Development of Inosine Monophosphate and Its Degradation Products during Aging of Pork of Different Qualities in Relation to Basic Taste and Retronasal Flavor Perception of the Meat

Abstract

Inosine monophosphate (IMP) and its degradation products, ribose and hypoxanthine, are all considered to be important constituents in meat flavor formation and development. The present study explored the fate of IMP during the aging of two qualities of pork (pH >5.7 and 5.5 < pH < 5.6) and the potential relationship between IMP, hypoxanthine, and sensory attributes of pork registered both as retronasal and basic taste responses in whole meat, meat juice, and the remaining meat residue. During aging the concentration of IMP decreased with a simultaneous increase in the concentrations of inosine, hypoxanthine, and ribose. The rates at which IMP was degraded to inosine and inosine to hypoxanthine during aging were found to be in agreement with the known rate constants of the dephosphorylation of IMP and the hydrolysis of inosine, respectively. Moreover, high-pH pork resulted in a significantly higher concentration of hypoxanthine throughout storage compared with low-pH pork due to an initially higher concentration of IMP in high-pH meat. The sensory analysis showed increasing intensity in bitterness and saltiness of pork as a function of aging, with the intensity being most pronounced in the meat juice. The increasing bitterness of the pork as a function of aging coincided with the higher content of hypoxanthine in these samples, thereby suggesting that degradation of IMP to hypoxanthine might influence pork flavor. In contrast, IMP was associated with nonaged meat and the sensory attributes meaty and brothy.

Differences in the Taste-active Compounds between Hanwoo Longissimus and Semitendinosus Muscles and Its Comparision with Angus Longissimus Beef Muscle

“…Earlier workers (Faustman and Cassens, 1991; Koutsidis et al, 2008a) studied on other cattle breeds also found that the Hx content was affected by the examined breed. IMP has been widely used as a flavor enhancer to increase palatability, its found to contribute to the sensory attributes like brothy and meaty (Chen et al, 2004;Tikk et al, 2006). The IMP contributes to the pleasant delicious taste and most to the umami taste by synergistic effect with MSG and GMP (Massa et al, 2003).…”

Improving meat quality through cattle feed enriched with mate extract: an integrated approach of the metabolic profile and redox chemistry of meat

“…29,[43][44][45] Amino acids, peptides, nucleotides and sugars correspond to meat polar metabolites and, many of them are water-soluble precursors of meat flavour. [51][52][53][54] The presence of nucleotides in meat is important not only for the flavour but also because some nucleotides are considered biomarkers for relevant metabolic pathways. 52,55,56 For example, inosine monophosphate (IMP), inosine and hypoxantine are related to the purine degradation pathway which yields uric acid as end product.…”

“…[51][52][53][54] The presence of nucleotides in meat is important not only for the flavour but also because some nucleotides are considered biomarkers for relevant metabolic pathways. 52,55,56 For example, inosine monophosphate (IMP), inosine and hypoxantine are related to the purine degradation pathway which yields uric acid as end product. IMP is converted to inosine and inosine to hypoxantine during the post mortem metabolism of meat when degradation pathways take place.…”

“…Inosine and hypoxantine are biomarkers for stress and both contribute for an undesirable bitter taste in meat whereas IMP is an important flavour enhancer. 54,55,57,58 Carbohydrates and phosphate forms of sugar can produce important flavour precursors in meat during cooking through the Maillard reaction. 51 Moreover, the Maillard reaction has been identified as a source of compounds with antioxidant activity.…”

“…An improvement of meat quality may be achieved by decreasing the formation of inosine through dephosphorylating of IMP, since this process has been shown to be associated with a high susceptibility to stress 54 . Furthermore, IMP is well known as a non-volatile flavour enhancer in meat and it is desirable to keep its concentration high by preventing its degradation during meat processing 56,58 .…”