OFFFLAVORS IN MILK

Since fluid milk is consumed regularly by people of all ages and most ethnic groups, this product is constantly being assessed for quality by consumers. If the flavor of milk is not appealing or appetizing, less of it will be consumed. Furthermore, off-flavored milk may cast an unfavorable reflection on other dairy products that are sold or distributed under the same brand name and thus unfavorably affect sales of those products as well.?

The flavor of whole milk should be pleasant and sweet and with neither a foretaste nor an aftertaste other than that imparted by the natural richness due to the milkfat and other milk solids. ?

Milk is generally considered to have a flavor defect if it manifests an odor, a foretaste, or an aftertaste, or does not leave the mouth in a clean, sweet, pleasant condition following tasting.

In general, off-flavors of milk may be categorized into four major (A-B-C-D) groupings:

·????????Absorbed (barny, cowy, feed, garlic/onion),

·????????Bacterial (acid, bitter, fruity/fermented, malty, rancid, unclean [i.e., psychrotrophic])

·????????Chemical (astringent, cooked, lacks freshness, light oxidized, metal oxidized, rancid) and

·????????Delinquency (flat, foreign, salty, unclean)

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To best judge flavor, the milk or cream should be tempered to 12.8 to 18°C.

The judge should swirl the bottle and then smell the milk or cream. Swirling serves to mix the sample and to spread a fine film on the inside of the container which gives maximum opportunity for volatiles to fill the headspace.

A small amount of sample should be poured into a clean odorless container. Glass is preferred. ?but plastic or paper is acceptable.

The judge should then take a sample into his or her mouth, and move it around in the mouth making sure to coat all the surfaces of the mouth from the front to deep in the back down to the throat, noting any off-flavors. While the sample is in the mouth, air is moved up through the nose to enhance odor detection. The sample should then be expectorated and a few moments allowed to observe aftertaste. Aftertaste and aroma sensation are enhanced by exhaling slowly through the nose.

Swallowing sample is not advised.