Acidification processes of carving vegetable using acid conditioning machine under temperature and pressure control

Abstract

. This research aimed to study the acidification processes of carving vegetable using acid conditioning machine under emperature and pressure control which was developed in this study. Four acidification procedures were done at normal atmospheric pressure (method 1), under vacuum pressure for 10 (method 2) and 20 min (method 3) and vacuum pressure alternating with normal atmospheric pressure for each of 1 hour. There were two main parts of acid conditioning machine including the temperature controller inside the pickle tank and heat conductor tank, and the pressure controller inside the pickle tank. The pickling temperature was stabled at 40oC under the pressure of 0.5 Bar. PLC (Programmable Logic Controller) program was used to write the ladder for controlling all processes and display through SCADA system. The results showed that the acidification method by soaking the carved-rose carrot under vacuum pressure alternating with normal atmospheric pressure showed the shortest time to equilibrium by 7 hours. Then, the carved-rose carrot was packed in the glass jar followed by sterilized in boiling water for 15 minutes and stored at room temperature for 7 days. Total bacteria count, Escherichia coli and Yeast-mold were not exceeded than the standard limit. Staphylococcus aureus was not detected throughout the storage periods