosine triphosphate (ATP) and related compounds, and betaines in the boiled–dried sample were lower than those in the raw muscle, which may have been due to the outflow of these compounds during boiling. Soup prepared from the boiled–dried scallop and chicken leg meat was assessed by sensory evaluation. This soup cooked with the scallop and chicken was stronger in sweetness, umami and body and rated higher in overall preference than the soup containing these ingredients after cooking separately. The inosine monophosphate (IMP) level in the former soup was 4.4 times higher than that in the latter. The adenosine monophosphate (AMP) deaminase (EC 3.5.4.6) activity in the crude extract from the chicken meat was 9.16 units l^?1, whereas no activity could be detected in the crude extract from the boiled–dried scallop. It is concluded that AMP, which was mainly derived from the boiled–dried scallop, was converted to IMP by AMP deaminase from the chicken meat during the preparation of the soup, resulting in an improvement in the taste. Copyright © 2004 Society of Chemical Industry     

First evaluation of unfermented and fermented rooibos (Aspalathus linearis) in preventing lipid oxidation in meat products

This study consisted of two trials aiming to evaluate, for the first time, the antioxidant potential of rooibos in meat products. With this purpose, the first trial evaluated three unfermented (green) rooibos forms (dried leaves, water extract, freeze-dried extract) added at 2% inclusion level to ostrich meat patties on an 8-day shelf-life trial. A Control group without green rooibos inclusion was also considered. The second trial evaluated the addition of different concentrations (0%, 0.25%, 0.5% and 1%) of a fermented rooibos extract to nitrite-free ostrich salami. The 2% green rooibos inclusion considerably lowered the TBARS content of ostrich patties, in this way extending their shelf-life. The fermented form (0.5% and 1%) was also effective in delaying lipid oxidation in ostrich salami until 15 days of ripening. The antioxidant potential of both green and fermented forms of rooibos in meat products was confirmed, even if its effect on lipid oxidation requires further study and long-term effects are not yet fully understood.     

加工方式对玉筋鱼干风味的影响

为研究加工方式对玉筋鱼干风味的影响，实验按加工方式分为加盐煮制冷风干燥（boiling in salt solution followed by cold air drying，SCC）组和冷风干燥（cold air drying，CD）组。采用电子鼻技术、气相离子迁移谱（gas chromatography-ion mobility spectroscopy，GC-IMS）技术、氨基酸自动分析技术、高效液相色谱技术测定玉筋鱼干中的风味成分。结果表明，不同加工方式制作的玉筋鱼干在气味、滋味方面存在显著差异。电子鼻、GC-IMS技术均能区分不同工艺制作的玉筋鱼干气味，采用GC-IMS技术共分析出68 种挥发性成分，庚醛、戊醛、3-甲基丁醛对玉筋鱼干独特风味的形成有重要影响，其中3-甲基丁醛源自CD工艺，其区别于SCC工艺气味的关键物质。玉筋鱼干中的主要鲜味氨基酸是Glu，主要呈味核苷酸是肌苷酸；CD组玉筋鱼干中的鲜味氨基酸和甜味氨基酸含量占总游离氨基酸的比重高于SCC组，同时CD组滋味活性值、味精当量值均高于SCC组，所以仅采用CD工艺制作的玉筋鱼干滋味优于加盐煮制后CD工艺制作的玉筋鱼干。     

Concentration of biologically active compounds extracted from Ilex paraguariensis St. Hil. by nanofiltration

The aim of this study was to characterise the bioactive compounds in mate (Ilex paraguariensis St. Hil) extract and in concentrated mate extract obtained by nanofiltration (NF). Also, the impact of NF on the antioxidant activity of both mate extracts was evaluated in vitro and using eukaryotic cells of Saccharomyces cerevisiae (yeast assay). The results showed a significant increase in the contents of total phenolics (338%), chlorogenic acid (483%), theobromine (323%), caffeine (251%), chlorophyll (321%), condensed tannins (278%) and saponins (211%) in the concentrated mate extract. The concentrated mate extract showed higher in vitro antioxidant activity than the mate extract. According to the results obtained, it can be stated that the use of nanofiltration membrane is a valid approach for the concentration of biologically active compounds in aqueous extract of mate.     

Isolation of a hydroxytyrosol-rich extract from olive leaves (<Emphasis Type="Italic">Olea Europaea</Emphasis> L.) and evaluation of its antioxidant properties and bioactivity

In this research, a phenol extract of high hydroxytyrosol (OLPE) content was obtained from olive leaves (Olea europaea L.), and subsequently tested under different contexts. The method used to obtain the OLPE basically involved two steps: the use of strongly-acid aqueous steam, generated from 10% HCl (v/v) at 100°C, to directly hydrolyse the native complex phenols from integral olive leaves, and OLPE recovery by liquid–liquid extraction with ethyl acetate. Hydrolysis time was 1 h. Finally, the dried extract was dissolved in distilled water. The OLPE total phenols were determined by Folin–Ciocalteu’s method and by HPLC analysis. Hydroxytyrosol was about 92% of the total phenols present in OLPE, and the yield was about 0.2% on fresh leaves. OLPE showed antioxidant effects on different food lipids and did not inhibit lactic acid bacteria growth; however, it showed cytotoxicity on NIH/3T3 fibroblasts and human umbilical vein endothelial cells at concentrations higher than 0.32 mM (as hydroxytyrosol).