切分及烹调对叶类蔬菜品质的影响

以芥菜、菜心、生菜等为主要原材料,研究切分方式与烹调方式对叶类蔬菜中维生素C、叶绿素和亚硝酸盐含量的影响,以明确加工条件对叶类蔬菜品质的影响。结果表明,切分后烫漂,叶类蔬菜中维生素C较新鲜蔬菜下降超过40%,亚硝酸盐含量下降超过45%,叶绿素下降不明显,且随细胞液的流失有明显上升趋势;油炒、烫漂和汽蒸三种烹饪方式对叶类蔬菜中叶绿素、维生素C、亚硝酸盐影响的研究表明,汽蒸加工可以保留叶类蔬菜中60~67%的维生素C,可降低40~70%的亚硝酸盐含量,而对叶绿素含量影响不大,是一种较理想的营养烹饪方式。本论文的研究成果具备良好的理论与实践意义,对减少叶类蔬菜烹饪加工过程中营养成分的损失、有害物质的产生、提高叶类蔬菜烹饪品质起到良好的方法借鉴。     

蔬菜维生素C保留因子的研究

目的:通过比较不同蔬菜、不同烹调方法间维生素C保留因子(RF)的差异,探讨影响蔬菜维生素C保留因子的因素。方法:选取常见的12种蔬菜,以炒、炖、炸、蒸、焯、盐腌的方法进行烹调,分别记录烹调前后蔬菜的质量。采用GB/T5009.86-2003荧光法测定蔬菜烹调前后维生素C的含量,计算相应的质量保留因子(保留率)和维生素C保留因子(保留率)。结果:鲜豆类蔬菜,焯和炖的维生素CRF>75,两种腌制菜肴的维生素C保留率仅为5%。根茎类蔬菜的情况比较复杂,缺乏规律性。叶菜类蔬菜,炒较之焯更利于维生素C的保留,RF值在80左右。炒对于茄果类蔬菜不会造成维生素C损失较大,RF>70。结论:炸、盐腌、蒸的烹调方法使维生素C损失较大,炒的烹调方法的维生素C保留率较高;温度、时间、蔬菜的品种是影响维生素保留因子的重要因素。     

炒对蔬菜中维生素B_1、B_2、C含量的影响

本文主要目的是研究炒对蔬菜中维生素B_1、B_2、C含量的影响,为家庭合理食用蔬菜,更好地摄入维生素提供科学依据。此方法模拟家庭蔬菜烹调过程,采用炒的方法分别对6种蔬菜(西兰花、番茄、椰菜、胡萝卜、菠菜、菜心)进行处理,以烹调至可食用状态为标准,然后测定蔬菜鲜样及炒后熟样中各维生素的含量,并比较炒后样品的维生素保存率,其中维生素B_1、B_2采用微量荧光法,维生素C采用高效液相色谱法。结果显示,6种蔬菜经炒处理后,维生素B_1、B_2、C保存率分别为19.4%~74.1%、39.3%~85.8%、30.7%~86.1%。经炒处理后熟样的维生素保存率,维生素B_1、维生素B_2均以西兰花最高,胡萝卜最低;维生素C以菜心最高,胡萝卜最低。其中炒西兰花、炒番茄与其对应鲜样中维生素B_2含量相比差异无显著性意义(P0.05),其它炒后样品与鲜样中维生素B_1、B_2、C含量比较差异均有显著性意义(0.01P0.05)或极显著差异(P0.01)。结论,经炒处理后蔬菜中维生素B_1、B_2、C含量均有下降,维生素B_2的损失率小于维生素B_1。蔬菜炒前的清洗方法和时间长短、炒的时间长短,炒的过程中是否加水炒等对维生素B_1、B_2、C的保存率有影响。     

