Bioavailability of calcium from milk-based formulas and fruit juices containing milk and cereals estimated by in vitro methods (solubility, dialyzability, and uptake and transport by caco-2 cells)

The application of ferritin in transporting and binding diverse metal ions

The ferritin cage can not only load iron ions in its inner cavity, but also has the capacity to carry other metal ions, thus constructing a new biological nano-transport system. The nanoparticles formed by ferritin and minerals can be used as ingredients of mineral supplements, which overcome the shortcomings of traditional mineral ingredients such as low bioavailability. Moreover, ferritin can be used to remove heavy metal ions from contaminated food. Silver and palladium nanoparticles formed by ferritin are also applied as anticancer agents. Ferritin combined with metal ions can be also used to detect harmful substances. This review aims to provide a comprehensive overview of ferritin's function in transporting and binding metal ions, and discusses the limitations and future prospects, which offers valuable insights for the application of ferritin in mineral supplements, food detoxifiers, anticancer agents, and food detections.

Advancements of the Molecular Directed Design and Structure-Activity Relationship of Ferritin Nanocage

Ferritin nanocages possess remarkable structural properties and biological functions, making them highly attractive for applications in functional materials and biomedicine. This comprehensive review presents an overview of the molecular characteristics, extraction and identification of ferritin, ferritin receptors, as well as the advancements in the directional design of high-order assemblies of ferritin and the applications based on its unique structural properties. Specifically, this Review focuses on the regulation of ferritin assembly from one to three dimensions, leveraging the symmetry of ferritin and modifications on key interfaces. Furthermore, it discusses targeted delivery of nutrition and drugs through facile loading and functional modification of ferritin. The aim of this Review is to inspire the design of micro/nano functional materials using ferritin and the development of nanodelivery vehicles for nutritional fortification and disease treatment.

Citric Acid: A Multifunctional Pharmaceutical Excipient

Citric acid, a tricarboxylic acid, has found wide application in the chemical and pharmaceutical industry due to its biocompatibility, versatility, and green, environmentally friendly chemistry. This review emphasizes the pharmaceutical uses of citric acid as a strategic ingredient in drug formulation while focusing on the impact of its physicochemical properties. The functionality of citric acid is due to its three carboxylic groups and one hydroxyl group. These allow it to be used in many ways, including its ability to be used as a crosslinker to form biodegradable polymers and as a co-former in co-amorphous and co-crystal applications. This paper also analyzes the effect of citric acid in physiological processes and how this effect can be used to enhance the attributes of pharmaceutical preparations, as well as providing a critical discussion on the issues that may arise out of the presence of citric acid in formulations.

Uma abordagem dos ensaios in vitro para estimar a absorção dos minerais em fórmulas infantis

Resumo A fórmula infantil é a opção de alimento mais recomendada quando a amamentação não é possível. Para o melhor entendimento do comportamento gastrointestinal e da absorção dos nutrientes presentes nas fórmulas infantis, realizam-se estudos que simulam os processos de digestão. Este trabalho teve como objetivo discutir a evolução das fórmulas infantis com foco na avaliação da absorção de Ca, Cu, Fe, K, Mg, Mn, P e Zn, identificando métodos disponíveis para a avaliação de bioacessibilidade e de biodisponibilidade, de forma a melhor entender a absorção desses nutrientes. Para isto, foi realizada uma revisão bibliográfica sobre fórmulas infantis e os métodos in vitro mais utilizados no estudo de minerais, com foco no consumo, na qualidade e nos aspectos tecnológicos. Foi constatada uma tendência mundial no aumento do consumo de fórmulas infantis e verificou-se que estudos de biodisponibilidade e bioacessibilidade de minerais, mesmo que ainda escassos, colaboram para a evolução e o desenvolvimento deste produto, visando a uma aproximação com a composição do leite materno. A pesquisa mostrou que a composição da fórmula infantil vem sendo constantemente aperfeiçoada por revisões das legislações e pela indústria, e que, para a obtenção de uma fórmula infantil com alta capacidade de absorção de nutrientes, devem ser realizados estudos de bioacessibilidade e/ou de biodisponibilidade, pois estes estudos possibilitam uma melhor compreensão da influência dos diferentes ingredientes na absorção dos nutrientes. Os estudos também mostraram que, para uma ingestão mais equilibrada, nas diferentes fases do lactente, são necessárias diferentes composições dos nutrientes nas fórmulas infantis.

