Membrane separation processes for enrichment of bovine and caprine milk oligosaccharides from dairy byproducts

Human Milk Oligosaccharides: Decoding Their Structural Variability, Health Benefits, and the Evolution of Infant Nutrition

Human milk oligosaccharides (HMOs), the third most abundant solid component in human milk, vary significantly among women due to factors such as secretor status, race, geography, season, maternal nutrition and weight, gestational age, and delivery method. In recent studies, HMOs have been shown to have a variety of functional roles in the development of infants. Because HMOs are not digested by infants, they act as metabolic substrates for certain bacteria, helping to establish the infant's gut microbiota. By encouraging the growth of advantageous intestinal bacteria, these sugars function as prebiotics and produce short-chain fatty acids (SCFAs), which are essential for gut health. HMOs can also specifically reduce harmful microbes and viruses binding to the gut epithelium, preventing illness. HMO addition to infant formula is safe and promotes healthy development, infection prevention, and microbiota. Current infant formulas frequently contain oligosaccharides (OSs) that differ structurally from those found in human milk, making it unlikely that they would reproduce the unique effects of HMOs. However, there is a growing trend in producing OSs resembling HMOs, but limited data make it unclear whether HMOs offer additional therapeutic benefits compared to non-human OSs. Better knowledge of how the human mammary gland synthesizes HMOs could direct the development of technologies that yield a broad variety of complex HMOs with OS compositions that closely mimic human milk. This review explores HMOs' complex nature and vital role in infant health, examining maternal variation in HMO composition and its contributing factors. It highlights recent technological advances enabling large-scale studies on HMO composition and its effects on infant health. Furthermore, HMOs' multifunctional roles in biological processes such as infection prevention, brain development, and gut microbiota and immune response regulation are investigated. The structural distinctions between HMOs and other mammalian OSs in infant formulas are discussed, with a focus on the trend toward producing more precise replicas of HMOs found in human milk.

Is it possible to obtain substitutes for human milk oligosaccharides from bovine milk, goat milk, or other mammal milks?

Considering the current level of chemical and biological synthesis technology, it was a sensible selection to obtain milk oligosaccharides (MOs) from other mammals as the potential substitute for human MOs (HMOs) that possessed various structural features in the infant formula. Through a comprehensive analysis of the content, structure, and function of MOs in six distinct varieties of mammal milk, it has been shown that goat milk was the most suitable material for the preparation as a human milk substitute. Goat MOs (GMOs) had a relatively high content and diverse structural features compared to those found in other mammalian milks. The concentration of GMOs in colostrum ranged from 60 to 350 mg/L, whereas in mature milk, it ranged from 200 to 24,00 mg/L. The acidic oligosaccharides in goat milk have attracted considerable attention due to their closeness in acidic content and structural diversity with HMOs. Simultaneously, it was discovered that some structures, like N-glycolylneuraminic acid, were found to have a certain content in GMOs and served essential functional properties. Moreover, studies focused on the extraction of MOs from goat milk indicated that the production of GMOs on an industrial scale was viable. Furthermore, it is imperative to do further study on GMOs to enhance the preparation process, discover of new MOs structures and bioactivity evaluation, which will contribute to the development of both the commercial production of MOs and the goat milk industry.

Qualitative and Quantitative Changes of Oligosaccharides in Human and Animal Milk over Lactation

The aim of this study was to investigate the changes in human and animal milk oligosaccharides over lactation. In total, 89, 97, 115, and 71 oligosaccharides were identified in human, bovine, goat, and camel milk. The number of common oligosaccharides between camel and human milk was the highest (16 and 17 in transitional and mature milk). With respect to the absolute concentration of eight oligosaccharides (2'-FL, 3-FL, α3'-GL, LNT, LNnT, 3'-SL, 6'-SL, and DSL), 2'-FL, 3'-FL, LNT, and LNnT were much higher in human than three animal species. 3'-SL had a similar concentration in bovine colostrum (322.2 μg/mL) and human colostrum (321.0 μg/mL), followed by goat colostrum (105.1 μg/mL); however, it had the highest concentration in camel mature milk (304.5 μg/mL). The ratio of 6'-SL and 3'-SL (1.77) in goat colostrum was similar to that in human colostrum (1.68), followed by bovine colostrum (0.13). In terms of changes of eight oligosaccharides over lactation, they all decreased with the increase of lactation in bovine and goat milk; however, α3'-GL, 2'-FL, and 3-FL increased in camel species, and LNT increased first and then decreased over lactation in human milk. This study provides a better understanding of the variation of milk oligosaccharides related to lactation and species.

Analyzing the phenolic enriched fractions from Nixtamalization wastewater (Nejayote) fractionated in a three-step membrane process

Nejayote is recognized as the main by-product resulting from the nixtamalization process of maize kernels, which is categorized as an alkaline residue with a chemical composition based on carbohydrates (37.8-55.7%), fiber (22.8-25.5%), protein (4.9-7.4%), and lipids (0.4-1.5%). In addition, Nejayote has an extensive content of simple (e.g., phenolic acids) and complex phenolic compounds (e.g., anthocyanins), which are responsible for the pigmentation and antioxidant activity of maize; therefore, there is a need of their identification depending on the type of maize. The current research has focused on the efficient extraction and identification of the phenolic acids contained in Nejayote after the processing of different types of maize. The target of this work was to fractionate Nejayote from white (NWM), red (NRM), and purple maize (NPM), using three different membranes, such as microfiltration (MF with a pore size of 1 μm) and ultrafiltration (UF100 and UF1 with a molecular weight cut-off of 100 kDa and 1 kDa, respectively), which were strategically applied to extract phenolic acids while retaining other molecules. Such a membrane system exhibited a retention in the first stage of almost all carbohydrates (MF-Retentate: ca. 12-19 g GE/L), while second stage (UF100-Permeate) a concentration of phenolic components was recovered ranging from 768 to 800 mg GAE/L. Finally, in the third stage (UF1-Permeate), 14 phenolic acids were identified, including ferulic and p-coumaric acids, derived from caffeic and ferulic acids, along with other molecules (e.g., glucose and fructose).

A Review on Ion-Exchange Membranes Fouling during Electrodialysis Process in Food Industry, Part 2: Influence on Transport Properties and Electrochemical Characteristics, Cleaning and Its Consequences

Ion-exchange membranes (IEMs) are increasingly used in dialysis and electrodialysis processes for the extraction, fractionation and concentration of valuable components, as well as reagent-free control of liquid media pH in the food industry. Fouling of IEMs is specific compared to that observed in the case of reverse or direct osmosis, ultrafiltration, microfiltration, and other membrane processes. This specificity is determined by the high concentration of fixed groups in IEMs, as well as by the phenomena inherent only in electromembrane processes, i.e., induced by an electric field. This review analyzes modern scientific publications on the effect of foulants (mainly typical for the dairy, wine and fruit juice industries) on the structural, transport, mass transfer, and electrochemical characteristics of cation-exchange and anion-exchange membranes. The relationship between the nature of the foulant and the structure, physicochemical, transport properties and behavior of ion-exchange membranes in an electric field is analyzed using experimental data (ion exchange capacity, water content, conductivity, diffusion permeability, limiting current density, water splitting, electroconvection, etc.) and modern mathematical models. The implications of traditional chemical cleaning are taken into account in this analysis and modern non-destructive membrane cleaning methods are discussed. Finally, challenges for the near future were identified.