Effects of presoaking-high hydrostatic pressure (PHHP) on cooking time, hardness, gumminess, springiness, and microstructure of brown rice were evaluated. Compared with traditional soaking treatment, PHHP significantly shorten the cooking time of brown rice from 34 to 14 min. The hardness of brown rice treated by PHHP reduced remarkably, which is lower than that treated by soaking process and similar to that of white rice. The gumminess and springiness of brown rice dramatically decreased under pressure above 500 MPa. However, the water uptake capacity of brown rice treated by PHHP was not obviously affected, whose moisture contents were much lower than that of soaked samples. The analysis of thermal properties revealed that the enthalpy of brown rice was influenced by PHHP, and the denaturation of brown rice components generated. These results and microstructure analysis revealed that the structures of pericarp and aleurone layer of brown rice were damaged by PHHP, which allows water to be easily absorbed by the rice kernel during cooking process. PHHP treatment could be a potentially applicable pretreatment for improving cooking properties of brown rice.

The effect of high pressure (HP) and thermal (TP) treatments on storage stability of Chinese bayberry juice was investigated. Samples were treated for 5 min at 500 MPa (HP treatment) at room temperature or in a water bath (TP treatment) at 55C for an effective time of 8 min and stored at 4 and 25C. The soluble solids content of the HP-and TP-treated samples was stable at both temperatures, while it decreased at 25C in control samples. Color retention was better in the HP-treated samples than in TP-treated samples. Anthocyanin retention values in the HP-and TP-treated samples were 96.5 and 85.1%, respectively, while ascorbic acid retention values were 89.2 and 58.3%, respectively. Anthocyanin and ascorbic acid degradation during storage followed a first-order kinetics, and the rate constants were lowest for the HP-treated samples followed by TP treatment and were highest for the control samples.

No abstract

No abstract