不同加工处理对卡亚草酸含量影响

采用比色法研究了不同加工处理对抗营养因子草酸含量影响,结果表明成熟叶中草酸含量较高为(0.615±0.00)%,其中30℃干燥处理、热烫处理能有效降低草酸含量,降低率均大于50%。     

不同加工处理对卡亚中单宁含量影响

通过比色法研究不同加工处理对卡亚单宁含量影响,其中沸水焯烫处理效果最佳,处理后卡亚成熟叶、嫩叶单宁含量分别降至0.15%、0.05%,基本符合一般果蔬可食部分的单宁含量。     

不同预处理对发酵酸豆乳品质及抗营养因子含量的影响

本文以大豆为研究对象,在浸泡温度为25℃、豆水比为1:4、浸泡时间16h的条件下,采用不同介质(水、0.45%柠檬酸溶液、0.45%碳酸氢钠溶液)浸泡及萌发等预处理后制备发酵酸豆乳,考察对酸豆乳抗营养因子变化及营养品质的影响。结果如下：以干豆榨取的豆乳作为对照组,酸豆乳中胰蛋白酶抑制剂的还原作用依次为发芽>碳酸氢钠>水>柠檬酸；植酸含量依次为发芽>柠檬酸>水>碳酸氢钠；单宁含量的降低作用依次是发芽>碳酸氢钠>柠檬酸>水。浸泡处理可有效降低酸豆乳中抗营养因子的含量,碳酸氢钠浸泡组去除抗营养因子效率最高,质量最好。此外,高温处理将胰蛋白酶抑制剂含量降低70%,植酸和单宁属于热不敏感因子,高温处理效果不够显著。因此,本研究最终确定的预处理条件为发芽,碳酸氢钠浸泡。     

挤压膨化加工对大豆抗营养因子的影响

主要研究挤压膨化加工大豆的方法对其抗营养因子的影响。通过采用试验与理论分析相结合的方法探讨挤压膨化加工参数对大豆抗营养因子的影响规律。研究表明 :挤压机出料口模孔直径的大小对大豆脲素酶活性的影响最显著 ,模孔直径越大脲素酶活性越大。     

抗营养因子的抗营养作用

抗营养因子普遍存在于植物性饲料中，主要包括蛋白质抑制剂，植物凝集素等。根据抗营养因子与不同营养素拮抗的特点，可将其抗营养作用分为降低蛋白质利用率，降低能量利用率，降低矿物质，微量元素利用率和降低维生素利用率等。     

饲料中的抗营养因子及处理方法

饲料是动物生产的物质基础。现今在配合饲料中90％以上韵组分为植物性饲料,植物性饲料都含有一种或多种抗营养因子。抗营养因子不但影响了饲料的营养价值和适口性,而且给动物的健康生长和生产带来了很大的危害。众所周知我国既是人口大国又是饲料生产大国,人畜争粮,饲料     

挤压膨化加工对大豆抗营养因子的影响

主要研究挤压膨化加工大豆的方法对其抗营养因子的影响。通过采用试验与理论分析相结合的方法探讨挤压膨化加工参数对大豆抗营养因子的影响规律。研究表明：挤压机出料口模孔直径的大小对大豆脲素酶活性的影响最显著，模孔直径越大脲素酶活性越大。     

常用处理技术对蚕豆抗营养因子影响

主要采用漂烫、浸泡、熟化三种常用处理技术对蚕豆进行处理,分析处理前后蚕豆中抗营养因子(单宁、胰蛋白酶抑制剂和棉籽糖、水苏糖等胀气因子)变化。试验结果表明,90℃、150 s或95℃、120 s漂烫处理较为合理;低温长时间浸泡,如25℃、10 h可在降低水溶性抗营养因子含量同时更节约能源,更为合理;常压水煮30 min、高压熟化20 min均可有效降低胰蛋白酶抑制剂活性。     