烹调对蔬菜中烟酸含量的影响

为研究不同烹调方法对蔬菜中烟酸含量的影响，对7种蔬菜(白萝卜、胡萝卜、豇豆、扁豆、茄子、土豆、菠菜)采用6种不同烹调方法(炒、炖、腌、蒸、焯、炸)进行处理，用微生物法测定其鲜样和烹调后样品的烟酸含量。以烹调至可食用状态为标准进行比较。蔬菜经6种不同烹调方法处理后，其烟酸保存率大部分在60％以上。经过炒、炖处理后的蔬菜中烟酸保存率较高；经过焯和大量失去水分的腌，蔬菜中烟酸保存率较低。其中炸扁豆、炒胡萝卜、炒茄子烟酸含量与其鲜样相比差异无显性意义(P＞0．05)，其它烹调后样品烟酸含量与未处理的鲜样比较差异均有显性意义(P＜0．01)。本研究结果对食品工业加工方法具有指导意义和参考价值。     

厨房中,餐桌上 不能惯的六个毛病

蔬菜久存不吃由于种种原因,一些人习惯在周末到市场买菜,新鲜的蔬菜存在家里达一周时间甚至更久。蔬菜久存不吃,其中的维生素就会损失掉,比如将菠菜置于20℃的环境中一段时间,维生素C会损失达84％。如果蔬菜必须要在家里存放一阵子,您可以选择避光、通风、干燥的地方存放。烧菜时不加锅盖人们在烧菜时常常会忘记了盖上锅盖。据测定,盖住锅盖烧菜,蔬菜中的维生素B。只损失15－20％,如果不盖锅盖,维生素B。就会损失2－3倍;不加锅盖煮菜7分钟所损失的维生素C和盖了锅盖煮25分钟所损失的量一样多Z不加锅盖煮菜,蔬菜中的维生素A也…     

不同烹饪方式下野生蔬菜中活性成分的比较研究

本文选取马齿苋、蕨菜、椿菜和百花菜为材料,研究其在微波处理、爆炒、焯制和煮制等不同烹饪方式下的总多酚、总黄酮以及叶酸等活性成分含量的变化,并以转移率、保存率和损失率等为评价指标,通过这三种评价指标可以进行对比分析,得出不同烹饪方式下野生蔬菜中各种活性成分的变化情况。实验结果表明,爆炒后椿菜总多酚保存率最高;四种蔬菜经过微波处理后,总多酚转移率大都高于其他烹饪方式,煮制是使总多酚转移率最低的烹饪方式;煮制后,马齿苋、蕨菜、椿菜和百花菜的实际热损失率较高,蕨菜可达到43.37%,微波条件下均为负数。爆炒方式下百花菜总黄酮保存率处于最高水平,为83.14%,微波是最不利于总黄酮保存的一种烹饪方式;为保证总黄酮转移率,宜采用煮制方式;煮制后的蔬菜实际热损失率整体高于其他烹饪方式。此外,焯制方式处理后的蔬菜叶酸含量最高。由此可见,不同烹饪方式下,野生蔬菜中活性成分的变化各不相同,需要合理选择烹饪方式。     

蔬菜烹饪中如何保护维生素C

维生素C是一种水溶性维生素,同时也是相当脆弱的维生素,遇水、热、光、氧、烟就会被破坏。加热烹调处理、让太阳直照、浸水等,都会让蔬菜的维生素C大幅度减少。如果菜品中的维生素C被破坏将直接影响到人体对它的摄入量,进而影响机体的新陈代谢,这就为探究维生素C的保护技巧提供了契机。一、烹饪中保护维生素C的意义在烹饪过程中,从原料的洗涤、初加工到烹制成菜,食物中的各种维生素会因水浸、受热、氧化等原因而引起不同程度的损失,从而导致膳食的     

不同蔬菜热烫对维生素C的影响

对黄瓜、菠菜、藕、蒜苔四种新鲜脆性蔬菜在不同温度、时间下进行热烫,运用2,6-二氯靛酚法测定其中的维生素C含量。结果表明:在70～100℃内,热烫温度越低,所需时间越长,而维生素C的损失越高;热烫温度升高,热烫时间缩短,维生素C损失降低;当热烫温度过高时,维生素C的损失增加。大多数蔬菜热烫的温度为90℃,时间为40～60s时,维生素C的保存率最高。     

