The effects of 5 lactic acid bacteria (LAB) fermentation on the pasting properties of glutinous rice flour were compared, and suitable fermentation strains were selected based on the changes of viscosity, setback value, and breakdown value to prepare LAB compound starter cultures. The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour. In particular, the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour. Moreover, the gelatinization enthalpy of the fermented samples increased significantly. For frozen glutinous rice dough stored for 28 days, the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough, and the freezable water content was lower than that of control dough. These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry, which has significance for its application.

It has been reported that fresh edible rice has more bioactive compounds and its protein is easier to digest and has lower hypoallergenic than mature rice. In this paper, the changes in structure and functional properties of proteins at five different stages, including early milky stage (EMS), middle milky stage (MMS), late milky stage (LMS), waxy ripe stage (WS) and ripening stage (RS), during the seed development were investigated. It was found that with the seed developing, the molecular weight of fresh rice protein gradually become larger while the secondary structure changed from the highest content of disordered structure at MMS to the highest content of ordered structure at RS, which affect the surface hydrophobicity and then the functional properties of proteins, including foaming properties, emulsifying properties and oil holding capacity. Fresh rice protein at MMS has the strongest surface hydrophobicity while fresh edible rice protein at RS has the strongest oil holding capability. The results of our study can provide a theoretical basis for the application of fresh rice protein in the food industry and help to develop new fresh edible rice food.

The relationships between chemical composition, structure and physicochemical properties such as pasting, thermal, and textural properties of 12 temperate rice cultivars grown in Heilongjiang Province, China were investigated in this study. There were significant differences in the content of fat, protein, ash, amylose, damaged starch among 12 cultivars. Brabender Viscograph results showed that gelatinization time, peak viscosity, pasting and peak temperature ranged from 9 min to 15 min, 2100 BU to 2500 BU, 58.75 ℃ to 72.00 ℃ and 63.75 ℃ to 84.45 ℃, respectively, except for the waxy one Longjing 9. T_o, T_p, T_c and ΔH were found in the range of 58.34 ℃ to 67.96 ℃, 65.39 ℃ to 75.38 ℃, 78.47 ℃ to 90.69 ℃ and 2.036 J/g to 3.127 J/g respectively. Scanning Electron Micro-photograph results showed that all starch granules were polyhedral with irregular shapes, except Longjing 9 showing signs of the loss of physical integrity. The hardness, adhesiveness, springiness, gumminess, cohesiveness and resilience ranged from 395.87 g to 1161.76 g, -90.842 g·mm to -36.4 g·mm, 0.498 to 0.747, 78.631 g to 466.837 g, 0.199 to 0.569, 0.321 to 0.504, respectively. Correlation studies indicated that amylose, damaged starch, protein, fat and ash played a more important role in determining the rice properties of pasting, thermal, crystallinity and texture.