Bitterness in Foods and Beverages

Bitterness is one of the four commonly accepted taste qualities (the others are sweet, salty and sour) and is surprisingly wide spread in foods. Bitter compounds have been reported in just about every food from avocado's to zucchini. Bitterness can be elicited from a diverse collection of chemical compounds encompassing a wide range of molecular size and functional groups. The complexity of the bitterness response can make the studies in this area perplexing. Because some individuals are almost totally blind to bitterness whereas others are extremely sensitive to bitterness, it is difficult for the food scientist to formulate or blend so that concentrations of bitter compounds are high sufficient for insensitive individuals but not too high for sensitive individuals.

This book was designed to be of practical assistance to those food scientists who may be struggling with a bitterness problem as well as those sensory scientists interested in bitterness. This is the most comprehensive text devoted to bitterness in foods and beverages. Each chapter has been written by individuals who have extensive experience with their subject matter.

The work is organized in four major sections. The first section introduces the subject of bitterness, how bitterness is sensed, why some compounds are more bitter than others and finally how these compounds are derived in food plants. The second section deals with sources of bitter compounds in foods and beverages. Some chapters are devoted to a single food or beverage such as coffee, tea, wine or apple ciders. Other chapters are more general in nature and deal with e.g. bitterness in dairy products, alcoholic beverages or the very wide ranging subject of food plants (primarily vegetables).

The last two sections deal with methods to separate and identify bitter compounds as well as methods to remove or reduce bitterness. It appears that HPLC is the method of choice to separate and study these compounds simply because most bitter compounds are generally nonvolatile or are thermally unstable. Identification is more difficult and various approaches are illustrated. Due to their economic importance, many approaches to remove or reduce bitterness in citrus juices have been developed. Therefore the last section uses citrus juices as examples of the various techniques which can be used to reduce bitterness in liquid food products. Methods to remove bitterness in solid foods are described in the chapter on soy beans.