Alternative Method for Hazelnuts Peeling

The paper proposes an improved peeling treatment for hazelnut fruits consisting in dipping them in a solution (NaOH 0.4 g/100 g, NaH2PO4 center dot H2O 0.2 g/100 g) for 10 min at 50 A degrees C, then scrubbing them with rubber rollers. The effects of the treatment on quality and peeling of four Italian hazelnut varieties were investigated. The data collected on peeling capability showed that the treatment proposed was effective in cuticle removal with a yield of peeling higher than 90%. The comparison of chemical-physical parameters in unpeeled and peeled hazelnut samples highlights that no difference was detected in texture, sugar, protein and alpha-tocopherol values. After the peeling process a significant change (p < 0.05) in colour, total fat and peroxide value was observed in peeled hazelnut samples when compared with the unpeeled ones. With regard to the sensorial parameters, no significant changes were found between unpeeled and peeled hazelnut samples. The peeling solution proposed in this study shows a good potential in industrial applications as an alternative to the usual manufacturing peeling method (roasting) that causes changes, not always desired, to some sensorial and chemical-physical parameters of the fresh fruit.