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Egg yolk contamination of egg whites continues to be a serious problem in the egg industry. The ability of egg whites to form stable and voluminous foams is greatly inhibited by yolk contamination, even at very low levels, between 0.01% and 0.2% w/w yolk in white. Experiments were conducted to determine if Mucor miehei lipase could regenerate the functional properties of yolk-contaminated egg whites. Lipase from M. miehei and colipase from porcine pancreas were added to yolk-contaminated (0.2%, w/w) egg white samples to hydrolyze triglycerides originating from egg yolk. Enzymatic hydrolysis of triacylglycerols was confirmed using thin-layer chromatography. Treatment of yolk-contaminated samples with lipase and colipase yielded significant ( P < 0.05) improvements in a number of the functional properties, including the final foam volume, foam capacity, and foaming power. These functional properties showed complete restoration to control levels. However, foam stability and foam drainage levels were not statistically different from yolk-contaminated samples that had not been enzymatically treated. Enzyme-treated yolk-contaminated egg whites were also tested in angel food cakes. Enzyme-treated, yolk-contaminated egg whites performed similarly to non-yolk-contaminated control, and much better than yolk-contaminated sample in angel food cakes. The results show that most negative effects of yolk contamination can be reversed by treatment with Mucor miehei lipase and colipase. The negative effects of egg yolk contamination in egg whites on the functional properties foam volume, foam capacity, and foaming power can be reversed by treatment with Mucor miehei lipase and porcine colipase. Improvement is also seen in angel food cakes prepared with contaminated egg whites treated with lipase and colipase. [ABSTRACT FROM AUTHOR]

Flaxseed has been identified as a potential functional food because of its high content of phytochemicals, alpha-linolenic ( α-linolenic) acid and lignans. Flaxseed can be used in baked goods because of its minimal loss of α-linolenic acid. Alpha-linolenic acid is susceptible to oxidation and the development of off-aromas and flavours in the food. The focus of this study was to determine the effectiveness of both synthetic and natural antioxidants that were incorporated into a yeast bread that contained 15% flaxseed as a partial replacement for bread flour. The study evaluated the effectiveness of the antioxidants on the physical and sensory characteristics of the bread. Physical properties, such as per cent moisture and loaf volume, were not affected ( P > 0.05) by the antioxidants, but ascorbic acid, butylated hydroxytoluene and butylated hydroxyanisole, independently, had a softening affect ( P < 0.05) on crumb firmness. Sensory analysis indicated significant ( P < 0.05) changes in aroma, grainy taste, aftertaste and moistness in all bread samples regardless of antioxidant, however, only ascorbic acid was rated as effective in maintaining a softer ( P < 0.05) crumb. [ABSTRACT FROM AUTHOR]

The shelf life quality of freshly harvested Golden Delicious apples coated with three individually developed lipid/hydrocolloid coatings was assessed throughout refrigerated storage. The apples were monitored for 8 weeks. The coatings resulted in low internal O2 and the least loss of fruit firmness when compared with the non-coated apple group. The coated apples had very little starch breakdown, minimum flesh colour development, or loss of titratable acidity content. Soluble solids and fresh weight loss remained unchanged for both the non-coated and coated groups. Sensory analysis confirmed that the coated apples maintained consistent quality in firmness, crispness and juiciness throughout the storage period. [ABSTRACT FROM AUTHOR]

The aim of the study was to incorporate and determine the effect of combining flaxseed meal (15%) and soya flour (5% and 10%) and monitoring the effect of the two ingredients on product quality in yeast bread while at the same time to evaluate the effect of soya flour in preventing the development of lipid rancidity in the stored soya/flax bread. Bread volume decreased ( P < 0.05) with increased addition of grains (flax and soya flour). Firming ( P < 0.05) of the crumb was observed with increased percentage of soya flour. There were no significant differences ( P > 0.05) in moisture in the flax and soya/flax breads. Darker crusts ( P < 0.05) were developed in the control and soya/flax breads, while a darker ( P < 0.05) crumb was found in flax and soya/flax breads. A 10% substitution level of soya flour did not have a significant effect on inhibiting lipid rancidity, but a lower peroxide value was produced in the bread. A 10% level of soya flour substitution also produced bread with lower quality sensory scores. [ABSTRACT FROM AUTHOR]

