Soluble and cell wall‐bound phenolic acids and ferulic acid dehydrodimers in rye flour and five bread model systems: insight into mechanisms of improved availability

Abstract

BackgroundThe bread-making process influences bread components, including phenolics that significantly contribute to its antioxidant properties. Five bread model systems made from different rye cultivars were investigated to compare their impact on concentration of ethanol-soluble (free and ester-bound) and insoluble phenolics.ResultsBreads produced by a straight dough method without acid addition (A) and three-stage sourdough method with 12 h native starter preparation (C) exhibited the highest, genotype-dependent concentrations of free phenolic acids. Dough acidification by direct acid addition (method B) or by gradual production during prolonged starter fermentation (24 and 48 h, for methods D and E) considerably decreased their level. However, breads B were enriched in soluble ester-bound fraction. Both direct methods, despite substantial differences in dough pH, caused a similar increase in the amount of insoluble ester-bound fraction. The contents of phenolic fractions in rye bread were positively related to activity level of feruloyl esterase and negatively to those of arabinoxylan-hydrolysing enzymes in wholemeal flour.ConclusionThe solubility of rye bread phenolics may be enhanced by application of a suitable bread-making procedure with respect to rye cultivar, as the mechanisms of this process are also governed by a response of an individual genotype with specific biochemical profile. © 2014 Plant Breeding and Acclimatization Institute, National Research Institute. © 2014 The Authors. Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

(Poly)phenolic Content and Profile and Antioxidant Capacity of Whole-Grain Cookies are Better Estimated by Simulated Digestion than Chemical Extraction

“…Ferulic acid was released from their bound form by sourdough fermentation only in WG cookies made with DUR and KHO, where the highest content of this phenolic acid was observed. A higher release of phenolic acids after sourdough than standard fermentation of WG cereals was previously reported in barley [ 28 ], wheat and rye malt [ 29 ], and in bread made with wheat, spelt, or rye flours [ 30 ], and it was ascribed to LAB feruloyl esterase activity [ 30 , 31 ]. Our results evidenced that the effect of sourdough fermentation was modulated by the cereal type.…”

Broa, an Ethnic Maize Bread, as a Source of Phenolic Compounds

“…The hydrolysis of the SF is usually performed to quantitate the total soluble and conjugated major phenolic acids of maize [ 18 , 24 , 25 ]. In the present work, the AA and PC were also measured in the SHF ( Table 2 ), in order to evaluate the effect of the hydrolysis procedure on the soluble phenolics and associated AA.…”

“…These findings show the importance of choosing other methods of analysis which can complement the global methods and give more detailed information, enabling the identification and quantitation of individual phenolics. Therefore, HPLC-DAD-ED analyses were performed in all fractions, allowing the quantitation of soluble-free, soluble-conjugated and insoluble ferulic (FA) and p -coumaric (pCA) acids and insoluble dehydrodiferulic acids ( Figure 1 ), as previously described for other cereal-based foods [ 18 , 24 , 25 ]. Additionally, since free and conjugated phenolics may exhibit different antioxidant activities and health effects [ 7 , 10 ], the major soluble-conjugated hydroxycinnamic acids derivatives (hydroxycinnamic acid amides), which are readily available for absorption after consumption, were also quantitated ( Figure 1 ).…”

Changes in the content of free phenolic acids and antioxidative capacity of wholemeal bread in relation to cereal species and fermentation type

“…Similarly, Ripari et al [23] demonstrated that selected combinations of L. hammesii DSM 16381 with two strains of the L. plantarum (LM01 and PM4) effectively reduced the content of bound ferulic acid in wheat sourdough (in some samples, bound ferulic acid was almost completely liberated into free and conjugated forms). Native cereal grain also exhibits feruloyl esterase activity [42].…”