Preparation, Characterization, and Mechanism of Antifreeze Peptides from Defatted Antarctic Krill ( Euphausia superba ) on Lactobacillus rhamnosus

Defatted Antarctic krill powder is the main by-product in the manufacturing of krill oil. Exploring a high value-added approach for utilizing this protein-rich material has received much attention in research and industry. Given this, the preparation and primary characterization of antifreeze peptid...

Full description

Bibliographic Details
Published in:Molecules
Main Authors: Yu Liu, Xuena Yu, Yanling Zhu, Wei Yang, Yan Zeng, Yi Hu, Wei Jiang
Format: Article in Journal/Newspaper
Language:English
Published: MDPI AG 2022
Subjects:
antifreeze peptide
Antarctic krill
by-products
cryoprotectant
Lactobacillus rhamnosus
freezing
Organic chemistry
QD241-441
Antarctic
Antarc*
Antarctic Krill
Euphausia superba
Online Access:https://doi.org/10.3390/molecules27092771
https://doaj.org/article/943edbb5079246babe4847b7a0f435d5
Description
Summary:Defatted Antarctic krill powder is the main by-product in the manufacturing of krill oil. Exploring a high value-added approach for utilizing this protein-rich material has received much attention in research and industry. Given this, the preparation and primary characterization of antifreeze peptides from defatted Antarctic krill (AKAPs) were carried out in this study. The cryoprotective effect of AKAPs on Lactobacillus rhamnosus ATCC7469 was also investigated. The results showed that Protamex was the optimum protease for AKAP preparation from defatted Antarctic krill. AKAPs were found to be rich in short peptides, with the MW ranging from 600 to 2000 Da (69.2%). An amino acid composition analysis showed that AKAPs were rich in glutamic acid (18.71%), aspartic acid (12.19%), leucine (7.87%), and lysine (7.61%). After freezing, the relative survival rate of Lactobacillus rhamnosus in the 1.0 mg/mL AKAP-treated group (96.83%) was significantly higher than in the saline group (24.12%) ( p < 0.05). AKAPs also retarded the loss of acidifying activity of L. rhamnosus after freezing. AKAPs showed even better cryoprotective activity than three commercial cryoprotectants (sucrose, skim milk, and glycerol). In addition, AKAPs significantly alleviated the decrease in β -galactosidase and lactic dehydrogenase activities of L. rhamnosus ( p < 0.05). Furthermore, AKAPs effectively protected the integrity of L. rhamnosus cell membranes from freezing damage and alleviated the leakage of intracellular substances. These findings demonstrate that AKAPs can be a potential cryoprotectant for preserving L. rhamnosus , providing a new way to use defatted Antarctic krill.

Similar Items