Encapsulation and Assessment of Antidiabetic Potential of α-Lactalbumin-Derived Hydrolysates.

Dipeptidyl peptidase-IV (DPP-IV) is an exopeptidase mainly present in epithelial tissues of the liver, kidney, and intestine. It is involved in the cleavage of a variety of substrates including the incretin hormones like glucagon-like peptide-1 (GLP-1). GLP-1 binds to the GLP-1 receptors of pancreatic ß-cells and leads to ß-cell proliferation and increases insulin secretion through associated gene expression. In diabetes, a constant increase in the glucose level leads to glucotoxicity, which destroys pancreatic ß-cells, decreases the insulin level, and further increases the blood glucose level. Inhibition of DPP-IV is one of the strategies for the treatment of type 2 diabetes. In recent years, peptides derived from a variety of dietary proteins have been reported to exhibit inhibitory activity against the DPP-IV enzyme. Such peptides should also be protected from the action of digestive enzymes to keep their bioactivity intact. Therefore, the present investigation was aimed to evaluate the in vitro DPP-IV inhibition potential and in vivo antidiabetic potential of α-lactalbumin in non-encapsulated hydrolysate (NEH), freeze-dried encapsulated hydrolysate (FDEH), and emulsified encapsulated hydrolysate (EEH) forms. Percent DPP-IV inhibition by the NEH, FDEH, and EEH after simulated gastrointestinal digestion was 36 ± 2.28, 54 ± 2.02, and 64 ± 2.02, respectively. The oral administration of the NEH, FDEH, and EEH at a dose of 300 mg/kg body weight was evaluated in nicotinamide-streptozotocin-induced type 2 diabetic experimental rats in a study of 30 days. Rats in the diabetic control group showed an increase in the blood glucose level and liver function enzymes and a decrease in GLP-1, insulin, and antioxidative enzymes. Administration of hydrolysates reversed the parameters by lowering the blood glucose level and increasing GLP-1 and insulin levels in plasma. The blood lipid profile, liver enzyme (ALT, AST, and AP) levels, and catalase and superoxide dismutase activity were also found to be normalized and better managed in experimental diabetic rats.

Physicochemical and rheological characterizations of a novel exopolysaccharide EPSKar1 and its iron complex EPSKar1-Fe: Towards potential iron-fortification applications.

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 Lacticaseibacillus rhamnosus strain Kar1) and its iron complex 'EPSKar1-Fe (II)'. Our findings demonstrate that EPSKar1 is a high molecular-weight (7.8 × 105 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 Î´ < 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.