Abstract: Walnut oil was encapsulated with β-cyclodextrin by saturated water solution. Based on a comprehensive evaluation of inclusion complex yield and inclusion efficiency, the optimal inclusion conditions were determined by one-factor-at-a-time and orthogonal array design methods to be: ratio of walnut oil and β-CD 1:4 (g/g), inclusion time 4.5 h, and inclusion temperature 65 ℃, under which, the inclusion efficiency was 81.6% and the inclusion complex yield 61.6%. UV spectrometric determination demonstrated the successful inclusion of walnut oil. The inclusion complex was a white powder-like solid and its solubility increased with increasing temperature. The storage stability of walnut oil was improved significantly after inclusion.

Key words: orthogonal array design, walnut oil, β-cyclodextrin, inclusion complex