The Influence of Soaking and Germination on the Phytase Activity and Phytic Acid Content of Grains and Seeds Potentially Useful for Complementary Feedin

ABSTRACT: Phytic acid, a potent inhibitor of mineral and trace element absorption, occurs in all cereal grains and legume seeds. The possibility to increase phytase activity and/or reduce the phytic acid content by soaking and germination was investigated in a wide range of grains and seeds, but not found to be effective. Germination, but not soaking, increased phytase activity 3 to 5-fold in some cereal grains and legume seeds, while the influence on phytic acid content was insignificant in most materials tested. High apparent phytase activity was found in untreated whole grain rye, wheat, triticale, buckwheat, and barley. Their usefulness as sources of phytase in complementary food production should be further investigated.     

体外消化/Caco-2细胞模型分析发酵对面粉铁生物利用率的影响

中国居民膳食以谷物为主食,谷物中铁吸收率低是造成营养性贫血的主要原因,适当的加工方式可缓解谷物中植酸、多酚等物质对铁生物利用率(Fe bioavailability,FeBV)的影响。为考察酵母发酵对面粉FeBV的影响,采用体外消化/Caco-2细胞模型。结果表明,面团在发酵后pH值呈下降趋势,酸度呈上升趋势;多酚、植酸含量降低,植酸酶活性升高,以上各指标在发酵前后差异均具有统计学意义(P0.05)。发酵后面粉样品的FeBV增加约5%~38%,大多数面粉FeBV发酵前后比较,差异具有统计学意义(P0.05)。结论:发酵可降低面粉的pH值,增加酸度,有利于面粉多酚和植酸的降解以及植酸酶活力的升高,可有效提高面粉FeBV。     

Production of Grain Whisky and Ethanol from Wheat,Maize and Other Cereals

Wheat replaced maize as the main cereal raw material for Scotch grain whisky production 20 years ago. However, other cereals might also have potential for use in grain distilleries and ethanol production. Studies of the properties of wheat, maize, sorghum and millet, showed that they had good potential for grain distilling and ethanol production at comparable nitrogen levels, and had physiological processing characteristics within the range accepted for wheat or maize. Rapid‐Visco Analysis (RVA) studies of low and high nitrogen wheat confirmed that, as well as influencing the amount of alcohol produced, the total nitrogen content of the grain had a strong influence on its processing characteristics. In contrast, the alcohol yield potential of maize, sorghum and millet appeared to be largely unaffected by the grain nitrogen levels. The study shows that, while it is possible for wheat to produce similar alcohol levels to those previously associated with maize, cereals other than wheat can potentially be used without detriment to alcohol yield or processing performance. These could be possible long term alternatives, if the economic viability of wheat was to change. The extracted cereal starches also showed significant differences from the original cereals, which had important implications for successful processing, both in terms of cereal selection as well as cooking and fermentation performance.     

Phytic acid concentration in selected raw materials and analysis of its hydrolysis rate with the use of microbial phytases during the mashing process

Phytic acid present in the raw materials can complex with many compounds and therefore limit their availability to the yeast during the alcoholic fermentation process. An effective utilization of biogenic compounds bound in phytates requires a detailed analysis of the raw materials for their phytic acid content. The aim of this study was to characterize the major technological parameters for selected raw materials used in the distilling industry (maize, rye, wheat and triticale grain) and to determine the phytic acid content and the IP6/total phosphorus ratio. The phytic acid hydrolysis rate during the mashing process, with the use of microbial phytases, was analysed. The highest phytic acid concentrations (2.30 ± 0.20 mg/g dry matter) and the highest IP6/total P (80.42 ± 6.99%) were observed in the maize grain samples. Therefore, further studies on the phytic acid hydrolysis rate with the use of various phytases were conducted for the maize grain. The highest hydrolytic activity was observed for the Phytase 10000L preparation. This was the preparation that hydrolysed the phytic acid completely in up to 90 min. The application of a highly effective phytase, in ethanol production from maize grain, could lead to a more effective utilization of the biogenic compounds during the fermentation process. Copyright © 2015 The Institute of Brewing & Distilling     

