The pecan is the only tree nut with commercial importance that is native to North America and is an important nut crop contributing to the agricultural economy and history of the United States. It has been used for centuries by Native Americans (Hall, 2000) and is an important tree grown for its edible nuts and timber. In 2006, the U.S. pecan production was 206 million lb deriving from stands of both native and improved varieties, with a total crop value of $321 million [U.S. Department of Agriculture (USDA), 2007]. Pecan production fluctuates greatly from year to year as a result of physiological and environmental causes (Conner and Worley, 2000; Wood, 1990), and, consequently, average in-shell pecan prices vary greatly. Price of in-shell nuts has reached a record price of $1.76/lb in 2004 and dropped to $1.18/lb in 2007 (USDA, 2008).
Over 1000 different pecan varieties have been described (Thompson and Young, 1985); however, ≈57% of improved acreage is composed of only four varieties (Stuart, Western Schley, Desirable, and Wichita) and ≈90% by 33 varieties (Thompson, 1990). In recent years, other varieties such as Pawnee have been extensively planted in newly established orchards; however, official data are not available (T.E. Thompson, pers. comm.).
When pecan fruit are physiologically mature, the shucks surrounding the nuts split, trees can be shaken, and the nuts harvested. After harvest, pecans can be sold in the shell or processed. Processing involves mechanically washing and sanitizing, cracking, and separating kernels from the shells (shelling). The shelling process accelerates the oxidation process, thus reducing the shelf life of pecans (Baldwin and Wood, 2006). Rancidity and development of off-flavors are common in pecan kernels when they are not stored properly as a result of the high content of oil (Worley, 1994). It is therefore very important for retailers and consumers to follow certain guidelines to maintain flavor, color, and texture of pecan kernels. Controlling storage temperature is the single most important strategy for extending shelf life of shelled or in-shell pecans (Santerre, 1994).
Pecan kernels can be sold as whole, pieces, or meal and are commonly used as an ingredient for desserts, candies, or ice cream, but, until recently, they were not considered of value for their nutritional attributes. Lately, however, pecan kernels have been observed to be beneficial for human health in numerous ways. They improve the serum lipid profile and may play an important role in reducing the risk for heart disease (Rajaram et al., 2000, 2001). These beneficial properties are likely the result of their high monounsaturated fatty acid content (Rajaram et al., 2001). Most recently, they have been identified as having phenolic compounds (Villarreal et al., 2007; Wu et al., 2004), which, according to several studies (Mertens-Talcott and Percival, 2005; Tam et al., 2006), act as antioxidants and have the ability to lower the incidence of chronic diseases such as Alzheimer's disease, Parkinson's disease, some types of cancer, and other degenerative diseases. Although the content in antioxidants is not reported by the USDA as a category in the National Nutrient Database (USDA, 2006), several studies indicated that pecans are a good source of this important group of phytochemicals (Chun et al., 2002; Kornsteiner et al., 2006; Wu et al., 2004). Wu et al. (2004) reported the antioxidant capacity of over 100 different kinds of foods across the United States. Several nuts, according to this study, ranked among the foods with high antioxidant capacity with pecans being the kind with the highest antioxidant capacity in the nut group. Varieties differ in their content of antioxidants, although very few varieties have been thoroughly investigated (Villarreal et al., 2007).
Despite these positive facts about pecans, per capita consumption in the United States averages only 0.49 lb of kernels annually, which is slightly lower than walnut consumption (0.53 lb) but less than half than that of almonds (1.01 lb) (USDA, 2007). Regardless of increased competition from almonds, and, to a lesser extent, walnuts, pecan consumption has remained relatively stable over the past 30 years (USDA, 2007).
The recent discoveries of the health attributes of pecan kernels have prompted pecan growers' associations to start marketing programs to promote pecan consumption and to inform the consumers about the proper ways to store pecan kernels to maintain flavor and health attributes (National Pecan Shellers Associationn, 2007; Texas Pecan Board, 2007).
The objective of the present study was to survey consumers' knowledge of the nutritional attributes, storage guidelines, and their preferences of consumption and use. Results from the present study will be used to develop more marketing strategies to inform consumers about health benefits related to the consumption of pecans.
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