Comparation sensory characteristic, non-volatile compounds, volatile compounds and antioxidant activity of MRPs by novel gradient temperature-elevating and traditional isothermal methods.

A novel gradient temperature-elevating Maillard reaction was developed to effectively produce light-colored MRPs. The main purpose of the present study was to compare the color, taste characteristic, non-volatile compounds, volatile compounds and antioxidant activity of MRPs prepared by the novel gradient temperature-elevating and traditional isothermal methods. The product prepared from soybean peptide, D-xylose and L-cysteine by gradient temperature-elevating method was termed MRP-60. Isothermal method was used to produce light and dark colored MRP, called PXC and PX, respectively. MRP-60 has not only the lowest brown intensity (A420, 0.088), also the highest overall acceptability taste from sensory evaluation. MRP-60 showed the lowest bitterness which could be attributed to the lowest content of bitter amino acids (1.48 mg/ml); MRP-60 also showed indistinctive mouthfulness compared with PXC which elucidated by the percentage of compounds with a molecular weight of 1,000-5,000 Da (15.03 %) and high antioxidant activity. Then, the MRPs prepared by gradient temperature-elevating method successfully attain desirable taste and high antioxidant activity.