Comparative evaluation of the efficacy of cereal and microbial phytases in growing pigs fed diets with marginal phosphorus supply

Two experiments with a total of 76 growing pigs (average initial body weight 16.6 kg) were conducted to compare the efficacy of cereal phytases (wheat and rye) and supplemented microbial phytase (Natuphos®). Using the slope ratio technique, the dose–response relationship between five levels of phytase (0, 50, 100, 150 and 200 U kg^?1) and the apparent absorption of phosphorus (P) within each source of phytase was calculated. Graded phytase levels in the diets were obtained by adding increasing amounts of microbial phytase or phytase‐containing wheat (Exp 1) or rye (Exp 2) to phytase‐inactivated basal diets at the expense of phytase‐inactivated wheat (Exp 1) or rye (Exp 2). Except for wheat phytase, addition of phytase to the basal diets increased (P < 0.05) apparent P absorption, with microbial phytase being more efficient (P < 0.05) than cereal phytase. There were no significant differences in apparent P absorption between the wheat‐ or rye‐based diets when either microbial or cereal phytases were supplemented from 0 to 200 U kg^?1. It could be derived from the results of this study, by means of regression analysis, that the efficacy of cereal phytases was 40% compared to microbial phytase. © 2002 Society of Chemical Industry     

The Fate of Mycotoxins During the Processing of Wheat for Human Consumption

Mycotoxins are a potential health threat in cereals including wheat. In the European Union (EU), mycotoxin maximum levels are laid down for cereal raw materials and final food products. For wheat and wheat‐based products, the EU maximum levels apply to deoxynivalenol (DON), zearalenone, aflatoxins, and ochratoxin A. This review provides a comprehensive overview on the different mycotoxins and their legal limits and on how processing of wheat can affect such contaminants, from raw material to highly processed final products, based on relevant scientific studies published in the literature. The potential compliance with EU maximum levels is discussed. Of the four mycotoxins regulated in wheat‐based foods in the EU, most data are available for DON, whereas aflatoxins were rarely studied in the processing of wheat. Furthermore, available data on the effect of processing are outlined for mycotoxins not regulated by EU law—including modified and emerging mycotoxins—and which cover DON derivatives (DON‐3‐glucoside, mono‐acetyl‐DONs, norDONs, deepoxy‐DON), nivalenol, T‐2 and HT‐2 toxins, enniatins, beauvericin, moniliformin, and fumonisins. The processing steps addressed in this review cover primary processing (premilling and milling operations) and secondary processing procedures (such as fermentation and thermal treatments). A special focus is on the production of baked goods, and processing factors for DON in wheat bread production were estimated. For wheat milling products derived from the endosperm and for white bread, compliance with legal requirements seems to be mostly achievable when applying good practices. In the case of wholemeal products, bran‐enriched products, or high‐cereal low‐moisture bakery products, this appears to be challenging and improved technology and/or selection of high‐quality raw materials would be required.     

Technologies for enhancement of bioactive components and potential health benefits of cereal and cereal-based foods: Research advances and application challenges

Cereal grains are a major source of human food and their production has steadily been increased during the last several decades to meet the demand of our increasing world population. The modernized society and the expansion of the cereal food industry created a need for highly efficient processing technologies, especially flour production. Earlier scientific research efforts have led to the invention of the modern steel roller mill, and the refined flour of wheat has become a basic component in most of cereal-based foods such as breads and pastries because of the unique functionality of wheat protein. On the other hand, epidemiological studies have found that consumption of whole cereal grains was health beneficial. The health benefit of whole cereal grain is attributed to the combined effects of micronutrients, phytochemicals, and dietary fibre, which are mainly located in the outer bran layer and the germ. However, the removal of bran and germ from cereal grains during polishing and milling results in refined flour and food products with lower bioactive compounds and dietary fibre contents than those from whole grain. Also, the level of bioactive compounds in cereal food is influenced by other food preparation procedures such as baking, cooking, extrusion, and puffing. Therefore, food scientists and nutritionists are searching for strategies and processing technologies to enhance the content and bioavailability of nutrients, bioactive compounds, and dietary fibre of cereal foods. The objective of this article was to review the research advances on technologies for the enhancement of bioactive compounds and dietary fibre contents of cereal and cereal-based foods. Bioactivities or biological effects of enhanced cereal and cereal-based foods are presented. Challenges facing the application of the proposed technologies in the food industry are also discussed.     

