Hybrid Solvent Retention Capacity (SRC) to predict Australian soft wheat cookie quality

Abstract

The Solvent Retention Capacity (SRC) method has been widely used in evaluating soft wheat quality elsewhere but not in Australia. This paper studies the potential of applying SRC to predict the Australian soft wheat quality in sugar snap cookies, which the Indonesian mills value. The cost-effective hybrid SRC method improves efficiency and repeatability in general by replacing the manual shaking mechanism with a programable multitube vortex shaker. The hybrid SRC method helps to reduce work health and safety risks by eliminating manual tube shaking steps. The collaborative laboratory study is conducted with two Indonesian mills and compared against SRC measured by the hybrid and automatic SRC methods. All SRC values measured using the hybrid SRC method are significantly correlated with those measured with manual and automatic SRC methods: SRC water (r = 0.8–1.0, p < 0.0001); sucrose (r = 0.9, p < 0.0001); sodium carbonate (r = 0.9, p < 0.0001); and lactic acid (r = 0.7–0.8, p < 0.01). Among the four SRC solvents, considering the SRC water is highly effective in discriminating hard and soft wheat, the high correlations between different laboratories, the relatively smaller standard deviation across laboratories and storage time and temperature at 22 °C and the significant correlation with cookie spread, it could be the best predictor of Australian soft wheat quality. Overall, the hybrid SRC method could be helpful in the Australian soft wheat breeding program, especially in the early-stage selection of soft wheat cultivars. The cookie spread negatively correlates with Rapid Viscosity Analyser peak viscosity (r = −0.8, p < 0.01), suggesting Australian soft wheat targets a lower pasting property for a better cookie performance. The SRC values of flour samples from four different soft wheat cultivars are affected by storage temperature at 22 °C and 32 °C over 12 months with inconsistent trends. The flour samples stored at various temperatures across 0, 1, 3, 6 and 12 moths, particularly those kept at a higher temperature, have more variability in their SRC values and higher uncertainty, which must be accounted for when comparing results between different laboratories. A standard SRC range will be established in collaboration with the Indonesian mills to categorise the Australian soft wheat quality suitable for the Indonesian market.