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Animals in agroecosystems
Published in Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz, Agroecology, 2023
Stephen R. Gliessman, V. Ernesto Méndez, Victor M. Izzo, Eric W. Engles, Andrew Gerlicz
All animals have limits to the kinds of macromolecules they can synthesize from organic carbon and nitrogen and other elements. For example, animals can only synthesize about half of the 20 amino acids that they need to make protein. The amino acids that animals cannot synthesize must be obtained from food; these are called the essential amino acids. Most animals require eight amino acids in their diet for proper nutrition. The protein in the food products produced by animals, such as meat, cheese, and eggs, contain all the essential amino acids, and are therefore called “complete” protein. Plant protein usually lacks several of the essential amino acids and therefore is called “incomplete” protein. For example, corn is deficient in tryptophan and lysine, and beans are deficient in methionine. (Putting the two together is a way for a vegetarian diet to obtain all the essential amino acids needed for complete protein nutrition.)
A comprehensive review on stability of therapeutic proteins treated by freeze-drying: induced stresses and stabilization mechanisms involved in processing
Published in Drying Technology, 2022
Zhe Wang, Linlin Li, Guangyue Ren, Xu Duan, Jingfang Guo, Wenchao Liu, Yuan Ang, Lewen Zhu, Xing Ren
Water replacement theory refers to the fact that in the lyophilization process, due to freezing concentration or drying, there maybe not enough water molecules to form sufficient hydrogen bonds with polar protein surfaces, while the hydroxyl groups of some non-reducing sugars (sucrose, trehalose, etc.) can form hydrogen bonds with proteins to meet the hydrogen bonding requirements of polar groups on protein surface.[74] These stabilizers form hydrogen bonds with proteins by replacing water to maintain the natural structure of proteins. Since the amorphous state of proteins and stabilizers allows the maximum hydrogen bond between proteins and stabilizer molecules, the crystallization of an amorphous stabilizer during freeze-drying leads to the phase separation between stabilizers and protein molecules, which leads to low efficiency of hydrogen bond formation and protein instability. This requires that stabilizers must be in the same amorphous phase as proteins.[75] Sugars are bound to the dried protein by hydrogen bonds, replacing the removed water, which can be measured by Fourier transform infrared spectroscopy (FTIR). Ideally, the sugar monolayer formed on the surface of protein molecules by substituting water at all hydrogen bonding sites should be sufficient to replace water to maintain a complete protein structure.[76]
Encapsulation of dairy protein hydrolysates: Recent trends and future prospects
Published in Drying Technology, 2021
Maiara Giroldi, Isabel Marie Grambusch, Daniel Neutzling Lehn, Claucia Fernanda Volken de Souza
Bovine whey proteins, known as whey protein, and casein are the most studied sources of dairy protein hydrolysates.[15–17] Whey protein is a complete protein containing all essential amino acids with high bioavailability,[18] which justifies its wide commercial use,[19] including as a dietary supplement.[20] These supplements are available for consumers as whey protein concentrate (WPC), whey protein isolate (WPI), and whey protein hydrolysate (WPH).[21] Hydrolysates can be prepared from cheese whey or its protein fractions. Cheese whey proteins are obtained using unit operations, such as selective precipitation or membrane filtration systems such as ultra-, nano-, and diafiltration.[22]
Molecularly imprinted hydrogel sensor for proteins
Published in Journal of Dispersion Science and Technology, 2023
This work has analyzed that an actuator with complete protein binding enhanced the system effectiveness, as coordinate covalent bonding developed between BSA and Co. On the other hand, cobalt acetate shows less and weak binding site availability with BSA, as this case referred to intermolecular interactions.[23] We have considered an excellent responsive actuator with a controlled swelling ratio in the biosensor industry for practical applications. The market has a massive demand for micro and macro-level biosensors. With a developed imprinting system, BSA increases its n-terminal site availability, considering this idea in response to hydrogel physical movement.[24,25]