Saltiness Enhancement through the Synergism of Pyroglutamyl Peptides and Organic Acids.

Excess sodium intake poses health risks, prompting the exploration of taste modulators to reduce the salt content in low-sodium foods yet maintain salty perception. Previous research found a subthreshold synergistic effect among pyroglutamyl dipeptides on saltiness enhancement. This study investigated the subthreshold synergistic effect of pyroglutamyl peptides and organic acids on saltiness perception. Pyroglutamyl dipeptides (pgluE, pgluV), pyroglutamyl tripeptides (pgluVL and pgluVC), and organic acids (malic acid and succinic acid) were explored in a model system and subsequently in commercial brown onion sauce. The detection thresholds of peptides (pgluE, pgluV, pgluVL, and pgluVC) were determined to be 646, 77, 273, and 221 µmol/L, respectively, and the subthreshold synergistic effect of the pyroglutamyl tripeptides and organic acids was determined using the isobologram method. One of the eight combinations of pyroglutamyl tripeptides with pyroglutamyl dipeptide (pgluV) showed a subthreshold synergistic effect, whereas four combinations of tripeptides with malic acid and one combination with succinic acid exhibited a subthreshold synergistic effect. In commercial brown onion sauce, 25 and 30% salt reductions were achieved using the combinations of the tripeptides with malic acid and succinic acid, respectively. This research lays the foundation for future investigations into the potential combinations of pyroglutamyl peptides and organic acids for saltiness enhancement in low-sodium foods.

Modulation of Brain-Derived Neurotrophic Factor (BDNF) Signaling Pathway by Culinary Sage (Salvia officinalis L.).

Culinary sage (Salvia officinalis L.) is a common spice plant in the mint family (Lamiaceae) well known for its distinctive culinary and traditional medicinal uses. Sage tea has been used traditionally as a brain-enhancing tonic and extracts from sage have been reported to have both cognitive and memory enhancing effects. Brain-derived neurotrophic factor (BDNF) is an endogenous signaling molecule involved in cognition and memory function. In this study, activity-guided fractionation employing preparative reverse-phase high performance liquid chromatography (RP-HPLC) of culinary sage extracts led to the discovery of benzyl 6-O-ß-D-apiofuranosyl-ß-D-glucoside (B6AG) as a natural product that upregulates transcription of neurotrophic factors in C6 glioma cells. Purified B6AG showed a moderate dose response, with upregulation of BDNF and with EC50 at 6.46 µM. To better understand the natural variation in culinary sage, B6AG was quantitated in the leaves of several commercial varieties by liquid chromatography-mass spectrometry (LC-MS). The level of B6AG in dried culinary sage was found to range from 334 ± 14 to 698 ± 65 µg/g. This study provided a foundation for future investigations, including quantitative inquiries on the distribution of B6AG within the different plant organs, explorations in optimizing post-harvest practices, and aid in the development of sage varieties with elevated levels of B6AG.

Biosynthesis of Benzylic Derivatives in the Fermentation Broth of the Edible Mushroom, Ischnoderma resinosum.

Employing isotope incubation studies, the biosynthetic pathway leading to a series of benzylic derivatives was elucidated in the fermentation broth of the edible mushroom Ischnoderma resinosum (P. Karst). Twenty-six hydroxy- and methoxy- benzylic derivatives were screened by gas chromatography-mass spectrometry (GC-MS) of which 13 were detected in the culture media. Results from the isotope incubation studies showed the transformation of both benzyl alcohol and benzoic acid into benzaldehyde. Benzaldehyde was then converted into 4-methoxybenzaldehyde via hydroxylation and subsequent methylation of the 4-C position. The resulting 4-methoxybenzaldehyde was then hydroxylated in the 3-C position followed by methylation into 3,4-dimethoxybenzaldehyde. Based on these findings, a novel metabolic scheme for the biosynthesis of benzylic derivatives in I. resinosum was proposed. The knowledge of the biosynthetic pathway was utilized to produce 4-hydroxy-3-methoxybenzaldehyde (vanillin) from 4-hydroxy-3-methoxybenzoic acid (vanillic acid). This is the first report to elucidate the biosynthetic pathway of benzyl derivatives and production of vanillin from I. resinosum.

Odorants from the Thermal Treatment of Hydrolyzed Mushroom Protein and Cysteine Enhance Saltiness Perception.

Innovative approaches to develop flavors with high sensory appeal are critical in encouraging increased consumer preference and adoption of low sodium foods. Gas chromatography-olfactometry, coupled with stable isotope dilution assays and sensory experiments, led to the identification of the odorants responsible for an enhancement in saltiness perception of chicken broth prepared with thermally treated enzymatically hydrolyzed mushroom protein and cysteine, then reacted under kitchen-like cooking conditions. Comparative aroma extract dilution analysis revealed 36 odorants with flavor dilution factors between a range of 1 and 256. Sixteen odorants were quantitated and odor activity values (OAVs) calculated. Important odorants included 2-furfurylthiol (coffee, OAV 610), 1-(2-furyl)ethanethiol (meaty, OAV 78), 3-sulfanylpentan-2-one (catty, OAV 42), sotolon (maple, OAV 20), indole (animal, OAV 8), 2-methyl-3-(methyldithio)furan (meaty, OAV 3), and p-cresol (barnyard, OAV 1). An odor simulation model was evaluated in two consumer sensory studies. These studies confirmed that the addition of the aroma model increased the perceived saltiness of low sodium chicken broth (p < 0.05).