3种传统中式高温烹饪工艺对牛肉食用品质的影响

为研究烤、炸、煎3种传统中式烹饪工艺对牛肉食用品质的影响,采用分光测色仪、质构仪测定牛肉制品的色泽、剪切力和硬度、咀嚼性、弹性、内聚性、回复性等指标,从而综合评定其食用品质。结果表明:3种烹饪工艺对牛肉的食用品质影响显著(P0.05)。对于烤制工艺,牛肉的L*与c*值随烹饪时间的延长显著减小(P0.05);160℃与180℃比200℃处理组的牛肉h°值大(P0.05);160℃与200℃烤制的牛肉b*值小于180℃处理的b*值(P0.05)。对于剪切力,160℃与180℃处理组显著小于200℃处理组(P0.05)。烹饪温度对牛肉的硬度、咀嚼性、回复性有显著影响(P0.05);160℃与180℃处理组的牛肉弹性、内聚性显著小于200℃的处理结果(P0.05)。对于炸制工艺,牛肉L*、b*值随烹饪时间的延长逐渐减小,c*与h°值逐渐增大;3min处理组的牛肉L*与c*值显著不同4 min与5 min的处理结果;3 min与4 min处理组的牛肉b*、h°值显著不同于5 min的处理结果(P0.05)。对于剪切力,3 min处理组显著小于5 min处理组(P0.05)。4 min与5min处理组比3 min处理组的牛肉硬度、咀嚼性大(P0.05);4 min处理组的牛肉弹性、内聚性、回复性显著小于3 min与5 min的处理结果。对于煎制工艺,牛肉a*值随烹饪时间的延长逐渐增大,其他肉色指标逐渐减小;2min与4 min处理组间的牛肉L*、a*、c*值差异性显著(P0.05);2 min与3 min处理组比4 min处理组的牛肉h°值大(P0.05)。对于剪切力,2 min与3 min处理组显著小于4 min处理组(P0.05)。2 min与3 min处理组比4 min处理组的牛肉咀嚼性小(P0.05);2 min煎制的牛肉弹性显著小于3 min与4 min的处理结果(P0.05)。综合分析发现,牛肉在160℃下烤制40 min以及在226~228℃下炸制3 min、煎制2~3 min均具有较高的食用品质。     

高温加工方式对肉品质的影响

以猪肉(红肉)、鸡鸭肉(白肉)为原料,以色泽、全质构(TPA)等为指标,研究高温加工方式(煎制、炸制、烤制)对常见红、白肉食用品质的影响。结果表明:3种加工工艺对3种肉样的色泽、剪切力、TPA影响均显著(P0.05)。经煎、炸、烤制工艺处理后,3种肉样L~*、b~*值均显著增大(P0.05),猪肉a~*值减小(P0.05),而鸡肉a~*值增大(P0.05);3种高温工艺处理后,猪肉、鸭肉剪切力值显著增大(P0.05),鸡肉剪切力变化均不显著(P0.05);煎、炸、烤3种工艺均能显著增大猪肉硬度(P0.05),对于白肉,除煎制2,3 min及炸制3min 3组外,肉样硬度均显著增大(P0.05);经3种高温工艺处理后,猪肉、鸡鸭肉弹性均显著增大(P0.05)。     

3种高温处理方式对羊肉营养成分含量的影响

为了研究煎、炸、烤3种高温处理对羊肉营养成分含量的影响,选用横山羊肉为研究对象,通过调控高温处理的时间和温度,分别测定高温处理后羊肉的水分、脂肪、蛋白质及矿物质等营养成分的含量。结果表明:煎制2 min和3 min的肉样水分和镁含量高于4 min(P0.05),粗脂肪、总SFA及MUFA含量低于4 min(P0.05);且3 min肉样总PUFA、粗蛋白和铁含量高于2 min(P0.05)。炸制3 min的肉样水分和钙含量高于5min(P0.05),粗脂肪含量最低(P0.05),总SFA、MUFA、PUFA含量均高于4 min且低于5 min(P0.05);3min和4 min的肉样粗蛋白及总灰分含量低于5 min,而镁含量高于5 min(P0.05);3 min和4 min处理间肉样粗蛋白、总灰分及镁含量无显著差异(P0.05)。160℃烤制的肉样水分、总灰分及镁含量高于180℃(P0.05),粗脂肪含量最低(P0.05),总SFA、MUFA和PUFA含量均高于180℃却低于200℃(P0.05);160℃和180℃条件下处理的肉样粗蛋白及铁含量低于200℃(P0.05),而160℃和180℃处理间差异不显著(P0.05)。综合分析,3种高温处理对羊肉的营养成分含量影响较大,肉样在226~228℃下煎制3 min、炸制3 min、在160℃下烤制40 min时营养成分保留较好,营养品质较高。     

