Development of Frozen Churros Added with Shrimp and Squid By-Products

Abstract

In order to add value to shrimp and squid by-products from the seafood industry, a new Churros product was developed (shrimp and squid Churros). Focus group was performed to study attitude and the product concept from the consumers (n = 30). The data obtained was used as the input for designing the product. The consumers opined that the new Churros product should be incorporated with both shrimp and squid meat and the texture of Churros should be soft with less oiliness. The prototype dough of the Churros consisted of 26.62% all-purpose flour, 44.37% water, 5.32% butter, 19.52% egg, 3.55% sugar and 0.62% salt. The proportion of wheat flour dough (WF), shrimp by-product (Sh) and squid by-product (Sq) was optimized using Augmented Simplex Centroid design. The optimized formulation of shrimp and squid Churros with the highest desirability (0.72) was composed of 63.81% WF, 17.51% Sh and 18.68% Sq. The acceptance scores in appearance, odor, flavor, texture and overall linking of the product were 7.22, 7.44, *7.34, 6.99 and 7.33, respectively. The experimental errors of all values ranged from 0.03 to 0.11%. Different hydrocolloid types and levels (0.5 and 1% Hydroxylpropyl methylcellulose (HPMC), 0.5 and 1% Guar gum (GG), and 0.05 and 0.1% Xanthan gum XG)) were applied to basic Churros for improving its quality especially preventing starch retrogradation of the Churros during frozen storage at -20 °C. The result of samples without frozen storage showed that the sample with XG had higher hardness than other samples (p < 0.05). Churros had lower specific volume and higher density when added with hydrocolloids. XG addition had the highest moisture retention, followed by GG and HPMC added samples (p < 0.05), respectively. In addition, Churros samples containing XG had the lowest fat content, followed by those with GG, HPMC and the control. Nevertheless, overall acceptance scores of all samples were not impacted by all hydrocolloid additions (p > 0.05). After 90 days of frozen storage, the hardness, specific volume and density of Churros added with hydrocolloids were not affected by frozen storage time with exception of 0.5% HPMC. Scanning electron micrographs showed that microstructure of the control (without hydrocolloid) showed gluten network with bigger void than other samples. While, the Churros with GG and XG showed dense and impact of the gluten network. However, after 90 days of frozen storage, the frozen control dough showed damage to the gluten network. The structure of Churros with HPMC, GG and XG showed slightly change throughout storage time. Starch retrogradation with prolonged time of storage in frozen was also observed. After 90 days of frozen storage, the control had higher enthalpies than sample with hydrocolloids (p < 0.05). The effect of frozen storage on quality changes of shrimp and squid Churros was carried out. The acceptance results showed that addition of hydrocolloid could prevent deteriorated effect and extend shelf-life of shrimp and squid Churros. Despite the fact that lipid oxidation, especially TBA, value was increased after 90 days of frozen storage, it did not affect on consumer acceptance.