Preparation of ACE-inhibitory peptides from milk protein in continuous enzyme membrane reactor with gradient dilution feeding substrate

Exploring novel ANGICon-EIPs through ameliorated peptidomics techniques: Can deep learning strategies as a core breakthrough in peptide structure and function prediction?

Dairy-derived angiotensin-I-converting enzyme inhibitory peptides (ANGICon-EIPs) have been regarded as a relatively safe supplementary diet-therapy strategy for individuals with hypertension, and short-chain peptides may have more relevant antihypertensive benefits due to their direct intestinal absorption. Our previous explorations have confirmed that endogenous goat milk short-chain peptides are also an essential source of ANGICon-EIPs. Nonetheless, there are limited explorations on endogenous ANGICon-EIPs owing to the limitations of the extraction and enrichment of endogenous peptides, currently. This review outlined ameliorated pre-treatment strategies, data acquisition methods, and tools for the prediction of peptide structure and function, aiming to provide creative ideas for discovering novel ANGICon-EIPs. Currently, deep learning-based peptide structure and function prediction algorithms have achieved significant advancements. The convolutional neural network (CNN) and peptide sequence-based multi-label deep learning approach for determining the multi-functionalities of bioactive peptides (MLBP) can predict multiple peptide functions with absolute true value and accuracy of 0.699 and 0.708, respectively. Utilizing peptide sequence input, torsion angles, and inter-residue distance to train neural networks, APPTEST predicted the average backbone root mean square deviation (RMSD) value of peptide (5-40 aa) structures as low as 1.96 Å. Overall, with the exploration of more neural network architectures, deep learning could be considered a critical research tool to reduce the cost and improve the efficiency of identifying novel endogenous ANGICon-EIPs.

Continuous production of velvet bean-based bioactive peptides in membrane reactor with dual enzyme system

One of the main challenges hindering the commercialization of bioactive peptides is the lack of scalable and consistent production methods. To overcome this obstacle, an automated enzyme membrane reactor was used to continuously produce bioactive peptides from velvet bean (Mucuna pruriens). The optimum operating conditions were [E]/[S] = 5%, pH = 7.5, and τ = 12 h. The long-term continuous operation of the EMR system demonstrated its ability to maintain steady-state conditions. To minimize membrane fouling, an industrially viable strategy was employed, which combines operation at threshold flux and performing regular membrane cleaning. Further fractionation of the hydrolysates with a 2-kDa PES membrane resulted in the highest bioactivity. The IC₅₀ values for antioxidant and ACE inhibition were 17.85 and 4.58 µg protein/mL, respectively. To map the overall bioactivities of the hydrolysates, LC-MS analysis coupled with BIOPEP-UWM database was performed and obtained DPP-4 and ACE inhibitors as the predominant bioactive activities.

Cardioprotective Peptides from Milk Processing and Dairy Products: From Bioactivity to Final Products including Commercialization and Legislation

Recent research has revealed the potential of peptides derived from dairy products preventing cardiovascular disorders, one of the main causes of death worldwide. This review provides an overview of the main cardioprotective effects (assayed in vitro, in vivo, and ex vivo) of bioactive peptides derived from different dairy processing methods (fermentation and enzymatic hydrolysis) and dairy products (yogurt, cheese, and kefir), as well as the beneficial or detrimental effects of the process of gastrointestinal digestion following oral consumption on the biological activities of dairy-derived peptides. The main literature available on the structure–function relationship of dairy bioactive peptides, such as molecular docking and quantitative structure–activity relationships, and their allergenicity and toxicity will also be covered together with the main legislative frameworks governing the commercialization of these compounds. The current products and companies currently commercializing their products as a source of bioactive peptides will also be summarized, emphasizing the main challenges and opportunities for the industrial exploitation of dairy bioactive peptides in the market of functional food and nutraceuticals.

