| บทคัดย่อ(English) |
Pasteurized beverages packed in plastic containers distributed in suburban and rural areas of the 14 southern provinces of Thailand were normally produced in small scale premises by local producers, farm women groups, cooperatives, etc. Many of these products could not meet the microbial standard of Ministry of Public Health (Notification no. 214 B.E. 2543). Thirty premises were proportional stratified randomly sampled from the total number of 59. Sixty percent of them received a registration number from Thai-FDA. The products of the sampled premises were found to be contaminated with yeast in 86% of cases, mold in 69%, coliform in 59%, and ~iE. coli~i in 13%. It was noted that production processes were found various among different kinds and even within the same kind of product. Based on their heat sensitivities, the products could be divided into 3 groups i.e. non-heat treatment, mild heat treatment and severe heat treatment. Two main causes of contamination in the products were under-processing and post-process contamination. The following processing conditions which were developed at laboratory scale for the selected 6 problem products could totally destroy coliform, E. coli, yeast and mold and still keep the desirable sensory qualities, i.e. (i) orange juice: blanching whole unpeeled orange for 10 s. or soaking in chlorinated water of (+,ณ) 200 ppm for 30 min before squeezing, (ii) pennywort juice: heating the juice at 72 (+,ฐ)C for 15 s. and immediately cooling, (iii) guava juice: heating the juice at 85 (+,ฐ)C for 15 s, (iv) Chinese black grass jelly in syrup: steaming jelly strips before filling with syrup, (v) hairy basil seed in syrup: heat-treating the seed by boiling or before filling with syrup, and (vi) coconut juice: heat-treating the coconut flesh by boiling or before filling with syrup. Water used in cooling and cleaning processes could be a cause of post-process contamination. Cooling water leaked into 100% of the hot filled capped plastic bottles. Coliform contaminated water used for cleaning utensils and rinsing one-way containers was the cause of contamination; however it could be 100% destroyed by rinsing with boiling hot water. Also, clean water must be used for rinsing the containers. |
