The thermal stability of L-5-methyltetrafolic acid (L-5-MTHF) was investigated in model/buffer systems and food systems. L-5-MTHF degradation followed first-order reaction kinetics with relatively greater (P < 0.01) stability at pH 4 compared to pH 6.8 in the buffer systems. This was confirmed using cyclic voltammetry. The stability (for example, k-values) of L-5-MTHF in an oxygen controlled environment improved (P < 0.001) proportionally when in the presence of increasing molar ratios of sodium ascorbate (NaAsc). The addition of NaAsc to L-5-MTHF after heat treatment was also effective at returning thermally oxidized L-5-MTHF back to its original form. A scheme was developed to explain the degradation and regeneration of L-5-MTHF. The importance of antioxidant protection of L-5-MTHF from thermal oxidation was extended using 2 distinct food systems; namely skim milk and soy milk, both with known antioxidant capacities. We conclude that the antioxidant activity of food components can enhance the stability of L-5-MTHF.
A standardized whole cranberry extract (WCE) was used to stabilize a model sunflower-casein emulsion prototype for future formulation activities with a fresh cream cheese product. The WCE contained total organic acids (20% w/w) and polyphenols (5%), the latter consisting of total anthocyanins (10%, w/w) and proanthocyanidins (12% w/w). Antioxidant capacity of the WCE was determined by ORAC, (hydrophilic ORAC = 348.31 ± 33.45 µmol of Trolox equivalents/g; lipophilic ORAC = 11.02 ± 0.85 µmol of Trolox equivalents/g). WCE was effective at stabilizing the model emulsion at a level of 0.375% (w/w), yielding a final pH of 5.6. Generation of initial lipid peroxidation products, hexanal and pentanal was inhibited by 92.4% ± 3.9% and 66.6% ± 5.3% (n = 3), respectively, when emulsions containing WCE were incubated at 50 °C for 90 h. This information was useful for formulating a fresh cream cheese product containing WCE to produce value-added potential and good self-life. The standardized WCE gave a final pH of 5.6 for the cheese premix and also significantly (P < 0.05) lowered both the PV and CD after 28 and 21 days at 4 °C storage, respectively, compared to untreated control. We conclude that there are important functional role(s) for cranberry constituents when presented as a standardized ingredient for producing value-added, stable fresh dairy products.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.