Yiwen Zhu,Xirui Zhou,Yan Ping Chen,Ziyuan Liu,Shui Jiang,Gaole Chen,Yuan Liu
Umami intensity promotes food flavor blending and food choice, while a universal quantification procedure is still lacking. To evaluate perceived umami intensity (PUI) in seven categories of foods, modified two-alternative forced choice (2-AFC) method with monosodium glutamate as reference was applied. Meanwhile, we explored whether equivalent umami concentration (EUC) by chemical analysis and electronic tongue (E-tongue) are applicable in PUI quantification. The results indicated that EUC was appropriate in quantifying PUI of samples from meat, dairy, vegetable and mushroom groups ( r = 1.00, p < 0.05). Moreover, models with a good prediction capacity for PUI and EUC ( R 2 > 0.99) were established in separated food categories by back propagation neural networks, where E-tongue data were set as input. This study explored the effectiveness of the three methods in evaluating the PUIs of various foods, which provides multiple choices for the food industry.
Gradient dilution feeding substrate (GDFS) is regarded as an effective method for the production of active peptides, as it compensates for substrate limitations and minimizes substrate contamination of the ultrafiltration membrane. This study further investigated the impact of ultrasound-assisted gradient dilution feeding substrate (UA-GDFS) on the peptide yield and the intensity of umami. The chicken breast was used as ingredients. The umami compounds in the hydrolysate were determined using an automatic amino acid analyzer and HPLC. The hydrolysate's umami intensity was determined by electronic tongue in all modes. These findings indicated that UA-GDFS enhanced the umami intensity and peptide yield. Hydrolysate from UA-GDFS with molecular weight below 1 kDa was analyzed by nano-scale liquid chromatography-tandem mass spectrometry (Nano-HPLC-MS/MS). Electronic tongue analysis showed that GPSGPVG and VDGPSGK had umami taste and could enhance the umami taste of monosodium glutamate (MSG) solution. Asn68 and His145 were important sites on T1R3 for umami peptide binding.
危险品化学品经营许可证（带存储）