Research On Eliminating Odor Of Durian Pulp Surface

Durian is rich of nutrition, but its peculiar smell is unbearable. The methods of ozonation, edible film masking and ozonation combined with edible film masking were applied to retain the unique flavor, taste and nutrition in durian pulp. And PEN3 portable electronic nose was used to detect the relative content of durian pulp odor.The main conclusions obtained in this study were as follows:1. Ozone is able to oxidate the sulfide on the surface of the durian pulp. After the oxidated, the content of superficial ethyl mercaptan was reduced from 0.99% to 0.17%, and the propyl mercaptan was oxidized completely; The content of caproic acid increased from 0.39% to 0.65%, the content of acetic acid increased from 6.37% to 12.93%, and it of 2-methyl butyric acid increased from 2.68% to 4.52%. In addition, the oxidation products of octoic acid, heptanoic acid, pelargonic acid, 9,12-octadecadienoic acid and 8,11-octadecadienoic acid came into being. The pH of durian pulp increased from 7.65 to 7.17; The color of the pulp is from yellow to green, and the aberration was 3.33, which showed a significant difference. But it is counter to the intensity. Therefore, ozone was able to oxidate the sulfide on the surface of the durian pulp.2. Electronic nose is able to identify and analyze the durian pulp odor. The result of PCA was that the contribution of the first principal component was as high as 98.71%, meanwhile, the contribution of the second principal component was 0.78%, which showed that both of the first principal component and the second principal component could represent the whole character of the odor. Loadings was applied to determine that sulfide was the main component of durian pulp odor; PLS was applied to establish a model of the relative content of durian pulp odor and get linear curve fitting. Detect the samples of three groups with 0, 8 and 16 holes on the basis of the curve. All of the errors of the results in each group were less than 10%, which showed that the model could be used to detect the relative content of durian pulp odor. Therefore, the use of electronic nose is a reliable and practical method to assess durian pulp odor accurately.3. Finding a method to remove the durian pulp surface odor. The relative content of the sanmle masked with stearic acid film was less than that of the samples masked with sodium carboxymethyl cellulose film and sodium alginate film. The masking effect of the stearic acid film of which concentration was 2.70g+45.00g+90.00g/L is the best; The relative contents of the samples masked with edible film, oxidated by ozone and masked with edible film after oxidation were respectively 1.38, 1.05 and 0.80, while the relative content of the control group was 1.62. Therefore, the eliminating effect of the method of edible film masking after oxidation is the best of all.