植酸酶在食品中的应用

植酸酶是能够水解植酸盐的主要作为单胃动物饲料添加剂应用的一种磷酸酶,降低食品中植酸盐含量能够增加矿物质的生物利用率。近年来,植酸酶不断应用于食品的生产加工中。在食品生产中加入植酸酶,除了能提高矿物质和微量元素的生物利用率,还能改善终产品的质量和产量。目前,植酸酶在面包加工、植物蛋白分离物的生产和谷物糠的分馏中都有应用。     

植酸酶在食品工业中的应用

植酸酶又称肌醇六磷酸酶,可以分解肌醇六磷酸,而后者是植物体内主要的磷酸储存形式。在动物的饲料中加入微生物植酸酶来取代无机磷酸盐饲料,有助于减少单胃动物磷的排泄。应用植酸酶可以减少高达50%的磷的排泄,很明显这对环境保护是非常有利的。植酸酶添加剂有助于提高矿物质和微量元素的利用率,植酸酶不仅可用作动物饲料添加剂,同样可用于食品添加剂。目前在这一领域的研究主要集中在提高矿物质吸收和改善食品加工技术上。几乎所有的植酸酶产品都是通过微生物发酵获得。近十年,研究人员发现了大量的植酸酶。利用转基因植物生产植酸酶的研究业已起步,关键是由发酵液中成功提取出所需产品。     

植酸酶在食品中的应用

植酸酶是在食品中应用的一种新型的添加剂，它能够降解食物中的植酸而提高食物中磷、锌、铁等的吸收率，对矿物质元素的利用具有全面的促进作用，应用于食品工业中，具有良好的发展前景。     

酶解植酸纤维在焙烤食品中的应用

纤维化焙 烤品在加工过程中的植酸具有相当的热稳定性，导至合螯矿物质营养素，造在此类食品一定程度的矿物质营养障碍。利用麦麸中植酸酶并在其适宜条件下，降解植酸则有效地解决焙烤食品中的应用问题。     

植酸酶的研究进展及应用

阐述了植酸酶的理化性质及作用机理,简要论述了植酸酶在饲料添加剂、肌醇磷酸盐或肌醇的生产、谷物沉淀加工废弃物的处理、食品加工等方面的应用及其发展前景。     

牛血在食品中的加工利用新技术

牛血含有丰富的蛋白质及矿物质,具有较高的营养保健价值,而且资源丰富,但利用率较低,因此在人类食品应用上的开发成为热点话题。本文从牛血的血浆蛋白、珠蛋白、血红素等组成成分进行营养及理化特性分析,进而阐述其在食品中的加工利用价值:血浆蛋白和珠蛋白可作为新型添加剂应用于灌肠类肉制品和焙烤类食品中,提高产品质量和得率;血红素生产合成卟啉锌可作为天然红色素应用在食品中,颜色稳定且补充人体所需矿物质。     

植物乳杆菌植酸酶理性设计及表达鉴定

植酸酶能将植酸水解成肌醇衍生物，并释放出无机磷酸，是一种重要的生物催化剂。植酸酶的热稳定性和比活性是决定其潜在应用价值的2个关键因素。该研究从植物乳杆菌中克隆到了具有233个氨基酸残基、高活性的植酸酶基因(LpPHY233),并在大肠杆菌中实现了高水平的异源表达，其表达水平是植物乳杆菌的800倍。基于理性设计的结果，通过二硫键工程显著提高了LpPHY233的温度特性和催化性能。突变体LpPHY233S58C/K61C的最适反应温度较LpPHY233提高了15℃。此外，它还具有良好的pH特性和动力学参数，在食品加工和饲料添加剂领域具有较大的应用前景。该研究结果为植酸酶的进一步分子修饰和工业应用提供了坚实的理论基础。     

不同品种的玉米-豆粕型日粮中添加植酸酶对肉仔鸡生长性能的影响

植酸很早就被认为是饲料中的抗营养因子。据报道，单胃动物仅能利用典型玉米－豆粕型日粮中磷的１５％～２０％。近年来，植酸酶生产的产业化为植物中磷的利用开辟了新途径。研究表明，添加植酸酶能提高日粮钙磷和氨基酸的利用率，改善动物生产性能。植酸酶的应用效果受日粮因素特别是日粮钙磷水平的影响。高油玉米是最近培育的新品种，含油量比普通玉米高１００％～１５０％，总能比普通玉米高８％～１０％。本试验在前人的试验基础上，在正常钙磷水平条件下，向２种玉米（普通玉米，高油玉米）－豆粕型日粮中添加两个水平的植酸酶，以研究…     

