"Processing" means canning, preserving, or fermenting, which materially alters the flavor, keeping quality, or any other property, the extracting of juices or other substances, or the making of any substantial change of form. It does not include refrigeration at temperatures which are above the freezing point nor any other treatment which merely retards or accelerates the natural processes of ripening or decomposition.
Ca. Food and Agric. Code § 42519