Judite Lapa-Guimarães

Effect of processing on amine formation and the lipid profile of cod (Gadus morhua) roe.

The processing of fish roe leads to changes in its chemical composition, the extent of which depends on the techniques and additives employed. This study aimed to investigate the effects of ripening temperature and the use of sodium benzoate and citric acid on the quality of ripened cod roe, with respect to the contents of volatile base nitrogen (VBN), trimethylamine (TMA), biogenic amines (BA) and on the lipid composition. In comparison with fresh roes, ripened roes presented higher contents of VBN, TMA, BA and the proportion of free fatty acids regardless of the temperature and additives used during the ripening process. The greatest increases were observed in the samples ripened at 17°C without additives, in which histamine was detected at 8.8mg/100g. A low ripening temperature was the main factor responsible for minimising changes in the cod roe composition. The addition of sodium benzoate as a preservative or citric acid to decrease the pH value had a significant effect in maintaining the quality of the cod roes, mainly at high ripening temperature.

Partial replacement of meat and fat with hydrated wheat fiber in beef burgers decreases caloric value without reducing the feeling of satiety after consumption

The aim of this study was to evaluate the effects of different levels of hydrated wheat fiber replacing meat and fat in beef burgers on technological characteristics, sensory acceptance and hunger satisfaction. The different levels of hydrated wheat fiber (1 g fiber: 6 g water) were 0, 1.25, 2.5, 3.75 and 5.0 g of fiber/80 g burger portion. Results showed that the greater the addition of hydrated wheat fiber, the lower the protein (P < .0001) and lipid (P = .0006) content and consequently the greater the reduction in caloric value. Burgers with up to 3.75 g fiber/80 g portion showed the same (P > .05) sensory acceptance as the Control burgers (those without added fiber). Sandwiches comprised of burgers with 2.5 and 5.0 g fiber/80 g portion caused the same (P > .05) hunger satisfaction (satiety feeling) as those comprised of Control burgers for up to 3 h after consumption. Burgers containing 3.75 g fiber/80 g burger may represent an interesting alternative for people who want to reduce caloric intake and/or increase the proportion of insoluble fiber in their diet.

Evaluation of Turmeric Extract as an Antioxidant for Frozen Streaked Prochilod (Prochilodus lineatus) Fillets

ABSTRACT This study aimed to investigate the efficiency of turmeric (Curcuma longa L.) extract, applied as a marinade or glaze, as an antioxidant for frozen streaked prochilod (Prochilodus lineatus) fillets. The turmeric extract contained 5.5 ± 0.1 mg curcumin/mL, and the experiment was performed using a diluted extract with 100 µg curcumin/mL. Analysis of the antioxidant activity with 2,2-diphenyl-picrylhydrazyl (DPPH) and 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals confirmed the high antioxidant activity of curcumin. However, under the experimental conditions, curcumin extract presented no effectiveness for inhibiting lipid oxidation in frozen streaked prochilod fillets, as the concentration of thiobarbituric acid reactive substances did not differ (p > 0.05) between treated and control fillets. Sensory evaluation of the fillet appearance indicated that the change toward a more yellow color in treated fillets negatively affected its acceptance. However, the acceptability of the odor of raw and cooked fillets was similar for treated and control samples. These results may be explained by the fact that good in vitro performance of antioxidants is not always replicated in foodstuffs owing to the complexity of food matrices. Additionally, the low lipid content of the fish and the low amount of curcumin applied to the fillets may have contributed to the inefficiency of turmeric extract.