Interaction of oxygen and moisture content on 'Barton' and 'Jackson' pecan storage

The effects of the nut moisture content (MC) and storage conditions on the physicochemical quality and volatile compound (VC) profile after storage of pecan nuts are still poorly understood. Therefore, the present study aimed to evaluate the effects of MC (6 and 4 %) and the interaction with atmospheric conditions (20.9 kPa) and low O2 partial pressure (2 kPa O2) on 'Barton' and 'Jackson' pecan storage. Color parameters, internal browning (IB) incidence and severity, respiration rate, acidity, peroxide value (PV), and VC profile after 8 and 12 months of storage at 20 degrees C were evaluated. 'Barton' and 'Jackson' pecans stored with 6 % MC + 2 kPa O2 presented the highest hue and luminosity (L) values, i.e. lighter color, after 8 and 12 months of storage. However, 'Barton' and 'Jackson' pecans stored with 6 % MC + 20.9 kPa O2 had the highest IB incidence and severity and respiration rate. After 8 months, pecans stored with 4 % MC + 20.9 kPa O2 had lower acidity and PV in both cultivars, compared with the pecans stored under 6 % MC + 20.9 kPa O2. The lower O2 in 'Barton' pecans stored with 6 % MC decreased PV, which was also the case for 'Jackson' nuts stored at 4 % MC. Regardless of the MC, pecans stored under 2 kPa O2 had the lowest hexanal and hexanol contents in both cultivars. Our findings suggest that it is necessary to choose between reducing MC or kPa O2 when aiming to maintain the quality of 'Barton' and 'Jackson' pecans stored under ambient temperature conditions (20 degrees C).

Automated summary

This study investigated the effects of nut moisture content and storage conditions on the physicochemical quality and volatile compound profile of pecan nuts. The results showed that different moisture content and oxygen pressure conditions during storage can impact the color, internal browning, respiration rate, acidity, peroxide value, and volatile compounds of pecan nuts.