Impact of acidity regulator and excipient nutrients on digestive solubility and intestinal transport of calcium from calcium phosphate and carbonate

The aim of the current study was to investigate the effect of an acidity regulator (SPORIX®), lactose, and vitamin D₃ as excipient ingredients on digestive solubility and intestinal transport of calcium from four different calcium materials (tricalcium phosphate (TCP), fish bone (FB), nano-fish bone (NFB), and algae calcium (AC)) through an in vitro digestion model system combined with Caco-2 cells. The concentration of ionized calcium (Ca²⁺) in an aqueous fraction after in vitro digestion increased with the addition of SPORIX®, and it was further enhanced by adding SPORIX® + lactose + vitamin D₃ into TCP, FB, NFB, and AC, respectively. In particular, FB with SPORIX® + lactose + vitamin D₃ enhanced calcium ionization to 33.89 ± 0.69 mg g^-1, which was about 11.76 times higher than that of FB only. In the case of intestinal cellular uptake of calcium, there was no significant difference in all the tested calcium materials with SPORIX® + lactose + vitamin D₃. However, the absolute amount of intestinal transport of calcium in FB (43.95 ± 3.29 μg) was significantly higher than other calcium materials with the addition of SPORIX® + lactose + vitamin D₃ (p < 0.05). This study suggests that the co-consumption of SPORIX®, lactose, and vitamin D₃ with FB could enhance the calcium bioavailability by lowering pH as well as improving calcium intestinal transport by modulating the paracellular and transcellular uptake mechanism.

Ferritin Nanocage: A Versatile Nanocarrier Utilized in the Field of Food, Nutrition, and Medicine

Compared with other nanocarriers such as liposomes, mesoporous silica, and cyclodextrin, ferritin as a typical protein nanocage has received considerable attention in the field of food, nutrition, and medicine owing to its inherent cavity size, excellent water solubility, and biocompatibility. Additionally, ferritin nanocage also serves as a versatile bio-template for the synthesis of a variety of nanoparticles. Recently, scientists have explored the ferritin nanocage structure for encapsulation and delivery of guest molecules such as nutrients, bioactive molecules, anticancer drugs, and mineral metal ions by taking advantage of its unique reversible disassembly and reassembly property and biomineralization. In this review, we mainly focus on the preparation and structure of ferritin-based nanocarriers, and regulation of their self-assembly. Moreover, the recent advances of their applications in food nutrient delivery and medical diagnostics are highlighted. Finally, the main challenges and future development in ferritin-directed nanoparticles’ synthesis and multifunctional applications are discussed.

Simple and fast ultrasound-assisted method for mineral content and bioaccessibility study in infant formula by ICP OES

Infant formula (IF) constitutes the sole source of mineral intake for infants who are only fed IF. The assurance of the amount of minerals declared on the label and the mineral levels and their chemical forms present a major concern related to providing a good amount of nutrients for absorption by these children. Thus, the objectives of this study were: (i) to evaluate several sample preparation methods for minerals in IF; (ii) to validate an analytical method using an ultrasonic bath for simultaneous determination of the Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn contents in IF by ICP OES and (ii) to establish the optimum analytical conditions of the in vitro method to study the dialyzability of these minerals from IF. The ultrasound-assisted method was shown to conform to 'green chemistry principles', being simple, fast and low cost compared with reference methods. The results were similar to those obtained with reference methods (microwave-assisted acid digestion and dry ashing) with regard to selectivity, sensitivity and linearity (r2 > 0.999). The accuracy and the precision were verified using certified reference materials, with recoveries and coefficients of variation ranging from 91 to 105% and from 1.1 to 5.2%, respectively. For in vitro dialyzability, the conditions established in this study allowed including an overnight step between the gastric and gastrointestinal stages (accuracy and precision ranging from 81 to 108% and 0.4 to 6.3%, respectively), contributing to establishing an in vitro digestion method suitable for infant gastrointestinal conditions.

