Bioactive Compounds, Physical and Sensory Properties of Cake Made with Walnut Press-Cake

Walnut press‐cake, a rich source of phenolics, is a by‐product of walnut oil processing. In this study, the effects of walnut press‐cake on cake quality, health‐enhancing substances and antioxidant activity were determined. Wheat flour was replaced with walnut press‐cake at 0, 5, 10, 15 and 20% levels. Results show that specific volume, firmness, resilience, cohesiveness, chewiness, crust a, b and crumb L, b values reduced with increasing walnut press‐cake levels. However, polyunsaturated fatty acids, tocopherols, total phenolic content and antioxidant capacity of cakes increased. Antioxidant capacity measured by 2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid) assays of cakes prepared with 20% walnut press‐cake were 10.04‐ and 5.56‐fold, respectively, greater than that of the cake without walnut press‐cake. Cakes added with 15% walnut press‐cake to wheat flour had the highest scores in all sensory parameters. Walnut press‐cake can be successfully incorporated into cake formulation to improve sensory properties and antioxidant activity of the cake. Practical Applications Interest in walnut oil has increased during the past years due to its high polyunsaturated fatty acid content. Although walnut oil has been used in the food, pharmaceutical and cosmetic industries, there is no information about the use of walnut press‐cake. Walnut press‐cake is a rich source of bioactive compounds, and it is a new by‐product with potential use in the baking industry as a supplement. The results of this study provide guidance for the use of walnut press‐cake in the manufacture of cakes with higher sensory and nutritional quality.