Using °Brix as an Indicator of Vegetable Quality: An Overview of the Practice

Introduction Many variables are used to assess fruit and vegetable quality. Some quality metrics such as size, shape, and color are relatively obvious and tend to influence “eye appeal.” Others, such as flavor, texture, aroma, and nutrient content, however, are more subjective. They may also require sophisticated techniques and equipment to assess. In addition, these subjective metrics tend to influence more complicated aspects of product appeal, such as eating quality and nutritional value. Quality-conscious buyers often pay specific attention to eating quality. A product’s appearance may help sell it the first time but the enjoyment of eating it is usually required for repeat sales. An item’s eating quality is based on its composition (physical, chemical makeup) and the consumer’s unique sensory apparatus. In fact, eating quality is best assessed by trained panelists because the human olfactory system is superior to all other “technology” or systems in its ability to differentiate samples based on key sensory properties. Not surprisingly, companies rely heavily on panel testing, which is timeconsuming and costly. Of course, farmers and produce managers and handlers cannot run extensive panel tests to identify which product(s) may please most of their customers most of the time. Instead, with instruction and experience, farmers and others can rely on proven indicators of quality and field-friendly tools for measuring them. The level of soluble solids in a fruit or vegetable influences how sweet it may taste. Just as yield is reported in pounds or tons per acre, soluble solids are usually reported in values of °Brix. °Brix values are important because they can be measured objectively and they relate to a subjective criterion that buyers and eaters use to assess vegetable quality—flavor or sweetness. When obtained and applied correctly, °Brix values can aid in variety selection, harvest scheduling, and other aspects of crop production including irrigation, fertility, and post-harvest management. Farmers and others should make special note that °Brix can be measured easily and reliably in the field, shop, or shed using a relatively inexpensive piece of equipment able to fit in most pockets: a refractometer. Four fact sheets have been prepared to guide farmers and produce buyers in using °Brix as an indicator of vegetable quality. This overview provides important background information on °Brix, outlines its application in horticultural crop production, and describes the benefits and limitations of measuring °Brix during vegetable