Identification of zinc-chelating pumpkin seed (Cucurbita pepo L.) peptides and in vitro transport of peptide-zinc chelates

Zn2+ chelating peptide GFLGSP: Characterization of structure/Zn2+ chelating mode and the potential mechanisms for promoting Zn2+ transport in Caco-2 cells

This study focused on exploring the Zn2+ chelating peptide GFLGSP: the characterization of structure/Zn2+ chelating mode and the potential mechanisms for promoting Zn2+ transport in Caco-2 cells. The findings revealed the bidentate chelating between Zn2+ and carboxyl oxygen atom in Pro6 residue. Thereafter, the secondary structure of GFLGSP remained unchanged, but there was an increase in zeta potential and particle size. Notably, the GFLGSP-Zn2+ complex enhanced the Zn2+ transport rate and modulated ZIP4 and ZNT1 expression in a Caco-2 cells monolayer model. As revealed by molecular docking analysis, GFLGSP interacted with ZIP4 through intermolecular hydrogen bonds as well as Van der Waals forces. The Zn2+ transport mechanisms of the GFLGSP-Zn2+ complex encompassed ZIP4 (vital channel), endocytosis (primary pathway) and paracellular transport (supplementary pathway). Based on these results, the tilapia skin collagen-derived GFLGSP hold promise as the potential dietary Zn2+ supplement.

Effect of baking on the structure and bioavailability of protein-binding zinc from oyster (Crassoetrea hongkongensis)

To compare the bioavailability of protein-binding zinc, we investigated the impact of baking on the structure of zinc-binding proteins. The results showed that zinc-binding proteins enriched in zinc with relative molecular weights distributed at 6 kDa and 3 kDa. Protein-binding zinc is predisposed to separate from proteins' interiors and converge on proteins' surface after being baked, and its structure tends to be crystalline. Especially -COO, -C-O, and -C-N played vital roles in the sites of zinc-binding proteins. However, baking did not affect protein-binding zinc's bioavailability which was superior to that of ZnSO4 and C12H22O14Zn. They were digested in the intestine, zinc-binding complexes that were easily transported and uptaken by Caco-2 cells, with transport and uptake rates as high as 62.15% and 15.85%. Consequently, baking can alter the conformation of zinc-binding proteins without any impact on protein-binding zinc's bioavailability which is superior to that of ZnSO4 and C12H22O14Zn.

Dietary zinc supplements: beneficial health effects and application in food, medicine and animals

Zinc, a crucial trace element is vital for the growth and development of humans. It is frequently described as 'the flower of life' and 'the source of intelligence'. Zinc supplements play a pivotal role in addressing zinc deficiency by serving as a vital source of this essential micronutrients, effectively replenishing depleted zinc levels in the body. In this paper, we first described the biological behavior of zinc in the human body and briefly described the physiological phenomena associated with zinc levels. The benefits and drawbacks of various zinc supplement forms are then discussed, with emphasis on the most recent zinc supplement formulations. Finally, the application of zinc supplements in food, medicine, and animal husbandry is further summarized. © 2024 Society of Chemical Industry.

Mineral-element-chelating activity of food-derived peptides: influencing factors and enhancement strategies

Mineral elements including calcium, iron, and zinc play crucial roles in human health. Their deficiency causes public health risk globally. Commercial mineral supplements have limitations; therefore, alternatives with better solubility, bioavailability, and safety are needed. Chelates of food-derived peptides and mineral elements exhibit advantages in terms of stability, absorption rate, and safety. However, low binding efficiency limits their application. Extensive studies have focused on understanding and enhancing the chelating activity of food-derived peptides with mineral elements. This includes obtaining peptides with high chelating activity, elucidating interaction mechanisms, optimizing chelation conditions, and developing techniques to enhance the chelating activity. This review provides a comprehensive theoretical basis for the development and utilization of food-derived peptide-mineral element chelates in the food industry. Efforts to address the challenge of low binding rates between peptides and mineral elements have yielded promising results. Optimization of peptide sources, enzymatic hydrolysis processes, and purification schemes have helped in obtaining peptides with high chelating activity. The understanding of interaction mechanisms has been enhanced through advanced separation techniques and molecular simulation calculations. Optimizing chelation process conditions, including pH and temperature, can help in achieving high binding rates. Methods including phosphorylation modification and ultrasonic treatment can enhance the chelating activity.

The Molecular Basis for Zinc Bioavailability

Zinc is an essential micronutrient, and its deficiency is perhaps the most prevalent and least understood worldwide. Recent advances have expanded the understanding of zinc’s unique chemistry and molecular roles in a vast array of critical functions. However, beyond the concept of zinc absorption, few studies have explored the molecular basis of zinc bioavailability that determines the proportion of dietary zinc utilized in zinc-dependent processes in the body. The purpose of this review is to merge the concepts of zinc molecular biology and bioavailability with a focus on the molecular determinants of zinc luminal availability, absorption, transport, and utilization.

Utilization of pumpkin, pumpkin powders, extracts, isolates, purified bioactives and pumpkin based functional food products: A key strategy to improve health in current post COVID 19 period: An updated review

Progression of today's world has been given setback due to the adversity of a novel, viral and deadly outbreak COVID 19, which raised the concerns of the scientists, researchers and health related officials about the inherent and adaptive immune system of the living body and its relation with healthy diet balanced with pharma foods. Choice of right food can help to build and boost adaptive immunity and pumpkin due to excellent profile of functional and nutraceutical constituents must be the part of both infected and non-infected person's daily diet. Vitamins, minerals, phenolic acids, essential oils, peptides, carotenoids and polysaccharides present in pumpkin could accommodate the prevailing deficiencies in the body to fought against the pathogens. Pumpkins are well equipped with nutraceuticals and functional ingredients therefore, consumption and processing of this remarkable fruit must be encouraged as pharma food due to its antihyperlipidemic, antiviral, anti-inflammatory, antihyperglycemic, immunomodulatory, antihypertensive, antimicrobial and antioxidant potential, and these pharmacological properties of pumpkin are directly or indirectly related to the COVID 19 outbreak. Utilization of pumpkin has a domain in the form of powders, extracts, isolates, and pumpkin incorporated food products. A wide range of healthy, nutritious and functional food products has been developed from pumpkin, which includes juice, soup, porridge, chips, biscuits, bread, cake, bar and noodles. In recent times some innovative and novel technologies have been applied to process and preserve pumpkin for its enhanced shelf life and bioaccessibility of nutrients. Need of healthy eating in current post COVID 19 period is very crucial for healthy population, and medicinal foods like pumpkin, and bioactive compounds present in this functional food could play a vital role in developing a healthy community around the globe.