The study – published in Food Chemistry – reveals that researchers have identified novel peptides in peanut protein waste that could elicit “intense umami and umami-enhancing effects”.
Led by Professor Mouming Zhao from the South China University of Technology, the team identified and purified two novel taste peptides from peanut hydrolysate after treating it with crude protease extract. The team explained that peanut hydrolysate is produced from defatted peanut meal – a major byproduct of peanut oil production.
“On the basis of the results obtained from this work, more work is needed to synthesize the purified peptide and clarify relationships between structure and taste of these peptides,” said the researchers.
Umami flavour
Umami taste – the fifth basic taste – was discovered by a Japanese scientist, Kikunae Ikeda, in 1908, and designated a savory, mouthfulness or monosodium glutamate (MSG)-like taste, which is evidently different from sweet, sour, salty and bitter.
Umami substances are naturally found in a wide variety of foods, such as meat, cheese, seafood and vegetables, whilst many peptides, generated by enzymatic hydrolysis or fermentation from plant and animal proteins, have also been reported to elicit intense umami taste properties.
Study details
Zhao and his team extracted the peanut hydrolysate from Aspergillus oryzae HN 3.042 – finding that certain extracts elicited “intense umami and umami-enhancing effects.”
To identify the peptides responsible for such effects, the team assessed the taste profiles, amino acid and organic acid composition of the hydrolysate after they were separated and filtered.
“The results revealed that peanut hydrolysate was mainly low molecular weight compounds,” said the Zhao and his colleagues. “Fractions of 1–3 kDa and below 1 kDa prominently contributed to the umami taste and umami-enhancing effect.”
Using further purification and sensory evaluation techniques the Chinese researchers identified and obtained two novel peptides: one umami flavor peptide (identified as Ser-Ser-Arg-Asn-Glu-Gln-Ser-Arg – SSRNEQSR, 963.9 Da) and one umami-enhancing peptide (Glu-Gly-Ser-Glu-Ala-Pro-Asp-Gly-Ser-Ser-Arg – EGSEAPDGSSR, 1091.1 Da).
Source: Food Chemistry
Published online ahead of print, doi: 10.1016/j.foodchem.2012.04.130
“Isolation and identification of two novel umami and umami-enhancing peptides from peanut hydrolysate by consecutive chromatography and MALDI-TOF/TOF MS”
Authors: G. Su, C. Cui, L. Zheng, B. Yang, J. Ren, M. Zhao