Almond quality is affected by the exposure of moisture and temperature post-harvest through the environment. Moisture exposure that causes moisture content ≥ 8% can result in a quality defect termed concealed damage, which is a brown discoloration of the nutmeat that occurs only after moderate to high heat treatments (roasting, blenching, etc.). Current industrial practice for reducing moisture in almonds prior to processing, is to apply low heat to in-hull almonds until a moisture content of ~6% is achieved. Drying can reduce the visual discoloration of the nutmeat, however the quality of these roasted almonds over a typical storage lifetime is unknown. To address this, almonds exposed to moisture (ME, ≥8%), and subsequently dried to ≦ 6% moisture, were roasted to achieve a light roast (LR) and dark roast (DR) level. Roasted almonds were held under accelerated shelf-life conditions (39°C, 15% RH) to promote rancidity development and evaluated over 12 months; sampling once a month. Peroxide value, free fatty acid value, conjugated dienes, and headspace volatiles, were evaluated. Descriptive and hedonic sensory analysis were performed at 0, 1, 3, 5, and 7 months of storage for the LR almonds. Descriptive analysis used trained panelists to rate specific sensory attributes and determined degree of differences (DOD). Hedonic analysis collected consumers’ likings on a 9-point scale. A significant difference in PV and FFAs were found between the ME and control almonds at both roasting level. Significant quality differences between ME and control almonds were detected in descriptive analysis. However, regular consumers did not notice any quality differences between the ME and control LR almonds.

Effect of post-harvest moisture exposure on stored roasted almonds

2019 Fall National Meeting

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