切分及烹调对叶类蔬菜品质的影响

随着我国经济的发展,人们对生活质量的追求也越来越高,其中叶类蔬菜的品质也越来越受到人们的重视。本文主要研究切分与烹调对生菜、芥菜、菜心等多种叶类蔬菜原材料的影响,研究内容分为对叶绿素含量的影响,对亚硝酸盐含量的影响和对维生素C含量的影响三个方面,从而探寻影响叶类蔬菜品质的加工条件。相关研究结果显示,切分后经过烫漂,会使叶类蔬菜中的叶绿素、亚硝酸盐和维生素C的含量都呈下降趋势。而对于汽蒸、油炒和烫漂三种烹调方式来说,汽蒸对叶类蔬菜含量的损失相对较小,是比较值得推广的一种烹调方式~([1])。     

浅谈营养配餐与科学烹饪(下)

正一、各种烹饪方法的优劣1、煮:是将原料放入一定量的汤汁或清水中,先用旺火煮开,再用温水煮烂的烹调方法。采用此方法,汤液中溶解了许多水溶性物质如维生素B1、维生素C及矿物质钙、磷等。糖及蛋白质在加热中部分水解,而脂肪无显著变化。蔬菜采用此方法,尽管不损失或很少损失胡萝卜素,但约30%的维B1和约60%的维C受破坏。煮沸时间长短,煮沸前食物处理方法对营养素的损失也有影响。烹调时间越长,维C损失越多。对大多     

Vitamin C losses in some frozen vegetables due to various cooking methods

Frozen spinach, peas, green beans and okra were commercially cooked in three different stewpans (double based stainless steel, teflon, pyrex) with and without thawing. The vitamin C levels were effected both by cooking methods and stewpans. Frozen peas were found to be the least (3.5% loss), and frozen green beans were found to be the most (19.6% loss) effected vegetables by thawing. In all of the stewpans, double based stainless steel pan retained more vitamin C than the others. While boiling spinach, peas, green beans, and okra without thawing resulted 46.5, 25.2, 18.2, and 21.6% vitamin C loss in double based stainless steel pan, boiling them in pyrex pan resulted 58.5, 36.0, 42.1, and 28.2% vitamin C loss, respectively. Besides, the losses in cooking processes were accelerated in thawed vegetables with the same tendency; that is more destruction occurred in samples boiled in pyrex pan (60.3% loss in spinach, 40.8% loss in peas, 48.4% loss in green beans, and 41.6% loss in okra). According to the results, it was found that thawing before cooking is useless and causes more vitamin C loss. Therefore, frozen vegetables must not be thawed before cooking. In order to prevent vitamin C from destruction, using double based stainless steel pan, minimum amount of water and cooking of frozen vegetables are recommended.     

Traditional cooked vegetable dishes as important sources of ascorbic acid and beta-carotene in the diets of Indian urban and rural families

BACKGROUND: Fresh vegetable produce is abundant during the winter season in Punjab. It is an important source of vitamins and minerals in the Punjabi diet, but the availability of ascorbic acid and beta-carotene from the vegetables is altered to varying degrees when they are subjected to traditional household processing methods. OBJECTIVE: To determine the importance of traditional cooked vegetable dishes as sources of ascorbic acid and beta-carotene among urban and rural families during the winter. METHODS: Information about vegetable consumption, storage, and cooking practices was collected from 60 families, 30 each from urban and rural areas of Ludhiana District, Punjab, India. Samples of the common cooked vegetable dishes were prepared in the laboratory by methods ascertained from the survey and analyzed for ascorbic acid and beta-carotene. RESULTS: The average total daily per capita consumption of vegetables by urban and rural families was 411.7 and 365.9 g, respectively. Cooked vegetable dishes provided 68.7% of the total vegetable intake for urban families and 85.0% for rural families. On average, the edible portion constituted 78.9% of the weight of the vegetables. Ten cooked vegetable dishes that were most frequently consumed by the families (mustard saag, potato-spinach, potato-fenugreek, potato-brinjal, potato-cauliflower, potato-capsicum, potato-carrots, potato-beans, potato-peas, and cabbage-peas) were selected for preparation in the laboratory and nutritional analysis. The average concentrations of ascorbic acid and beta-carotene in the cooked vegetable dishes were 46.0 mg/100 g and 794.2 microg/100 g fresh weight, respectively. The percentage losses of ascorbic acid and beta-carotene during preparation and cooking were 26.1% and 25.9%, respectively. CONCLUSIONS: For adult Indian men and women, the recommended dietary allowance of ascorbic acid is 40 mg, and that of beta-carotene is 2,400 microg. Cooked vegetable dishes provided 269.9% and 77.5% of the recommended dietary allowances of ascorbic acid and beta-carotene, respectively, indicating that these dishes are good sources of these nutrients in the diets of both urban and rural families during the winter season.     

