The columns were eluted at ambient temperature with 0.05 mollL sodium phosphate buffer (pH 70)containing 2.0%SDS. Chromatography conditions included a flow rate of 0.7 ml/min and temperature of 28 c with protein detection t 214 nm. Measurements were conducted in triplicate. Extractability of gluten proteins in SDS containing medium (sDSEP. was calculated from the peak area and expressed as percentage of the peak area of gluten extracted with the SDS buffer in the presence of 1.0x dithiothreitol (DTT). 2.6. Pasting properties Pasting properties of lyophilized and ground noodles were measured by a Rapid Viscosity Analyser (RVAA500, Perten Instruments, NSW, Australia) according to AACC Method 76-21 (AACC, 2000. The tests were conducted in the programmed heat- ing and cooling cycle of STD1. The viscosity was expressed in cP 2.7 Starch gelatinization Gelatinization of starch in noodles during steaming was determined using DSC (Q2000, TA Instruments, New Castle, America) according to Guler, Koksel, and Ng (2002), Lyophilized noodles (2 mg) and 6 L of distilled water were placed in an aluminum DSC pan, sealed, and allowed to equilibrate for 24 h at room temperature. The samples were heated as a determined temperature program (25-95 °C, 10 °C/min) using an empty pan as reference. Onset temperature and peak temperature were determined for each endotherm. The transition enthalpy of gelatimization was calculated from the peak area and expressed as J/g of dry matter 2.8. Statistical analysisthe steaming pretreatment of noodles was performed in triplicate. The data were expressed as the mean of at least three replicate terminations and analyzed by one-way analysis of variance (ANOVA) and Duncan's test by using the software 190 for windows (SPss Inc. Chicago, IL USA) Significance was defined at P <0.05 3, Results and discussion 3.1, Cooking properties The cooking properties can be evaluated in terms of cooking loss and water absorption. Cooking loss is referred as the total contents of solids present in the cooking water, which is widely used as an indicator of the overall cooking performance. Considering the special manufacturing processes of frozen cooked noodles, the precooking loss and reheating loss were measured. As shown in the Fig. 1 a,steaming significantly(P<0.05)decreasedthe precooking loss of control and white salted noodles. It has been reported that the beat treatme pasta causes denaturation of proteins,leading to a stiffening of pasta structure, preventing leaching of starch and thus decreasing cooking loss(Nouviaire et al., 2008). The influence of steaming time on the precooking loss was not significant (P>0.05). In addition, the reheating loss was not less than or equal to that of non-steam-treated noodles until the steaming time was 3 min and then it slightly decreased (Fig. 1b) That might be due to the poorer structure formed during the first 2 min. However, yellow alkaline noodles exhibited an increase in the precooking loss except those of steaming 6 and 8 min, and an increase in reheating loss that of steaming 8 min. But with the increase of steaming time, as a result of starch gelatinization. a coated film might be generated on the surface, resulting in lower cooking loss. water uptake shows the capacity of noodle to respond to cooking. Excess water uptake often results in too soft and sticky noodle
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