Anacardium occidentale L. - Anacardiaceae - cajúeiro (port.), cashew tree, Cashew, Kaschubaum
Evergreen tree or large shrub, up to 10m high, native to tropical South America, cultivated elsewhere.
„The edible seeds are referred to as cashew nuts. They are surrounded by a leathery shell (mesocarp), which is rich in liquid. This substance is an important raw material for resin. The liquid contains skin-irritant toxic compounds, which are removed by heating. The fleshy hypocarp, or cashew apple, is processed into jam and dried fruit.“ http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=200012676
„Cashew apples have a sweet but astringent taste. This astringency has been traced to the waxy layer on the skin that contains a chemical, urushiol, which can cause minor skin irritation to areas that have had contact with it. It is almost identical to the astringency caused by the skin of a mango, which also contains urushiol. The astringency from mango skin can be mildly tasted in the flesh of mango fruit, just as the astringency of cashew apple skin can be mildly tasted in the flesh of cashew apples. In cultures that consume cashew apples, this astringency is sometimes removed by steaming the fruit for five minutes before washing it in cold water; alternatively, boiling the fruit in salt water for five minutes or soaking it in gelatin solution also reduces the astringency. When mixed in drinks or used as a flavoring, the astringency becomes highly diluted and typically causes no irritation to those without urushiol allergies.“
„Cashew apple nectar is a secondary product from the production of cashew nuts and possesses an exotic tropical aroma. Aroma volatiles in pasteurized and reconstituted (from concentrate) Brazilian cashew apple nectars were determined using GC-MS and split, time-intensity GC−olfactometry (GC-O)/GC-FID. Methional, (Z)-1,5-octadien-3-one, (Z)-2-nonenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, β-damascenone, and δ-decalactone were identified for the first time in cashew apple products. These compounds plus butyric acid, ethyl 3-methylbutyrate, 2-methylbutyric acid, acetic acid, benzaldehyde, homofuraneol, (E)-2-nonenal, γ-dodecalactone, and an unknown were the most intense aroma volatiles. Thirty-six aroma volatiles were detected in the reconstituted sample and 41 in the pasteurized sample. Thirty-four aroma active components were common to both samples. Ethyl 3-methylbutyrate and 2-methylbutyric acid were character impact compounds of cashew apple (warm, fruity, tropical, sweaty). Using GC-pFPD, 2-methyl-3-furanthiol and bis(2-methyl-3-furyl) disulfide were identified for the first time in cashew apple. Both were aroma active (meaty).“
[Gas chromatographic-olfactometric characterization of aroma compounds in two types of cashew apple nectar., Valim, M.F., Rouseff, R.L., Lin, J., Journal of agricultural and food chemistry, Vol.51(4), 2003, 1010-1015]
„The headspace volatile components of the juice of cashew apples from a commercial Brazilian dwarf genotype were separated by high-resolution gas chromatography and identified by GC/MS. Five judges evaluated the GC effluents using the Osme technique in order to determine the importance of each compound to the characteristic cashew aroma. Esters methyl 3-methyl butanoate, ethyl 3-methyl butanoate, methyl butanoate, ethyl butanoate, ethyl trans-2-butenoate and methyl 3-methyl pentanoate were important to the sweet, fruity and cashew-like aroma. Cis-3-hexenol, hexanal and 2-methyl-2-pentenal presented different green notes. In spite of the flame ionisation detector being unable to detect sulphur compounds, the olfactometric analysis revealed chromatographic regions where sulphur-like odours were perceived by the Osme sensory panel. The most intense unpleasant odour was due to 2-methyl butanoic acid, which was described as very stinky.“
[Evaluation of volatile flavour compounds from cashew apple (Anacardium occidentale L) juice by the Osme gas chromatography/olfactometry technique., Garruti, D. S., Franco, M. R. B., da Silva, M.A.A., Janzantti, N.S., Alves, G.L., Journal of the Science of Food and Agriculture, Vol.83(14), 2003, 1455-1462]
„There is a considerable loss of volatile compounds during the thermal concentration of cashew apple juice, damaging product quality… the purpose of this research was to identify the aroma volatiles evaporated off from cashew apple juice and recovered in the water phase during concentration of this beverage in an industrial plant. Water phase volatiles were extracted using dichloromethane, concentrated under a nitrogen flow, separated by gas chromatography (GC) and identified by GC-mass spectrometry. In order to determine the contribution of each volatile to the cashew aroma, five trained judges evaluated the GC effluents using the Osme GC-olfactometry technique.
