Use of Canola meal (CM) in spite of suitable protein compound has been limited in food and feed because of various anti-nutritional factors containing crude fiber, phytate (P) and glucosinolate (G). To study the effect of processing of solid state fermentation (SSF) on the nutrients and antinutritional factors (ANF) of the processed CM (PCM), three inoculation densities 105, 106 and 107 Aspergillus niger spores/g were used. The contents of P, G and tannin and phenolic compounds (TF) of the fermented products (averagely) decreased significantly (P<0.05) 74.3, 63.4 and 29.8% in comparison to those of control treatment, respectively. Although, the lowest contents of acid detergent fiber (ADF) (9.76%) and neutral detergent fiber (NDF) (7.55%) were observed in the fermented PCM with 107 spores/g that they had significantly (P<0.05) differences compared to those of control treatment. With an increase at inoculation density (from 105 to 107 spores/g), the contents of crude protein (from 53.51 to 55.81%) and true protein (from 48.87 to 51.89%) increased significantly (P<0.05) in the fermented PCMs compared to those of control treatment (48.08 and 41.52%, respectively). The highest contents of lysine and methionine were recorded significantly (P<0.05) at inoculation density 107 spores/g (3.67 and 2.00%, respectively) compared to those of control treatment (2.48 and 0.92%, respectively). In vitro protein digestibility of the fermented products increased significantly (P<0.05) from 51.73% (control) to 75.32% (107 spores/g). The results showed that the produced canola protein concentrate (CPC) in the present study had higher nutritive value compared to the common produced CPCs.

Keywords