Ferritin cage for encapsulation and delivery of bioactive nutrients: From structure, property to applications

Ferritin is a class of naturally occurring iron storage proteins, which is distributed widely in animal, plant, and bacteria. It usually consists of 24 subunits that form a hollow protein shell with high symmetry. One holoferritin molecule can store up to 4500 iron atom within its inner cavity, and it becomes apoferritin upon removal of iron from the cavity. Recently, scientists have subverted these nature functions and used reversibly self-assembled property of apoferritin cage controlled by pH for the encapsulation and delivery of bioactive nutrients or anticancer drug. In all these cases, the ferritin cages shield their cargo from the influence of external conditions and provide a controlled microenvironment. More importantly, upon encapsulation, ferritin shell greatly improved the water solubility, thermal stability, photostability, and cellular uptake activity of these small bioactive compounds. This review aims to highlight recent advances in applications of ferritin cage as a novel vehicle in the field of food science and nutrition. Future outlooks are highlighted with the aim to suggest a research line to follow for further studies.

Influence of rye flour enzymatic biotransformation on the antioxidant capacity and transepithelial transport of phenolic acids

Enzymatic biotransformation enhanced the release of phenolic acids and Caco-2 transepithelial transport of vanillic acid.

An Exploration of the Calcium-Binding Mode of Egg White Peptide, Asp-His-Thr-Lys-Glu, and In Vitro Calcium Absorption Studies of Peptide-Calcium Complex

The binding mode between the pentapeptide (DHTKE) from egg white hydrolysates and calcium ions was elucidated upon its structural and thermodynamics characteristics. The present study demonstrated that the DHTKE peptide could spontaneously bind calcium with a 1:1 stoichiometry, and that the calcium-binding site corresponded to the carboxyl oxygen, amino nitrogen, and imidazole nitrogen atoms of the DHTKE peptide. Moreover, the effect of the DHTKE-calcium complex on improving the calcium absorption was investigated in vitro using Caco-2 cells. Results showed that the DHTKE-calcium complex could facilitate the calcium influx into the cytosol and further improve calcium absorption across Caco-2 cell monolayers by more than 7 times when compared to calcium-free control. This study facilitates the understanding about the binding mechanism between peptides and calcium ions as well as suggests a potential application of egg white peptides as nutraceuticals to improve calcium absorption.

Bioaccessibility of four calcium sources in different whey-based dairy matrices assessed by in vitro digestion

Numerous calcium sources are available to enrich food, but their behavior during digestion is still unknown. This study focused on the influence of the gastro-intestinal pH, the food structure and the calcium source on the bioaccessibility of the nutrient. Four calcium sources were studied: calcium carbonate, calcium citrate malate, calcium phosphate and calcium bisglycinate. These were added to dairy matrices, containing cream and whey proteins, of different forms (liquid or gel). The kinetics of solubility and ionic calcium concentration during in vitro digestion were studied, as function of gastro-intestinal pH. All calcium sources were almost fully soluble in the gastric compartment, and then became insoluble in the intestinal phase. The level of calcium insolubilisation in the intestinal phase was not significantly influenced by the matrix structure (liquid or gel), but was more dependent on the calcium source, this effect leading to different final calcium bioaccessibility from 36% to 20%.

Evaluation of Iodine Bioavailability in Seaweed Using in Vitro Methods

Due to the high levels of iodine present in seaweed, the ingestion of a large amount of this type of food can produce excessive intake of iodine. However, the food after ingestion undergoes different chemistry and physical processes that can modify the amount of iodine that reaches the systemic circulation (bioavailability). Studies on the bioavailability of iodine from food are scarce and indicate that the bioavailable amount is generally lower than ingested. Iodine in vitro bioavailability estimation from different commercialized seaweed has been studied using different in vitro approaches (solubility, dialyzability, and transport and uptake by intestinal cells). Results indicate that iodine is available after gastrointestinal digestion for absorption (bioaccessibility: 49-82%), kombu being the seaweed with the highest bioaccessibility. The incorporation of dialysis cell cultures to elucidate bioavailability modifies the estimation of the amount of iodine that may reach the systemic circulation (dialysis, 5-28%; cell culture, ≤3%). The paper discusses advantages and drawbacks of these methodologies for iodine bioavailability in seaweed.

