Slightly acidic electrolyzed water treated bamboo culm straws: a promising alternative to plastic straws

Abstract

Natural biodegradable alternatives to plastic straws have attracted more attention because of the environmental problems caused by disposable plastic straws. The hollow bamboo culm of Sasa fortunei is a promising substitute for plastic straws because of its small diameter, fast-growing, naturally renewability, and biodegradability. However, bamboo culm straw is easily affected by mildew infection. This study investigated the impact of electrolyzed water (EW) treatment on the anti-mildew properties of Sasa fortunei culm straws using an orthogonal test (L₉(3³)) considering pH value, treatment time and temperature. The anti-mildew properties, contact angle, thermal degradation, water stability and mechanical properties of bamboo culm straws were tested. The results showed that the factors affecting the anti-mildew performance of bamboo culm straws were pH value, treatment temperature and treatment time in sequence. The optimal parameters of the EW were pH value of 6.0 at 60 °C for 120 min, with the best anti-mildew effect of 9.37% infection area rate. The bamboo straw treated by slightly acidic electrolyzed water (SAEW) had a larger surface contact angle and a smaller surface energy. The mechanical properties of bamboo straw immersed in green tea, orange juice, coke and milk showed higher than those of the untreated group. Therefore, the Sasa fortunei bamboo straw treated by SAEW has good water and thermal stability, excellent mechanical properties and anti-mildew properties, being a potential material to replace the traditional plastic straw.