Barley Melanoidins: Key Dietary Compounds With Potential Health Benefits

Physiological Mechanisms by Which the Functional Ingredients in Beer Impact Human Health

Nutritional therapy, for example through beer, is the best solution to human chronic diseases. In this article, we demonstrate the physiological mechanisms of the functional ingredients in beer with health-promoting effects, based on the PubMed, Google, CNKI, and ISI Web of Science databases, published from 1997 to 2024. Beer, a complex of barley malt and hops, is rich in functional ingredients. The health effects of beer against 26 chronic diseases are highly similar to those of barley due to the physiological mechanisms of polyphenols (phenolic acids, flavonoids), melatonin, minerals, bitter acids, vitamins, and peptides. Functional beer with low purine and high active ingredients made from pure barley malt, as well as an additional functional food, represents an important development direction, specifically, ginger beer, ginseng beer, and coix-lily beer, as consumed by our ancestors ca. 9000 years ago. Low-purine beer can be produced via enzymatic and biological degradation and adsorption of purines, as well as dandelion addition. Therefore, this review paper not only reveals the physiological mechanisms of beer in overcoming chronic human diseases, but also provides a scientific basis for the development of functional beer with health-promoting effects.

Protective effects of melanoidins from black garlic on zearalenone-induced toxicity in zebrafish embryonic developmental model

Zearalenone (ZEN), a ubiquitous mycotoxin that widely occurs in grain and foodstuff may induce serious toxic effects after accumulation in vivo. Melanoidins (MLDs) have shown multiple bio-functional properties such as antioxidant, anti-bacterial and prebiotic activities. Black garlic exhibits several advantages over fresh garlic related to health improvement. In this study, the alleviative effects of black garlic MLDs on ZEN-induced toxicity and the potential mechanisms were studied using zebrafish embryonic developmental model. The results showed that MLDs restored the ZEN-induced adverse influences on zebrafish embryonic development, including delay in hatching time, morphological abnormality and the impairment of nervous development. Further studies showed that MLDs significantly inhibited the ZEN-induced production of reactive oxygen species (ROS) and enhanced the intrinsic antioxidant ability by increasing the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) and the content of glutathione (GSH). In addition, co-exposure of MLDs significantly inhibited the ZEN-stimulated cellular apoptosis in zebrafish larvae through down-regulation of pro-apoptotic genes of bax, caspase-3 and caspase-9 and up-regulation of anti-apoptotic gene bcl-2. Moreover, MLDs inhibited the in vivo accumulation of ZEN in zebrafish larvae. To sum up, MLDs attenuated the ZEN-induced zebrafish embryonic developmental toxicity through suppression of the oxidative stress and intervention on mitochondria apoptosis pathway as well as inhibiting the absorption of ZEN in zebrafish embryos/larvae. The results suggest that black garlic MLDs have potential to be used as a functional ingredient against the adverse effects of exogenous toxins.

Bioactive Properties of Instant Chicory Melanoidins and Their Relevance as Health Promoting Food Ingredients

Instant chicory is a caffeine-free brew worldwide consumed as a coffee substitute. Like coffee grounds processing, chicory roots suffer a roasting process, which may lead to the formation of high-molecular weight nitrogen-brown compounds, the melanoidins. It is hypothesized that similarly to coffee, chicory melanoidins have health promoting potential. In this work, the chemical composition and biological activity of chicory high molecular weight material (HMWM) was evaluated. The chicory HMWM is composed by 28.9% (w/w) of carbohydrates, mainly fructose-rich polysaccharides (18.7% w/w) and 5.7% (w/w) of protein, distinct from coffee. The phenolic compounds constituent of the HMWM were mainly present in glycosidically linked and condensed structures (0.9 g/100 g and 5.8 g/100 g), showing in vitro ABTS^•+ scavenging (IC₅₀ = 0.28 mg/mL) and ferric ion reducing capacity (ca. 11 µg Fe²⁺ eq/mg). Chicory HMWM revealed to be effective against Gram-positive bacteria, mainly Staphylococcus aureus and Bacillus cereus, although not so efficient as coffee. It also showed potential to inhibit α-glucosidase activity (15% of inhibition), higher than coffee HMWM, approaching acarbose activity that is used in type 2 diabetes mellitus treatment. Thus, chicory melanoidins, when used as a food ingredient, may contribute to an antioxidant diet and to prevent diabetes, while increasing the protective effects against pathogenic bacteria.

Melanoidins present in traditional fermented foods and beverages

Traditional fermented foods and beverages (TFFB) are an important dietary component consumed in large quantities worldwide. Currently, much attention has been focused on the health benefits of TFFB. Melanoidins, a class of bioactive substance produced in the final stage of the Maillard reaction, not only have a significant impact on sensory properties of TFFB but also contribute to the health effects. Melanoidins formed in the fermentation system with a long reaction time at low temperature could be different from those obtained from high-temperature, short-duration roasted systems due to the multiple formative stages and involvement of microorganisms and enzymes. In this paper, the current state of knowledge regarding the formation, distribution, extraction and purification, physicochemical properties, structure characteristics, and biological activities of TFFB melanoidins are comprehensively reviewed, with predominant focus on TFFB that are typically brown like douchi, miso, cheonggukjang, soy sauce, huangjiu (Chinese rice wine), beer, vinegar, and sweet wine. The current challenges and prospective recommendations for the research of melanoidins in fermented systems are also presented. In future, people should pay more attention to the basic research on TFFB melanoidins, especially purification methods and formation mechanisms, further substantiation of health properties of TFFB melanoidins in vivo, and development of specific melanoidins to fulfill technological, productive, or health needs of consumers.