不同加工方式下菠萝蜜种子物理性质及挥发性成分的比较分析

比较研究了干燥、煮熟及粉碎处理下菠萝蜜种子样品的粒度大小、水合能力、持油性、溶胀性及其挥发性成分的变化。结果表明,菠萝蜜煮熟种子表面积平均粒径为116.13μm,大于新鲜种子的74.15μm和干燥种子的29.22μm,新鲜种子体积平均粒径最大为550.26μm,干燥种子比表面积最大为0.21 m2/g;干燥种子的持水性（5.25）和膨胀性（4.00）比新鲜种子和煮熟种子强,新鲜种子的持油性最强为1.66。从菠萝蜜新鲜种子检出31种挥发性化合物,占总相对含量的77.37%;干燥和煮熟种子分别检出24种和32种化合物,分别占总含量的63.32%和35.74%,表明干燥和水煮处理会减少菠萝蜜种子风味物质。而煮熟种子中酯类化合物达16种,多于新鲜种子的8种和干燥种子的9种,且经过干燥和煮熟加工之后,甲醇等有毒成分得到清除,益于食用,为菠萝蜜种子的食用加工提供一定的理论依据。     

Rapid Species Identification of Cooked Red Snapper Using Isoelectric Focusing

A rapid method using isoelectric focusing (IEF) was developed to identify species of cooked snapper. The IEF protein band patterns of red snapper as impacted by two extraction systems (water and 8M urea), various cooking times (raw, 5, 10, 15, 20, 25 and 30 min) and cooking methods (microwave, bake, steam, broil, deep fry, and pan fry) were investigated. Samples were desalted and cleaned using a 10-sec rinsing procedure. The characteristic IEF protein pattern of red snapper was reproducible for various cooking conditions. Both 8M urea and water could be used as extractant of snapper sarcoplasmic proteins. IEF protein bands in the acidic region of the polyacrylamide gel (pH 3.5-9.5) were useful as markers for species identification.     

京津两地蔬菜防腐剂、保鲜剂和添加剂使用情况的调查研究

目的：了解北京和天津地区夏季蔬菜产、储、运环节中三剂（防腐剂、保鲜剂和添加剂）的使用情况。方法：2012年夏季（7、8月份）对京津两地主要蔬菜生产基地的种植户和蔬菜批发市场的销售商进行现场问询调查并随机购买蔬菜,7月份取样蔬菜有10种,8月份有17种,取样后带回实验室进行检测,分析三剂的使用情况。结果：问卷调查结果显示,京津两地蔬菜生产基地和批发市场所抽查的蔬菜没有使用三剂对蔬菜进行贮藏保鲜的情况,但分析检测发现,7、8月份使用甲醛对蔬菜进行防腐保鲜的比例分别为93．3％、89．2％,而且在蔬菜批发市场还发现有使用硫磺对胡萝卜、生姜、蒜熏色处理的现象以及使用含有仲丁胺的冰块对蔬菜贮藏保鲜,此外某些蔬菜多茵灵、哒螨灵、霜酶威残留超标较严重。结论：北京、天津两地主要蔬菜批发市场以及蔬菜生产基地存在添加使用防腐剂、保鲜剂和添加剂的情况,应引起种植者、销售者和有关部门的重视。     

Enhanced bioaccessibility of β‐carotene from yellow‐orange vegetables and green leafy vegetables by domestic heat processing

