Oil (healthier lipid combination of olive, linseed and fish oils)-in-water emulsions stabilized with different protein systems (prepared with sodium caseinate (SC), soy protein isolate (SPI) and microbial transglutaminase (MTG)) were used as pork backfat replacers in low-fat frankfurters. Composition (proximate analysis and fatty acid profile), sensory analysis and technological (processing and purge losses, texture and colour) properties of frankfurters were analysed as affected by the type of oil-in-water emulsion and by chilling storage (28C, 41 days). Frankfurters produced with oil combinations had lower levels of saturated fatty acids (SFA, 19.3%), similar levels of MUFA (46.9%) and higher levels of PUFA (33.6%) than control frankfurters (all pork fat) (39.3, 49.5 and 10.6%, respectively). PUFA/SFA and n-6/n-3 PUFA ratios in control sample were 0.27 and 9.27; in reformulated frankfurters the PUFA/SFA ratio was higher (1.7) and the n-6/n-3 PUFA ratio was lower (0.47). In general, frankfurters had good fat and water binding properties. Colour parameters were affected by formulation and storage time. Compared to control sample, frankfurters made with oil-in-water emulsions had higher ( p<0.05) hardness, springiness and chewiness values. Emulsified oil stabilizing systems did not affect sensory characteristics of frankfurters, and all products were judged as acceptable.

Five protein-stabilized oil-in-water emulsions were prepared using sodium caseinate (O/SC), soy protein isolate (O/SPI), sodium caseinate and microbial transglutaminase (O/SC þ MTG), sodium caseinate, microbial transglutaminase and meat slurry (O/SC þ MTG þ MS) and SPI, sodium caseinate and microbial transglutaminase (O/IPS þ SC þ MTG); their composition (proximate analysis and fatty acid profile) and physicochemical characteristics were examined. The lipid phase was a combination of healthy fatty acids from olive, linseed and fish oils, containing low proportions (15%) of saturated fatty acids (SFA) and high proportions of monounsaturated fatty acids (MUFA, 47%) and polyunsaturated fatty acids (PUFA, 36%), with a PUFA/SFA ratio >2, and a n-6/n-3 PUFA ratio of 0.4. All the oil-inwater emulsions showed high thermal and creamy stability. Results of penetration test and dynamic rheological properties showed la existencia de different types of oil-in-water emulsion structures according to stabilizing system of emulsion. Those structures ranged from concentrate solution-like (stabilized only with SC) (gel strength 0.06 mJ) to gel-like (samples containing MTG) behaviours (gel strength ranged between 3.4 and 6.2 mJ). Morphological differences in the organization of the network structure were observed (by scanning electron microscopy) as functions of the protein system used to stabilize the oil-in-water emulsions.

Oil (healthier lipid combination of olive, linseed and fish oils)-in-water emulsions stabilized with different protein systems (prepared with sodium caseinate (SC), soy protein isolate (SPI), and microbial transglutaminase (MTG)) were used as pork backfat replacers in low-fat frankfurters. Microstructure, lipid oxidation, nitrite content, microbiological changes and biogenic amine formation of frankfurters were analyzed and found to be affected by the type of oil-in-water emulsion and by chilling storage (2° C, 41 days). Although the lipid oxidation levels attained were low, replacement of animal fat by healthier oil combinations in frankfurter formulation did promote a slight increase in lipid oxidation. Residual nitrite was affected (P < 0.05) by formulation and storage. Only 51-61% of the added nitrite was detectable in the product after processing and 17-46% at the end of storage. The microbial population was low in all formulations during chilling storage. Spermine was the most abundant amine (19-20 mg/kg), but similar in level to all samples.

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This study evaluated the effect of an industrial scale continuous flow microwave volumetric heating system in comparison to conventional commercial scale pasteurisation for the processing of tomato juice in terms of physicochemical properties, microbial characteristics and antioxidant capacity. The effect against oxidative stress in Caco-2 cells, after in vitro digestion was also investigated. Physicochemical and colour characteristics of juices were very similar between technologies and during storage. Both conventional and microwave pasteurisation inactivated microorganisms and kept them in low levels throughout storage. ABTS[Symbol: see text](+) values, but not ORAC, were higher for the microwave pasteurised juice at day 0 however no significant differences between juices were observed during storage. Juice processed with the microwave system showed an increased cytoprotective effect against H2O2 induced oxidation in Caco-2 cells. Organoleptic analysis revealed that the two tomato juices were very similar. The continuous microwave volumetric heating system appears to be a viable alternative to conventional pasteurisation.

Reported salt levels in whole-muscle cured meat products differ substantially within and among European countries, providing substantial scope for salt reduction across this sector. The objective of this study was to identify the minimum acceptable salt levels in typical whole-muscle cured products in terms of physicochemical, microbial and sensorial properties. Salt levels in a small selection of commercial Irish meat products were determined to establish a baseline for reduction. Subsequently, eight different back bacon rasher and cooked ham products were produced with varying levels of salt: 2.9%, 2.5%, 2% and 1.5% for bacon, and 2%, 1.6%, 1.0% and 0.8% for ham. Salt reduction produced products with significantly harder texture and higher microbial counts, with no difference in the colour and affecting the sensory properties. Nonetheless, salt reduction proved to be feasible to levels of 34% and 19% in bacon and ham products, respectively, compared to baseline.

The capacity of hydroxytyrosol (HXT) to inhibit lipid oxidation in cooked pork meat batter, oil-in-water emulsions and potential functional frankfurters formulated with a healthier oil combination (as animal fat replacer) was studied during chilling storage, and its effect compared with those produced by synthetic antioxidants (BHA/BHT).Although efficiency varied, HXT was an effective antioxidant during chilling storage in the three food matrices studied. In general the order of inhibition capacity of HXT against lipid oxidation (thiobarbituric acid-reactive substances-TBARS) was cooked meat batter > oil-in-water emulsion > frankfurters, whereas in the case of BHA/BHT (with lower inhibitory activity than HXT) it was cooked meat batter > oil-in-water emulsion, and there was no antioxidative effect in frankfurters. Whereas significant correlations were established between lipid oxidation (TBARS) and antioxidative capacity measured by photochemiluminescence (PCL) in frankfurters supplemented with HXT and BHA/BHT, no significant correlations were found between ferric reducing/antioxidant power assay (FRAP) and TBARS and PCL.

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