AbstractThe performance of maltodextrin gel as a replacement (25%, 50%, 75% and 100%) for shortening along with sucrose and high fructose corn syrup-90 (HFCS-90), adjusted for sweetness in each treatment, was evaluated in a high-ratio white-layer cake formulation. Two controls were used as a reference to fat-replaced cakes: control A (100% fat and 100% sucrose) and control B (100% fat with 50% sucrose/50% HFCS-90), which closely matched the sugar system of the fat-replaced cakes. Volume of cakes showed that treatment F (100% fat-substituted) was significantly (P < 0.05) different from the other treatments. Crust and crumb L- and b-values indicated that control B produced a dark crust (P < 0.05) with a light crumb (P < 0.05) whereas treatment E (75% fat substituted) produced a light crust (P < 0.05) and treatment F a darker crumb (P < 0.05) with a significantly (P < 0.05) higher moisture content. Degree of staling significantly (P < 0.05) increased over time for all treatments. Sensory results indicated that treatment F produced a significantly (P < 0.05) moister, less adhesive and cohesive cake. Tenderness and sweetness scores indicated that treatments E and F were significantly (P < 0.05) tougher and less sweet, respectively, when compared with the other treatments. Results from both the physical and sensory analyses indicated that the combination of maltodextrin gel up to a 75% reduction for shortening and sucrose/HFCS-90 resulted in satisfactory cakes. [ABSTRACT FROM AUTHOR]

Low-fat muffins were prepared using as fat substitutes a combination of maltodextrin and high-fructose corn sweetener 90 (HFCS-90), which replaced sucrose at a rate of 25%, 50%, 75% and 100%. The focus of the investigation was to determine the synergistic effects of these two ingredients on the physical properties in a Iow-fat muffin. Results indicated that maltodextrin and HFCS-90 were effective in maintaining moisture and water activity (a[sub w]) levels similar (P> 0.05)to the full-fat muffin. Texture profiles indicated that the Iow-fat variations were firmer (P < 0.05) than the full-fat counterpart. Increased levels of HFCS-90 had a significant effect (P < 0.05) on crust and crumb darkening. Maltodextrin alone significantly (P&lt 0.05) impeded the staling rate during storage. However, when maltodextrin was combined with increased levels of HFCS-90, the staling rate accelerated. The two ingredients were found to be effective in maintaining product quality, but HFCS-90 could only be used up to a 50% replacement before any adverse effects in product quality were observed. [ABSTRACT FROM AUTHOR]

This study investigated the effect of liquid honey as a partial substitute for sugar on the baking and keeping qualities of a fat-reduced muffin. In the formulation, the fat-reduced muffin used a hydrocolloid fat replacer, bacterial and fungal amylases and an emulsifier (DATEM). Honey caused a significant (P0.05) increase in crust and crumb colour at all replacement levels; however, the use of honey at the 25% replacement level was favourably increased the crust colour in the fat-reduced formulation. The addition of honey increased moisture content and decreased water activity, but did not decrease firmness or the staling rate, especially after prolonged frozen storage. Sensory results indicated that honey increased cohesiveness and decreased tenderness in the muffin. The added moisture in the fat-reduced muffin did not improve the perceived moistness, as indicated by the results. [ABSTRACT FROM AUTHOR]

Selected emulsifiers, enzymes and a carbohydrate-based fat substitute were incorporated into a standard muffin recipe, and their effects were compared with a full-fat counterpart. The control muffin had a significantly (P < 0·01) more yellow crumb, was less firm (P < 0·01) and contained less moisture (P < 0·01). Sodium stearoyl-2-lactylate (SSL) and diacetyl tartaric acid methyl esters (DATEM) contributed to a less firm crumb (P < 0·01) and helped to maintain moisture (P < 0·01) in the fat-reduced muffin. Sensory analysis yielded complementary results to the physical date with respect to crumb firmness and crust colour. However, the full-fat muffin was significantly (P < 0·01) moister. The emulsifiers along with the enzymes were found to be responsible for reducing crumb size (P < 0·01). [ABSTRACT FROM AUTHOR]

The effect of three different carbohydrate-based fat substitutes in a baking powder biscuit was studied. The various fat replacers were substituted for fat in the biscuit formula at a rate of 33%, 66% and 100%. The biscuit variations were assessed by objective and sensory measurements. Comparable objective and sensory results indicated that crust colour was lightened significantly with increased use of the individual fat substitute. Tenderness decreased as substitute use increased when biscuits were rated by the sensory panel, but opposite results were obtained by the texture analyser. Objective analysis indicated that an increase in use of the fat substitute produced a moister biscuit, which was in agreement with the sensory panel. Consumer location testing rated the biscuits as moderately acceptable, but data did indicate a willingness for a product of this type to become available in the marketplace. The overall results do indicate that a fat substitute can be a viable additive in the basic biscuit, but there is a maximum at which the substitute can be used for fat and still produce an acceptable product. [ABSTRACT FROM AUTHOR]