玉米多肽制备方法及其功能活性研究进展

玉米蛋白粉是玉米湿磨生产淀粉中的主要副产品,其低水溶性、必需氨基酸缺陷等因素限制了其在食品工业中的应用。水解玉米蛋白粉制备玉米多肽是其高附加值利用方式之一,可以极大提高玉米蛋白粉的功能性和生物活性。本文重点介绍了玉米多肽的主要制备方法以及玉米多肽在抗氧化、抗血糖、抗高血压、醒酒护肝等方面的生物学功能,归纳总结了现有研究存在的问题及未来的发展前景,对食品企业高效利用玉米蛋白粉开发生物活性肽、提升行业经济效益具有重要意义。     

食物源蛋白肽铁配合物的研究进展

综述食物源蛋白多肽铁配合物的制备、分离纯化、结构分析、生物活性以及安全性研究进展。     

核桃多肽生物活性研究进展

核桃经压榨制油后的副产物饼粕,常用于饲料或丢弃,附加值极低。核桃饼粕富含高达50%的蛋白质,可进行深加工利用。为了促进核桃饼粕的综合利用,综述了核桃多肽的制备工艺及其生物活性。以核桃饼为原料,采用碱溶酸沉法制备核桃蛋白,再进一步用蛋白酶酶解获得核桃多肽。核桃多肽具有抗氧化、抗肿瘤、降血压、健脑、免疫调节等多种生物活性。     

大米生物活性肽研究进展

对大米生物活性多肽的制备和开发研究进展及关键问题进行综述，以期为大米蛋白的综合利用提供理论支持。     

基于专利信息技术分析的我国玉米蛋白研发趋势研究

为了解国内外玉米蛋白专利申请的情况,把握玉米蛋白产品的研发趋势,为我国玉米蛋白产品的研究与市场发展提供决策参考和技术依据,对国内玉米蛋白技术专利进行了检索分析。结果表明:(1)从2007开始,玉米蛋白专利技术取得了较大的技术突破和跨越式发展;(2)在玉米蛋白专利技术中,主要分为玉米蛋白做为饲料的加工利用技术、以玉米蛋白原料生产功能性多肽的专利技术和玉米蛋白新型材料及其制备方法等几个方面。     

小麦蛋白肽的酶解制备方法及研究进展

小麦蛋白肽具有多种生物活性,具备很好的保健功能,且具有成本低的优势,因而在功能性食品领域、保健品领域市场前景广阔。其制备方法已由原本制备效果较差的酸水解逐渐转向酶解。综述国内外几种酶解小麦蛋白制备多肽的方法及研究进展。     

玉米肽的制备及其生物活性研究进展

来源于植物的多肽类化合物因具有广泛的生物活性, 逐渐成为人们研究的热点。玉米作为一种重要的 活性肽的来源, 也受到了人们的青睐。本文综述了国内外关于玉米肽的制备方法、分析、功能活性及其应用研 究现状, 并预测了玉米活性肽的发展趋势和前景, 为玉米肽的进一步研究和应用提供了参考。     

复合蛋白酶法制备玉米胚蛋白多肽及其抗氧化活性研究

利用复合酶(碱性蛋白酶∶木瓜蛋白酶=1∶1)酶解玉米胚蛋白制备蛋白多肽,在单因素实验的基础上,采用Box-Behnken设计响应面法,以蛋白多肽的还原力为检测指标,优化酶解条件。确定玉米胚蛋白的最佳酶解条件为:加酶量9 200 IU/g,底物浓度11%,酶解时间188 min,在此条件下测定的还原力为0.229。将玉米胚蛋白多肽添加到面条中,考察其在面条中的抗氧化防褐变能力,并与抗坏血酸的添加效果进行对比。结果表明,玉米胚蛋白多肽粉添加到面条中具有防褐变的作用,添加量为0.9%时对鲜面条褐变速率的抑制作用最强,与添加抗坏血酸的效果相当。此外质构仪分析(TPA)实验结果表明,在面条中添加0.9%的玉米胚蛋白多肽粉,对面条的硬度、弹性有一定程度的改善作用。     

酶法水解谷朊生产生物活性肽

生物酶法改性食品蛋白是提高蛋白功能的重要途径。采用酶法水解谷朊制备生物活性肽 ,对蛋白酶的选择、酶水解工艺参数、多肽苦味的去除及酶解后产品性能进行了系统研究 ,并提出可行性生产工艺路线。     

蛋源降血压肽研究进展

鸡蛋不仅是人们饮食营养的重要来源,而且还含有许多生物活性蛋白。鸡蛋活性蛋白经酶解后会产生许多具有生物活性的多肽,其中最重要的就是具有降血压活性的多肽。本文介绍了鸡蛋来源的降血压多肽的发现、特性、生产和分离及体内外活性,以期为国内相关研究提供参考。     

