The total concentration and bioaccessible fraction of nutrients in purées, instant cereals and infant formulas by ICP OES: A study of Dietary Recommended Intakes and the importance of using a standardized in vitro digestion method

Edible Halophytes with Functional Properties: In Vitro Protein Digestibility and Bioaccessibility and Intestinal Absorption of Minerals and Trace Elements from Australian Indigenous Halophytes

Halophytes are considered emerging functional foods as they are high in protein, minerals, and trace elements, although studies investigating halophyte digestibility, bioaccessibility, and intestinal absorption are limited. Therefore, this study investigated the in vitro protein digestibility, bioaccessibility and intestinal absorption of minerals and trace elements in saltbush and samphire, two important Australian indigenous halophytes. The total amino acid contents of samphire and saltbush were 42.5 and 87.3 mg/g DW, and even though saltbush had a higher total protein content overall, the in vitro digestibility of samphire protein was higher than the saltbush protein. The in vitro bioaccessibility of Mg, Fe, and Zn was higher in freeze-dried halophyte powder compared to the halophyte test food, suggesting that the food matrix has a significant impact on mineral and trace element bioaccessibility. However, the samphire test food digesta had the highest intestinal Fe absorption rate, whereas the saltbush digesta exhibited the lowest (37.7 vs. 8.9 ng/mL ferritin). The present study provides crucial data about the digestive "fate" of halophyte protein, minerals, and trace elements and increases the understanding of these underutilized indigenous edible plants as future functional foods.

Selenium in selected samples of infant formulas and milk commercialized in Belgium and Brazil: Total content, speciation and estimated intake

Total selenium (Se) and Se species concentrations were determined in 50 infant formulas and milk samples commercialized in Brazil and Belgium. Infant formula categories were starter, follow-up, specialized and plant-based (soy and rice), while milk samples included whole, skimmed, semi-skimmed and plant-based products. Total Se content was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), after microwave digestion. An enzymatic extraction method was applied to evaluate the Se species, mostly selenomethionine (SeMet), Se(IV) and Se(VI), through High Performance Liquid Chromatography coupled to ICP-MS (LC-ICP-MS). Starters and follow-up samples presented the highest total Se concentrations and values up to 30 µg/kg were observed in the reconstituted product. The lowest level (below the LOQ = 10 µg/kg) was verified in an anti-regurgitation specialized formula. The relative agreement between the measured total Se and the Se content declared on the label varied from 55 % to 317 %. Concentrations in infant formulas were not markedly different from concentrations in milk except for rice and oat milk samples that showed values below the LOQ. SeMet was the main species found in milks, while in infant formulas the species concentrations varied according to the product. The daily intake (DI) of Se via infant formula consumption was calculated and compared with the Adequate Intake (AI) value and the Dietary Reference Intake (DRI) established by the EFSA NDA Panel and ANVISA, respectively. Estimated maximum intakes of total Se obtained for reconstituted infant formula were 40.6 mg/day, corresponding to 400 % and 202 % of the DRI and AI, respectively.

Starch Digestion in Infants: An Update of Available In Vitro Methods-A Mini Review

Complementary feeding starts at around six months of age because neither breast milk nor formula assure the proper nutrition of infants. Therefore, along with breast milk, solid foods are gradually introduced, particularly cereal-based foods, which will provide starch as a new source of energy and nutrients. As a result, the need of an adequate in vitro digestion method to study the influence of different aspects of weaning period is unquestionable. This critical review summarizes the in vitro digestion methods available for the analysis of starch hydrolysis under infant conditions considering different features, namely, starch digestion, infant digestive conditions and in vitro models suitable for the study of starch digestion (static, semi-dynamic and dynamic). Key factors such as enzyme concentrations, transit time, oral, gastric and intestinal conditions and differences with current adult models, have been addressed. The need for standardized infant digestion models adapted to the complementary feeding period was discussed. Existing literature data demonstrate that more effort has to be done to improve the research on this issue, in order to obtain comparable results that would address a better understanding of the digestibility of different food nutrients under infant conditions facilitating the development of appropriate formulations that may assure proper infant nutrition.

