Physicochemical quality and sensory attributes of two grafted pine nuts (Pinus koraiensis) affected by different roasting conditions

Two kinds of grafted Pinus koraiensis were cultivated in the northeasteran area of China as a viable effort to foster Korean pine nut production. The physical characteristic, color (L*, a*, b* value) and texture (instrumental hardness), along with the chemical and sensory properties were significantly influenced by species graft and roasting conditions. Both raw grafted pine nuts showed significant differences in all proximate analyses, except for ash content. Fatty acid profiles were similar, while linoleic acid was accounted to be the largest proportion. During roasting, malondialdehyde content reached the highest at 180 °C for 30 min (sixfold). Bioactive compounds (total phenolic, total flavonoid, and proanthocyanidin) and antioxidant properties were gradually increased during roasting, while some major individual phenolic acid and flavonoid was quantified by HPLC. Multivariate analysis and sensory evaluation showed that a favourable healthy nut composition and desired sensory quality for both pine nuts could be achieved at 150 °C for 20 min.