Increase Mineral Bioavailability Research Articles

Strategies to increase the bioaccessibility and bioavailability of iron and zinc from cereal products.

Cereal products provide 50 % of iron and 30 % of zinc in the UK diet. However, despite having high content, the bioavailability of minerals from cereals is low. This review discusses strategies to increase mineral bioavailability from cereal-based foods. Iron and zinc are localised to specific tissue structures within cereals; however, the cell walls of these structures are resistant to digestion in the human gastrointestinal tract and therefore the bioaccessibility of these essential minerals from foods for absorption in the intestine is limited. In addition, minerals are stored in cereals bound to phytate, which is the main dietary inhibitor of mineral absorption. Recent research has focused on ways to enhance mineral bioavailability from cereals. Current strategies include disruption of plant cell walls to increase mineral release (bioaccessibility) during digestion; increasing the mineral:phytate ratio either by increasing the mineral content through conventional breeding and/or agronomic biofortification, or by reducing phytate levels; and genetic biofortification to increase the mineral content in the starchy endosperm, which is used to produce white wheat flour. While much of this work is at an early stage, there is potential for these strategies to lead to the development of cereal-based foods with enhanced nutritional qualities that could address the low mineral status in the UK and globally.

Mineral and Phytic Acid Content as Well as Phytase Activity in Flours and Breads Made from Different Wheat Species.

Wheat is of high importance for a healthy and sustainable diet for the growing world population, partly due to its high mineral content. However, several minerals are bound in a phytate complex in the grain and unavailable to humans. We performed a series of trials to compare the contents of minerals and phytic acid as well as phytase activity in several varieties from alternative wheat species spelt, emmer and einkorn with common wheat. Additionally, we investigated the potential of recent popular bread making recipes in German bakeries to reduce phytic acid content, and thus increase mineral bioavailability in bread. For all studied ingredients, we found considerable variance both between varieties within a species and across wheat species. For example, whole grain flours, particularly from emmer and einkorn, appear to have higher mineral content than common wheat, but also a higher phytic acid content with similar phytase activity. Bread making recipes had a greater effect on phytic acid content in the final bread than the choice of species for whole grain flour production. Recipes with long yeast proofing or sourdough and the use of whole grain rye flour in a mixed wheat bread minimized the phytic acid content in the bread. Consequently, optimizing food to better nourish a growing world requires close collaboration between research organizations and practical stakeholders ensuring a streamlined sustainable process from farm to fork.

Improving Nutritional and Health Benefits of Biscuits by Optimizing Formulations Based on Sprouted Pseudocereal Grains.

A mixture design (MD) was used to evaluate the effect of replacing wheat flour (WF) with sprouted cañihua (Chenopodium pallidicaule Aellen), kiwicha (Amarathus caudatus L.), and quinoa (Chenopodium quinoa Willd.) flours (SCF, SKF, and SQF, respectively) on the content of phytic acid (PA), γ-aminobutyric acid (GABA), total soluble phenolic compounds (TSPC), and antioxidant activity (AA) in biscuits. Generally, sprouted pseudocereal flours contained lower amounts of starch and protein, comparable fat, ash, PA content, and increased levels of bioactive compounds (GABA and TSPC) and AA compared with wholegrain flours. Moreover, it was confirmed that sprouted pseudocereal flours were nutritionally superior to refined WF. MD allowed the modeling of target parameters showing that PA, GABA, TSPC, and AA were positively influenced by the proportion of flours in the biscuit. The models that better described the variation in nutritional parameters as a function of the formulation displayed typically linear and binary interactions terms. SKF exerted the highest influence on the increased content of PA. Therefore, to increase mineral bioavailability, the use of SCF and SQF in the formulation of biscuits was suggested. SCF and SQF positively influenced in GABA, TSPC, and AA in biscuits. The optimal ternary blends of flours that maximize the content of bioactive compounds and AA of biscuits and simultaneously minimize PA content were identified. To study the fate of biscuits in digestion, the optimal formulation for biscuits containing SQF/SCF was selected. For this type of baked product, reduced starch digestibility and glycemic index was observed compared with the control (100% WF). Moreover, the amounts of bioaccessible GABA, TSPC, and AA were higher in gastric and intestinal digests compared with control biscuit. Overall, these results highlighted the nutritional and health benefits of incorporation of flours from sprouted Andean grains in the production of biscuits.

A single nucleotide substitution in the SPDT transporter gene reduced phytic acid and increased mineral bioavailability from Rice grain (Oryza sativa L.).