传统中式烤、炸、煎工艺对牛肉营养品质的影响

通过调控温度和时间,分别对牛肉进行烤、炸、煎3种高温处理,筛选出较优的高温烹饪条件,为消费者选择营养物质含量较高的烹饪工艺提供理论参考。研究测定了肉样的水分、粗蛋白质、粗脂肪及脂肪酸质量分数,从而综合评价其营养品质。结果表明,烤、炸、煎3种传统中式高温处理方式对牛肉营养品质影响显著(P0.05)综合分析发现,在160℃下烤制40 min以及在226～228℃下炸制3 min、煎制2～3 min的牛肉具有较高营养品质。     

高温处理对羊肉中主要有害物质的影响

为研究煎、炸、烤3种高温处理对羊肉中有害物质的影响,试验选用横山羊肉,通过调控其高温处理时间和温度,采用分光光度法、气相色谱-质谱(GC-MS)外标法和高效液相色谱(HPLC)外标法分别测定高温处理后羊肉中的亚硝酸盐、反式油酸(C18:1 trans-9)及多环芳烃(PAHs)。结果表明:煎制2 min和3 min处理的羊肉中亚硝酸盐含量较低(p0.05);处理时长对C18:1 trans-9含量影响差异不显著(p0.05);2 min和3 min处理的羊肉中菲、芘和二苯并[a,h]蒽含量均较低(p0.05);炸制3 min处理的羊肉中亚硝酸盐,C18:1 trans-9,芘、苯并[k]荧蒽、苯并[a]芘和二苯并[a,h]蒽、苯并[a]蒽5种PAHs含量均最低(p0.05);160℃烤制处理的羊肉中亚硝酸盐含量最低(p0.05);160℃和180℃处理的羊肉中C18:1 trans-9含量较低(p0.05);160℃处理的羊肉中萘、菲和苯并[a]芘含量低于180℃,菲、苣、苯并[k]荧蒽和苯并[a]芘含量低于200℃(p0.05)。综合分析,3种高温处理对羊肉中有害物质有较大影响,羊肉在226～228℃下煎制2～3 min、炸制3 min、在160℃下烤制40 min时3类有害物质含量相对较低。     

红、白肉主要营养素受高温加工的影响

为探索红、白肉营养素受高温的影响,主要研究了3种高温加工(煎制、炸制、烤制)处理后红、白肉(猪肉、鸡鸭肉)营养素的变化。结果表明,经加工后3种肉水分含量均显著降低,烤制工艺水分含量最低(p 0. 05);脂肪含量在炸制处理时急剧增大(p 0. 01);加工后脂肪酸含量呈不同程度的增高;加工后蛋白质含量均极显著增大(p 0. 01),烤制时含量最高;氨基酸含量受加工工艺影响较显著(p 0. 05),但氨基酸组成无明显变化,烤制对氨基酸的影响较大。对比红白肉发现,对照组与加工后的猪肉水分含量均稍低于鸡鸭肉,而脂肪含量均高于鸡鸭肉;对于蛋白质,除煎制组和炸制4 min外,其他处理组猪肉蛋白质含量均高于鸡鸭肉。这些研究结果为提高红、白肉高温加工肉制品的营养品质以及为消费者更加科学地选择高温加工工艺提供了理论依据和现实指导。     