Phytate/calcium molar ratio does not predict accessibility of calcium in ready-to-eat dishes

BACKGROUND

Phytic acid (PA), a naturally occurring compound of plant food, is generally considered to affect mineral bioavailability. The aim of this study was to investigate the reliability of the PA/calcium molar ratio as a predictive factor of calcium accessibility in composed dishes and their ingredients.

RESULTS

Dishes were chosen whose ingredients were rich in Ca (milk or cheese) or in PA (whole-wheat cereals) in order to consider a range of PA/Ca ratios (from 0 to 2.4) and measure Ca solubility using an in vitro approach. The amounts of soluble Ca in composed dishes were consistent with the sum of soluble Ca from ingredients (three out of five meals) or higher. Among whole-wheat products, bread showed higher Ca accessibility (71%, PA/Ca = 1.1) than biscuits (23%, PA/Ca = 0.9) and pasta (15%, PA/Ca = 1.5), and among Ca-rich ingredients, semi-skimmed milk displayed higher Ca accessibility (64%) than sliced cheese (50%) and Parmesan (38%). No significant correlation between the PA/Ca ratio and Ca accessibility was found (P = 0.077).

CONCLUSION

The reliability of the PA/Ca ratio for predicting the availability of calcium in composed dishes is unsatisfactory; data emphasized the importance of the overall food matrix influence on mineral accessibility. © 2016 Society of Chemical Industry.

Effect of ultra-high pressure homogenization on the interaction between bovine casein micelles and ritonavir

PURPOSE

The aim of this work was to develop a milk-based powder formulation appropriate for pediatric delivery of ritonavir (RIT).

METHODS

Ultra-high pressure homogenization (UHPH) at 0.1, 300 and 500 MPa was used to process a dispersion of pasteurized skim milk (SM) and ritonavir. Loading efficiency was determined by RP-HPLC-UV; characterization of RIT:SM systems was carried out by apparent average hydrodynamic diameter and rheological measurements as well as different analytical techniques including Trp fluorescence, UV spectroscopy, DSC, FTIR and SEM; and delivery capacity of casein micelles was determined by in vitro experiments promoting ritonavir release.

RESULTS

Ritonavir interacted efficiently with milk proteins, especially, casein micelles, regardless of the processing pressure; however, results suggest that, at 0.1 MPa, ritonavir interacts with caseins at the micellar surface, whilst, at 300 and 500 MPa, ritonavir is integrated to the protein matrix during UHPH treatment. Likewise, in vitro experiments showed that ritonavir release from micellar casein systems is pH dependent; with a high retention of ritonavir during simulated gastric digestion and a rapid delivery under conditions simulating the small intestine environment.

CONCLUSIONS

Skim milk powder, especially, casein micelles are potentially suitable and efficient carrier systems to develop novel milk-based and low-ethanol powder formulations of ritonavir appropriate for pediatric applications.

A novel calcium supplement prepared by phytoferritin nanocages protects against absorption inhibitors through a unique pathway

The consumption of milk is declining in industrialized countries, leading to inadequate calcium intake. Therefore, it is important to explore a new class of Ca-enriched nutrient for the fortification of food. In this work, we prepared a novel class of soluble and edible Ca-protein complexes where approximately 140 calcium ions were encapsulated within a phytoferritin nanocage. As an alternative to other organic and/or inorganic carriers, protein nanocages were found to provide a unique vehicle of biological origin for the intracellular delivery of calcium ions for supplementation. Such encapsulation can protect calcium ions within protein cages against dietary factors such as tannic acid (TA), oxalic acid (OA), and other divalent metal ions in foodstuffs. We demonstrated that the calcium-containing ferritin composites can be absorbed by Caco-2 cells through a process where a TfR1 receptor is involved, whereas the uptake of free calcium ions has been known to be associated with another receptor, DMT1, indicating that the calcium ions encapsulated in supramolecular protein cages can be internalized by the Caco-2 cells through a different pathway from its free analogs for calcium supplementation.