大豆中营养因子和抗营养因子研究进展

大豆中含有抗营养因子和营养因子,营养因子包括大豆磷脂、大豆异黄酮等,抗营养因子包括蛋白酶抑制因子、抗原蛋白、凝集素、植酸等,大豆低聚糖和皂甙具有营养和抗营养双重作用。对大豆中的营养因子和抗营养因子的生理功能,对动物的营养及危害作用进行了论述。     

Effect of age of regrowth on chemical composition of chaya (Cnidoscolus aconitifolius) leaves

The chemical composition of chaya (Cnidoscolus spp) leaves, as a promissory edible tropical shrub for both humans and animals was evaluated. The chemical composition of C aconitifolius did not differ significantly with age of regrowth, with the exception of ether extractives and the oxalic acid content. Galactose, glucose and xylose were the most important sugars found in the insoluble fraction and, galactose and uronic acid were the main components in the soluble portion of non‐starch polysaccharides (NSP). There was a total content of 197.2 g kg^?1 NSP, of which 68.72 and 31.26% corresponded to the insoluble and soluble components respectively. The amino acid composition of C aconitifolius ranged from 0.416 for lysine to 0.641 for valine relative to their contents in soyabean meal. Nevertheless, without exception, the concentrations of all the essential amino acids in C aconitifolius were higher than the corresponding values in alfalfa, a fibrous foodstuff widely acceptable in diets for farm animals. Copyright © 2003 Society of Chemical Industry     

发芽处理对蚕豆主要营养成分与抗营养因子的影响

研究发芽处理对启豆2号蚕豆主要营养成分与抗营养因子含量的影响。对蚕豆发芽前后蛋白质、脂肪、淀粉、VC、氨基酸、植酸和单宁含量测定。结果表明：蚕豆在发芽1d时可溶性蛋白质含量显著增加,随后逐渐下降;粗脂肪和淀粉含量均呈下降趋势;发芽2d时VC含量显著增加,达到最大58.65mg/100g,随后逐渐下降,5d后VC含量仍高于未发芽的;发芽后1～2d蚕豆的氨基酸含量略有增加;发芽1d抗营养因子植酸含量下降了33.55%,随后平缓;发芽1d蚕豆的单宁含量增加到462.70mg/100g,2～3d增加比较平稳,5d急剧增加至1306.10mg/100g。可推知,将启豆2号蚕豆发芽1～2d的作为食用及加工的较佳时期。     

Effect of Processing on Proximate Composition and Mineral Content of Sea Cucumbers (Parastichopus spp.)

The nutrient content, texture and holothurin content of two sea cucumber species were determined for fresh, dried and canned products. Fresh sea cucumber contained 89–91% moisture, 5–6% protein, 0.3% fat, 3% ash and 0.3% carbohydrate; dried sea cucumber contained 2–6% moisture, 61–70% protein, 2–3% fat, 16–24% ash, and 2–3% carbohydrate. Fresh sea cucumber contained 90 mg of holothurin per 100g of tissue. Canned sea cucumber contained moisture and protein levels similar to those generally found in marine finfish. Processing methods for canned sea cucumber resulted in a significant (P<0.01) decrease in potassium and increase in sodium. No significant differences (P<0.01) were found in the texture of canned products made from fresh-cooked, salted-cooked and cooked-dried raw material.     

Reduction of Cyanogenic Compounds in Flaxseed (Linum usitatissimum L.) Meal Using Thermal Treatment

