Color variation in nut kernels during storage under different dry methods

PILATTI, L; A.M. SANCHO; IRURUETA M; GRIGIONI G

Mar del Plata

Congreso; AIC Interim Meeting 2010. Color and Food: from the farm to the table; 2010

International Color Association

In the present work were evaluated the effect of drying processes and storage conditions on kernels of three walnut varieties (Juglans regia L.) through instrumental color assessment. The walnuts were harvested in the province of Catamarca, Argentina. After collected, they were subjected to two drying methods: natural and in oven. The color of the kernels was determined every 45 days using a BYK Gardner ColorView. At the beginning of storage, statistically significant differences (p < 0.05) were observed between the three varieties on L* parameter. Being Chandler kernels the brightest (54.0 ± 1.4), followed by California (49.0 ± 0.66) and Criolla (42.0 ± 3.5). Parameters a* and b* showed significant differences between Criolla and Californian varieties (Chandler and California), even tough no differences were observed among them. It was observed a decrease of the parameter L* during storage for the three varieties, being statistically significant (p < 0.05) in Californian walnuts after 180 days. Parameter a* increased significantly in the three varieties while the parameter b* decreased significantly only in California walnuts. Comparing oven and natural drying methods, it was observed that kernels from the first method were less brightness, redder and less yellow.