植酸/植酸钠在食品工业上的应用研究进展

植酸/植酸钠广泛存在于谷类、豆类和油料作物等中,应用非常广泛,在食品工业上可用作食品抗氧化剂、抑菌剂、护色剂、螯合剂和保鲜剂等。本文简述了植酸/植酸钠的结构、组成和理化特性,并且综述其在食品工业中的应用与研究进展。重点介绍了植酸/植酸钠在果蔬制品、饮料、发酵食品、酿造酒、油脂和脂肪制品、水产品、肉制品、焙烤制品和面制品等加工中的应用及研究进展。同时探讨了目前植酸/植酸钠在食品工业应用中存在的问题及解决对策,并对其发展趋势进行展望。指出目前高纯度植酸和固体植酸的生产成本较高,将来可以在植酸的色谱层析分离材料上进行改进。同时,为了增加植酸在油溶性食品中的应用范围,可以通过植酸的改性或借助于乳化、微乳化技术制备植酸/植酸钠的乳液和微乳液产品,是将来的发展方向。     

Effects of sowing and harvesting dates on yield and some quality characteristics of crops in sugar beet/cereal rotation system

BACKGROUND: Cereals are the main crops in rotation following sugar beet harvest. However, a delay in planting winter cereals as a result of late sugar beet harvest is a disadvantage in sugar beet/cereal rotations. In this study, field trials were carried out to investigate the effects of sowing and harvesting dates on the yield and quality of sugar beet (Beta vulgaris L.) and cereals (wheat, Triticum aestivum L., and six‐rowed barley, Hordeum vulgare L.) during two consecutive years. Beet was sown on three dates and harvested on four dates, followed by cereals which were sown on four dates. Root yield and digestion ratio (sugar beet) and grain yield, 1000‐kernel weight, test weight and protein content (wheat and barley) were determined. RESULTS: The highest root yield (52.53 t ha^?1) was obtained from early sown (5 April) and late harvested (1 November) beet, while the highest digestion ratio (17.4%) was obtained from late sown (3 May) and late harvested (1 November) beet. Lower cereal grain yields were obtained from later sowings. The highest grain yields (5.87 and 6.02 t ha^?1) were obtained from earlier sown wheat. Protein content was also affected by sowing date, which appeared to be very important under unstable climatic conditions. CONCLUSION: It is essential to consider the timing of sowing of cereal crops when unstable climatic conditions are present. Hence sowing date recommendations in regular climatic conditions may be misleading for countries dependent on winter rainfall for cereal production. Copyright © 2007 Society of Chemical Industry     

Lactic Fermentation of Non-Tannin and High-Tannin Cereals: Effects on In Vitro Estimation of Iron Availability and Phytate Hydrolysis

The effect on iron availability estimated in vitro and phytate hydrolysis was investigated in non-tannin and high-tannin cereals, lactic fermented as flour/water slurries or gruels. A natural starter culture initiated fermentation and addition of germinated flour and phytase in the fermentation process was tested. Lactic fermentation of nontannin cereals with added flour germinated sorghum seeds or wheat phytase increased iron solubility from about 4% up to 9 and 50%, respectively. Soaking flour in water before adding starter culture had a similar effect. The increase in soluble iron was strongly related to enzymatic deeradation of phytate (p<0.001). The reduction of inositol hexa- and pentaphosphates was about 50% with added germinated flour. Reduction was > 90% after soaking the flour prior to fermentation and almost complete with 50 mg phytase added. High-tannin cereals showed a minor increase in soluble iron after fermentation, ascribed to the inhibitory effect of tannins (both on iron solubility and on enzymatic hydrolysis of phytate). Lactic-fermented cereal foods have a potential in developing countries to improve iron nutrition.     

