Food grading involves the inspection, assessment and sorting of various foods regarding quality, freshness, legal conformity and market value. Food grading is often done by hand, in which foods are assessed and sorted. Machinery is also used to grade foods, and may involve sorting products by size, shape and quality. For example, machinery can be used to remove spoiled food from fresh product.
A screenshot from the electronic grading system showing USDA Choice, Yield Grade 2 beef. The left is the natural color view of the cut; the right is the instrument enhanced view that details the amount of marbling, size, and fat thickness.
Optical sorting achieves non-destructive, 100 percent inspection in-line at full production volumes.
Inspected beef carcasses tagged by the USDA
Dark-roasted coffee beans
Maple syrup is a syrup made from the sap of maple trees. In cold climates, these trees store starch in their trunks and roots before winter; the starch is then converted to sugar that rises in the sap in late winter and early spring. Maple trees are tapped by drilling holes into their trunks and collecting the sap, which is processed by heating to evaporate much of the water, leaving the concentrated syrup.
Sugar Making in Montreal, October 1852
A "sugar shack" where sap is boiling.