Degradation of the insecticide azinphos methyl in orange and peach juices during storage at different temperatures

The degradation of azinphos methyl in orange and peach juice was studied. The insecticide was aseptically added to packed orange and peach juices and stored at 40, 20 and 0°C. Samples were removed at regular intervals and were analysed for residues of azinphos methyl. Residues were determined with a simple gas-chromatographic method using a 30m glass capillary column and an NP detector. The recoveries of azinphos methyl were 87-110% for orange juice and 92-108% for peach juice, and the limit of determination was 0.004mg/kg for both juices. From the experimental data, rate constants, half-lives, and times needed to reach legal limits for the decomposition of azinphos methyl in orange and peach juices were evaluated. Half-lives for orange and peach juices were 6.5 and 7.8 days at 40°C, 86.6, and 92.4 days at 20°C, and 407.7 and 495.1 days at 0°C, respectively.     

梳棉机锡林—回转盖板隔距与梳理质量

为了提高生条质量,减少盖板落棉,分析了锡林与回转盖板的梳理原理,对比了标准盖板与非标准盖板对条干、棉结杂质及锡林—盖板隔距与质量的关系,探讨了降低盖板总高误差及锡林—盖板隔距变化的方法。指出：锡林—盖板隔距增大使生条结杂增多、短绒率降低,当隔距增大0.025mm时生条质量恶化,增大0.051mm时生条严重恶化;锡林—盖板隔距和刺辊工艺优化组合,生条棉结降低25.6%,短绒率降低0.65%、棉结降低35.5%,条干CV值降低0.07个百分点;隔距的准确性、稳定性关系到质量与节棉的双重效益;减小盖板针布总高误差及隔距差异,有利于设备更好地发挥工艺特性,取得质量和节棉双赢。     

肉及其加工制品的掺假鉴别技术研究进展

肉因其较高的营养价值和独特的风味而成为广大消费者饮食中最重要的组成成分之一。在高额利益的驱动下,肉及肉制品的加工生产中掺假问题频繁发生。因此开发出能够对肉及肉制品的掺假进行有效鉴别的技术与方法对保障消费者的利益具有重要意义。产品和消费方式的不同决定了对掺假鉴别的侧重点不同,因而对相应掺假鉴别技术的要求也不同。本文阐述了目前用于肉及肉制品掺假检测的常见方法的基本原理及其研究进展,包括基于蛋白质组学的免疫和质谱技术,基于DNA的聚合酶链式反应技术以及基于无损检测的传感器和光谱技术。同时也对目前已知方法所存在的鉴别盲区和新的掺假鉴别技术的开发提出了建议,以期为肉类及其加工制品掺假鉴别提供一定的理论依据。     

Dephytinization of food stuffs by phytase of Geobacillus sp. TF16 immobilized in chitosan and calcium-alginate

In this work, Geobacillus sp. TF16 phytase was separately immobilized in chitosan and Ca-alginate with the efficiency of 38% and 42%, respectively. These enzymes exhibited broad substrate specificity. Maximal relative phytase activity was measured at pH 5.0 and 95°C and pH 3.0 and 75°C for chitosan and Ca-alginate, respectively. The enzymes were highly stable in a wide pH and temperature range. Values of K_m and V_max were determined as 2.38 mM and 3401.36 U/mg protein for chitosan, and 7.5 mM and 5011.12 U/mg protein for Ca-alginate. The immobilized enzymes showed higher resistance to proteolysis. After 4 h incubation, hydrolysis capacities of chitosan- and Ca-alginate immobilized enzymes for soymilk phytate were calculated as 24% and 33%, respectively. The chitosan- and Ca-alginate immobilized phytases conserved its original activity after 8 and 6 cycles of reuse, respectively. The features of the enzymes were very attractive and they might be useful for some industrial applications.     

Effects of high hydrostatic pressure on nutritional composition and cooking quality of whole grains and legumes

Whole grains and legumes are important sources of nutrients and have essential influences in the human diet. However, the consumption of whole grains and legumes faces many challenges, such as their poor edible and cooking qualities. Antinutritional factors and allergens also affect consumption of whole grains and legumes. High hydrostatic pressure (HHP) treatment is a recent non-thermal processing technology, which can improve the edible quality of whole grains and legumes. HHP also preserves the natural nutrition and freshness of food by lowering the concentration of antinutritional elements and sensitizing allergens while minimally altering the color and scent of the food components. This review summarized the principle of HHP treatment technology, the effects of HHP treatment on the nutritional components, antinutritional factors, and cooking qualities of whole grains and legumes. This review also described the potential effects of HHP-treated whole grains and legumes on some diseases. This review is expected to provide references for the application of HHP treatment in whole grains and legumes.     