烤制时间对羊肉串品质和营养物质的影响

目的:研究新疆羊肉串烤制过程中品质和三大营养物质的变化规律,为深入研究其他小分子物质及痕量物质的产生提供必要的实验依据。方法:选用新疆绵羊后腿肉为原料制作成30mm×20mm×8mm的肉块,将肉块用新疆传统无烟煤烤制的方式分别烤制0~9min,每隔1min为一组,感官评定各组样品的风味、色泽和多汁性,并测定各组样品的出品率、Lab值、剪切力、总糖、总脂肪、蛋白质含量的变化。结果:在0~9min的烤制过程中,风味、色泽、多汁性、出品率、b值、总糖、总脂肪、蛋白质含量有极显著变化(p0.01),L值、a值无显著性变化(p0.05);烤制7min的羊肉串感官评分最高,综合得分8.8(10分制),感官品质最佳;出品率在烤制0~3min下降较快,平均每分钟下降7.3%,烤制3~9min下降较慢,平均每分钟下降2.6%;L值在烤制0~3min由32.7上升到45.6,烤制3~6min由45.6缓慢下降至42.6,烤制6~9min由42.6下降至32.3;L值在烤制过程中变化不显著(p0.05);a值在烤制0~3min由16.3上升至18.9,有缓慢上升趋势,烤制3~9min由18.9变化至20.0,保持稳定状态;a值在烤制过程中变化不显著(p0.05);b值在烤制0~3min由7.3上升至20.8,极显著性升高(p0.01),烤制3~9min变化不显著(p0.05),保持稳定;剪切力在烤制0~3min由4 710.7g下降至3 132.7g,下降极显著(p0.01),烤制3~7min变化不显著(p0.05),保持稳定,烤制7~9min由3 523.3g上升至7 533.5g,极显著性升高(p0.01);总糖和总脂肪在烤制3~6min含量极显著下降(p0.01),在烤制0~3min和烤制6~9min呈微弱降低趋势;蛋白质在烤制0~4min含量保持稳定;在烤制4~9min变化极显著(p0.01),含量先上升再下降。结论:烤制时间对羊肉串风味、色泽、多汁性、出品率、Lab值、剪切力、总糖、总脂肪和蛋白质含量的影响较大。羊肉串完全烤熟时的风味、色泽、多汁性的综合得分最高。烤制中期时L值、b值较大,剪切力较小,总糖、总脂肪、蛋白质含量变化较快,羊肉串具有酱黄油亮、肉质嫩等特点。     

宰后成熟过程中羊肉食用品质及蛋白稳定性的变化研究

研究陕北横山羊肉宰后48 h内,不同部位肉块嫩度、持水性等相关指标的变化规律。分别在宰后4、8、12、24、48 h取背最长肌(HQ)和腹部肌肉(LQ),测定了剪切力、汁液流失率和蒸煮损失率、肌浆蛋白和肌原纤维蛋白的溶解度、肌原纤维蛋白降解聚合情况。随着宰后时间延长,两类肉样剪切力在4~8 h显著增大(p0.05),12 h之后显著减小(p0.05);肉样汁液流失率、蒸煮损失率和肌浆蛋白溶解度均显著增加(p0.05);肉样肌原纤维蛋白溶解度4~12 h显著减小(p0.05)而12 h之后逐渐增加(p0.05)。在宰后过程中,HQ肉样剪切力、汁液流失率和蒸煮损失率显著小于LQ肉样(p0.05),肌浆蛋白溶解度显著高于LQ组(p0.05);在宰后12 h内,HQ肉样肌原纤维蛋白溶解度显著低于LQ组(p0.05),但20 h之后反超且显著高于LQ组(p0.05)。两类肉样肌原纤维蛋白的SDS-PAGE电泳结果与溶解度变化趋势一致。宰后2 d内,横山羊肉的嫩度逐渐趋于嫩化,持水性减弱,稳定性减弱;背最长肌羊肉较低品质肉的嫩度和持水性较优、蛋白稳定性较差。     

