Package sealing apparatus

A method of preparing a sealed package containing food, the method comprising:

• providing a packaging containing food, the packaging having an opening formed from two opposing walls;
• compressing the opposing walls of the packaging together with opposing heat sealing members, thereby closing the opening and fusing the walls together to form a first heat-sealed portion of the packaging;
• compressing the first heat-sealed portion of the packaging with opposing cooling sealing members to prevent formation of microchannels in the first heat-sealed portion,
• wherein one of the cooling sealing members has a surface, wherein a first portion of the surface is a patterned surface comprising peaks and troughs and a second portion of the surface is flat and extends across at least a portion of the first heat-sealed portion of the packaging during the compressing with the cooling sealing members, wherein the opposing cooling sealing member includes a flat section that corresponds to the second portion of the one cooling sealing member.