Abstract

Chile is the main exporter of walnuts from the southern hemisphere and is among the first three suppliers worldwide with an export volume, in 2016, of 72,133.2 tons equivalent to US $ 243 million FOB. Walnuts are exported with or without the shell. Even though the highest revenues are obtained with the latter, their exportation is limited by the lack of technical tools that ensure the shelf-life of the products and they tend to become rancid after processing. Until this moment, the Chilean industry does not have standardized process for walnut drying, therefore, the diagnostic of the current processes is a first step in the generation of a productive strategy to extent the shelf-life of a high-quality product. Samples of walnuts dried at different temperatures (33, 43 and 33°C) were recovered from industry and were characterized in terms of humidity, acid value, whiteness index and peroxide value. Shelf-life was analyzed along 3 months, maintaining the samples in modified atmosphere package (Co2/N2) at 15°C. No significant differences were detected in terms of humidity and acid value of samples dried at different temperatures. In terms of whiteness index and peroxide value, the lower values were obtained in samples dried at 33°C, while no significant differences were obtained between samples dried at 40 and 43°C. Along 3 months of storage, the only parameter whose values show a tendency to decrease is the whiteness index of samples dried at 43°C. These results are currently being complemented by TBAR, ORAC and organoleptic analysis.