Phytic acid content in milled cereal products and breads

Phytic acid was determined in cereal (brans, flours and milled wheat-products) and breads. The method was based on complexometric titration of residual iron (III) after phytic acid precipitation. The cereal flours showed values ranged between 3–4 mg/g for soft wheats, 9 mg/g for hard wheat and 22 mg/g for whole wheat. Corn, millet and sorghum flours reported a mean of 10 mg/g and oat, rice, rye and barley between 4 and 7 mg/g. Wheat brans had wide ranges (25–58 mg/g). The phytic acid for oat brans was half that of wheat bran (20 mg/g) and higher value (58 mg/g) than that for rice bran. The milling products (semolinas) from hard wheat exhibited 10 mg/g and soft wheat a mean of 23 mg/g. The breads made with single or mixture cereal flours exhibited ranges between 1.5 and 7.5 mg/g. The loss of phytic acid relative to unprocessed flours was between 20% for oat bread and 50% for white bread.     

高粱食品:一种古老作物带来新的健康

高粱是一种古老的作物初次被驯化于非洲,并在公元前3000年左右推广到了世界各地.高粱是一种抗旱的谷类作物,生长在其它作物无法生存的半干旱气候条件下,在2002年世界高粱产量达到5450万公吨.美国高粱年产量可达1300～1500万公吨左右,其中30%～50%用于出口,在西方国家中用高粱喂养动物已非常普遍,大约世界高粱产量的40%被用于作为非洲和印度等国家人民的食物.在美国对于患有腹乳糜泻疾病无法适应面筋蛋白的人已经用白色食品级的杂交作物生产出运用于无小麦产品作为食用,不能食用小麦或其它谷类作物比如黑麦,大麦,他们提供了些刺激性小的面粉已成为用于制造无小麦食品的原料.当高粱缺乏面筋时,高粱粉便不能生产有黏性和弹性的生面团,因此蛋奶糊配方被用于制造高粱产品,包括面包威化饼干、面条和比萨饼皮,这些原来都是由面粉制成.研究表明,高粱系生产高质量食物,因此种植高梁将被用于改善提高食物质量,最近一些研究表明由于这种古老作物包括含有二十烷醇(policosanols)的多酚复合物和高粱蜡的高抗氧化水平,可能对健康有独特的益处,对于保护心血管的健康至关重要.尤其在把小麦作为主要食物的西方世界,对于给患有腹乳糜泻疾病的人们提供了健康稳定的主食是一个挑战.因此高粱这种古老的作物作为21世纪的主要谷类作物引来了新的兴趣和前途,这是由于(1)它对于患有腹乳糜泻疾病的人是一种富有潜力的主食.(2)保持食物的营养和健康的高抗氧化水平和蜡含量.(3)由于它的抗干旱性和有限供水量的高生产量,2030年预期人口指数增长明显.     

植酸酶在食品和医药方面的应用展望

从植酸及其盐类的抗营养作用出发，简单介绍了植酸酶的分类，来源，着重阐述了植酸酶在食品和医药方面应用及所面临的困难和应用前景。     

Sourdough fermentation of wheat fractions rich in fibres before their use in processed food

