4 CONCLUSIONS
SSF using A. niger NRRL 334
and A. oryzae NRRL 5590 was applied on CP and HE canola meals to
modify their nutritional value with ~50% DH achieved
after 72 h of fermentation. While HE meal naturally contains more
protein than CP meal, 72 h SSF with A. niger increased the
protein content of CP meal to levels comparable to unfermented HE meal.
Similar fermentation conditions did not result in the same increase in
protein in HE meals. The SSF lowered the lipid content of both meals.
The levels of phytic acid and total phenolics decreased significantly
after fermentation with % reduction (after 72 h) being 74-85% for PAC
and 65-81% for TPC in both CP and HE meals. Enzymes from fungal cells,
including lipase, proteinase and phytase, played critical roles in
changing meal composition. In terms of fungal strain, A. nigerperformed better to reduce PAC in CP meals and TPC in HE meals. The
effective reduction of PAC and TPC, as well as similar DH values between
meals, indicates that the high residual oil content in CP meals did not
interfere with the growth of the fungi. SSF for 72 h brought decreases
in IVPD to all meals except for HE by A. niger (unchanged)
whereas 24 h fermentation improved IVPD for both HE meals and the CP
meal fermented with A. oryzae . The recommended fungal strain and
fermentation time for canola meal will depend on the desired outcome as
increased protein content, decreased ANFs, and increased IVPD could not
all be achieved at the same time under the conditions tested.