# Volatile Profile of Nuts, Key Odorants and Analytical Methods for Quantification
## 4 Effect of Harvesting Conditions and Healthy State of Nuts on Volatile Profile  
The main volatile compounds reported in raw nuts are reviewed in Table 2. As expected, several differences are detected that could be related to nut composition. Additionally, different factors could change the characteristic volatile profile of raw nuts. In this section, the effect of harvesting conditions is reviewed as well as the healthy state of nuts.  
The current limitation of water resources is threatening nut productivity, so new sustainable agronomic practices, such as regulated deficit irrigation (RDI), have been implemented. These irrigation strategies do not affect fruit quality [46; 47]; however, water stress during the growing of nuts can modify its volatile profile [48]. For example, almonds produced under an RDI strategy presented higher total volatile content. In a study with pistachios, it was found lower water stress conditions produced nuts with higher terpene content such as \(\alpha\)-pinene [49; 50]. This compound is the most important volatile compound in pistachio samples, and it was observed that weather can influence the biosynthesis of VOCs [51] and also the harvesting time [23; 25]. In another study, it also evidenced that the flavor of pistachios was minimized by irrigation [49].  
Moreover, the volatile organic profile of nuts could be modified by the state of health of the nut. The navel orangeworm (NOW) is among the major concerns in the almond industry, due to it being able to cause fungal infection. VOCs emission of almonds and their relationship with NOW have been investigated [52]. Although differences in the volatile profile have been found, the identification of particular compounds and their relationship to NOW have not been addressed. Mature almonds from the Monterey variety were evaluated for their volatile composition after mechanical damage and compared with the volatile composition of undamaged almonds. 3-pentanol and two isomers of a spiroketal chalcogen were found in the damaged almonds. Moreover, the concentration of some compounds such as a spiroketal conophthorin, numerous four-carbon esters and ketones as well as alcohol derivatives, in addition to two eight-carbon chain compounds, increased in the damaged almonds [52; 53].  
Changes in volatile organic compounds have been evaluated as an indicator of aflatoxin contamination [31; 54; 55]. [PERSON] et al. studied the volatile emissions of whole and blanched almonds naturally contaminated with aflat. Volatiles indicative of fatty acid decomposition were predominant in the samples that underwent some form of blanching. Moreover, they found an increase in the concentration of some aldehydes (e.g., hexanal, heptanal, octanal) and hexanoic acid [56]. A similar study was carried out with pistachios. A comparison of volatile compounds in healthy and naturally or artificially aflatoxin-contaminated pistachios was carried out by [PERSON] et al. They found some differences in specific compounds such as C-8 alcohols and aldehydes, sesquiterpenes, and monoterenes, among others. These compounds allowed differentiation among contaminated and healthy pistachios by applying principal component analysis [28].