JIA-2019-11

2659 Ji-Eun Kim et al. Journal of Integrative Agriculture 2019, 18(11): 2652–2663 with whiteness indexes of surface in NSCSB. Stress relaxation and hardness of KSSB showed negative correlation with protein content ( r =–0.76 ** and r =–0.68 ** , respectively) and SDS sedimentation volume based on flour weight ( r =–0.75 ** and r =–0.78 ** , respectively). Stress relaxation was negatively correlated with optimum water absorption of Mixograph in KSSB ( r =–0.66 * ) and WSRC in NSCSB ( r =–0.68 * ). Hardness of KSSB was negatively correlated with SDS sedimentation volume based on protein weight ( r =–0.68 * ), but there was no significant correlation between hardness and flour characteristics in NSCSB. Multiple regression analyses were conducted for quality attributes for KSSB and NSCSB (Table 5). Diameter, height, volume of steamed bread could be predicted by flour characteristics in KSSB, but only height of bread was available in NSCSB. However, crumb properties, stress relaxation, and hardness, and whiteness index of surface and crumb were difficult to predict with flour characteristics evaluated in this study. Mixing tolerance of Mixograph and SucSRC had strong influences on diameter and height of KSSB. Pasting properties, peak viscosity and final viscosity, also influenced diameter and height of KSSB. These parameters can predict diameter of KSSB ( R 2 =0.70). The height of KSSB could be predicted by adding these characteristics and average of particle size of flour and WSRC ( R 2 =0.91). However, height of NSCSB can be expected from protein content, mixing time, SDS sedimentation volume based on flour weight and SCSRC ( R 2 =0.84). Volume of KSSB can be predicted from average of particle size of flour, protein content, LASRC, and SucSRC ( R 2 =0.89). The effects of glutenin compositions and kernel hardness on quality of steamed bread are presented in Table 6. Variation of Glu-A1 allele had no significant influences on quality of both KSSB and NSCSB. Korean wheat cultivars carrying Glu-B1i allele showed lower height (58.5 mm) of steamed bread than Glu-B1f allele (66.5 mm) in NSCSB. Cultivars carrying Glu-D1f allele had higher height (65.3 mm) than Glu-D1d allele (60.0 mm) in NSCSB and Glu-D1f allele produced harder texture of crumb (7.6 N) than Glu-D1d allele (5.7 N) in KSSB. Glu-A3c allele produced higher volume (704.7 mL) and softer texture of crumb (6.7 N) than Glu-A3d allele (645.8 mL and 8.3 N, respectively) in KSSB while Glu- A3c allele showed higher diameter (105.3 mm) than Glu-A3d allele (97.4 mm) in NSCSB. Glu-B3i allele showed softer texture of crumb (8.9 N) than other alleles and Glu-B3a allele produced harder texture (22.2 N) than others but Glu-B3d and Glu-B3h alleles (14.7 and 15.4 N, respectively) were not different in NSCSB. Hard wheat cultivars carrying Pina-D1b or Pinb-D1b allele produced higher height (62.8mm) and volume of steamed bread (712.5 mL), and lower stress relaxation (21.3%) and hardness of crumb (6.5 N) than soft wheat cultivars carrying Pina-D1a and Pinb-D1a allele, (56.6 mm, 660.0 mL, 19.5% and 7.8 N, respectively) in KSSB, although there were no differences in these parameters according to variations of glutenin and puroindoline as kernel hardness in NSCSB. 4. Discussion 4.1. Effect of allelic composition on flour characteristics Flour characteristics of 11 Korean wheat cultivars were evaluated. The values of physico-chemical properties of the Korean wheat flour were similar to the results of previous study with Korean wheat cultivars (Kang et al . 2014; Kim et al . 2017). The different physicochemical properties of flour, particle size, damaged starch and protein content, and SDSSF according to kernel hardness as hard and soft type among Korean wheat cultivars are consistent with previous results of Korean wheat cultivars (Park et al . 2010). Variation of particle size of flour and damaged starch content of Korean wheat cultivars were determined by the effect of Glu-1 , Glu-3 , and Pin-D1 alleles, and glutenin and puroindolines significantly affected the variation of protein content and SDSSF (Shin et al . 2012). SDSSF is generally influenced by protein content and quality, and SDSSP is used to determine protein quality independent of protein content. Glu-B1b and Glu-D1b alleles of Chinese wheat Table 5 Regression equations for prediction of steamed bread quality attributes of Korean style steamed bread (KSSB) and northern-style Chinese steamed bread (NSCSB) Parameter Equation 1) R 2 Probability>F KSSB Diameter (DIA) DIA=–1.21×MTOL+0.13×PV–0.20×SucSRC+163.32 0.70 <0.01 Height (HT) HT=0.39×PSI+0.82×MTOL–0.05×FV+0.36×SucSRC–0.15×WSRC+1.66 0.91 <0.01 Volume (VOL) VOL=2.08×PSI+24.41×Protein–1.67×LASRC+1.96×SucSRC+241.91 0.89 <0.01 NSCSB Height (HT) HT=0.81×SCSRC–2.40×Protein–3.62×MTIME+0.30×SDSSF+25.54 0.84 <0.01 1) MTOL, mixing tolerance of Mixograph; PV, peak viscosity; SucSRC, sucrose solvent retention capacity (SRC); PSI, average of particle size of flour; FV, final viscosity; WSRC, water SRC; LASRC, lactic acid SRC; SCSRC, sodium carbonate SRC; MTIME, mixing time of Mixograph; SDSSF, sodium dodecyl sulfate (SDS) sedimentation test conducted on a constant flour weight.