Identification of phenolic compounds and their relationships to in-vitro digestibility of sorghum leaves from bird-resistant and non-bird-resistant varieties

Soluble phenolics in leaf blades and sheaths from the crop residues of 24 sorghum varieties were studied. Apigenin, luteolin, apigenin and luteolin 7-O-glucosides, p-coumaric acid, butin and apigeninidin were identified. This is the first report of butin in sorghum tissues. Derivatives of the following compounds were also detected but not characterised further: apigeninidin, luteolinidin, chalcone, flavanone and/or dihydroflavonol, cinnamic acid, apigenin and luteolin. The composition of phenolics was clearly different between leaf blades (LB) and sheaths (LS), and also between leaf sheaths of bird-resistant (BR) and non-bird-resistant (NBR) varieties. Routes of flavonoid biosynthesis in BR and NBR varieties appear to diverge at the flavanone/dihydroflavonol level. Several negative correlations were found between HPLC peaks and in-vitro digestibilities, ie true dry matter and neutral-detergent fibre digestibility. These were highly significant with butin and significant with several luteolin derivatives but only with one apigenin derivative. Butin in turn was highly negatively correlated with colorimetric measurements of 3-desoxyanthocyanidins. This may suggest that butin—rather than the 3-desoxyanthocyanidins as previously reported—is implicated in reducing dry matter digestibility. Selecting varieties low in luteolin derivatives and butin and rich in apigenin should enhance the digestibilities of sorghum crop residues.     

Millets as potential nutri-cereals: a review of nutrient composition,phytochemical profile and techno-functionality

Millets are sustainable drought-resistant crops capable of surviving a wide range of climatic conditions. They are small-seeded grains rich in proteins, minerals and bioactive compounds inducing several health benefits and provide protection against chronic and degenerative modern lifestyle disorders. Hypoglycaemic profile and bioactive composition are the key elements for the popularity of millets as functional ingredients for the development of novel food products of commercial importance. Despite numerous health benefits and agro-economic potential, millets have lost their popularity due to coarse nature and are underutilised in developed countries. Food scientists and nutritionists are characterising and valorising millets to enhance their use for food applications. The present article reviews research investigations about nutritional composition (macro- and micro-nutrients), biologically active components (phenolic acid, flavonoids, phytosterols and related antioxidant potential) and techno-functionality of millets. Pharmacological impact and their utilisation in value-added products have also been included.     

Composition and Structural Characteristics of Isolated Soy Proteins from Broken and Damaged Seeds

RACT ISOLATED soy proteins (ISP) from broken (mechanical action) or damaged (fungi) seeds had denaturation enthalpies (AH) and temperatures at peak maximum (T max) similar to those of ISP from normal seeds by DSC. They had different composition and/or conformation as measured by surface hydrophobic@ (So and Se) and SH and SS content. Also, damaged seeds produced ISP with less 7S fractions (due to fewer α and β subunits) and 11S fractions, suggesting proteo-lysis. 7S and 11S fractions had different Tmax and ΔH, SH and SS contents and surface hydrophobicity. Also 7S proteins from damaged seeds showed less a and β-subunits. The 11S proteins from broken and damaged seeds maintained gel forming properties in spite of structural differences. Isolation and characterization of 7S and 11S fractions partially accounted for changes in physicochemical properties of the ISP.     

Antioxidant properties and phenolic,isoflavone, tocopherol and carotenoid composition of Maryland-grown soybean lines with altered fatty acid profiles

One cultivar and five experimental lines of Maryland-grown soybeans with improved fatty acid profiles were investigated for their phytochemical and antioxidant properties. Soybean oils were extracted and analyzed for their fatty acid profiles, tocopherols, and carotenoids. Two of the experimental lines were low in α-linolenic acid and another one was low in both α-linolenic and total saturated fatty acids. The defatted flours were extracted in 50% acetone and 70% ethanol, and estimated for isoflavone compositions, total phenolic contents (TPC), and scavenging capacities against peroxyl (ORAC), hydroxyl (HOSC), and 2,2-diphenyl-1-picryhydrazyl (DPPH) radicals. No difference was observed in tocopherols, carotenoids, TPC, and antioxidant properties between soybeans with reduced α-linolenic and/or saturated fats and the ones with ‘normal’ fatty acid profiles. This study indicates the possibility to produce soybeans with reduced linolenic and/or saturated fat and with desirable levels of health beneficial phytochemicals and antioxidant properties.