Flaxseed (Linum usitatissimum L.) provides multiple nutritional benefits, including high quality protein, dietary fiber, and is the most abundant source of α-linolenic acid (C_18:3). However, the presence of anti-nutritional factors, such as cyanogenic compounds, restricts flaxseed's consumption as a food or feed. This study investigated the reduction of cyanogenic compounds, measured as hydrocyanic acid (HCN), in full-fat flaxseed using extrusion processing without a die by following the response surface methodology. The ranges of processing variables selected were: barrel exit temperature of 76.3–143.6°C; screw speed of 59.6–160.5 rpm; and feed rate of 26.4–93.6 kg/h. The experimental values of HCN reduction obtained were from 60.8 to 86.6%. Optimum extrusion conditions of barrel exit temperature, screw speed, and feed rate were found to be 143.6°C, 133.5 rpm, and 57.8 kg/h for maximum (89.1%) reduction of HCN. This effect was mainly dependent on barrel exit temperature, whereas screw speed and feed rate had no or minimal effect. The mutual interaction effect of barrel exit temperature and screw speed was found to be significant (p ≤ 0.01). The degree of correlation (R²) for HCN reduction was 97.2%, which showed the validity of applied second-order response model. The results of this study demonstrated that significant reduction of HCN in flaxseed can be achieved commercially using an extruder without a die.     

蔗糖处理对费菜黄酮含量及其抗氧化性的影响

本文以费菜为研究对象,采用不同浓度5、10、20、30、40 mmol/L蔗糖培养液对费菜嫩枝进行培养,选取费菜黄酮含量富集作用较强的蔗糖培养液,并研究该浓度下费菜的抗氧化性。结果表明:选取20 mmol/L蔗糖培养液对费菜培养,对黄酮有较好的富集作用,该浓度培养液的费菜黄酮含量(鲜重)平均值为对照组的1.58倍;蔗糖处理明显提升了费菜DPPH自由基清除能力及总酚的含量;与对照组相比,蔗糖处理组苯丙氨酸解氨酶(phenylalanine ammonialyas,PAL)酶活力也一直保持较高水平;超氧化物歧化酶(superoxide dismutase,SOD)、抗坏血酸过氧化物酶(ascorbate peroxidase,APX)、过氧化物酶(peroxidase,POD)等抗氧化酶活力在外源蔗糖的影响下均高于对照组。这些结果表明了外源蔗糖处理较好地提高了费菜黄酮含量和抗氧化性,为费菜黄酮的富集提供了新的思路和理论依据。     

清江流域烤烟类胡萝卜素降解产物的因子分析和综合评价

以湖北清江流域8个烤烟主产区24个烟叶样品为供试材料,对烤烟12种类胡萝卜素降解产物进行了相关分析和因子分析,并利用因子得分进行综合评价。结果表明,烤烟类胡萝卜素降解产物间存在显著或极显著的相关性。相关系数矩阵前3个特征根的累计贡献率已达85．05％。由类胡萝卜素降解产物的因子载荷矩阵得到3个公因子,即巨豆三烯酮类因子、大马酮类因子和庚烯类因子。因子分析法综合评价的结果与评吸结果基本一致,为用化学指标评价烤烟品质提供了新方法。     

Processing optimization and characterization of gelatin from lizardfish (Saurida spp.) scales

Response surface methodology (RSM) with a 4-factor, 5-level central composite design (CCD) was conducted to ascertain the optimum gelatin extraction conditions from lizardfish scales. The effects of concentration of NaOH (%, X₁), treatment time (h, X₂), extraction temperature (°C, X₃) and extraction time (h, X₄) were determined. The responses included extraction yield (%), gel strength (g) at 9-10 °C and viscosity (cP) at 25 °C. The results showed the optimum conditions for the highest values of the three responses when a concentration of NaOH at 0.51%, a treatment time at 3.10 h, an extraction temperature at 78.5 °C and an extraction time at 3.02 h. The predicted responses were 10.7% extraction yield, 240 g gel strength and 5.61 cP viscosity. The experimental values were 10.6 ± 0.82% extraction yield, 252 ± 1.21 g gel strength and 7.50 ± 0.28 cP viscosity. The physicochemical properties of the lizardfish scales gelatin were characterized and the results indicated high protein and low ash content. Texture profile analysis (TPA) with compression was carried out at 30% deformation. The lizardfish scales gelatin was found to contain 20.4% imino acids (proline and hydroxyproline). Furthermore, slightly loose strands of the gel microstructure were observed using scanning electron microscopy (SEM).