Comparison study of oral iron preparations using a human intestinal model

Iron deficiency and related iron deficiency anaemia (IDA) are the most prevalent nutritional disorders worldwide. The standard treatment involves supplementation with solid or liquid iron supplement preparations, usually based on a ferrous salt such as ferrous sulphate, ferrous fumarate, or ferrous gluconate. In the present study, we compared iron uptake and absorption from various solid and liquid iron supplement preparations currently available in the United Kingdom using the well-characterised human epithelial adenocarcinoma cell line Caco-2. Intracellular ferritin protein formation by the Caco-2 cell was considered an indicator of cellular iron uptake and absorption. We investigated the effects of formulation ingredients at a defined pH on iron uptake and absorption, and designed a novel two-stage dissolution-absorption protocol that mimicked physiological conditions. Our experiments revealed wide variations in the rate of dissolution between the various solid iron preparations. Conventional-release ferrous iron tablets dissolved rapidly (48 ± 4 mins to 64 ± 4 mins), whereas modified-released tablets and capsules took significantly longer to undergo complete dissolution (274 ± 8 to 256 ± 8 mins). Among the solid iron preparations, ferrous sulphate conventional-release tablets demonstrated the highest iron absorption, whereas modified-release ferrous preparations demonstrated uniformly low iron absorption, as compared to the control (P < 0.05). Taken together, our results demonstrate that there are wide-ranging variations in dissolution times and iron uptake from oral iron preparations, with the physical characteristics of the preparation as well as the form of iron playing a key role.

The probiotic bacterial strain Lactobacillus fermentum D3 increases in vitro the bioavailability of Ca, P, and Zn in fermented goat milk

We determined calcium, magnesium, phosphorus and zinc levels in a total of 27 samples of commercial goat- and cow-milk fermented products and 9 samples of a goat-milk fermented product with addition of a probiotic bacterial strain, Lactobacillus fermentum D3, manufactured experimentally by our research group. Atomic absorption spectroscopy with flame atomization and UV/VIS spectrophotometry were used as analytic techniques. The results of an in vitro digestion process showed that the bioavailability of calcium, phosphorus, and zinc was significantly higher in our fermented milk containing the probiotic bacterial strain than it was in commercial goat-milk fermented products. Furthermore, our product showed a significantly higher bioavailability of calcium and zinc compared to goat- and cow-milk fermented products made with other microorganisms. We conclude that, in in vitro assays, strain D3 seems to increase the bioavailability of these minerals and that this new product may constitute a better source of bioavailable minerals compared to other products already on the market.

Effect of added calcium, phosphorus, and infant formula on calcium and phosphorus dialyzability in preterm donor human milk

OBJECTIVES

We studied the effect of preparing donor human milk (DHM) with commonly used nutritional additives on the dialyzability of calcium and phosphate. We hypothesized that the additives to DHM would decrease the dialyzability of calcium and phosphate when prepared according to hospital protocols.

METHODS

An in vitro system simulating premature infant digestion was developed to measure dialyzability of calcium and phosphate in DHM. Dialyzable calcium and phosphate were measured after in vitro digestion in DHM before and after preparation of DHM with the following additives according to hospital protocols: calcium glubionate, sodium potassium phosphate, calcium glubionate and sodium potassium phosphate added together, Similac human milk fortifier, Similac NeoSure, or Enfamil Enfacare.

RESULTS

The percentage of dialyzable calcium in DHM with added calcium and calcium and phosphate together was greater than the percentage of dialyzable calcium in DHM with added powdered infant formulas (P<0.0001). Dialyzable calcium was greater in DHM with added calcium and with added calcium and phosphate than in all other treatment groups (P<0.0001). Dialyzable calcium in DHM without additives was not different from dialyzable calcium in DHM with added phosphate or with added powdered infant formulas. Dialyzable phosphate did not differ between the treatment groups.

