Zita E. Martins

Influence of oven and microwave cooking with the addition of herbs on the exposure to multi-mycotoxins from chicken breast muscle

Mycotoxins can contaminate poultry production via fungal infection of feeds. The impact of different cooking methods on mycotoxins stability and bioaccessibility is scarcely studied. Recent cooking practices such as the use of roasting bags along with some seasonings to cook chicken have become a trend to maintain the tenderness of the meat. This study evaluated the impact of oven roasting and microwaving of chicken breast muscles, with/without roasting bags and/or herbs addition on the stability and bioaccessibility of the 10 prevalent mycotoxins. Cooking itself reduced mycotoxins content, while using bags did not confer any advantage; adding herbs reduced mycotoxins content by up to 60%, but also appeared to increase their bioaccessibility. Thus, strategies to reduce their increased bioaccessibility should be the subject of future research. Notwithstanding, adding herbs prior to cooking could be used as a mitigation strategy to reduce mycotoxins in meat.

Viability of dietary substitution of live microalgae with dry Ulva rigida in broodstock conditioning of the Pacific oyster (Crassostrea gigas)

ABSTRACT The current study evaluated the microalgae replacement by dry macroalgae (Ulva rigida) in the reproductive success and biochemical composition of the Pacific oyster (Crassostrea gigas) during broodstock conditioning. Five nutritional regimes were tested: 100% macroalgae (diet 1), 50% macroalgae+50% microalgae (diet 2), 25% macroalgae+75% microalgae (diet 3) and 100% microalgae (diet 4). An unfed group was used as a negative control. The microalgae blend was composed of 33% Isochrysis galbana and 67% diatoms (75% Skeletonema costatum+25% Chaetoceros calcitrans). Gonadal maturation was reflected in the physiological condition of the individuals. All treatments, except diet 1, showed an increase in condition index and were fully matured at the end of the trial, with the best physiological condition observed in oysters fed diet 3 and diet 4. Protein and total lipid content increased during the conditioning period, whereas glycogen content decreased. Oysters conditioned with diet 3 had higher protein and total lipid content and lower glycogen content than the other treatments. In addition, diet 3 showed the highest percentage of viable veliger larvae. The current study demonstrated that it is possible to replace 25% of microalgae with macroalgae in the broodstock conditioning, minimizing the operative cost in bivalve hatcheries. This article has an associated First Person interview with the first author of the paper. Summary: The use of an alternative diet with 25% microalgae replacement by dry macroalgae is beneficial during broodstock conditioning and allows the operation costs of bivalve hatcheries to be minimized.

Development of fibre-enriched wheat breads: impact of recovered agroindustrial by-products on physicochemical properties of dough and bread characteristics

Dietary fibre is easily available in plant foods. However, western diet frequently does not meet recommended levels. Fibre supplementation of bread is an opportunity due to its daily consumption. In this work, fibre-enriched extracts were recovered from elderberry (EE), orange (OE), pomegranate (PE), and spent yeast (YE), and their fibre composition was characterized. The impact of wheat flour replacement by different fibre extract amounts on dough properties indicates that (1) optimum water absorption increased with higher concentrations of OE, PE, and YE; (2) development time for EE, PE, and YE was shortened, while the opposite was observed for OE; (3) the onset of starch gelatinization and maximum tanδ increased significantly with 36% EE and 4% PE; (4) protein structure, observed with confocal laser scanning microscopy, was modified by addition of extracts; and (5) maximum and final dough height decreased significantly, except for 4% EE. Wheat flour replacement also had an impact on bread parameters, since (1) volume and specific volume decreased at the highest concentrations in every extract; (2) significant changes were observed in crumb texture and structure, at higher extract concentrations. Multivariate PLS regression highlights the relationships between dough and bread data.