Bioaccessibility of some minerals in infant formulas

To guarantee the adequate intake of nutrients a variety of food supplementation (including infant formulas) has been used to ensure the nutrition of infants. Considering that the total concentration of nutrients is not enough to determine whether the food provides all the nutritional needs, the objective of this study was to evaluate the total concentration and bioaccessibility of some elements in thirty commercial infant formulas consumed in Brazil. A standardized in vitro gastrointestinal digestion method was used to obtain the soluble fraction of each mineral, which was analyzed by ICP OES after microwave oxidative digestion to obtain the bioaccessibility values. The total concentration and the bioaccessibility of the elements varied considerably according to the sample type (traditional infant formulas, formulas for infants with gastrointestinal problems, formulas for premature and soy-based). The bioaccessibility values are 3-43% (Ca), 53-97% (Cu), 35-100% (Fe), 70-114% (K), 47-90% (Mg), 52-95% (P), 31-92% (Zn). In general, the total concentration values for the elements were higher than that declared by the manufacturers, also than the current legislation as well, regarding the DRI. Although these results, it is important to emphasize that the consumption of infant formulas can provide an adequate intake of minerals for the infants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05215-0.

Bioacessibilidade in vitro de carotenoides e compostos fenólicos e capacidade antioxidante de farinhas do fruto pequi (Caryocar brasiliense Camb.)

Resumo Este trabalho objetivou avaliar a bioacessibilidade in vitro de α-caroteno, β-caroteno, licopeno e de compostos fenólicos, e a capacidade antioxidante em farinhas de amêndoa, polpa e casca do fruto pequi. Além disso, inter-relacionar estes resultados com a atividade de água, acidez e parâmetros de cor, por meio da análise de componentes principais. Os frutos foram coletados no estado de Mato Grosso, sendo higienizados, descascados, despolpados e retiradas as amêndoas. A quantificação das concentrações totais e bioacessíveis dos carotenoides e compostos fenólicos e a capacidade antioxidante foram feitas por espectrofotometria UV-Visível. Os ensaios de bioacessibilidade in vitro foram feitos por meio de três etapas: digestão salivar, gástrica e intestinal. As maiores concentrações de α-caroteno (63,81 µg/g), β-caroteno (59,83 µg/g) e licopeno (40,66 µg/g) foram obtidas para farinha da polpa do pequi. Porém, as maiores porcentagens de bioacessibilidade de α-caroteno (59,69%), β-caroteno (96,14%) e licopeno (44,13%) foram encontradas na farinha da amêndoa. Os teores de compostos fenólicos totais foram: 210,50, 402,21 e 9475,69 mg GAE/100g, para as farinhas de amêndoa, polpa e casca, respectivamente, sendo a maior porcentagem de bioacessibilidade (86,68%) encontrada na farinha da polpa. A farinha da casca do pequi apresentou maior capacidade antioxidante (EC50) 45,71 g/g de DPPH. Os maiores resultados de L* (42,19), a* (4,17), b* (8,39) e acidez titulável (17,83 mL NaOH/100 g) foram verificados na farinha da polpa e o menor pH (3,34), na farinha da casca. A análise de componentes principais indicou que o pH e a acidez titulável podem influenciar na bioacessibilidade de compostos fenólicos e carotenoides, e na capacidade antioxidante. Os resultados sugerem que as farinhas do pequi apresentam compostos bioativos bioacessíveis e boa capacidade antioxidante, e podem ser uma alternativa tecnológica no enriquecimento de produtos alimentícios.

Multi-elemental risk assessment of various baby rice cereals: some cause for concern?

This study used batch and online methods to accurately determine how much arsenic (As), chromium (Cr), selenium (Se), cadmium (Cd), lead (Pb), copper (Cu), iron (Fe), and zinc (Zn) can be leached from baby rice cereals into a baby’s body. Speciation analysis of the saliva and gastric juice leachates was conducted to further assess the risk associated with the continued consumption of baby rice cereal for infants. A simple 15 min chromatographic analysis successfully separated eight species consisting of As(III), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), As(V), Se(IV), Se(VI), Cr(III), and Cr(VI). Given that 95%–100% As, 29%–100% Cr, 62%–100% Pb, 70%–100% Se, 63%–100% Cd, 36%–100% Cu, 67%–100% Fe, and 70%–100% Zn were bio-accessible and the speciation analysis results showed all bio-accessible As and Se to be in the forms of As(V) and Se(VI) and 70%–100% of Cr to be in the Cr(III) form, a variety of foods should be fed to infants rather than just baby rice cereal to ensure a well-balanced diet and less exposure to As at such a young age.