CONCLUSIONS

The addition of calcium alone or calcium and phosphate together increased calcium dialyzability in DHM significantly, whereas the addition of powdered human milk fortifier or formulas did not. The addition of calcium or calcium with phosphate together to DHM may provide the most dialyzable calcium.

Application of in vitro bioaccessibility and bioavailability methods for calcium, carotenoids, folate, iron, magnesium, polyphenols, zinc, and vitamins B(6), B(12), D, and E

A review of in vitro bioaccessibility and bioavailability methods for polyphenols and selected nutrients is presented. The review focuses on in vitro solubility, dialyzability, the dynamic gastrointestinal model (TIM)™, and Caco-2 cell models, the latter primarily for uptake and transport, and a discussion of how these methods have been applied to generate data for a range of nutrients, carotenoids, and polyphenols. Recommendations are given regarding which methods are most justified for answering bioaccessibility or bioavailability related questions for specific nutrients. The need for more validation studies in which in vivo results are compared to in vitro results is also discussed.

Addition of Calcium and Phosphorus to Preterm Donor Human Milk and the Impact on Protein, Fat, and Calcium Digestibility In Vitro

Infants born prematurely are at risk for metabolic bone disease and may need increased minerals for normal bone mineralization. In these situations, supplementation of human milk with calcium and phosphorus is common in the United States. The interaction of these nutrients and their carriers with other nutrition components of human milk has not been systematically investigated. The primary goal was to study the effect of calcium and phosphorus supplementation on the digestibility of protein, free fatty acids, and calcium in preterm donor human milk (DHM). An in vitro model of the premature infant’s gastrointestinal tract was used to simulate digestion. Protein, free fatty acids, and ionized calcium were measured before and after in vitro digestion in milk with and without added calcium glubionate and sodium potassium phosphate. Calcium and phosphorus supplementation did not negatively affect total protein, protein breakdown, protein digestibility, or fat breakdown when compared with unfortified DHM. Supplemental calcium increased ionized calcium, which may replace ionized calcium lost during milk expression, storage, and processing. Supplemental calcium glubionate and sodium potassium phosphate do not affect protein or fat breakdown in vitro. DHM contains less ionized calcium than fresh human milk because it loses CO2 during expression and processing. Adding supplemental calcium increases ionized calcium in DHM.

Effect of simulated gastrointestinal digestion on sialic acid and gangliosides present in human milk and infant formulas

The effects of simulated gastrointestinal digestion upon sialic acid and gangliosides in infant and follow-on formulas and human milk, as well as their bioaccessibility, have been evaluated. The gastric stage is the step that causes a greater decrease in sialic acid and ganglioside contents. The intestinal stage only decreases the total and individual contents of gangliosides. After gastrointestinal digestion, neither sialic acid nor gangliosides were found in the nonbioaccessible fraction. The highest bioaccessibility (100 × content in soluble fraction after gastrointestinal digestion/total content) of sialic acid is found in human milk (87%), followed by infant formula (77%) and follow-on formula (16%). In the case of gangliosides, the highest bioaccessibility is present in the follow-on formula (51%), followed by human milk (29%) and infant formula (5%).

Organic acid bioavailability from banana and sweet potato using an in vitro digestion and Caco-2 cell model

INTRODUCTION

Organic acids from plant food have been shown to play an important role in the prevention of chronic diseases (osteoporosis, obesity), inherent to western diets, but little is known about their bioavailability in the small intestine, information that needs to be determined in order to quantify likely effects on human health.

METHODS

An in vitro model of human digestion was carried out, comprising simulated oral, gastric and pancreatic digestion followed by an in vitro model of small intestine absorption using Caco-2 cell monolayers. As models for fruits and vegetables, freeze-dried or raw samples of banana and sweet potato were used.

RESULTS

Organic acids have been found to be slowly released from the food matrix during simulated digestion of both banana and sweet potato, either raw or after freeze-drying. In the Caco-2 cell assay, malic and oxalic acids were absorbed more than citric acid. Oxalic and citric acids, but not malic acid, were transported across the cell monolayer. The release and uptake of major organic acids from model fruits and vegetables using established in vitro simulation processes was not quantitative and varied with acid type.