油炸对鹅肉理化性质、质构与微观结构的影响

为选择鹅肉合适的油炸条件,采用常规物化特性测定方法,研究油炸对鹅肉理化性质、质构与微观结构的影响。结果表明,随油炸温度升高、时间延长,油炸损失率逐渐增加,135℃油炸5 min比120℃油炸2.5 min的损失率增加了12.87%(P0.05);p H值与剪切力的变化规律相似,呈现出了总体上升趋势,120℃与135℃油炸5 min时,剪切力值分别为40.432 N与55.783 N(P0.05);油炸后,鹅肉L*值降低,a*值与b*值逐渐增加,135℃油炸5 min的a*值与b*值分别比油炸2.5 min的增加了27.85%与32.95%;油炸后鹅肉硬度、咀嚼性总体变大,弹性、凝聚力、黏性及恢复性总体变小。120℃油炸3.5 min时,肌束膜内出现少许颗粒,125℃油炸3.5 min时,肌束膜变形严重,部分溶解,至135℃油炸5 min时,肌细胞结构已十分模糊。130℃油炸3 min是鹅肉较好的油炸条件,在此条件下,鹅肉损失率为38.24%、剪切力值为41.897 N、色泽金黄、质构特性良好。     

不同热加工方法对羊肉制品体外模拟可消化性研究

以藏绵羊为研究对象,通过调控处理时间和温度进行微波、蒸制、炸制、煎制和煮制5种工艺处理,采用胃蛋白酶-胰蛋白酶体外模拟消化法测定了不同热加工方法的羊肉制品中蛋白质的体外消化率。结果表明:随着加热终点温度的增大,羊肉制品中蛋白质的体外消化率呈现先增大后降低的趋势。胃蛋白酶消化后,经微波、煎制、炸制加热处理的羊肉制品肉样中心温度为80℃时蛋白质消化率显著大于其50、60、70、90℃的蛋白质消化率(p﹤0.05),经蒸制和煮制加热处理的羊肉制品肉样中心温度为70℃时蛋白质消化率显著大于其50、60、80、90℃的蛋白质消化率(p﹤0.05),蒸制加热肉样至70℃时蛋白质消化率达到最大(65.58%±6.14%);经胃蛋白酶和胰蛋白酶两步消化后,5种加热处理的羊肉制品中蛋白质消化率与经胃蛋白酶消化的变化一致,蒸制加热肉样至70℃时蛋白质消化率达到最大(83.1%±4.74%)。该研究结果对人们合理选择羊肉的热加工方法以及工艺条件具有一定的指导意义。     

Mineral contents of some southern Italian wines. II. Determination of Li, Na, Mg, K, Ca, Co, As, Rb, Sr, Ag, Sb, Ba

Following our study of the mineral contents of some Southern Italian wines, this work reports on the detection of 12 elemental components. The elements were determined using ICP-AES, flame atomic emission or absorption spectroscopy. The values determined for Li, Na, Mg, K, Ca, Rb, Sr and Ba were within the usual ranges for wines (average values for these elements were: 0.010, 26.2; 94.4; 888; 94.0; 3.30, 0.82 and 0.11 mg/l respectively). All the wines contained low levels of As, the concentrations of which were always under 0.20 mg/l, the maximum level permitted by E.E.C. standards. The measuring of Co, Ag, and Sb led us to ascertain, in all the wines, concentrations lower than 0.01 mg/l for Co and Ag and below the instrumental detection level for Sb (0.06 mg/l). In a previous study wines from D.O.C. areas of Southern Italy were analysed by the technique of inductively coupled plasma atomic emission spectroscopy (ICP-AES), for 14 minerals. This paper deals with further investigation of the mineral composition of the same wines for different metal constituents, analysed by ICP-AES, flame atomic emission, or atomic-absorption spectroscopy (two techniques). The first technique was applied to the detection of Co, As, Sr, Ag, Sb, and Ba. The alkaline metals Li, Na, K, and Rb were determined by flame atomic emission, a technique which possesses better detection limits for these elements. For Mg and Ca the atomic absorption methods were applied.     