植酸酶在环保型饲料的应用

植酸酶作为饲用酶制剂被广泛应用于环保型饲料中,主要介绍了植酸酶对家禽生产性能、家畜生产性能的影响,以及植酸酶对氮、磷代谢和植酸酶对矿物质元素代谢的影响,最后对植酸酶发展前景进行了展望。     

植酸酶在环保型饲料的应用北大核心

植酸酶作为饲用酶制剂被广泛应用于环保型饲料中,主要介绍了植酸酶对家禽生产性能、家畜生产性能的影响,以及植酸酶对氮、磷代谢和植酸酶对矿物质元素代谢的影响,最后对植酸酶发展前景进行了展望。     

Intrinsic mineral labeling of edible plants: methods and uses

The fate of minerals can be conveniently studied through intrinsic labeling techniques. The mineral of interest is biologically incorporated into the food in a form that can be distinguished analytically from the natural form of the element. Radiolabels have traditionally been used to study such problems as the uptake of minerals by plants, the gross and subcellular mineral distribution in plant tissues, the form and associations of the deposited mineral, and the bioavailability of minerals to animals and humans. The use of stable (nonradioactive) isotopes as a label offers the potential of safely studying bioavailability of minerals from individual foods in human population groups of all ages using foods processed in normal food handling and processing facilities.     

Barriers impairing mineral bioaccessibility and bioavailability in plant-based foods and the perspectives for food processing

Abstract

Plant-based foods gain more importance since they play a key role in sustainable, low-meat and healthy diets. In developing countries, these food products, especially legumes and cereals, are important staple foods. Nevertheless, the question arises on how efficient they are to deliver minerals and if it is useful to encourage their consumption to reduce the prevalence of mineral deficiencies? This review paper focuses on the discrepancy between the mineral content and the amount of minerals that can be released and absorbed from plant-based foods during human digestion which can be attributed to several inherent factors such as the presence of mineral antinutrients (phytic acid, polyphenols and dietary fiber) and physical barriers (surrounding macronutrients and cell wall). Further, this review paper summarizes the effects of different processing techniques (milling, soaking, dehulling, fermentation, germination and thermal processing) on mineral bioaccessibility and bioavailability of plant-based foods. The positive impact of these techniques mostly relies on the fact that antinutrients levels are reduced due to removal of fractions rich in antinutrients and/or due to their leaching into the processing liquid. Although processing can have a positive effect, it also can induce leaching out of minerals and a reduced mineral bioaccessibility and bioavailability.     

IMPROVING ENZYMATIC REDUCTION of MYO-INOSITOL PHOSPHATES WITH INHIBITORY EFFECTS ON MINERAL ABSORPTION IN BLACK BEANS (PHASEOLUS VULGARIS VAR. PRETO)

Activation of endogenous or addition of exogenous phytases during food processing gives a chance to reduce the phytate content in the final product to a nutritionally acceptable level. Optimal conditions for the endogenous phytases of black beans, this is 60C and pH 6.0, resulted in a 55% reduction in 1P₆ after soaking and cooking. the sum of 1P5 and 1P₅ was reduced by 54%. 1P₆ reduction was most extensive when black beans were soaked at 50C while adding exogenous phytases during the last 2 h of soaking. After soaking and cooking 1P₆ was degraded by 85% and the sum of 1P6 and 1P5 was reduced by 82 % compared to the values in raw beans when adding Escherichia coli phytase. Using rye phytase the values were estimated to be 73% and 70%, thereby a clear accumulation of IP₄ occurred. Thus, a significant improvement in reduction of mnyo-inositol phosphates with adverse effects on mineral bioavailability has been achieved in comparison to the usual household procedure.     

