The storage attributes, moisture content and water activity, did
not show significant differences among roasted almonds heated
with different methods under the same storage conditions. Peroxide value and the concentration of aliphatic aldehydes of all
roasted almond samples increased significantly during storage.
Roasted almonds, packaged in paper bags, were oxidised and rancid
after 3 months of storage. The changes might have been induced
by the high oil content and polyunsaturated fatty acids
which produced volatile aliphatic aldehydes such as hexanal, heptanal,
(E)-2-octenal, octanal, and nonanal. Hexanal and nonanal
concentrations were better indicators of the shelf life of roasted almonds
than peroxide value. The quality of roasted almonds produced
with SIRHA and HA heating was similar after the 3-month
storage period that is typically required in the food industry. It
was concluded that SIRHA roasting is an effective method for producing
pasteurised almonds with similar quality as HA and has potential
for lowering production costs due to reduced roasting time
compared with conventional hot air roasting.