Antioxidant and Functional Activities of MRPs Derived from Different Sugar–Amino Acid Combinations and Reaction Conditions

Abstract

The Maillard reaction (MR), or non-enzymatic browning, involves reducing sugars reacting with amino acids, peptides, or proteins when heated to produce an abundance of products that contribute to sensory, nutritional, and functional qualities of the food system. One example of an important functional quality of MR relates to antioxidant capacity, which has relevance to preserve food quality and also to extend a potential role that may promote gastrointestinal health. The addition of Alphacel (10%), a non-reactive polysaccharide, to MR reactants produced small significant (p < 0.05) reductions in yield of soluble Maillard reaction products (MRPs), sugar loss, and color change of products formed respectively, for reducing sugars. A similar effect was also noticed for different free-radical scavenging capacity (p < 0.05), using chemical (e.g., 2,2-diphenyl-1-picrylhydrazyl (DPPH)), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. An inflamed Caco-2 cell model revealed nitric oxide (NO) inhibitory activity for Glu-amino acid MRPs, which contrasted the NO stimulatory activity obtained with Fru-amino acid MRPs, especially when glycine was used as the amino acid. Pre-treating Caco-2 cells with Fru-glycine MRPs protected against loss in trans-epithelial resistance (TEER) (p < 0.05) and reduced (p < 0.05) disruption of Caco-2 intestinal epithelial tight-junction (TJ) protein cells when exposed to 7.5% ethanol. A low molecular weight Fru-glycine (e.g., <1 kDa) fraction contributed to the protective effect, not observed with the corresponding high molecular weight MRP fraction. The presence of Alphacel had minimal effect on generating MRPs with relative modified protection against intestinal dysfunction in cultured Caco-2 cells. Rather, different types of sugar–amino acid combinations used to generate MRPs contributed more to mitigate injury in stress-induced Caco-2 cells. With the growing evidence that MRPs have a wide range of bioactive activities, this study concludes that specificity of substrate precursors that produce MRPs in heated foods is a critical factor for antioxidant and related cellular functions that represent a healthy gut.

Glycation of tilapia protein hydrolysate decreases cellular antioxidant activity upon in vitro gastrointestinal digestion

“…3 B–C) were positively correlated with changes in colorless and fluorescent MRPs ( Fig. 1 D–E), which is in agreement with Kitts (2021) who reported that early stage MRPs with fluorescent characteristics typically exhibited antioxidant activity. However, the extended glycation of the xylose from 8 to 12 h, including X 8 H n , X 10 H n , and X 12 H n , did not show the same rate in increasing antioxidant activities ( Fig.…”

Lysine-Derived Maillard Reaction Products Inhibit the Growth of Salmonella enterica Serotype Typhimurium

“…It is important to note that the composition of melanoidins from different sugar–lysine combinations may differ in respect to the physical, chemical or biological properties of pre-melanoidin components that form a complex mixture of HMW melanoidins [ 24 ]. These complex set of reactions define both intermediate (pre-melanoidin) and final (melanoidin) stages, that are sugar-specific in terms of final composition [ 19 , 24 ]. In addition to temperature, the pH is also a factor, as under slightly basic conditions, Schiff base and Amadori rearrangement, products will tend to lead to a 2,3-enolization reaction [ 24 ].…”

“…Typhimurium was not significantly different from other sugar–lysine sources of MRPs ( Table 3 ). A possible explanation for this finding is that the MRPs were relatively crude mixtures of HMW components [ 21 ] that, when combined, exceeded the threshold concentration to show differences in the maximum growth rate of S. Typhimurium between the different MRP treatments [ 19 ].…”

“…A commonly used indicator to characterize the stages of Maillard reaction is the use of spectrophotometric measurements. At an absorbance of 420 nm (Ab 420 ), brown pigments which are indicative of melanoidin equivalents are detected [ 18 , 19 ]. HMW MRPs, termed melanoidins for the purpose of this study, were measured in a 96-well plate at Ab 420 at 23 °C using a microplate reader (SpectraMax M2; Molecular Devices, Sunnyvale, CA, USA).…”

Melanoidins present in traditional fermented foods and beverages

“…Cocoa beans are roasted at 150, 135, 120, and 110°C for 25, 40, 75, and 85 min, respectively (Oracz et al., 2019). In model systems, the temperature and time for the synthesis of melanoidins are variable, for instance, at 150°C for 20 min or 40 min (Kitts, 2021), at 160°C for 10 min (Mohsin et al., 2020), and from 130°C to 200°C for 10 min (Mohsin et al., 2018).…”