Fourier transform mid-infrared spectroscopy (MIR-FTIR) and a partial least square algorithm (PLS-1) were used to predict the deterioration indices, pH, and chemical composition of Atlantic bluefin tuna, crevalle jack, and Atlantic Spanish mackerel chilled fillets. To build calibration models, 90 samples from the 3 fish species were analysed to different seasons and were stored for various times. The performance of the regression models was evaluated based on the coefficients of determination (R2), residual predictive deviation of cross-validation (RPDcv), and percentage relative difference (% RD). Chemometric models provided good reliability in the prediction of the chemical composition (R2 between 0.969 and 0.992, RPDcv between 5.01 and 5.59%), the pH (R2 = 0.987, RPDcv = 7.18), and can be used for screening of deterioration indices (R2 between 0.944 and 0.969, RPDcv between 3.21 and 3.67%). The results demonstrated that the MIR-FTIR coupled with the PLS-1 algorithm could be simultaneously applied to predict the chemical parameters of chilled fillets of three fish species.
14 March 2019 in Journal of the Iranian Chemical Society
The fatty acid profile of crevalle jack was compared with that of Atlantic bluefin tuna, Atlantic Spanish mackerel, red snapper, and Nile tilapia. Crevalle jack and Atlantic Spanish mackerel showed similarities in their fatty acid profiles, with the saturated fatty acid > monounsaturated fatty acid > polyunsaturated fatty acid pattern. Atlantic bluefin tuna and red snapper followed a similar pattern to each other, with the polyunsaturated fatty acid > saturated fatty acid > monounsaturated fatty acid pattern, and the pattern for Nile tilapia was saturated fatty acid > monounsaturated fatty acid ≈ polyunsaturated fatty acid. In winter, the DHA+EPA content of crevalle jack (493.2 mg/100 g fillet) was 37% lower than Atlantic bluefin tuna and Atlantic Spanish mackerel, 35% higher than for the red snapper, and 2.8 fold higher than for the Nile tilapia. The best nutritional indices were for Atlantic bluefin tuna > red snapper > Atlantic Spanish mackerel > crevalle jack > Nile tilapia.
In the present work, the total phenolic content (TPC), total flavonoids content (TFC), antioxidant activity, and phenolic profile from pulp (PU) and peel (PE) extracts obtained from the ciricote (Cordia dodecandra A. DC.) fruit by ultrasound-assisted extraction (UAE) in immature (IM), semimature (SM), and mature (MM) stages were investigated. The effect of the diameter of the ultrasonic probe in the IM stage was also evaluated. The TPC and antioxidant activity in IM fruit extracts by UAE increased up to 11.01 and 23.82 times, respectively, compared to the maceration method. The main phenolic compounds in the PE of IM fruit identified by UPLC-DAD-ESI-MS/MS were quantified as caffeic acid, rutin, and rosmarinic acid, distributed as 45.82, 41.45, and 12.72%, respectively. The PE extracts of IM fruit obtained with the 3 mm diameter probe had 1.27, 2.44, and 1.37 times the TPC (19.93 ± 0.28 mg GAE (Gallic equivalents) g−1 dw), TFC (34.85 ± 4.99 mg RE (Rutin equivalents) g−1 dw), and antioxidant activity (122.09 ± 17.09 µTE (Trolox equivalents) g−1 (DPPH)), respectively, compared to those obtained with a 13 mm diameter probe. The results obtained suggest the use of the ciricote native fruit as a source of bioactive compounds, directly as fresh fruit or processed, thus helping to increase its production and consumption.