Physiological and quality changes of 'Phulae' pineapple during cold storage under dry mist humidifying system

'Phulae' pineapple is a Geographical Indication (GI) of Chiang Rai, Thailand. With unique characteristics as small size, aromatic taste and crispy, it became an important commercial fruit increasing in demand for both the domestic and overseas market. However, temperature and relative humidity are important factors that affect quality and storage life of fresh pineapple. Low temperature storage for a long time may lead to susceptibility to internal browning (IB) which is a main problem during transportation as well as weight loss. This work aimed to study the effect of dry mist humidifying (DMH) system on physiological and quality changes of 'Phulae' pineapple during cold storage. Fresh 'Phulae' pineapples were stored under three conditions: DMH system, DMH combined with electrolyzed water so called dry electro mist humidifying (DEMH) system and without humidifying system as a control, at 10±1°C for 35 days. Relative humidity in DMH and DEMH system was maintained between 90-95%. The incidence of IB was observed around the core of the control sample after 14 days of storage while the sample stored under humidifying system was found on day 21. Ethylene production was firstly detected in the control sample on day 28 with the increasing of severity of IB symptom. The presence of mold was observed only in the area of cutting end and crown leaves of all samples after 14 days of storage. Nevertheless, the sample stored under the DEMH system had a lower percentage of disease incidence compared to the DMH system due to its antimicrobial function of 100 ppm acidic electrolyzed water used to generate dry mist whereas DMH generated from distilled water did not possess a cloud having antimicrobial property. In addition, lower percentage of weight loss and vitamin C degradation was significantly found in the samples stored under DMH and DEMH system. The results indicated that DMH and DEMH system might be an alternative technique to alleviate IB and maintain quality of 'Phulae' pineapple during cold storage.