Incorporation of spray-dried encapsulated bioactive peptides from coconut (Cocos nucifera L.) meal by-product in bread formulation.

This study aimed to stabilize and mask the bitterness of peptides obtained from the enzymatic hydrolysis of coconut-meal protein with maltodextrin (MD) and maltodextrin-pectin (MD-P) as carriers via spray-drying. Essential (~35%), hydrophobic (~32%), antioxidant (~15%), and bitter (~45%) amino acids comprised a significant fraction of the peptide composition (with a degree of hydrolysis of 33%). The results indicated that the peptide's production efficiency, physical and functional properties, and hygroscopicity improved after spray-drying. Morphological features of free peptides (fragile and porous structures), spray-dried with MD (wrinkled with indented structures), and MD-P combination (relatively spherical particles with smooth surfaces) were influenced by the process type and feed composition. Adding free and microencapsulated peptides to the bread formula (2% W/W) caused changes in moisture content (35%-43%), water activity (0.89-0.94), textural properties (1-1.6 N), specific volume (5.5-6 cm3/g), porosity (18%-27%), and color indices of the fortified product. MD-P encapsulated peptides in bread fortification resulted in thermal stability and increased antioxidant activity (DPPH and ABTS+ radical scavenging: 4.5%-39.4% and 31.6%-46.8%, respectively). MD-P (as a carrier) could maintain sensory characteristics and mask the bitterness of peptides in the fortified bread. The results of this research can be used to produce functional food and diet formulations.

Nutritional, biological, and structural properties of bioactive peptides from bellflower, Persian-willow, and bitter-orange pollens.

In this study, the composition of amino acids, nutritional characteristics, degree of hydrolysis (DH), antioxidant properties, and antibacterial activity of proteins and hydrolysates of bellflower (Campanula latifolia), Persian willow (Salix aegyptiaca), and bitter orange (Citrus aurantium L.) were investigated under the influence of different proteases (Alcalase: Al, trypsin: Tr, pancreatin: Pa, and pepsin: Pe). Evaluation of the structural features of the proteins showed amide regions (amide A, B, I-III) and secondary structures. Hydrophobic amino acids (∼38%), antioxidants (∼21%), and essential types (∼46%) form a significant part of the structure of flower pollen. The digestibility and nutritional quality (PER) of the hydrolyzed samples (CP: 1.67; CA: 1.89, and PW: 1.93) were more than the original protein. Among proteins and peptides, the highest degree of hydrolysis (34.6%: Al-PWH), inhibition of free radicals DPPH (84.2%: Al-CPH), ABTS (95.2%: Pa-CPH), OH (86.7%: Tr-CAH), NO (57.8%: Al-CPH), reducing power (1.31: Pa-CPH), total antioxidant activity (1.46: Pa-CPH), and chelation of iron ions (80%: Al-CPH and Al-CAH) and copper (50.3%: Pa-CAH) were affected by protein type, enzyme type, and amino acid composition. Also, the highest inhibition of the growth of Escherichia coli (25 mm) and Bacillus cereus (24 mm) were related to CP and PW hydrolysates, respectively. The results of this research showed that hydrolyzed flower pollens can be used as a rich source of essential amino acids as well as natural antioxidants and antibacterial in food and dietary products. PRACTICAL APPLICATION: Enzymatic hydrolysis of Campanula latifolia, Persian willow, and Citrus aurantium pollen proteins was performed. The hydrolyzed ones had high nutritional quality and digestibility (essential amino acids and PER index). Antioxidant properties and chelation of metal ions of peptides were affected by the type of protein and enzyme. The hydrolysates showed inhibitory activity against the growth of Esherichia coli and Bacillus cereus.