Isolation,Composition, Structure,Properties, Modifications,and Uses of Yam Starch

Starch is the major carbohydrate in yam tubers and can amount up to 80% of the dry matter. The starch quality determines the quality of food and industrial products made from yam tubers. This review summarizes the present knowledge of the isolation, composition, structure, property, modifications, and uses of starches from diverse yam species. Compared with other tuber and root starches, there is a lack of systematic information on the yam starches. This hinders the further development of yams as sustainable crops as well as the value‐added processing of the starches. Therefore, suggestions on how to better understand and utilize these starches are provided.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Survey of trace elements (Al,As, Cd,Cr, Co,Hg, Mn,Ni, Pb,Se, and Si) in retail samples of flavoured and bottled waters

Concentrations of eleven trace elements (Al, As, Cd, Cr, Co, Hg, Mn, Ni, Pb, Se, and Si) were measured in 39 (natural and flavoured) water samples. Determinations were performed using graphite furnace electrothermetry for almost all elements (Al, As, Cd, Cr, Co, Mn, Ni, Pb, and Si). For Se determination hydride generation was used, and cold vapour generation for Hg. These techniques were coupled to atomic absorption spectrophotometry. The trace element content of still or sparkling natural waters changed from brand to brand. Significant differences between natural still and natural sparkling waters (p < 0.001) were only apparent for Mn. The Mann–Whitney U-test was used to search for significant differences between flavoured and natural waters. The concentration of each element was compared with the presence of flavours, preservatives, acidifying agents, fruit juice and/or sweeteners, according to the labelled composition. It was shown that flavoured waters generally increase the trace element content. The addition of preservatives and acidifying regulators had a significant influence on Mn, Co, As and Si contents (p < 0.05). Fruit juice can also be correlated to the increase of Co and As. Sweeteners did not provide any significant difference in Mn, Co, Se and Si content.     

Varied Composition of Tocochromanols in Different Types of Bran: Rye,Wheat, Oat,Spelt, Buckwheat,Corn, and Rice

The profiles of tocopherol (T) and tocotrienol (T3) homologues in 37 samples of seven different types of bran (rye, wheat, oat, spelt, buckwheat, rice, and corn), available on the Polish market, were studied. Tocochromanols were identified and quantified by reverse phase-high-performance liquid chromatograph/fluorescence detector and reverse phase-ultra performance liquid chromatography-electrospray ionization/mass spectrometry. Only rice bran contained all eight tocochromanol types. Corn bran lacked β-T3; rye, wheat, oat, and spelt bran lacked γ-T3 and δ-T3; and buckwheat bran lacked β-T3, γ-T3, and δ-T3. In buckwheat and corn bran tocopherols predominated (98 and 78%, respectively); whereas rye, wheat, oat, spelt, and rice bran were rich in tocotrienols (78, 76, 66, 87, and 66%, respectively). The average total tocochromanol contents in the oat, corn, spelt, buckwheat, wheat, rye, and rice bran were 5.5, 16.2, 15.8, 14.7, 12.8, 10.7, and 9.1 mg/100 g of dry weight, respectively. Tocochromanol concentrations in samples of the same type bran from different sources varied considerably. Better labeling of bran products to reflect this variation would assist with control of vitamin E daily dietary requirements.     

Optimization of extraction conditions of total phenolics, antioxidant activities, and anthocyanin of oregano, thyme, terebinth, and pomegranate

The purpose of this study was to evaluate the total phenolic extracts and antioxidant activity and anthocyanins of varieties of the investigated plants. These plants include oregano, thyme, terebinth, and pomegranate. The optimum extraction conditions including temperature and solvent of the extraction process itself were investigated. Total phenolic and anthocyanin extracts were examined according to Folin-Ciocalteu assay and Rabino and Mancinelli method, respectively. The effect of different extracting solvents and temperatures on extracts of phenolic compounds and anthocyanins were studied. Plant samples were evaluated for their antioxidant chemical activity by 2, 2-diphenyl-1-picrylhydrazl assay, to determine their potential as a source of natural antioxidant. Results showed that all tested plants exhibited appreciable amounts of phenolic compounds. The methanolic extract (60 °C) of sour pomegranate peel contained the highest phenolic extract (4952.4 mg/100 g of dry weight). Terebinth green seed had the lowest phenolic extract (599.4 mg/100 g of dry weight). Anthocyanins ranged between 3.5 (terebinth red seed) and 0.2 mg/100 g of dry material (thyme). Significant effect of different extracting solvents and temperatures on total phenolics and anthocyanin extracts were found. The methanol and 60 °C of extraction conditions found to be the best for extracting phenolic compounds. The distilled water and 60 °C extraction conditions found to be the best for extracting anthocyanin.     

