Tree nuts

With the exception of peanuts, most of the important nuts from around the world are home on trees, many of them from native seedlings. Among the latter group are the beechnut, Bra2il nut, butternut, chestnut, filbert, hickory nut, pecan, pine nut, and black walnut. The pecan, Knglish walnut, filbert, and almond are the four principal edible tree nuts produced in the United States, where the term Knglish walnut is used synonymously with the Persian or Carpathian walnut (2). 

Most nuts for commercial use are characteri2ed by high oil and protein contents (see Proteins) as well as a low percentage of carbohydrates (qv). However, some varieties, mostly inedible tree nuts such as acorn, horse chestnut, and chufa, contain at least as much sugar and/or starch as protein. The edible water chestnut is also in this category, as is the cashew nut, which contains starch in addition to a rich store of oil. The proximate composition of a number of nuts and of some nut products are given in Table 2 (3). 

Nuts and Nut Products. Nuts are used mainly as edible products and marketed either with or without the shell, as the demand requites. The most popular nuts ia the shell are English walnut, filbert, almond, Brazil nut, peanut, pistachio, and the improved, or paper-shell, pecan the most popular salted and roasted nut kernels iaclude these as well as the cashew, macadamia, and pignofla. Each year more nuts are shelled ia ceatraHy located plants and marketed as meats. The annual per capita consumption of shelled tree nuts ia the United States rose from 0.78 kg in 1987 to 1.00 kg in 1992 (132). 

English or Persian Walnuts. Walnuts are produced in more countries than any of the other tree nuts but production figures are unrehable. The United States is the leading producer of walnuts, at 234,913 t in 1990—1991 (valued at 279,720,000). Production, mostly in Califomia and Oregon, is nearly one-half of the world total. Many countries produce substantial quantities of walnuts. The USDA considers estimates of the commercial crop more rehable than the total yearly production figures, which in 1990—1991 were 152,500 t in China, 66,000 t in Turkey, 17,000 t in India, 13,000 t in Prance, and 12,000 t in Italy. Walnuts, both in-sheU and shelled, may be imported from many countries, eg. Prance, Italy, China, Turkey, and India. Most imported walnuts are smaller than domestic walnuts and are used by the confectionery and baking industries. 

USDA Economic Research Service, Fruit and Tree Nuts Situation and Outlook Report, USDA Economic Research Service, 1993. 

J. G. Woodroof, Tree Nuts Production, Processing Products, Avi Publishing, Westport, Conn., 1979. 

The most frequent elicitators of food allergy in children are peanuts and tree nuts [ 17]. In France the prevalence of food allergy has been estimated to be 3.2% [18]. Furthermore, in this study, food was identified as the most common cause of anaphylaxis. Here the major identified food allergens besides peanuts and tree nuts were shellfish, wheat and lupine flour [18]. 

These data suggest that due to an increase of food allergy and in particular tree nut and peanut sensitization, the risk for anaphylaxis has been increased at the same time. 

Sicherer SH, Munoz-Furlong A, Sampson HA Prevalence of peanut and tree nut allergy Chn Immunol 2003 112 1203-1207. 32... 

Sicherer SH. Furlong TJ, Munoz-Furlong A, Burks AW. Sampson HA A voluntary registry for peanut and tree nut allergy characteristics of the first 5,149 49... 

Air, water, soil, and plant (pasture grass hay, forage, cucurbits, citrus, pome fruit, tree nuts, fruiting vegetables, and cotton) and animal materials (tissues, milk, blood,... 

Citrus, pome fruit, tree nut, fruiting vegetables, and cotton substrates... 

Eor tree nuts acetonitrile-methanol-0.05 M potassium dihydrogenphosphate (8 5 7, v/v/v)... 

The average recoveries and standard deviations for the many citrus, pome fruit, tree nut, fruiting vegetables, and cotton substrate sample types were acceptable when fortified at concentration levels ranging from 0.01 to 4 mg kg. The LOQ of the method was 0.01 mgkg , except for citrus oil (0.02mgkg Q, and the LOD was 1.25 ng injected. 

Kris-Etherton PM, Hu FB, Ros E and Sabate J. 2008. The role of tree nuts and peanuts in the prevention of coronary heart disease multiple potential mechanisms. J Nutr 138(9) 1746S—1751S. 

The photochemiluminiscence (PCL) assay was initially used by Popov and others (1987). Popov and Lewin (1994 1996) have extensively studied this technique to determine water-soluble and lipid-soluble antioxidants. The PCL assay measures the antioxidant capacity, toward the 02 radical, in lipidic and water phase. This method allows the quantification of both the antioxidant capacity of hydrophilic and/or lipophilic substances, either as pure compounds or complex matrices from different origin synthetic, vegetable, animal, human, etc. The PCL method is based on an approximately 1,000-fold acceleration of the oxidative reactions in vitro by the presence of an appropriate photosensitizer. The PCL is a very quick and sensitive method. Chua and others (2008) used this assay to determine the antioxidant potential of Cin-namomum osmophloeum, whereas Kaneh and Wang and others (2006) determined the antioxidant capacity of marigold flowers. The antioxidant activity of tree nut oil extracts was also assessed by this method (Miraliakbari and Shahidi 2008). 

Miraliakbari H and Shahidi F. 2008. Antioxidant activity of minor components of tree nut oils. Food Chem 111 (2) 421—427. 

Sicherer, S.H., Munoz-Furlong, A. and Sampson, H.A., Prevalence of peanut and tree nut allergy in the United States determined by means of a random digit dial telephone survey A 5-year follow-up study. J. Allergy Clin. Immunol., 112, 1203, 2003. 

If it is required to perform the determination by digestion and distillation, refer to Method 5.6b. Determination of organic plus ammonium-N by digestion and distillation, but use 2 g oven-dry plant sample ground to 1 mm. Also, for the calculation, multiply the sample titre minus blank titre by 0.35 to give the % N in the sample. Multiply the % N by 6.25 to get the % crude protein. This assumes there are 160 g N kg- plant protein. Traditional factors for other products are almonds, 5.18 brazil nuts and peanuts, 5.46 coconuts and tree nuts, 5.30 dairy products, 6.38 wheat, 5.7. Note about 20% of any nitrate present will be included. 

---