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    Comparison of physicochemical properties of jackfruit seed starch with potato and rice starches
    (Taylor and Francis Group, 2021-03-08) Wong KT; Poh GYY; Goh AFSTARASTAR; Wee MSM; Jeyakumar Henry C
    The physicochemical properties of jackfruit seed starch (JSS) were investigated and compared with rice (RS) and potato (PS) starch. The amylose content of JSS (25%) was similar to PS (27%) but higher than RS (17%). The small granules of JSS (7.9 μm) was comparable to RS (9.7 μm), and both starches had A-type crystallinity. In contrast, PS had larger granules (43.4 μm) and displayed B-type crystallinity. The DSC results showed that peak gelatinization temperature of JSS (85.0°C) was significantly higher than RS (66.9°C) and PS (63.7°C), corresponding to higher pasting temperatures and lower swelling power at lower temperatures. There was no significant difference in stability between the starch gels after four freeze-thaw cycles. Formation of JSS gels with significantly higher hardness, chewiness and elastic modulus (G′), but lower fracturability demonstrated JSS ability to form strong gels. This would be beneficial for food applications requiring gelation with firm and elastic textural attributes.
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    The effect of planting date on maize: Silage yield, starch content and leaf area
    (2014) Tsimba, R; Edmeades, GO; Millner, JP; Kemp, PD; Morris, NJ
    Four field experiments were established in the Waikato and Manawatu regions over two years to determine planting date (PD) influence on growth, silage yield (SY) and starch content of seven maize (Zea mays) hybrids. Silage yield response to PD was best described using quadratic regression models. The PD at which silage yield was maximised (optimum PD) was later in the cooler, high latitude environment of Manawatu (23 October) than the more northerly locations in Waikato (9-15 October). In both regions, planting 2 or 3 weeks either side of the optimum PD reduced SY by <5%. In Waikato, the optimum PD in a warmer than average spring (+1°C) was 1-2 weeks earlier. Under non-limiting moisture conditions later planting reduced yields in both Waikato (24.22 versus 21.06 t/ha) and Manawatu (30.09 versus 22.50 t/ha). This was attributed to decreased temperatures (<15°C) and radiation (<17 MJ/m2 /d) during grain filling. Due to more rapid reductions in autumn temperature and radiation in Manawatu, yield decline beyond the optimum PD was greater (-183 kg/ha/d (0.6%), R 2 =0.81) than Waikato (-50 to -85 kg/ha/d (0.3%), R 2 ≥0.67). Starch content was highest for plantings before 6 November, dropping thereafter with harvest index. Highest maximum leaf area index was observed at mean daily temperatures of 17-19°C.