RESUMEN
Duck meat is less utilized than other meats in processed products because of limitations of its functional properties, including lower water holding capacity, emulsion stability, and higher cooking loss compared with chicken meat. These limitations could be improved using surimi technology, which consists of washing and concentrating myofibrillar protein. In this study, surimi-like materials were made from duck meat using two or three washings with different solutions (tap water, sodium chloride, sodium bicarbonate, and sodium phosphate buffer). Better improvement of the meat's functional properties was obtained with three washings versus two washings. Washing with tap water achieved the highest gel strength; moderate elevation of water holding capacity, pH, lightness, and whiteness; and left a small amount of fat. Washing with sodium bicarbonate solution generated the highest water holding capacity and pH and high lightness and whiteness values, but it resulted in the lowest gel strength. Processing duck meat into surimi-like material improves its functional properties, thereby making it possible to use duck meat in processed products.
RESUMEN
Aqueous and ethanol extracts of oven and freeze-dried Streblus asper leaves were investigated using DPPH assay. The presence of phenolic compounds and flavonoids in the extracts, which were detected by Folin and colorimetric assays, respectively, may be responsible for the antioxidant activities of S. asper. The different drying treatments resulted in significant differences (p < 0.05) in the antioxidant properties as well as the phenolic and flavonoid contents of the S. asper extracts. Freeze-dried S. asper leaf extracts exhibited high DPPH radical scavenging activity ranging from 69.48% ± 0.03% to 89.25% ± 0.01% at concentrations ranging from 0 to 1 mg/mL, significantly higher compared with the oven-dried extracts which were in the range of 68.56% ± 0.01% to 86.68% ± 0.01%. Generally, the 70% ethanol extract of the freeze-dried samples exhibited higher phenolic and flavonoid content than the aqueous extract, with values of 302.85 ± 0.03 mg GAE/g and 22.70 ± 0.02 mg QE/g compared with 226.8 ± 0.03 mg GAE/g and 15.38 ± 0.05 mg QE/g, respectively. This study showed that S. asper leaf extracts contain a number of health promoting bioactive compounds, such as phenolic compounds, and are potential sources of natural antioxidants.
RESUMEN
The nutritional properties of surimi-like materials produced from spent duck meat processed conventionally (CDS) and processed with acid and alkaline solubilization (ACDS and ALDS, respectively) were studied. The essential amino acids (EAAs) content was significantly higher (p < 0.05) in the ACDS and ALDS than in control (CON) and CDS, with values of 436.78 ± 13.67, 450.30 ± 9.72, 377.29 ± 7.20 and 400.61 ± 14.7 mg/g protein, respectively. All duck surimi-like materials had a higher chemical score, amino acid score and EAA index than the CON. The saturated fatty acid compositions of the ACDS and ALDS samples were significantly lower (p < 0.05) than that of the CDS sample, whereas the opposite pattern was observed for the polyunsaturated fatty acid content. ACDS samples had significantly higher (p < 0.05) contents of minerals than ALDS samples. The results indicated that acid-alkaline solubilization permitted recovery of high-quality surimi-like material from spent duck meat, which has potential for human food uses.