ABSTRACT

This study aimed to characterize ozone gas (O₃) decomposition kinetics when injected at low pressure for controlling Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), and its effect on popcorn kernel quality. The ozonation of the kernels was conducted in a 70-L hypobaric chamber, using samples of 5.0 kg of grains packaged in woven polypropylene bags. Firstly, the internal pressure of the chamber was reduced to 250 hPa, and ozone was injected at concentrations of 5.0, 6.7, 8.5, and 13.0 mg L⁻¹ until reaching a pressure of 940 hPa. The ozone concentration decay inside both the chamber and package was continuously monitored. The quality parameters assessed included the expansion volume, moisture content, electrical conductivity, and color of the popcorn kernels. The decomposition kinetics followed a first-order model in all concentrations studied. The values of decomposition rate constant (k) ranged from 0.030 to 0.014 min⁻¹, inside the package, and from 0.030 to 0.015 min⁻¹, inside the chamber. The ozone half-lives ranged from 22.7 and 49.8 min, inside the package, and from 20.6 and 46.5 min, inside the chamber. Ozone applied in a low-pressure system at 13.0 mg L⁻¹ controlled 94.45% of the S. zeamais insects in the grain mass. The injection of ozone gas at low pressure did not change the expansion volume, moisture content, and electrical conductivity of the popcorn kernels.

摘要

本研究旨在描述在低压下注入臭氧气体 (O ₃ ) 以控制Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae)时的分解动力学及其对爆米花仁质量的影响。使用包装在编织聚丙烯袋中的 5.0 公斤谷物样品，在 70 升的低压室中对谷粒进行臭氧处理。首先，将室内压力降至250 hPa，注入臭氧浓度为5.0、6.7、8.5和13.0 mg L ^-1直到达到 940 hPa 的压力。连续监测腔室和包装内的臭氧浓度衰减。评估的质量参数包括爆米花仁的膨胀体积、水分含量、电导率和颜色。在所研究的所有浓度下，分解动力学都遵循一阶模型。分解速率常数(k)的值在封装内部为0.030至0.014 min ^-1，在腔室内为0.030至0.015 min ^-1。臭氧半衰期在包装内为 22.7 至 49.8 分钟，在室内为 20.6 至 46.5 分钟。在低压系统中应用 13.0 mg L ^{-1 的}臭氧控制了 94.45% 的玉米链球菌谷物中的昆虫。在低压下注入臭氧气体并没有改变爆米花仁的膨胀体积、水分含量和电导率。