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Chicken patties elaborated with a novel polymer from Agrobacterium radiobacter k84 (ARB) were characterised during 60 days of frozen storage. After cooking, formulations without ARB (F0), with ARB 5 g/100 g (F5) and ARB 10 g/100 g (F10) presented 4.23%, 2.83% and 0.11% fat, respectively. No differences were observed to water holding capacity, cooking yield and shear force among formulations. Microstructural analysis showed formation of meat emulsion for F5 and gel for F10. Colour and chicken flavour decreased with increase of ARB; no difference was found for tenderness among the formulations. Overall acceptance showed higher scores for F0 when compared to F5 and F10. Lipid oxidation was not a limiting factor for stability of patties; all formulations presented suitable microbiological quality over the assessed period. These results suggest ARB as a promising fat substitute, capable of maintain the quality aspects of chicken patties, although a negative impact in colour has been found.

Different modified wheat starches were used in a model pound cake recipe. The properties of the starches were linked to differences in batter viscosity, cake height and protein extractability during baking, collapse during cooling and final cake quality. The impact of incorporation of 30% cross-linked (CL) starches on batter properties during baking was much smaller than that of incorporation of the same level of hydroxypropylated (HP) starches. Incorporation of HP starches with various degrees of modification in the recipe caused batter viscosity during baking to start rising from 92 or 88 °C rather than at 96 °C and diminished oven rise significantly. Furthermore, the extractability of the protein in cakes containing HP starch was significantly higher. During cooling, control cake collapsed less than did CL starch-containing cake, which itself collapsed significantly less than did HP starch-containing cake. Presumably, most of the cake collapse takes place before the starch gel is formed during cooling. Protein and starch apparently function in determining cake quality, by providing the cell walls with structural material and high resistance to collapse. Starch does not prevent cake collapse, but still co-determines crumb structure, whereas a strong correlation was found between the gel-forming capacity of starch blends and intrinsic crumb firmness ( r = 0.99). Furthermore, a strong negative correlation was found between springiness and percentage of extractable protein in final cakes ( r = −0.95). We conclude that the combination of a protein network, formed during baking, with a starch gel, formed during cooling, makes up the crumb cell walls and determines cake quality.

The effect of plasma powder addition, with or without NaCl, to meat emulsion has been studied. The Raman spectroscopy and rheological characteristics of four model systems [plasma powder (PP), rehydrated plasma powder (PPW), meat emulsion (ME) and meat emulsion with addition of rehydrated plasma powder (MEPPW)] were evaluated. The MEPPW system showed the highest (p

In order to evaluate the role of gluten in cake-making, gluten-starch (GS) blends with different ratios of gluten to starch were tested in a research pound cake formula. The viscosities of batters made from commercial GS blends in the otherwise standardised formula increased with their gluten content. High viscosities during heating provide the batters with the capacity to retain expanding air nuclei, and thereby led to desired product volumes. In line with the above, increasing gluten levels in the cake recipes led to a more extended oven spring period. Cakes with a starch content exceeding 92.5% in the GS blend suffered from substantial collapse during cooling. They had a coarse crumb with a solid gummy layer at the bottom. Image analysis showed statistical differences in numbers of cells per cm(2), cell to total area ratio and mean cell area (p

Effects of incorporation of native and preheated defatted walnut on the physicochemical, emulsifying and rheological properties of meat batters, as affected by final heating temperature were investigated. Replacing meat protein with native defatted walnut in meat product formulations reduced (P < 0.05) gel strength and emulsifying properties and hence the firmness and stability of meat batters but enhanced water- and fat-binding properties and hence the yield of a processed meat product. However, incorporation of preheated defatted walnut, in addition to improving (P < 0.05) water- and fat-binding properties during thermal treatment, improved the gelling ability of myofibrillar proteins, probably because the preheating of the defatted walnut promoted interactions between walnut proteins and muscle proteins. © 2007 Elsevier Ltd. All rights reserved.

The viability of a fibrinogen–thrombin system (FT) to bind fresh deboned hams for incorporation in the salting and ripening processes, to produce cured ham, was studied. The effects of the different processing variables (pH, NaCl concentration, temperature and gelation time) on FT, a meat emulsion mixed with FT, fresh pork portions and deboned hams restructured with FT were analyzed. The most stable and firmest fibrin gels were obtained after 6 h of adding the FT, with less than 2% NaCl and pH 7–8.4. Scanning electron microscopy of the fibrin gel showed fibrillar structures with a high degree of cross-linking and a high density. Two structures were found in the binding area of restructured meat; one in the central part with similar characteristics to fibrin gels and, another in the area of contact between the meat surfaces, where a filamentous structure connected the fibrin gels with the muscle bundles.

The factors which determine the instantaneous irreversible binding of sulphur dioxide when sodium metabisulphite is added to comminuted meat are considered. The most important variable which affects the reactivity of sulphur dioxide in comminuted fillet steak, pork steak, pork chop, braising steak, shin beef and belly pork, is fat content, reactivity decreasing with increase in fat-content. This observation is explained in terms of liquid fat tending to smear, during comminution, over components of meat which are reactive towards the additive, thereby providing a protective barrier. In meat other than pork steak or chop, the reactive food components include disulphide bonds of proteins. The amount of S-sulphonate formed on addition of sulphur dioxide correlates with the cystine-content of the meat. The highest yield of S-sulphonate was obtained for shin beef where cleavage of disulphide bonds accounts for 48% of the additive which had undergone reaction. No S-sulphonate formation was observed for pork steak or pork chop samples.