Opportunities for plant-derived enhancers for iron,zinc, and calcium bioavailability: A review

Understanding of the mechanism of interactions between dietary elements, their salts, and complexing/binding ligands is vital to manage both deficiency and toxicity associated with essential element bioavailability. Numerous mineral ligands are found in both animal and plant foods and are known to exert bioactivity via element chelation resulting in modulation of antioxidant capacity or micobiome metabolism among other physiological outcomes. However, little is explored in the context of dietary mineral ligands and element bioavailability enhancement, particularly with respect to ligands from plant-derived food sources. This review highlights a novel perspective to consider various plant macro/micronutrients as prospective bioavailability enhancing ligands of three essential elements (Fe, Zn, and Ca). We also delineate the molecular mechanisms of the ligand-binding interactions underlying mineral bioaccessibility at the luminal level. We conclude that despite current understandings of some of the structure–activity relationships associated with strong mineral–ligand binding, the physiological links between ligands as element carriers and uptake at targeted sites throughout the gastrointestinal (GI) tract still require more research. The binding behavior of potential ligands in the human diet should be further elucidated and validated using pharmacokinetic approaches and GI models.     

Phenolic contents,antioxidant activities and potential bioaccessibilities of industrial pomegranate nectar processing wastes

Antioxidant potential and bioaccessibility of co‐products from industrial pasteurised pomegranate nectar (PN) processing such as peel (PP), press cake (PC) and precipitate after clarification (PAC) in comparison with raw material (arils) and final products (CON and PN) were determined. Total phenolic (TPC), flavonoid (TFC), anthocyanin (TAC), tannin contents (TTC) and antioxidant activity (TAA) were determined besides identifying major phenolics and investigating in vitro bioaccessibility after gastrointestinal (GI) digestion. PP showed the highest values, except for TAC. Phenolics (12.7–43.0%) were found to be more stable than anthocyanins (0.6–2.1%) after in vitro GI digestion. PAC was found to be a better source for anthocyanins than CON and also showed higher phenolic bioaccessibility (28.8%) than PN (19.6%). PC and PAC possessed as much TPC, TFC, TTC and TAA levels as CON, with some exceptions. Therefore, these results indicated that not only PP but also PC and PAC should be valorised as a good source for phenolics and anthocyanins.     

基于胃肠动态消化系统分析两种不同藻油剂型的消化特性和生物可及性

利用体外动态模拟消化系统评价了两种不同二十二碳六烯酸(Docosahexaenoic acid,DHA)藻油剂型的消化速率及其生物可及性,以期找到消化特性更佳的DHA藻油产品。对凝胶糖果和软胶囊两种不同剂型的DHA藻油样品进行体外胃肠动态消化,并从粒径及表面电势、微观结构和DHA含量等方面对消化特性进行分析,多角度探究两种剂型藻油产品对其消化行为的影响。结果表明添加胰酶组在肠消化60 min后,凝胶糖果消化产物粒径极显著低于软胶囊消化产物(p0.01);未添加胰酶组软胶囊肠消化30 min至90 min后,产物粒径显著大于凝胶糖果(p0.05)。添加胰酶组中凝胶糖果肠消化产物ζ电位绝对值随时间增加而增大,且均高于30 mV。随着肠消化时间延长,凝胶糖果游离脂肪酸(Non esterified fatty acid,NEFA)释放量逐步增加,达到缓释效果,软胶囊NEFA量与消化时间无明显关系。凝胶糖果消化产物在荧光图像中呈现分散均一的小液滴,软胶囊消化产物形态大小各异,均一性差。综上所述,凝胶糖果的消化特性及油脂的释放与分散性能更好,且其DHA释放量为软胶囊的6.75倍,具有较好的生物可及性。     

Bioaccessible Iron and Zinc in Native and Fortified Enzyme Hydrolyzed Casein and Soya Protein Matrices

Casein and soybean are superior quality proteins; however, these are known to inhibit mineral absorption. These investigations were aimed at enzymatic modification of these proteins and to study their effect on mineral bioaccessibility. Casein and soybean proteins were hydrolyzed with alcalase and trypsin individually under optimum conditions. The protein hydrolysates, prepared with different degrees of hydrolysis, were freeze dried, fortified with either iron or zinc and analyzed for bioaccessible minerals in vitro. Proteolytic hydrolysis enhanced the bioaccessibility of iron and zinc in proportion to the degree of hydrolysis. Tryptic hydrolysis enhanced the bioaccessible iron from 1–4% in casein and from 1.3–3.3% in soybean. Alcalase hydrolysis showed a comparatively higher enhancement with both the proteins. Tryptic hydrolysis enhanced zinc bioaccessibity by 3-fold in casein and alcalase hydrolysis enhanced by 2- to 2.5-fold. In soybean, dephytinization showed a synergistic effect. In conclusion, enzymatic hydrolysis of proteins looks promising for enhancing bioaccessibility of minerals in protein matrices.     

