The intermediate operations can serve both the traditional markets and international markets, but their true niche is the middle of the domestic market. The Mexican middle class is interested in quality and marketing services to some degree but is unable or unwilling to pay the prices that the top-of-the-line produce commands. These firms size, clean, and package their produce but they often don't have as modern facilities as the industry leaders. Moreover, they may not have the same degree of coordination between the farm and the packing house as the industry leaders, so their supply tends to be relatively small and of less consistent quality. Canning, Freezing, and other Processing Operations One way to reduce the perishability of a product is to process it. For fruits and vegetables, this usually involves canning or freezing. With canning, the product becomes nonperishable and with freezing the product becomes nonperishable if it is kept frozen. Canned fruit and vegetables have never been as important in Mexico as in the United States, at least in part because the climate allows fresh production of most products throughout the year. Nevertheless, Mexico's largest fruit and vegetable canner, Herdez, had gross sales in 1993 of 924,077 New Pesos, or about $300 million. Frozen vegetables are becoming an important product, primarily for export to the United States, though domestic consumption is also expanding. Other important frozen products are strawberries, avocado mix, and frozen concentrated orange juice. The longer production year and lower labor costs tend to offset the higher transportation costs to U.S. markets, relative to U.S. competitors. Most of the plants geared for exporting were set up by U.S. companies, such as Green Giant and Birds Eye, with U.S. grade machinery and are built to U.S. standards.