Effect of heat treatment involved in domestic cooking on the bioaccessibility of β‐carotene from yellow‐orange as well as green leafy vegetables was evaluated. Heat treatment of these vegetables by pressure‐cooking, stir‐frying and open‐pan boiling had a beneficial influence on the bioaccessibility of β‐carotene. The extent of increase in the per cent bioaccessibility of β‐carotene as a result of pressure‐cooking was 21–84%. Stir‐frying in presence of a small quantity of oil brought about an enormous increase in the bioaccessibility of β‐carotene from these vegetables, the extent of increase being 67–191%. Open‐pan boiling of vegetables increased the bioaccessibility of β‐carotene in the range 23–36%. Thus, among the three domestic heat processing methods, stir‐frying results in maximum bioaccessibility of this provitamin. The use of suitably heat‐processed vegetable sources of β‐carotene could form a dietary strategy to derive this micronutrient maximally by the population dependent on plant foods.     

中国传统菜肴工业化可行性分析

<正>中国菜肴烹饪技术是流传几千年的瑰宝,中华美食的一绝。中国传统菜肴讲究“色、香、味、形、质、营、器”七大特点,闻名中外,是具有传统特色的食品。中式传统菜肴与西式菜肴各具特色,在主料、配料、调味以及烹饪方法上有很大差异。中式菜肴的烹饪技术种类繁多,蒸、炸、烩、烧、烤、煎、爆、熏、滚、煲、炖等,各有其特点。中     

Effect of method of cooking on identification of heat processed beef using polymerase chain reaction (PCR) technique

Effects of various cooking methods including boiling, roasting, pressure cooking, and pan frying on species determination of beef by PCR was studied. The meat was cooked by boiling at 97.5°C for 140, 200 or 230min, by roasting at 200°C for 80, 120, or 150min or by autoclaving at 120°C for 30, 60, or 90min. The beef sample was pan fried until the meat was acceptable for sensory attributes (45min, meat temperature 115°C, fat temp 173°C) and further cooked until unacceptable. DNA was extracted from samples taken after cooking and a 271bp fragment of the mitochondrial DNA was amplified by PCR. The results indicated that with the exception of pan frying for 80min, beef was determined in all meat samples including the broth and sauce of the roasted meat.     

子午岭林区常见野生蔬菜硝酸盐、亚硝酸盐及维生素C含量的测定

测定了子午岭林区常见19种野生蔬菜中的硝酸盐、亚硝酸盐和维生素C的含量,比较蔬菜中硝酸盐分级评价标准和我国制定的无公害蔬菜亚硝酸盐限量标准及维生素C的含量发现,香椿硝酸盐含量处于安全水平,但亚硝酸盐含量高于我国制定的无公害蔬菜亚硝酸盐的限量标准,且维生素C含量小于50 mg/100g,不属于无公害蔬菜的范畴,建议少量食用或经过特殊处理后再食用;其余17种野生蔬菜均属于安全无公害蔬菜,且维生素C的含量高,可放心食用.     

不同利用方式对几种根茎类蔬菜亚硝酸盐含量的影响

以山药、胡萝卜、莲藕为实验材料,研究不同贮藏条件、烹饪方法和熟菜保存方式下3种根茎类蔬菜中亚硝酸盐含量的变化。结果表明：无论常温还是低温贮藏,贮藏7d内,3种根茎类蔬菜的亚硝酸盐含量均呈现先增加后降低的趋势,虽然常温贮藏的亚硝酸盐含量高于低温贮藏,但两者均小于4mg/kg。不同烹饪加工可显著降低3种蔬菜的亚硝酸盐含量,煮制、炒制、烤制加工方式的亚硝酸盐含量降幅分别为70%～83%、66%～80%和33%～55%,其中胡萝卜的亚硝酸含量降幅最大,莲藕的最小。低温和常温保存的熟菜,菜体中亚硝酸盐含量随时间延长而增加,保存到48h时,3种菜体的亚硝酸盐含量均小于4mg/kg,且低温远低于常温(前者最大为1.03mg/kg,后者最大为1.98mg/kg),参照食用的亚硝酸盐标准,低温(4℃)和常温(20℃)保存的熟制根茎类蔬菜食用安全期均达48h,且煮制和炒制加工的熟菜优于烤制。