Effect of Freeze Drying and Simulated Gastrointestinal Digestion on Phenolic Metabolites and Antioxidant Property of the Natal Plum (Carissa macrocarpa)

Natal plums (Carissa macrocarpa) are a natural source of bioactive compounds, particularly anthocyanins, and can be consumed as a snack. This study characterized the impact of freeze drying and in vitro gastrointestinal digestion on the phenolic profile, antioxidant capacity, and α-glucosidase activity of the Natal plum (Carissa macrocarpa). The phenolic compounds were quantified using high performance liquid chromatography coupled to a diode-array detector HPLC-DAD and an ultra-performance liquid chromatograph (UPLC) with a Waters Acquity photodiode array detector (PDA) coupled to a Synapt G2 quadrupole time-of-flight (QTOF) mass spectrometer. Cyanidin-3-O-β-sambubioside (Cy-3-Sa) and cyanidin-3-O-glucoside (Cy-3-G) were the dominant anthocyanins in the fresh and freeze-dried Natal plum powder. Freeze drying did not affect the concentrations of both cyanidin compounds compared to the fresh fruit. Both cyanidin compounds, ellagic acid, catechin, epicatechin syringic acid, caffeic acid, luteolin, and quercetin O-glycoside from the ingested freeze-dried Natal plum powder was quite stable in the gastric phase compared to the small intestinal phase. Cyanidin-3-O-β-sambubioside from the ingested Natal plum powder showed bioaccessibility of 32.2% compared to cyanidin-3-O-glucoside (16.3%). The degradation of anthocyanins increased the bioaccessibility of gallic acid, protocatechuic acid, coumaric acid, and ferulic acid significantly, in the small intestinal digesta. The ferric reducing antioxidant power (FRAP), 2,2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) activities, and inhibitory effect of α-glucosidase activity decreased in the small intestinal phase. Indigenous fruits or freeze-dried powders with Cy-3-Sa can be a better source of anthocyanin than Cy-3-G due to higher bioaccessibility in the small intestinal phase.

Phenolic profiles, bioaccessibility and antioxidant activity of plum (Prunus Salicina Lindl)

Plum (Prunus Salicina Lindl) is a rich source of phenolic compounds. However, the bound phenolics and its bioaccessibility and antioxidant activity remain unclear. Hence, the purpose of this study was to determine: 1) phenolic profiles of plum, including both free and bound phenolic fractions, 2) bioaccessibility of phenolic compounds in plum during simulated gastrointestinal digestions, 3) their antioxidant properties. A total of 17 phenolic compounds were identified by UPLC-Q-Exactive Orbitrap/MS with most epicatechin, neochlorogenic acid and procyanidin B2 in the free phenolics fraction, while catechin and epicatechin was the main compounds in the bound phenolics fraction. After the gastrointestinal digestion phase, the most bioaccessible phenolics were quercetin-pentoside (61.64%), cyanidin-3-O-glucoside (43.26%), and naringenin-7-O-β-D-glucoside (42.04%). The antioxidant capacity of both undigested plum and its digested fractions showed a positive correlation with the total phenolics, and with specific individual phenolic compounds such as neochlorogenic acid, epicatechin and procyanidin B2 in undigested plum whereas catechin, neochlorogenic acid, and epicatechin in digested one. The results confirm that bound fraction of plum contribution to the total phenolic content must be taken into account in the assessment of the improving human health effects of plum.