Phosphorus (P) flow in agricultural land depends on the P taken off from harvested product, its losses through runoff and fertilizer applied to balance the removed P. Phytic acid (PA), the major storage form of phosphorus (P) in cereal grains is a key anti-nutrient for human and non-ruminants leads to eutrophication of waterways. As the natural non-renewable P reserves are limited, enhancing P use efficiency is needed for field crops. SULTR-like phosphorus distribution transporter (SPDT) is a novel rice transporter transfer P to the grain. Any alteration in transporter gene reduce grain P with concomitant rise in the leaves. A low PA (3.0g/kg) rice Khira was identified where a single nucleotide mutation in LOC_Os06g05160 gene encoding SPDT showed low P transportation to grain. An amino acid change was detected as Valine-330 to Alanine at the 3' end of fifth exon. Highest expression of SPDT was observed in node I of rice as compared to low PA genotype. The mutation in SPDT could significantly affect P and PA accumulation in the grains with increased mineral bioavailability. PRACTICAL APPLICATIONS: Excessive P application in crop leads to higher production cost as well as rapid depletion of limited rock phosphate. Alteration of P transporter function in the rice lower PA and total P accumulation in the grains with increased mineral bioavailability. The re-distributed P in the straw can be applied as manure to the rice field. Thus, less P will be removed from the field, result in the decreased requirement for P fertilizer.

Improving wheat as a source of iron and zinc for global nutrition.

Wheat is the staple food crop in temperate countries and increasingly consumed in developing countries, displacing traditional foods. However, wheat products are typically low in bioavailable iron and zinc, contributing to deficiencies in these micronutrients in countries where wheat is consumed as a staple food. Two factors contribute to the low contents of bioavailable iron and zinc in wheat: the low concentrations of these minerals in white flour, which is most widely consumed, and the presence of phytates in mineral‐rich bran fractions. Although high zinc types of wheat have been developed by conventional plant breeding (biofortification), this approach has failed for iron. However, studies in wheat and other cereals have shown that transgenic (also known as genetically modified; GM) strategies can be used to increase the contents of iron and zinc in white flour, by converting the starchy endosperm tissue into a ‘sink’ for minerals. Although such strategies currently have low acceptability, greater understanding of the mechanisms which control the transport and deposition of iron and zinc in the developing grain should allow similar effects to be achieved by exploiting naturally induced genetic variation. When combined with conventional biofortification and innovative processing, this approach should provide increased mineral bioavailability in a range of wheat products, from white flour to wholemeal.

Novel insights on the functional/nutritional features of the sourdough fermentation

As one of the most traditional biotechnologies, sourdough fermentation has deep effects on rheology, sensory and shelf life attributes of baked goods. The most recent literature has also highlighted the effects of sourdough fermentations on several functional/nutritional features of baked goods. While some aspects such as the potential to lower glycemic index, increase mineral bioavailability and decrease the gluten content have been proven almost definitively, others potentialities are emerging, which deserve novel insights. This reviews reports the main evidence on the use of sourdough fermentation for salt reduction in baked goods, management of irritable bowel syndrome (IBS), synthesis/release of bioactive compounds, especially the metabolism of phenolic compounds, and exploitation of the potential of non-conventional flours (legumes and pseudo-cereals) and milling by-products (bran and germ). A brief description on the spiritual, cultural and functional/nutritional significance of leavened bread throughout centuries has also given.

Strain improvement of Pichia kudriavzevii TY13 for raised phytase production and reduced phosphate repression.

SummaryIn this work, we present the development and characterization of a strain of Pichia kudriavzevii (TY1322), with highly improved phytate‐degrading capacity. The mutant strain TY1322 shows a biomass‐specific phytate degradation of 1.26 mmol g−1 h−1 after 8 h of cultivation in a high‐phosphate medium, which is about 8 times higher compared with the wild‐type strain. Strain TY1322 was able to grow at low pH (pH 2), at high temperature (46°C) and in the presence of ox bile (2% w/v), indicating this strain's ability to survive passage through the gastrointestinal tract. The purified phytase showed two pH optima, at pH 3.5 and 5.5, and one temperature optimum at 55°C. The lower pH optimum of 3.5 matches the reported pH of the pig stomach, meaning that TY1322 and/or its phytase is highly suitable for use in feed production. Furthermore, P. kudriavzevii TY1322 tolerates ethanol up to 6% (v/v) and shows high osmotic stress tolerance. Owing to the phenotypic characteristics and non‐genetically modified organisms nature of TY1322, this strain show great potential for future uses in (i) cereal fermentations for increased mineral bioavailability, and (ii) feed production to increase the phosphate bioavailability for monogastric animals to reduce the need for artificial phosphate fortification.

Phytases from Enterobacter and Serratia species with desirable characteristics for food and feed applications.

