Encapsulation of ascorbyl palmitate in corn starch matrix by extrusion cooking: Release behavior and antioxidant activity.

The main limitation associated with the oral delivery of ascorbyl palmitate, a potent food antioxidant, is its susceptibility to oxidative deterioration. The main objective of the current research was to encapsulate ascorbyl palmitate into corn starch matrix using extrusion cooking and evaluate its release behavior and oxidative stability. Results showed that ascorbyl palmitate was efficiently encapsulated (96.06-99.28%) in the starch matrix using the extrusion technique. The release behavior of ascorbyl palmitate from the extruded starch matrix during simulated upper gastrointestinal tract conditions was slow but steady (18.92-28.32% after 180 min) and presented a sustainable antioxidant activity. Acid treatment (pH 2.0) increased the release rate of ascorbyl palmitate from the extruded starch matrix. Furthermore, the antioxidant capacity of ascorbyl palmitate released from the extruded samples stored in both darkness and under UV radiation at 40 °C was found to be remarkably retained (p > 0.05) for up to three months.

Enhancing the oxidative stability of algal oil powders stabilized by egg yolk granules/lecithin composites.

This study reported a powder formulation containing omega-3-rich algal oil emulsions stabilized by egg yolk granules (EYGs)/lecithin composites. The improved physical stability of the algal oil samples due to increasing pH and lecithin addition was beneficial to the oxidative stability through analysis of free radical scavenging activities, metal ion chelating activities, and the release of primary and secondary oxidation products during accelerated storage (12 days, 60 °C). In addition, the effect of three antioxidants, i.e. ascorbic acid (VC), ascorbyl palmitate (AP), and α-tocopherol (VE), on lipid oxidation was investigated. Results showed that antioxidant partitioning at different regions of the emulsion system influenced its ability to prevent oxidation with the effectiveness of AP (at the O/W interface) > VE (in the oil phase) > VC (in the aqueous phase). This study developed a new powder-based emulsion formulation for algal oils with superior oxidative stability as an alternative source of omega-3.

Comparative study of rosemary extracts and several synthetic and natural food antioxidants. Relevance of carnosic acid/carnosol ratio.

The antiradical power, at equal concentrations of active principles, of the following antioxidants were studied using the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay: butylated-hydroxyanisole, butylated-hydroxytoluene, tert-butylhydroquinone, ascorbyl palmitate, tocopherol, grape seed extract, olive extract and five rosemary extracts with different concentrations of carnosic acid (CA) and carnosol (COL). The reaction kinetics of DPPH scavenging activity in each studied substance identified significant variations in the time needed to reach the steady state. Rosemary extracts were seen to be more effective than the other compounds. CA had higher antioxidant activity than COL, although COL seemed to react faster with DPPH. The relevance of the CA/COL ratio for the antioxidant activity of rosemary extracts was also analysed. The presence of COL in rosemary extracts increased the antioxidant activity with an optimal CA/COL ratio of 2.5-3.0. Olive extract and grape seed extract seem to be very promising additives for use as technological antioxidants.

Formation and mitigation of N-nitrosamines in nitrite preserved cooked sausages.

Literature on formation and mitigation of N-nitrosamine (NA) and especially non-volatile NA (NVNA) in meat products is scarce and the present study is therefore a relevant contribution to the field. We found positive correlation between the levels of N-nitrosopiperidine (NPIP), N-nitrosohydroxyproline (NHPRO), N-nitrosoproline (NPRO), N-nitrosothiazolidine-4-carboxylic acid (NTCA) and N-nitroso-2-methyl-thiazolidine-4-carboxylic acid (NMTCA) and the amount of nitrite added to cooked pork sausages. The levels studied were 0, 60, 100, 150, 250 and 350 mg kg(-)(1). The levels of N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR) remained at or below limit of quantification. Erythorbic acid inhibited the formation of NHPRO, NPRO, NPIP and NTCA. This inhibition was for NTCA and NMTCA counteracted by addition of free iron. Ascorbyl palmitate had less inhibitory effect than erythorbic acid and a combination of the two provided no further protection. Increasing the black pepper content increased the levels of NPIP and NMTCA. Only slight effects of increased fat content and addition of tripolyphosphate were observed.