Analysis of cheese for histamine, tyramine, tryptamine, histidine, tyrosine, and tryptophane

A method is described for determining the content of selected biologically active amines (histamine, tyramine, tryptamine) and amino acids (histidine, tyrosine, tryptophane) in cheeses by high performance liquid chromatography. The amines and amino acids were quantified by employing a counter ion-containing mobile phase and by comparing peak areas of high performance liquid chromatography charts for sample cheeses versus standard cheeses containing known amounts of added amines based on dual injections of samples and standards. Recovery of amines and amino acids varied from 87.5 to 111%. Histamine, which has been associated with food poisoning in concentrations of 185 mg/100 g in Swiss cheese and 180 to 500 mg/100 g in fish, was found in concentrations above 500 mg/100 g in Swiss cheese. The high performance liquid chromatography analytical method should be useful for screening to detect cheese samples containing toxic amounts of histamine and for research studies designed to determine the cause and effect relationships for histamine production in cheese.     

ICP-MS测定饼干中的铅、砷、铬、镉、铜、锌、铁和锰

探讨了应用电感耦合等离子体质谱仪测定饼干中铅、砷、铬、镉、铜、锌、铁和锰8种重金属元素的方法。运用微波消解系统对样品进行消解,以铋、锗、钪和铟作为内标物,用ICP-MS对消解液进行检测,并采用国标方法对其结果进行验证。利用加标回收率试验和国家标准物质小麦(GBW 10052)检测试验考察了方法的准确性和可靠性。结果表明,该方法所测元素在标准溶液浓度范围内呈线性关系,相关系数均大于0.999,方法检出限在0.002~0.500 mg/kg之间,相对标准偏差均小于6.55%,本法与国标方法测量结果的相对偏差在3.73%~8.40%之间,加标回收率在88.0%~106%之间,标准物质的测定值与标准参考值符合要求。     

接装纸中汞、砷、铅等8种元素的分析研究

本文利用电感耦合等离子体发射光谱仪(ICP-AES法)同时测定接装纸样品中铅、铜、镉、铬、锡、锑元素含量,汞、砷元素含量采用冷原子吸收光谱法和银盐法测定.结果表明接装纸样品中锡元素含量最高,铜次之,汞、砷、铅相比,砷元素含量较高,部分样品中砷、铅元素含量超出食品包装用纸的最高限量标准.采用ICP-AES法同时测定接装纸6种元素,操作简便,重复性好,回收率高.此外,本文还对接装纸荧光物质和脱色程度进行了测定分析,从随机抽检的47份国产、进口接装纸样品看,进口白色接装纸无荧光,国产白色接装纸有荧光,珠光色接装纸个别有荧光,纸边为白色的接装纸荧光程度不一.脱色试验表明,进口接装纸,国产印刷型接装纸、珠光纸不脱色,涂布型接装纸均有不同程度的脱色.     

Physicochemical,morphological, thermal,pasting, and textural properties of starch acetates

Acetylated starches are a commercially important group of modified starch known for their reduced retrogradation tendency, high clarity, low viscosity, high swelling power, and lower gelatinization temperature and time. Due to these remarkable properties, acetylation is a commonly used chemical modification for preparing stabilized starches. This review summarizes the methods used for preparation of starch acetates and corresponding effects of acetylation on morphological, thermal, pasting, digestibility, textural, and other functional characteristics of starches isolated from various botanical sources. Starch acetates are also useful as packaging material, as wall material for encapsulating active ingredients, and to improve the storage stability of different products.