Ejecute lo siguiente:
echo "SELECT CONCAT_WS(',', ${MYSQLTABLE}.created_at, ${MYSQLTABLE}.product_options) FROM ${MYSQLTABLE} WHERE ${MYSQLTABLE}.product_id=1 ORDER BY ${MYSQLTABLE}.created_at" | \
mysql ${MYSQLOPTS} | tr '\t' ',' > ${MYSQLDUMP}
El tr
el comando reemplaza un carácter con otro.