Fibre‐rich fractions of wheat are an important source of minerals but also contain considerable amounts of phytic acid, known to impair mineral absorption. This study explores the efficiency of wheat bran sourdough fermentation on phytate hydrolysis and mineral solubility, in comparison with whole‐wheat flour. In vitro trials were performed to assess the consequences of the addition of calcium carbonate (CaCO₃), an alkalinising salt, on phytic acid breakdown and mineral bioavailability during sourdough fermentation. Sourdough fermentation was found effective for solubilising minerals in whole‐wheat flours but was less effective with bran. In addition, sourdough acidity was blunted by the addition of CaCO₃, whereas degradation of phytic acid remained effective. Despite extensive breakdown of phytic acid (almost 70%), the addition of calcium exerted a very negative effect on zinc solubility. In conclusion, a pre‐fermentation process of whole cereals or bran, in suitable conditions of hydration, allows degradation of the major part of phytic acid and optimal mineral bioavailability. Copyright © 2007 Society of Chemical Industry     

Analysis of Phytic Acid in Foods by HPLC

A quantitative HPLC method for the analysis of phytic acid in foods was developed based on the precipitation of phytic acid with ferric chloride followed by conversion to sodium phytate before injection onto a C₁₈ reversed-phase column. Standard food grade wheat bran samples were analyzed by the method of standard addition and recovery of phytic acid ranged from 99 – 103%. 3% H₂SO₄ was found to be as effective as 3% TCA in the extraction of phytic acid. AAS was shown to be potentially valuable as a metal specific detector for the HPLC of phytate-metal complexes.     

Molar Ratio of Phytic Acid and Zinc During Cereal Flake Production

The phytic acid content and distribution of phosphorus during cereal flaking were determined as well as the level of some minerals, and the molar ratios of phytic acid: zinc were calculated. Statistical analyses showed that there were no differences in the amount of total phosphorus, between oats and wheat and between rye and barley. The phytic/non-phytic phosphorus ratio was about 3 in wheat and oats, about 2 in barley and about 13 in rye. The technological processing did not affect ( P< 0·05) phytic acid content. The molar ratio of phytic acid: zinc for the flakes was only slightly below that of the whole grain, indicating that the technological process, primarily a hydrothermal treatment and flaking, did not improve zinc availability.     

Application of cereals and cereal components in functional foods: a review

The food industry is directing new product development towards the area of functional foods and functional food ingredients due to consumers' demand for healthier foods. In this respect, probiotic dairy foods containing human-derived Lactobacillus and Bifidobacterium species and prebiotic food formulations containing ingredients that cannot be digested by the human host in the upper gastrointestinal tract and can selectively stimulate the growth of one or a limited number of colonic bacteria have been recently introduced into the market. The aim of these products is to affect beneficially the gut microbial composition and activities. Cereals offer another alternative for the production of functional foods. The multiple beneficial effects of cereals can be exploited in different ways leading to the design of novel cereal foods or cereal ingredients that can target specific populations. Cereals can be used as fermentable substrates for the growth of probiotic microorganisms. The main parameters that have to be considered are the composition and processing of the cereal grains, the substrate formulation, the growth capability and productivity of the starter culture, the stability of the probiotic strain during storage, the organoleptic properties and the nutritional value of the final product. Additionally, cereals can be used as sources of nondigestible carbohydrates that besides promoting several beneficial physiological effects can also selectively stimulate the growth of lactobacilli and bifidobacteria present in the colon and act as prebiotics. Cereals contain water-soluble fibre, such as beta-glucan and arabinoxylan, oilgosaccharides, such as galacto- and fructo-oligosaccharides and resistant starch, which have been suggested to fulfil the prebiotic concept. Separation of specific fractions of fibre from different cereal varieties or cereal by-products, according to the knowledge of fibre distribution in cereal grains, could be achieved through processing technologies, such as milling, sieving, and debranning or pearling. Finally, cereal constituents, such as starch, can be used as encapsulation materials for probiotics in order to improve their stability during storage and enhance their viability during their passage through the adverse conditions of the gastrointestinal tract. It could be concluded that functional foods based on cereals is a challenging perspective, however, the development of new technologies of cereal processing that enhance their health potential and the acceptability of the food product are of primary importance.     