Phytases are enzymes of great industrial importance with wide range of applications in animal and human nutrition. These catalyze the hydrolysis of phosphomonoester bonds in phytate, thereby releasing lower forms of myo-inositol phosphates and inorganic phosphate. Addition of phytase to plant-based foods can improve its nutritional value and increase mineral bioavailability by decreasing nutritional effect of phytate. In the present investigation, 43 phytase positive bacteria on PSM plates were isolated from different sources and characterized for phytase activity. On the basis of phytase activity and zone of hydrolysis, two bacterial isolates (PSB-15 and PSB-45) were selected for further characterization studies, i.e., pH and temperature optima and stability, kinetic properties and effect of modulators. The phytases from both isolates were optimally active at the pH value from 3 to 8 and in the temperature range of 50–70 °C. Further, the stability of isolates was good in the pH range of 3.0–8.0. Much variation was observed in temperature and storage stability, responses of phytases to metal ions and modulators. The K m and V max values for PSB-15 phytase were 0.48 mM and 0.157 μM/min, while for PSB-45 these were 1.25 mM and 0.140 μM/min, respectively. Based on 16S rDNA gene sequence, the isolates were identified as Serratia sp. PSB-15 (GenBank Accession No. KR133277) and Enterobacter cloacae strain PSB-45 (GenBank Accession No. KR133282). The novel phytases from these isolates have multiple characteristics of high thermostability and good phytase activity at desirable range of pH and temperature for their efficient use in food and feed to facilitate hydrolysis of phytate-metal ion complex and in turn, increased bioavailability of important metal ions to monogastric animals.

Effects of dietary citric acid on growth performance, mineral status and intestinal digestive enzyme activities of large yellow croaker Larimichthys crocea (Richardson, 1846) fed high plant protein diets

The positive effects of citric acid (CA) on aquaculture species have been reported. However, extensive application of CA needs a comprehensive understanding of its nutritional functions. A 9-week feeding trial was conducted to determine the effect of dietary CA on growth performance, tissue mineral content, intestinal enzyme activities and oxidative status of large yellow croaker Larimichthys crocea fed high plant protein diets. Six isonitrogenous and isolipidic diets were formulated and fed to triplicated groups of fish. A high fish meal diet formulated with 45% fish meal and 11.5% soybean meal was set as the positive control diet, while a high plant protein diet formulated with 31.50% fish meal and 30.63% soybean meal was used as the negative control diet. The other four diets were supplemented with 0.4%, 0.8%, 1.6% and 3.0% of CA into the negative control diet, respectively. The results showed that the specific growth rate, feed efficiency, protein and phosphorus retention, phosphorus and zinc concentrations in whole body and intestine, activities of the leucine-aminopeptidase, alkaline phosphatase and Na+, K+-ATPase were significantly reduced after soybean meal replacement and recovered by dietary CA supplementation (P<0.05). Data on oxidative stress and anti-oxidative responses of intestine showed that the content of malondialdehyde was significantly increased in soybean meal-enhanced diets, which decreased with supplementation of CA varying from 0.4% to 1.6% (P<0.05). The total anti-oxidative capacity, activities of total superoxide dismutase and Cu–Zn superoxide dismutase were decreased by soybean meal replacement and increased as CA level increasing from 0.4% to 0.8% (P<0.05). In conclusion, 0.8–1.6% of CA in diet is helpful for large yellow croaker fed high plant protein diets to get better growth performance. The improvement of growth performance could be partly due to the increased mineral bioavailability, enhanced intestinal antioxidant capacity and recovered intestinal function by dietary CA supplementation.Statement of relevance: This study is not a test of commercial aquaculture.

Phytase-active lactic acid bacteria from sourdoughs: Isolation and identification

Whole-grain foods play an important role in human diet as they are relatively rich in minerals, however, the absorption of those minerals in human gut can be very low due to high content of the mineral binding phytate. Therefore, the object of this study was to identify phytase-active lactic acid bacteria (LAB) which could be used as a starter to increase mineral bioavailability in whole-meal bread. Hence, LAB isolates were isolated from Lithuanian sourdoughs, tested for phytase activity, and phytase active isolates were identified. Studies of phytase activity of the isolates were carried out at conditions optimal for leavening of bread dough (pH 5.5 and 30 °C). The phytase active isolates belonged to the species Lactobacillus panis, Lactobacillus reuteri, Lactobacillus fermentum, and Pediococcus pentosaceus. Phytase activities of the tested LAB isolates were both extra- and intra-cellular. The highest extracellular phytase production was found in L. panis with a volumetric phytase activity of 140 U/mL. Phytate degradation in whole-wheat dough fermented with L. panis or L. fermentum was 90% and 70%, respectively.