Bioconjugation Strategy for Ceramic Membranes Decorated with Candida Antarctica Lipase B-Impact of Immobilization Process on Material Features

A strategy for the bioconjugation of the enzyme Candida antarctica lipase B onto titania ceramic membranes with varied pore sizes (15, 50, 150, and 300 kDa) was successfully performed. The relationship between the membrane morphology, i.e.,the pore size of the ceramic support, and bioconjugation performance was considered. Owing to the dimension of the enzyme (~33 kDa), the morphology of the ceramics allowed (50, 150, and 300 kDa) or did not allow (15 kDa) the entrance of the enzyme molecules into the porous structure. Such a strategy made it possible to better understand the changes in the material (morphology) and physicochemical features (wettability, adhesiveness, and surface charge) of the samples, which were systematically examined. The silane functionalization and enzyme immobilization were accomplished via the covalent route. The samples were characterized after each stage of the modification, which was very informative from the material point of view. As a consequence of the modification, significant changes in the contact angle, roughness, adhesion, and zeta potential were observed. For instance, for the 50 kDa membrane, the contact angle increased from 29.1 ± 1.5° for the pristine sample to 72.3 ± 1.5° after silane attachment; subsequently, it was reduced to 57.2 ± 1.5° after the enzyme immobilization. Finally, the contact angle of the bioconjugated membrane used in the enzymatic process rose to 92.9 ± 1.5°. By roughness (S_q) controlling, the following amendments were noticed: for the pristine 50 kDa membrane, S_q = 1.87 ± 0.21 µm; after silanization, S_q = 2.33 ± 0.30 µm; after enzyme immobilization, S_q = 2.74 ± 0.26 µm; and eventually, after the enzymatic process, S_q = 2.37 ± 0.27 µm. The adhesion work of the 50 kDa samples was equal to 136.41 ± 2.20 mN m⁻¹ (pristine membrane), 94.93 ± 2.00 mN m⁻¹ (with silane), 112.24 ± 1.90 mN m⁻¹ (with silane and enzyme), and finally, 69.12 ± 1.40 mN m⁻¹ (after the enzymatic process). The materials and physicochemical features changed substantially, particularly after the application of the membrane in the enzymatic process. Moreover, the impact of ceramic material morphology on the zeta potential value is here presented for the first time. With an increase in the ceramic support cut-off, the amount of immobilized lipase rose, but the specific productivity was higher for membranes possessing smaller pores, owing to the higher grafting density. For the enzymatic process, two modes of accomplishment were selected, i.e., stirred-tank and cross-flow. The latter method was characterized by a much higher effectiveness, with a resulting productivity equal to 99.7 and 60.3 µmol h⁻¹ for the 300 and 15 kD membranes, respectively.

Continuous hydrolysis of milk proteins in membrane reactors of various configurations

Introduction. The article provides a review of technologies for membrane fractionation of various hydrolyzed food substrates in membrane bioreactors (MBR). In food industry, MBRs are popular in functional food production, especially in the processing of whey, which is a very promising raw material due to its physicochemical composition. Study objects and methods. The research was based on a direct validated analysis of scientific publications and featured domestic and foreign experience in MBR hydrolysis of protein raw material. Results and discussion. The MBR hydrolysis of proteins combines various biocatalytic and membrane processes. This technology makes it possible to intensify the biocatalysis, optimize the use of the enzyme preparation, and regulate the molecular composition of hydrolysis products. The paper reviews MBRs based on batch or continuous stirring, gradient dilution, ceramic capillary, immobilized enzyme, etc. Immobilized enzymes reduce losses that occur during the production of fractionated peptides. Continuous MBRs are the most economically profitable type, as they are based on the difference in molecular weight between the enzyme and the hydrolysis products. Conclusion. Continuous stirred tank membrane reactors have obvious advantages over other whey processing reactors. They provide prompt separation of hydrolysates with the required biological activity and make it possible to reuse enzymes.

Membrane Fractionation of Protein Hydrolysates from By-Products: Recovery of Valuable Compounds from Spent Yeasts

Spent brewer’s yeast (Saccharomyces sp.), the second most generated by-product from the brewing industry, contains bioactive and nutritional compounds with high added value such as proteins (40–50%), polysaccharides, fibers and vitamins. Molecules of interest from agro-industrial by-products need to be extracted, separated, concentrated, and/or purified so that a minimum purity level is achieved, allowing its application. Enzymatic hydrolysis has been successfully used in the production of peptides and protein hydrolysates. The obtained hydrolysates require efficient downstream processes such as membrane technology, which is an important tool for the recovery of thermolabile and sensitive compounds from complex mixtures, with low energy consumption and high specificity. The integration of membrane techniques that promote the separation through sieving and charge-based mechanisms is of great interest to improve the purity of the recovered fractions. This review is specifically addressed to the application of membrane technologies for the recovery of peptides from yeast protein hydrolysates. Fundamental concepts and practical aspects relative to the ultrafiltration of agro-industrial protein hydrolysates will be described. Challenges and perspectives involving the recovery of peptides from yeast protein hydrolysates will be presented and thoroughly discussed.