In vitro evaluation of the bioaccessibility of antioxidative properties in commercially baby foods

Fruit-vegetable based products are essential for infants as they widely used the first complementary solid foods. This study aimed to investigate the physicochemical properties, the antioxidant capacities, total phenolic content, and bioaccessibility of 24 different commercially fruit-vegetable based complementary foods. To determination of bioaccessibility, samples were processed by an in vitro digestive enzymatic extraction that mimics the conditions in the gastrointestinal tract. Total polyphenol content was analyzed using Folin-Ciocalteu assay, and antioxidant capacities were assessed by CUPRAC and ABTS methods. The total phenol content of the samples ranges from 892.21 to 1729.13 mg GAE mg/100 g. While the antioxidant capacity of the samples averages 256.26 µmol TE mg/100 g according to the ABTS method, they were found 2417.79 µmol TE mg/100 g for CUPRAC method. Also, the bioaccessibility of total phenol content determined 62.72-98.48% of all samples. As a result, antioxidant properties and bioaccessibility of the samples were changed according to the sample content and chemical composition. The use of fruit or fruit juice in the preparation of commercial baby food has improved antioxidant capacity and bioaccessibility, thus increasing the beneficial health effect and nutraceutical properties of the baby meal.

Simplified Method of Multi-Elemental Analysis of Dialyzable Fraction of Tea Infusions by FAAS and ICP OES

A fast and straightforward sample preparation procedure of the dialyzable fraction of infusions of teas prior to their analysis on Al, Ba, Ca, Cu, Fe, Mg, Mn, Ni, Sr, and Zn contents by flame atomic absorption spectrometry (FAAS) and inductively coupled plasma optical emission spectrometry (ICP OES) was developed and validated. The proposed methodology was based on acidification with HNO3 only and demonstrated good analytical performance, i.e., precision (0.80-5.0%), accuracy (< 5%), recoveries of elements (97.4-105%), and their detection limits (0.075-1.1 μg L-1) along with linearity of calibration curves in the whole studied concentration ranges. Applicability of the evaluated procedure, being a useful alternative to time-consuming wet digestions, was tested by determining bioaccessibility of elements in 20 infusions of black (BT) and green (GT) teas as assessed with the aid of in vitro gastrointestinal digestion. Average contributions of bioaccessible fractions (%) of studied metals were as follows: 1.18 (Al)-40.7% (Ca) and 4.65% (Al)-46.3% (Ca) for BTs and GTs, respectively. Drinking daily four cups (1 L) of tea, recommended dietary intakes (RDIs) of Ca, Cu, Fe, Mg, and Zn were covered to a small degree (< 1.5%). Only bioaccessibility of Mn highly contributed to RDI for this metal. According to provisional tolerable weekly intakes (PTWIs) for toxic elements such as Al and Ni, consumption of both types of teas should not represent any health risk. Additionally, analysis of variance of results clearly indicated that BTs and GTs were mostly differentiated due to concentrations of the bioaccessible fraction of Al, Ba, Cu, and Ni.

Aluminum content and effect of in vitro digestion on bioaccessible fraction in cereal-based baby foods

The aim of this work was to determine the total concentration and the effect of in vitro digestion on the bioaccessible fraction of aluminum (Al) in 35 different cereal-based baby food samples and estimate the exposure to this element considering the consumption of this product. Total Al content was determined by inductively coupled plasma optical emission spectrometry after oxidative microwave digestion. An in vitro digestion method was applied and optimized to evaluate the bioaccessible fraction. The methods performance was efficient for both approached analysis and presented limits of detection and quantitation of 53 μg kg^-1 and 89 μg kg^-1, respectively. Total concentration and bioaccessibility varied according to the product composition (rice, oat, wheat, barley, corn, multicereal and fruit). Multicereals and fruit-based (plum) cereals presented the highest total Al concentrations (8.82 mg kg^-1 and 7.49 mg kg^-1, respectively), whilst lower values were observed for corn and rice flour cereals (0.92 mg kg^-1 and 1.09 mg kg^-1, respectively). The bioaccessible fraction varied from 1.5% to 10.4% in the evaluated samples. Exposure to Al was estimated and compared with the Provisional Tolerable Weekly Intake (PTWI) of 2 mg kg^-1 body weight. The results showed that the daily consumption of three portions of cereals contributes up to 10.48% of the PTWI, when considering the total Al concentration reported in this study.