Phytic Acid Degradation in Complementary Foods Using Phytase Naturally Occurring in Whole Grain Cereals

Complementary foods based on cereals and legumes often contain high amounts of phytic acid, a potent inhibitor of mineral and trace element absorption. The possibility to degrade phytic acid during the production of complementary foods by using whole grain cereals as the phytase source was investigated. Whole grain rye, wheat, or buckwheat (10%) were added to cereal‐legume‐based complementary food mixtures, and phytic acid was shown to be completely degraded in a relatively short time (1.5 to 3 h) when incubated at optimal conditions for cereal phytase. The potential usefulness of the method for industrial production was demonstrated with a complementary food based on wheat and soybean.     

Effect of phytic acid degradation by soaking and exogenous phytase on the bioavailability of magnesium and zinc from Pisum sativum, L.

The effect of dephytinization of Pisum sativum, L. flour on the bioavailability of Mg and Zn was evaluated in growing rats. Processing of legume flours under optimal conditions for phytase activity (pH 5.5, 37 °C, 60 min) and subsequent removal of the soaking solution led to a 42 and 61% reduction in the content of Mg and Zn, respectively. Treatment with phytase led to an additional reduction in the concentration of the above-mentioned seed flour components, compared to the raw pea flour (69% and 74% for Mg and Zn, respectively). The considerable reduction in the content of inositol phosphates with high degree of phosphorylation attained under both processing conditions did not affect the digestive utilization of Mg, whereas the metabolic utilization of this mineral increased significantly. The digestive and metabolic utilization of Zn increased significantly in response to both processes assayed, reaching the highest values in the experimental group that was fed the phytase-treated pea flour diet. The amount of Mg retained by the experimental animals was reflected in the content of this mineral in the different tissues studied (femur, sternum, kidney, and heart), whereas no correlation was found in the case of Zn.     

Effect of phytase treatment on iron bioavailability in faba bean (Vicia faba L.) flour

The effect of dephytinisation, using an exogenous phytase under optimal conditions (pH 5.5, 37 °C), and subsequent removal of the soaking solution after processing, on the bioavailability of iron from faba bean (Vicia faba L.) flour was studied. Soaking of the faba bean flour led to a considerable reduction in the content of iron (39%), whereas a lower reduction in iron content (10%), was obtained after additional treatment with phytase, than in the soaked faba bean flour. The digestive utilisation of iron from the raw and soaked faba bean flours by growing rats was negligible, but increased significantly as a result of phytase treatment. The low iron absorption obtained for the former two treatments, during an experimental period of 10 days, was not reflected in any of the haematological indices (red blood count, haemoglobin, haematocrit) or tissues (femur, heart, kidney) studied, with the exception of the sternum. The latter appears to be a useful indicator of iron bioavailability.     

改善番茄红素生物利用度的研究进展

番茄红素的生物利用度是决定其营养价值的关键因素,天然存在的番茄红素生物利用度较低。番茄红素的异构化、食品分散体系以及食品组分与番茄红素之间的相互作用对番茄红素的生物利用度有着重要影响。近年来,食品加工、赋形剂乳液和构建共消化体系等方法越来越多地应用于改善番茄红素生物利用度中,相关的研究也成为热点。本文从番茄红素的吸收机制、影响番茄红素生物利用度的因素、改善番茄红素吸收的方法和番茄红素生物利用度的评价方法等方面进行综述,并对番茄红素生物利用度研究趋势和前景进行展望。     

Potential of non‐GMO biofortified pearl millet (Pennisetum glaucum) for increasing iron and zinc content and their estimated bioavailability during abrasive decortication

Two non‐GMO biofortified and one traditional pearl millet varieties were compared in abrasive decortication studies to evaluate their potential for increasing iron and zinc content. The phytate‐to‐mineral ratios were used to estimate mineral bioavailability. Iron and zinc contents in the biofortified varieties Tabi and GB8735 were two to threefold higher than in the traditional variety. Iron content reached 7.2 and 6.7 mg per 100 g DM in the biofortified varieties, which corresponds to the target values of biofortification programs. Zinc content was, respectively, 5.6 and 4.1 mg per 100 g DM in the GB8735 and Tabi varieties. Because of the presence of phytate and other chelating factors that were only partially removed during decortication, there was no improvement in iron bioavailability in the biofortified varieties. But whatever extraction rate, phytate‐to‐zinc ratios ranged between 6 and 18; zinc absorption could be improved by using these biofortified varieties for food processing.