Effect of two pasteurization methods on the content of bioactive compounds and antioxidant capacity of nance (Byrsonima crassifolia) pulp and their kinetics of loss during refrigerated storage

The aim of this work was to evaluate the effect of two pasteurization methods: Low Temperature Long Time (LTLT) carried out at 63 ± 2.0 °C/30 min and High Temperature Short Time (HTST) performed at 73 ± 2.0 °C/15 s on the physicochemical parameters, bioactive compounds, and antioxidant activity of the treated pulp during the refrigeration storage (4 °C) of nance pulp. The material processed by LTLT presented the lowest decrement of ascorbic acid, phenolic compounds, and antioxidant activity (DPPH). Rates of losses of ascorbic acid, phenolic compounds, and antioxidant capacity (DPPH and ABTS) were described by a first order kinetics. The rate constants obtained were higher for HTST pulp, except for the antioxidant capacity determined by ABTS which was slightly higher for LTLT pulp. The t_1/2 values were, consequently, larger for LTLT pulp indicating a longer time for decreasing the concentration of the bioactive and the antioxidant capacity. Five main phenolic compounds were identified by HPLC: gallic, trans-ferulic and caffeic acids, rutin, and quercetin and the observed increment of the intensity of quercetin peak for LTLT treated pulp could be due to the breakage of rutin. Both pasteurization methods reduced microbial loads to recommended standards and LTLT reduced it more pronouncedly. LTLT pasteurization could be recommended the best alternative for the pasteurization of this pulp.