The Preparation And The Evaluation Of Dog Food Palatability Enhancer

Dog food palatability enhancer is a kind of non-nutritive additive which can improve theflavour and the palatability of dog food. In this study, SPME-GC-MS was used to analyse thevolatiles of commercial dog foods and palatability enhancer, combining with the results ofsensory evaluation, the flavour characteristics of palatability enhancer were confirmed.Palatability enhancer was prepared by enzymatic hydrolyzed chicken protein throughMaillard reaction, and the process conditions and basic formulas of enzymatic hydrolysis andMaillard reaction were studied. At last, the effect of prepared palatability enhancer wasevaluated by animal test.The results of SPME-GC-MS showed that the volatiles of commercial dog food andpalatability enhancer contained aldehydes, alcohols, acids, ketones, esters, hydrocarbons,heterocycles and sulfocompounds. These compounds above had odours which like fat, meaty,roast, caramel, nut, mushroom, metal, milk, etc. Combined with the results of sensoryevaluation, we confirmed that meaty odour and roasted order were the major smellcharacteristics of dog food palatability enhancer and the major compounds which weregenerated most from heterocycles and sulfocompounds.In this study, hydrolyzed chicken protein was used as protein sources. The optimumhydrolysis conditions of papain were as follows: temperature45°C, pH6.5, solid/solutionratio1:2. At this condition, added1.0×104U/g papain and hydrolyzed for24h, thehydrolysate was found to be abundant in free amino acid(FFA), and the content of FFAincreased with the extension of time. Peptide molecular weight of hydrolysate was less than3000Da, while the content of peptides and amino acids with molecular weight under1000Dawas high, So the enzymatic hydrolysate was suitable for preparing palatability enhancer. Thesensory evaluation indicated that chicken protein hydrolyzed4h was most suitable forMaillard reaction, and other optimal conditions were as follows: adding4.0%D-xylose,1.0%L-cysteine hydrochloride and1.0%phosphoric acid, then reacting at45°C for50min withthe initial pH value of6.5. The prepared palatability enhancer had strong meaty odour androasted odour, and the spray drying product had stronger roasted odour. Benzaldehyde,decanal,3-Mercapto-2-Pentanone,2-methyl-3-furanthiol and2-furanmethanethiol inpalatability enhancer volatile were the important compounds contributed to meaty odour androasted odour.The effect of prepared palatability enhancer was tested by the animal palatability test.The results of single bowl test showed that both prepared palatability enhancer andcommercial palatability enhancer could improve the palatability of dog food, but there was noobvious difference between them, their intake ratios were both80%～90%. The first choicetest and the two bowls test indicated that the first choice amount and consumption ratio of dogfood covered with prepared palatability enhancer were much higher than that of dog foodwithout prepared palatability enhancer. The spray drying product was more effective with theconsumption ratio reaching about90%. In palatability comparison experiment, the first choiceamount of dog food with prepared palatability enhancer was high than that of dog food with commercial palatability enhancer. For the commercial dog food, the prepared palatabilityenhancer was well effective. The consumption ratio of commercial dog food with preparedpalatability was about65%, and the first choice amount of it was higher.