Phytic acid interactions in food systems

Phytic acid is present in many plant systems, constituting about 1 to 5% by weight of many cereals and legumes. Concern about its presence in food arises from evidence that it decreases the bioavailability of many essential minerals by interacting with multivalent cations and/or proteins to form complexes that may be insoluble or otherwise unavailable under physiologic conditions. The precise structure of phytic acid and its salts is still a matter of controversy and lack of a good method of analysis is also a problem. It forms fairly stable chelates with almost all multivalent cations which are insoluble above pH 6 to 7, although pH, type, and concentration of cation have a tremendous influence on their solubility characteristics. In addition, at low pH and low cation concentration, phytate‐protein complexes are formed due to direct electrostatic interaction, while at pH >6 to 7, a ternary phytic acid‐mineral‐protein complex is formed which dissociates at high Na concentrations. These complexes appear to be responsible for the decreased bioavailability of the complexed minerals and are also more resistant to proteolytic digestion at low pH. Development of methods for producing low‐phytate food products must take into account the nature and extent of the interactions between phytic acid and other food components. Simple mechanical treatment, such as milling, is useful for those seeds in which phytic acid tends to be localized in specific regions. Enzyme treatment, either directly with phytase or indirectly through the action of microorganisms, such as yeast during bread‐making, is quite effective, provided pH and other environmental conditions are favorable. It is also possible to produce low‐phytate products by taking advantage of some specific interactions. For example, adjustment of pH and/or ionic strength so as to dissociate phytate‐protein complexes and then using centrifugation or ultrafiltration (UF) has been shown to be useful. Phytic acid can also influence certain functional properties, such as pH‐solubility profiles of the proteins and the cookability of the seeds.     

拥有全面营养的谷类食品(英文)

从一万年前生长在Crescent 地区的野生草类首次被驯化,到了解到它们全面的潜在营养价值,谷类谷物对现代人类进展而言仍然是必不可少的。世界上十二种最主要的作物中,有五种谷类 - 大米、小麦、玉米、大麦、高粱,仅此五类就占世界人口消耗热卡的一半以上。科学机构已经开始了解到谷类食品在热量能源之外的重要作用。包含全谷类食品的平衡膳食的重要性不能被过分强调。全谷类食品是食物碳水化合物、微量营养素和植物固醇的来源。一个例子是谷物糊粉层,在许多植物甾醇方面尤其丰富,并有潜在的抗氧化性质。另一个例子是麸皮中的可溶和不可溶的细胞壁成分,它是食物纤维的重要来源。在文献中提供了证实高纤维和全谷物食品在保持身体健康和预防的严重疾病的科学证据。膳食因素被认为可以影响人的体重和人体的防病的总体状况。这个会议将会总结复合糖的关系,全谷类产品和防止某些疾病包括二型糖尿病和冠心病等疾病。     

Replacing human-edible feed ingredients with by-products increases net food production efficiency in dairy cows

Global demand for food is increasing, and use of large amounts of potentially human-edible feedstuffs for dairy cows is an important concern. The present study examined whether feeding a by-product-based concentrate combined with high-quality grass silage to high-producing dairy cows affected feed intake and milk production compared with a conventional diet, as well as the effect on efficiency of human food production. In a changeover experiment with four 21-d periods, 24 dairy cows in mid-lactation were offered 9.6 kg of dry matter per day with 1 of 4 concentrates and high-quality grass silage ad libitum. The control concentrate was based on cereal grain (wheat, oat, and barley) and soybean meal, whereas the 3 by-product-based concentrates contained sugar beet pulp in combination with mainly heat-treated rapeseed meal, distillers grain, or a mixture of both. All diets were formulated to be isoenergetic and isonitrogenous. The cows had 10-fold higher starch intake when fed the control diet than when fed the by-product-based concentrates. Silage intake (13 kg of dry matter/d) and milk production (33 kg of energy-corrected milk/d) were not affected by the change in diet. Therefore, replacing cereals and soybean meal with human-inedible by-products in a high-quality forage diet to dairy cows increased net food protein production substantially without lowering milk production.