Production of Bovine Equol-Enriched Milk: A Review

Abstract

Milk and dairy products are important sources of nutrients in the human diet because they contain a number of essential substances and other biologically active components. Many of these substances can be modified, and thus offer opportunities to use milk and dairy products as functional food. Isoflavones are particularly important in human nutrition due to their diverse pharmacological and antioxidant properties. The clinical effectiveness of isoflavone-rich products is believed to be dependent on their ability to metabolize daidzein to equol, which may directly exert cancer preventive effects. However, only approximately 30–40% of humans are able to produce equol, while animals, in general, produce equol. Equol is the predominant product of bacterial metabolism of isoflavones and can be found in various amounts in some food of animal origin, especially in milk. Therefore, milk and dairy products can be considered to be sources of equol for humans who are not able to produce this metabolite. When the content of isoflavones in milk is to be modified, two groups of factors should be considered, i.e., dietary factors that include the source of isoflavones and the processing effects on feedstuffs and animal factors that include the intake of isoflavones, ruminal and postruminal changes, and the health and physiological status of animals. The approximate content of isoflavones in milk can be predicted using carry-over rates for different dietary sources or using a formula that describes the relationship between equol concentration in milk and formononetin intake. Processing and storage can affect the content and profile of isoflavones in milk and dairy products.

Advances in the Metabolic Mechanism and Functional Characteristics of Equol

“…Daidzein and genistein were the most abundant among the free glycosides. The bound glycosides are formed by three free aglycones linked with glucose, malonyl glucose, and acetyl glucose via β -glycosidic bond [ 14 ]. Natural soy isoflavone mainly exists in the form of non-bioactive glycosidic bonds, accounting for about 97–98%, and can be absorbed only when it is decomposed into free aglycones by β -glucosidase.…”

Water Stress Influences Phytoestrogen Levels in Red Clover (Trifolium pratense) but Not Kura Clover (T. ambiguum)

“…12,13 Additionally, human exposure to phytoestrogens can occur through consumption of plant products containing these phenolic compounds as well as through milk produced by ruminants fed diets rich in phytoestrogens. 14,15 Hence, there is a growing interest in understanding the factors that modulate the concentrations of phytoestrogens in plants fed to dairy animals and other livestock or consumed directly by humans. 10 Phytoestrogens are thought to play a role in plant defense, serving to protect plants from environmental stress as well as perform roles in plant−microbe signaling and a range of other physiological functions.…”

“…Despite its many benefits to agriculture, red clover is also a potentially significant source of phytoestrogens, especially the isoflavones formononetin, biochanin A, and others. , Phytoestrogens are a group of plant-produced secondary metabolites that are structurally and functionally similar to the mammalian sex hormone estrogen . When livestock ingest substantial quantities of forages that are high in phytoestrogens, their reproductive health can be impacted in a variety of ways. , Additionally, human exposure to phytoestrogens can occur through consumption of plant products containing these phenolic compounds as well as through milk produced by ruminants fed diets rich in phytoestrogens. , Hence, there is a growing interest in understanding the factors that modulate the concentrations of phytoestrogens in plants fed to dairy animals and other livestock or consumed directly by humans …”

Supplementation with antioxidants and phenolic compounds in ruminant feeding and its effect on dairy products: a systematic review

“…The enrichment of ruminant diets with agro-industrial by-products (for example, citrus pulp, grape pomace and pulp, molasses and olive leaves) that are rich in bioactive compounds such as polyphenols has been demonstrated to improve the nutritional and chemical composition of milk and dairy products (Křížová et al ., 2021). Dietary supplementation has an important role regarding the presence of antioxidants in milk and dairy products.…”

“…However, the chemical composition and presence of different bioactive compounds in the milk of these species can fluctuate due to several factors, such as animal breed, stage of lactation, season, management and nutrition. Many strategies have been implemented to enhance dairy ruminant product quality, one of which is to focus on the influence of dietary supplementation.The enrichment of ruminant diets with agro-industrial by-products (for example, citrus pulp, grape pomace and pulp, molasses and olive leaves) that are rich in bioactive compounds such as polyphenols has been demonstrated to improve the nutritional and chemical composition of milk and dairy products (Křížová et al, 2021). Dietary supplementation has an important role regarding the presence of antioxidants in milk and dairy products.…”