Effects of Porphyra haitanensis polysaccharides on gelatinization and gelatinization kinetics of starches with different crystal types

The effects of Porphyra haitanensis polysaccharide (PHP) on the gelatinization and gelatinization kinetics of corn starch (CS), potato starch (PS) and lotus seed starch (LS) were studied. The gelatinization, rheological and thermal enthalpy properties of the samples were measured by a rapid viscosity analyzer (RVA), a rheometer, and a differential scanning calorimeter (DSC), respectively. And the kinetic equations were further established. RVA confirmed that the addition of 0.4 %, 0.8 % and 1.2 % PHP elevated the gelatinization viscosity of CS and LS but decreased that of the PS, and also elevated the thermal balance of CS, PS, and LS, especially PS (The breakdown viscosity was decreased to 363.00 & PLUSMN; 6.08, 370.00 & PLUSMN; 1.15, and 362.00 & PLUSMN; 0.58, respectively). And the rheometer indicated that the addition of 0.4 %, 0.8 % and 1.2 % PHP improved the apparent viscosity of CS, PS and LS, especially PS (The consistency coefficient was increased to 18.26 & PLUSMN; 0.02, 21.71 & PLUSMN; 0.04, and 23.26 & PLUSMN; 0.01, respectively). Eventually, DSC displayed that the addition of 0.4 %, 0.8 % and 1.2 % PHP extended the gelati-nization temperature and enthalpy of CS, PS, and LS, especially PS. Among them, the gelatinization temperature (63.40 & PLUSMN; 0.03, 70.26 & PLUSMN; 0.02 and 74.61 & PLUSMN; 0.01, respectively) and the gelatinization enthalpy (1.55 & PLUSMN; 0.01) of PS increased the most with 1.2 % PHP. Moreover, gelatinization kinetics displayed that the addition of 0.4 %, 0.8 % and 1.2 % PHP decreased the rate constants of CS, PS, and LS and accelerated the activation energies of CS (666.37 & PLUSMN; 4.23, 623.89 & PLUSMN; 4.21 and 558.39 & PLUSMN; 2.35, respectively) and PS (752.53 & PLUSMN; 4.13, 699.61 & PLUSMN; 3.78 and 662.15 & PLUSMN; 4.52, respectively) while reducing that of the LS (938.87 & PLUSMN; 3.38, 669.98 & PLUSMN; 4.61 and 491.48 & PLUSMN; 4.29, respectively). Therefore, the addition of PHP at all concentrations inhibited the gelatinization procedure of CS and PS but promoted that of the LS. This study provided a theoretical basis for the creation of new products based on PHP and starch.