The effect of &lt;i&gt;Moringa oleifera&lt;/i&gt; leaf meal supplementation on tibia strength, morphology and inorganic content of broiler chickens

This study was conducted to assess the effects of dietary Moringa oleifera leaf meal (MOLM) supplementation as a possible alternative to antibiotic growth promoters on bone breaking strength (BBS), tibia bone morphology and inorganic ash content in broiler chickens. A total of 2400 one-day-old Cobb-500 broiler chicks of mixed sex were randomly allocated to five dietary treatments in six replications of 80 birds per pen. Dietary treatments were as follows: T1, positive control, 668 g salinomycin and 500 g zinc bacitracin per kg of feed; T2, T3 and T4, graded levels of MOLM, that is (starter (1, 3 and 5 g), grower (3, 9 and 15 g) and finisher (5, 15 and 25 g)) per kg of feed; and T5, a negative control (without supplementation). Birds were provided with feed and water ad libitum. Bodyweights (BW) and feed intake (FI) of broilers were measured weekly, and feed conversion ratio (FCR) and average daily gains were calculated accordingly. At 35 days (d) of age, 12 birds per treatment, two from each replicate pen, were randomly selected, stunned electrically at 70 volts, and slaughtered by cervical dislocation. Six left and right tibiae were randomly chosen from each treatment, without being de-fleshed, and were sealed individually in plastic bags to minimize moisture loss. The tibiae were stored at −18 ºC for BBS and tibia ash determination, as well as analyses of their calcium (Ca) and phosphorus (P) composition. Of birds fed diets with higher MOLM levels, T4 had the highest BW, while T1 had the lowest. On days 7 and 21, birds on T4 had the highest average daily gain (ADG) and T1 the lowest, respectively. There were no significant dietary effects in FI on days 7, 21 and 35; while on days 21 and 35, FCR (feed : gain) was highest in MOLM-supplemented birds and lowest in T1 birds, respectively. There were no treatment effects on tibia length (TL), tibia weight (TW) and/or dried tibia weight (DW). A positive correlation (r = 0.667) was observed between TW and DW. There were no treatment effects on BBS and ash percentage, but tibia ash weight was highest in T4 and lowest in T2. Calcium percentage was highest in T1, and lowest in T2 and T5. Phosphorus percentage was lowest in T1 and highest in T5. The highest Ca : P ratio was obtained in T4. The positive correlation observed between BW, TW and TL, and the high P, Ca and ash levels in tibiae from MOLM-supplemented birds depicts the genetic relationship that exists among these parameters. Furthermore, it reveals the effectiveness of MOLM supplementation to enhance nutrient utilization efficiency, increase mineral bioavailability and support bone strength.Keywords: Bone quality, calcium, Cobb-500 broilers, antibiotic growth promoters, phosphorus

Mineral bioavailability in grains of Pakistani bread wheat declines from old to current cultivars

Estimating variation in grain mineral concentration and bioavailability in relation to grain yield and the year of cultivar release is important for breeding wheat with increased content of bioavailable minerals. The grain yield and yield components, grain phytate concentration, and concentration and bioavailability of minerals (zinc Zn, iron Fe and calcium Ca) in wheat grains were estimated in 40 wheat cultivars released in Punjab (Pakistan) during the last five decades. Mean grain Zn and Ca concentrations in current-cultivars were significantly lower (≥14%) than in obsolete cultivars released during the Green Revolution (1965–1976). Much of this variation was related to increased grain weight in current-cultivars. There was a positive correlation among minerals (r = 0.39 or higher, n = 40) and minerals with phytate in wheat grains (r = 0.38 or higher, n = 40). The tested cultivars varied widely in grain yield and grain phytate-to-mineral molar ratios (phytate:mineral). Compared to obsolete cultivars, the current-cultivars had a higher phytate:mineral ratio in grains, indicating poor bioavailability of minerals to humans. The study revealed a non-significant relationship between grain yield and phytate:mineral ratios in grains. Therefore, breeding for lower phytate:mineral ratios in wheat grains can ensure increased mineral bioavailability without significant reduction in the yield potential. Future breeding should be focused on developing new genotypes suitable for mineral biofortification and with increased mineral bioavailability in grains.

Soluble Dietary Fiber

ABSTRACT: Soluble dietary fibers (SDFs) are present in small quantities in almost each and every commodity and in combination with insoluble dietary fiber contribute towards total dietary fiber. The beneficial properties of SDFs have been associated with their significant role in human physiological function. Reductions in cholesterol level and blood pressure, prevention of gastrointestinal problems, protection against onset of several cancers, which include colorectal, prostate, and breast cancer, increased mineral bioavailability, and many more are the salient features of their potential. Some of the new unexplored soluble fibers are still under investigation for their use in a variety of commercial foodstuffs. This review outlines the various SDFs available, their major sources, and their potential functional role in human health.

