115 Stability of Thiamine Supplied by Vitamin Premix and Yeast Ingredients in Canned Cat Food

Abstract

Abstract Despite numerous process modifications, thiamine retention of canned cat food has not improved. Yeasts possess a binding protein which may provide a thiamine form able to withstand retort processing. Therefore, the objective was to evaluate dried yeasts as thiamine sources in canned cat food. Treatments were arranged as a 2ｘ4 factorial with 2 levels of vitamin premix (with or without) and 4 sources of yeast (none (NY), LBV, BY, or EA). Inclusion of LBV matched the thiamine contribution from the vitamin premix and BY and EA were capped at 5%. Three replicates were processed in a horizontal still retort to an average total F0 of 79.23 minutes. Thiamine degradation was calculated as the difference between pre- and post-retort thiamine contents. Data were analyzed as a randomized complete block design with pre-retort thiamine content as a covariate and production day as a random effect. The Fisher’s LSD post hoc comparison test was performed with ⍺ = 0.05. On average, experimental formulas retained 33.75% thiamine. Thiamine degradation was not affected by the inclusion of vitamin premix (P = 0.0670), but was affected by the inclusion of yeast (P = 0.0232) and the interaction between vitamin premix and yeast (P = 0.0002). Thiamine loss between NY (-31.3 mg/kg DM) and BY (-33.8 mg/kg DM) were similar (P > 0.05) whereas EA (-40.5 mg/kg DM) and LBV (-55.6 mg/kg DM) lost more (P < 0.05) thiamine than NY. The treatment of EA with vitamin premix (-70.3 mg/kg DM) lost more (P < 0.05) thiamine than no yeast, BY, or EA without vitamin premix (average -17.4 mg/kg DM) and all others (average -57.3 mg/kg DM) were intermediate (P > 0.05). Inclusion of vitamin premix with yeast did not minimize thiamine loss and BY exhibited similar thiamine degradation as intrinsic thiamine in standard ingredients.