CONCLUSION

Partial uptake is consistent with a dual nutritional role for organic acids as alkalinising agents (fraction which is taken up) and as modulators of large intestinal function (fraction which is not taken up in the small intestine). Studies of in vivo digestive release and uptake are needed in order to identify the contribution of organic acids to the nutritional value of fruits and vegetables.

Milk versus caseinophosphopeptides added to fruit beverage: resistance and release from simulated gastrointestinal digestion

The influence of simulated gastrointestinal digestion on caseinophosphopeptides (CPPs) formation in milk-based fruit beverage was evaluated, together with resistance of a pool of CPPs added to fruit beverage. In milk-based fruit beverage, four CPPs were identified that can be justified by their presence in raw milk or due to processing. When it was subjected to simulated gastrointestinal digestion, 10 CPPs were identified, and only 1 presented the cluster (SpSpSpEE) (3 phosphoseryl group followed by 2 glutamic acid residues), which corresponded to alpha(s2)-CN(1-19)4P. CPPs added to fruit beverage are resistant to simulated gastrointestinal digestion, and 16 CPPs were identified originating from the fragmentation of added CPPs, and with a greater presence of the cluster compared with CPPs originating from milk-based fruit beverage. This could justify the use of CPPs as functional ingredients, and offer a good alternative to milk-based fruit beverage for improving mineral bioavailability.

Effect of dephytinization on bioavailability of iron, calcium and zinc from infant cereals assessed in the Caco-2 cell model

AIM: To test the effect of the dephytinization of three different commercial infant cereals on iron, calcium, and zinc bioavailability by estimating the uptake, retention, and transport by Caco-2 cells.

METHODS: Both dephytinized (by adding an exogenous phytase) and non-dephytinized infant cereals were digested using an in vitro digestion protocol adapted to the gastrointestinal conditions of infants younger than 6 mo. Mineral cell retention, transport, and uptake from infant cereals were measured using the soluble fraction of the simulated digestion and the Caco-2 cells.

RESULTS: Dephytinization of infant cereals significantly increased (P < 0.05) the cell uptake efficiency (from 0.66%-6.05% to 3.93%-13%), retention (from 6.04%-16.68% to 14.75%-20.14%) and transport efficiency (from 0.14%-2.21% to 1.47%-6.02%), of iron, and the uptake efficiency (from 5.0%-35.4% to 7.3%-41.6%) and retention (from 4.05%-20.53% to 14.45%-61.3%) of zinc, whereas calcium only cell uptake showed a significant increase (P < 0.05) after removing phytate from most of the samples analyzed. A positive relationship (P < 0.05) between mineral solubility and the cell uptake and transport efficiencies was observed.

CONCLUSION: Removing phytate from infant cereals had a beneficial effect on iron and zinc bioavailability when infant cereals were reconstituted with water. Since in developing countries cereal-based complementary foods for infants are usually consumed mixed with water, exogenous phytase additions could improve the nutritional value of this weaning food.

Iron bioavailability in fortified fruit beverages using ferritin synthesis by Caco-2 cells

The bioavailability of iron from fortified fruit beverages was estimated by an in vitro system including enzymatic digestion, iron uptake by Caco-2 cells, and ferritin formation determined via an enzyme immunoassay (ELISA). Thus, the aim of the present study was to assess iron bioavailability as influenced by the presence of known dietary promoter and inhibitory factors in fortified fruit beverages containing iron and/or zinc and/or skimmed milk. No negative effect ( p > 0.05) derived from micronutrient interaction can be ascribed to zinc supplementation on iron availability. Besides, the presence of caseinophosphopeptides derived from casein hydrolysis during digestion may confer enhancing effects on iron absorption in samples with milk added with respect to nonadded samples ( p < 0.05). Therefore, from a nutritional point of view, individuals in need of optimal iron absorption may choose dairy samples to ensure optimal iron bioavailability.