Low Phytic Acid Lentils (Lens culinaris L.): A Potential Solution for Increased Micronutrient Bioavailability

Phytic acid is an antinutrient present mainly in seeds of grain crops such as legumes and cereals. It has the potential to bind mineral micronutrients in food and reduce their bioavailability. This study analyzed the phytic acid concentration in seeds of 19 lentil ( Lens culinaris L.) genotypes grown at two locations for two years in Saskatchewan, Canada. The objectives of this study were to determine (1) the levels of phytic acid in commercial lentil genotypes and (2) the impact of postharvest processing and (3) the effect of boiling on the stability of phytic aid in selected lentil genotypes. The phytic acid was analyzed by high-performance anion exchange separation followed by conductivity detection. The Saskatchewan-grown lentils were naturally low in phytic acid (phytic acid = 2.5-4.4 mg g(-1); phytic acid phosphorus = 0.7-1.2 mg g(-1)), with concentrations lower than those reported for low phytic acid mutants of corn, wheat, common bean, and soybean. Decortication prior to cooking further reduced total phytic acid by >50%. As lowering phytic acid intake can lead to increased mineral bioavailability, dietary inclusion of Canadian lentils may have significant benefits in regions with widespread micronutrient malnutrition.

Is there a role for organic trace element supplements in transition cow health?

Optimal transition cow health is the key to success of the subsequent lactation, and increasing attention has been focused on management and nutritional practices that support it. Physiological stress during the transition period alters the efficiency of the immune system, making the lactating dairy cow more susceptible to infectious diseases, such as mastitis and metritis, with subsequent impairment of reproductive performance.Trace elements have a specific role in free radical control at the cellular level and influence the anti-oxidant/free radical balance. Dietary trace elements must be available for absorption throughout the whole of the digestive process until they reach the final site of absorption in the small intestine. Negative interactions between minerals can occur and, as the intestinal environment lowers the absorption of ionic minerals, chelation technology has been developed to increase mineral bioavailability. Organic trace elements have been used in dairy cow experiments, resulting in significant improvements in udder health, lameness and reproductive performance.

Phytic acid and inositol phosphates in raw flours and infant cereals: The effect of processing

Inositol phosphate modification in infant cereals was examined during industrial processing which included roasting and alpha-amylase treatment. A considerable ( p<0.05) decrease in phytate content was observed after both treatments in all the samples analysed. However, the industrial processing observed was not sufficient to cause degradation of the phytate to achieve phytate mineral ratios optimal for mineral absorption in infant cereals. All samples analysed had a phytate/iron molar ratio >1.3, and of the 6 samples, 5 had a phytate/zinc molar ratio >14. The bioavailability of minerals is particularly important during weaning when minerals stores in infants are naturally low. Further studies are needed to evaluate the efficacy and effectiveness of phytase treatment to increase mineral bioavailability in infant foods.

Impact of sourdough on the texture of bread

Sourdough has been used since ancient times and its ability to improve the quality and increase the shelf-life of bread has been widely described. During sourdough fermentation, lactic acid bacteria (LAB) produce a number of metabolites which have been shown to have a positive effect on the texture and staling of bread, e.g. organic acids, exopolysaccharides (EPS) and/or enzymes. EPS produced by LAB have the potential to replace more expensive hydrocolloids used as bread improvers. Organic acids affect the protein and starch fractions of flour. Additionally, the drop in pH associated with acid production causes an increase in the proteases and amylases activity of the flour, thus leading to a reduction in staling. While improving the textural qualities of bread, sourdough fermentation also results in increased mineral bioavailability and reduced phytate content. In this review we will be discussing the effect of sourdough on wheat and rye bread as well as the potential of sourdough to improve the quality of gluten-free bread.

Phytate Reduction in Oats during Malting

ABSTRACTTo reduce phytate in oat products and thereby increase mineral bioavailability, optimal conditions for phytate degradation in oats were investigated. The effects of malting and incubation on phytate reduction in oats were determined and compared with phytate degradation in wheat, rye and barley. Studies of incubation temperatures showed an optimum for phytate reduction in oats between 37–40°C which differed from that in wheat (55°C). Malting of oats for 5 days at 11°C and subsequent incubation for 17 hr at 37–40°C reduced phytate by 98%. Addition of malted rye also reduced the phytate content of oats to low levels.