71 volatiles were identified; of these, 47 were odour active. Alcohols were preferentially recovered in the cashew water phase, notably heptanol, trans-3-hexen-1-ol and 3-methyl-1-butanol, representing 42% of the total chromatogram area and imparting green grass and fruity aroma notes to the water phase. Esters represented 21% of the total chromatogram area, especially ethyl 2-hydroxyhexanoate, ethyl trans-2-butenoate and ethyl 2-methylbutanoate, and were responsible for the fruity/cashew-like aroma of the water phase. On the other hand, 3-methylbutanoic and 2-methylbutanoic acids were the volatiles that presented the greatest odour impact in the GC effluents of the water phase…
Overall, the results of the present study strongly indicated that further concentration of the esters recovered in the water phase, either by partial distillation or by alternative technologies such as pervaporation, could generate a higher-quality natural cashew apple essence.“
[Aroma volatiles recovered in the water phase of cashew apple (Anacardium occidentale L.) juice during concentration., Sampaio, K.L., Garruti, D.S., Franco, M.R.B., Janzantti, N.S., Da Silva, M.A.A., Journal of the Science of Food and Agriculture, Vol.91(10), 2011, 1801-1809]
Volatile compounds in a heated aqueous extract of cashew included (FID peak area %): Propanal (7.59), acetone (1.69), methylpropanal (30.48), 2-methylfuran (13.95), butanone (1.62), 2-pentanone (7.62), 3-methylbutanal (11.49), 2-methylbutanal (8.08), acetol (1.9), hexanal (0.35), methylpyrazine (0.68), dihydro-2-methyl-3(2H)-furanone (coffee furanone; 0.45), furfural (7.44), dimethylpyrazines (0.44), acetylfuran (0.49), benzaldehyde (0.24), 5-methylfurfural (0.42), phenylacetaldehyde (0.46).
[Coleman III, W. M., J. L. White Jr, and T. A. Perfetti. „Characteristics of heat-treated aqueous extracts of peanuts and cashews.“ Journal of Agricultural and Food Chemistry 42.1 (1994): 190-194]
„…Strecker aldehydes, including methylbutanal, 2-methylpropanal, and acetaldehyde, were at the highest concentration in roasted cashews. The Maillard reaction contributed to the formation of most of the volatiles in cashews from the 3 countries. There was also degradation of sugars to form furan-type compounds and oxidation of lipids to form alkanals such as hexanal.“
[Volatile profile of cashews (Anacardium occidentale L.) from different geographical origins during roasting., Agila, A., Barringer, S.A., Journal of food science, Vol.76(5), 2011, C768-C774]
„In cashew nuts, acetic acid and acetaldehyde contribute to a pungent aroma, and phenylethanol is responsible for sweet and floral aromas. The main aromas come from pyrazines and aldehydes. Pyrazines are responsible for a nutty aroma and aldehydes such as methylbutanal and 2-methyl propanal are responsible for a pleased aroma in many roasted foods. Lipid oxidation products such as hexanal and nonane are also contributed to green and herbaceous odors, while ethyl butanoate is responsible for sweet, fruity and cashew-like aromas.“
Roasted cashews showed higher concentrations (μg/L) of organic volatiles than raw cashews. This is especially true for compounds like acetic acid, acetaldehyde, 2-methylpropanal, methylbutanal, methanol, ethanol, hexane, heptane, styrene, ethyl butanoate, acetone, as well as mono-, di- and trimethyl pyrazines.
[Agila, Amal. Volatile Profile of Cashews (Anacardium occidentale L.), Almonds, and Honeys from Different Origins by Selected Ion Flow Tube Mass Spectrometry. Diss. The Ohio State University, 2012]
Jacquin, N.J. von, Selectarum stirpium Americanarum historia (2nd -luxury- ed.)
[New York Botanical Garden] (1780-1781) Select. Stirp. Amer. Hist., ed. 1780-1781