Kumari Manorama, Kumari Rolly, Nataraj Basavaprabhu Haranahalli, Shelke Prashant Ashok, Ali Syed Azmal, Nagpal Ravinder, Behare Pradip V
Technofunctional Starter Lab, National Collection of Dairy Cultures (NCDC), Dairy Microbiology Division, National Dairy Research Institute, Karnal, 132001, Haryana, India.
Dairy Technology Division, National Dairy Research Institute, Karnal, 132001, Haryana, India.
Curr Res Food Sci. 2023 Mar 6;6:100478. doi: 10.1016/j.crfs.2023.100478. eCollection 2023.
Iron is a micronutrient essential for human health and physiology. Iron-deficiency anemia, the most common form of anemia, may occur from an iron homeostasis imbalance. Iron fortification is a promising and most sustainable and affordable solution to tackle the global prevalence of this anemia. Herein, we investigate physicochemical, rheological and stability characteristics of a novel exopolysaccharide 'EPSKar1' (derived from strain Kar1) and its iron complex 'EPSKar1-Fe (II)'. Our findings demonstrate that EPSKar1 is a high molecular-weight (7.8 × 10 Da) branched-chain heteropolysaccharide composed of galactose, N-acetylglucosamine, and mannose in a molar ratio of 8:4:1, respectively, and exhibits strong emulsifying and water-holding capacities. We find that EPSKar1 forms strong complexes with Fe, wherein the interactions between EPSKar1-Fe (II) complexes are mediated by sulfate, carboxyl, and hydroxyl groups. The rheological analyses reveal that the EPSKar1 and EPSKar1-Fe (II) complexes exhibited shear thickening and thinning properties in skim milk and water, respectively; however, the suspension of EPSKar1 in skim milk is viscoelastic with predominantly elastic response (G'>G" and tan δ < 1). In comparison, EPSKar1-Fe (II) complex exhibits remarkable stability under various processing conditions, highlighting its usefulness for the development of fortified dairy products. Together, these findings underpin considerable prospects of EPSKar1-Fe (II) complex as a novel iron-fortifier possessing multifarious rheological benefits for food applications.
铁是人体健康和生理所必需的微量营养素。缺铁性贫血是最常见的贫血形式，可能由铁稳态失衡引起。铁强化是解决全球这种贫血症流行问题的一种有前景且最具可持续性和成本效益的解决方案。在此，我们研究了一种新型胞外多糖“EPSKar1”（源自菌株Kar1）及其铁络合物“EPSKar1-Fe(II)”的物理化学、流变学和稳定性特征。我们的研究结果表明，EPSKar1是一种高分子量（7.8×10 Da）的支链杂多糖，分别由半乳糖、N-乙酰葡糖胺和甘露糖以摩尔比8:4:1组成，并具有很强的乳化和持水能力。我们发现EPSKar1与铁形成强络合物，其中EPSKar1-Fe(II)络合物之间的相互作用由硫酸根、羧基和羟基介导。流变学分析表明，EPSKar1和EPSKar1-Fe(II)络合物在脱脂牛奶和水中分别表现出剪切增稠和剪切变稀特性；然而，EPSKar1在脱脂牛奶中的悬浮液具有粘弹性，主要表现为弹性响应（G'>G"且tanδ<1）。相比之下，EPSKar1-Fe(II)络合物在各种加工条件下表现出显著的稳定性，突出了其在强化乳制品开发中的实用性。总之，这些发现为EPSKar1-Fe(II)络合物作为一种新型铁强化剂在食品应用中具有多种流变学益处奠定了可观的前景。