Minerals in vitro bioaccessibility and changes in textural and structural characteristics of uncooked pre-germinated brown rice influenced by ultra-high pressure

Ultra-high pressure (UHP) is considered as an effective processing method to enhance micronutrients utilization efficiency in germinated brown rice (GBR), but there is little information available for the effects of UHP treatments on mineral bioaccessibility and related structural characteristics. Therefore, this work examined the changes induced by UHP in the in vitro bioaccessibility of selected minerals and structural and textural properties at pressures, as well as their potential relationship. UHP treatments were applied at 100, 300 and 500 MPa for 10 min, and 0.1 MPa as control. Proximate analysis showed that free fatty acids (FFA) and moisture in GBR greatly increased after UHP treatment. Three representative minerals with different levels were chosen to assess the bioaccessibility, including phosphorus (P), magnesium (Mg) and manganese (Mn). The results demonstrated that the minerals bioaccessibility, measured by percentage solubility, were the highest when at 300 MPa whereas it decreased at 500 MPa. Correspondingly, microstructure imaging by scanning electron microscope (SEM) showed that the gelatinization of starch granule occurred at 300 MPa and it became more obvious when increased to 500 MPa. Starch gelatinization significantly lowered the hardness of GBR grains, simultaneously accompanied with the decrease of cohesiveness, gumminess and resilience through texture profile analysis (TPA). Multivariate analysis by principal component analysis and canonical correspondence analysis indicated a highly intra-associated (p < 0.01) TPA parameters and a close correlation between the bioaccessibility and hardness, chewiness and springiness. These results provide information on minerals bioaccessibility and structural properties of uncooked GBR after UHP treatment, which could lay the foundation for further elucidating the correlation between structure and micronutrients bioaccessibility.     

New tools to assess toxicity, bioaccessibility and uptake of chemical contaminants in meat and seafood

Meat and seafood chemical contaminants can be very dangerous for human health. The way in which food chemical contaminants are currently controlled is not optimal as the food cooking, processing and eating habits are generally not considered by authorities. The current review discusses the available information related to the toxicity of the most relevant meat and seafood chemical contaminants, their bioaccessibility after cooking or processing, and the implications for human health. In addition, the current in vivo toxicity and alternative tests carried out for testing the effects of food chemical contaminants are illustrated, as well as new detection tools. The use of non-carcinogenic functional cell models, of alternative animal models like zebrafish embryos, and a toxicogenomic approach seem to be the most promising strategy for the toxicity assessment of food chemical contaminants.     

In vitro digestion and DGT techniques for estimating cadmium and lead bioavailability in contaminated soils: influence of gastric juice pH

A sensitivity analysis was conducted on an in vitro gastrointestinal digestion test (i) to investigate the influence of a low variation of gastric juice pH on the bioaccessibility of Cd and Pb in smelter-contaminated soils (F_B, using the unified bioaccessibility method UBM) and fractions of metals that may be transported across the intestinal epithelium (F_A, using the diffusive gradient in thin film technique), and (ii) to provide a better understanding of the significance of pH in health risk assessment through ingestion of soil by children. The risk of metal exposure to children (hazard quotient, HQ) was determined for conditions that represent a worst-case scenario (i.e., ingestion rate of 200 mg day^− 1) using three separate calculations of metal daily intake: estimated daily intake (EDI), bioaccessible EDI (EDI-F_B), and oral bioavailable EDI (EDI-F_A). The increasing pH from 1.2 to 1.7 resulted in: (i) no significant variation in Cd-F_B in the gastric phase but a decrease in the gastrointestinal phase; (ii) a decrease in soluble Pb in the gastric phase and a significant variation in Pb-F_B in the gastrointestinal phase; (iii) a significant decrease in Cd-F_A and no variation in Pb-F_A; (iv) no change in EDI-F_B and EDI-F_A HQs for Cd; (v) a significant decrease in EDI-F_B HQs and no significant variation in EDI-F_A HQ for Pb. In the analytical conditions, these results show that risk to children decreases when the bioavailability of Pb in soils is taken into account and that the studied pH values do not affect the EDI-F_A HQs. The present results provide evidence that the inclusion of bioavailability analysis during health risk assessment could provide a more realistic estimate of Cd and Pb exposure, and opens a wide field of practical research on this topic (e.g., in contaminated site management).     

纳米乳液改善多酚性能及在食品中的应用进展

国内外研究人员一直关注植物多酚促进人体健康的潜在作用,发现在实际应用中,多酚的稳定性差、溶解性差、生物利用率低等问题亟待解决。纳米乳液递送体系粒径小、稳定性佳,是极佳的多酚递送体系,应用前景广阔。经纳米乳液包埋后的多酚可改善稳定性,提高在体内的生物利用率,表现出更佳的生物可及性、抗氧化性及抗肿瘤活性,更适合应用于食品工业。该研究结合国内外研究者的成果综述了多酚的分类及作用;多酚纳米乳液制备新技术;纳米乳包载对多酚多种性能的改善效果与作用机制。基于多酚纳米乳液需解决的首要问题提出了乳液优化方案,并阐述了多酚纳米乳液在食品工业中的现状及潜在应用,对多酚纳米乳液未来的制备方向进行展望。