Relative importance of moisture migration and amylopectin retrogradation for pound cake crumb firming

Sucrose substitution in cake systems is not a piece of cake

Successful sucrose replacement in cake systems requires thorough understanding of its functionality. Time-domain 1H NMR showed that water in the viscous aqueous phase isolated from cake batter by ultracentrifugation [i.e. the batter liquor (BL)] exhibits low mobility by its low T2 relaxation time (T2,D RT). This is due to its interactions with sucrose or sucrose replacers. The T2,D RT itself is positively related with the effective volumetric hydrogen bond density of sucrose or sucrose replacers. Sucrose additionally co-determines the quantity and viscosity of cake BL and thereby how much air the batter contains at the end of mixing. Like sucrose, maltitol and oligofructose provide adequate volumes of BL with low water mobility and thus sufficient air in the batter, while the rather insoluble mannitol and inulin do not. Differential scanning calorimetry and rapid viscosity analysis revealed, however, that, in contrast to sucrose and maltitol, oligofructose fails to provide appropriate timings of starch gelatinisation and protein denaturation, resulting in poor cake texture. The shortcomings of mannitol and oligofructose in terms of respectively ensuring appropriate gas content in batter and biopolymer transitions during baking can be overcome by using mixtures thereof. This work shows that successful sucrose substitutes or substitute mixtures must provide sufficient BL with low water mobility and ensure appropriate timings of starch and protein biopolymer transitions during baking.

Texture staling of pound cakes assessed by front face fluorescence spectroscopy in tandem with chemometric analysis

Two vegetal oils have been selected for the formulation of pound cakes, rapeseed oil (RO) and palm oil (PO). The freshness of these products has been monitored during 58 days of storage. The RO pound cakes of 58 days as well as PO pound cakes presented higher values (p < .05) of hardness (N), Young's modulus (N.cm^-2 ) and compressive stress (N.cm^-2 ) than those aged of 5 days. For both vitamin A and tryptophan spectra, the maximum of fluorescence intensity varied according to the aging period. For both RO and PO recipes, lipid oxidation indicators (peroxide value, para-anisidine value, and total oxidation value [TOTOX]) were interestingly correlated to Young's modulus (R²  = 0.99) as well as compressive stress (R²  = 0.99), using polynomial model. The application of partial least squares regression to the vitamin A spectra provided excellent predictive results for both compressive stress (R²  = 0.99) and TOTOX (R²  = 0.99). Good results were observed for tryptophan spectra for the prediction of TOTOX (R²  = 0.77). Thus, the use of front face fluorescence spectroscopy may provide rapid and accurate results for the monitoring of pound cakes freshness throughout storage.

Physicochemical Properties of Sponge Cake Fortified by Olive Stone Powder

Olive stones are by-products in olive oil extraction and in table olive industries. Nonetheless, they contain beneficial nutritive elements such as fiber, phenolic compounds, and omega-3 and -6 fatty acids. In this research, olive stone powder (OSP) was used to substitute 0, 15, 25, and 35% of wheat flour in sponge cake recipe. The effects of this substitution were examined on the physiochemical and sensory properties of sponge cakes. The fiber content and the total phenolic compounds of the cake samples increased significantly from 0.67 to 8.60% and from 89.14 to 739.23 μg/ml, respectively, by increasing the OSP from 0 to 35%. With increased amounts of OSP, batter viscosity and consistency decreased (from 27430 to 11030 centipoise and from 8.67 to 13.42 g/s, respectively), while the specific volume of the cakes increased (from 2.08 to 6.21 cm3/g). Parallel to the increased levels of substitution, the hardness and springiness of cakes decreased, whereas the gumminess and chewiness increased. The crumb structure of OSP-enriched cakes was more porous than that of the control. Color analysis indicated significant differences between the control and treated samples regarding L∗a∗, and b∗ parameters. Cakes had colors that were darker than expected when treated with OSP (p<0.05). According to sensory evaluations, no significant differences were observed between OSP cakes and the control sample in terms of taste, after taste, color, and odor (p>0.05). In conclusion, substituting OSP for flour by 25% can yield acceptable dietary fiber content and antioxidant phenolic compounds while showing no undesirable changes in sensory properties.

Effects of celery powder on wheat dough properties and textural, antioxidant and starch digestibility properties of bread

In order to investigate the effects of celery powder (CP) on bread quality, wheat flour was replaced by CP which was produced from two celery varieties ('Jinnan Shiqin' and 'Ventura') at different levels (1, 2, 3 and 5/100 g flour). For both kinds of CPs, Mixolab analysis showed that the water absorption of dough increased with the increase of CP, while the protein network weakening (C2), peak viscosity (C3) and crystallinity of starch (C5-C4) decreased. The specific volume of bread decreased at higher CP level, whereas its crumb hardness and chewiness showed a reverse trend. The addition of CP significantly increased the total phenolics content of bread, and thus caused a significant improvement in antioxidant activities. The addition of CP significantly reduced the content of rapidly digestible starch in bread, while the contents of slowly digestible starch and resistant starch were increased. Additionally, bread prepared with a higher CP content showed a lower predicted glycaemic index. Based on the results of sensory analysis, bread incorporated with 2 g/100 g flour for 'Jinnan Shiqin' or 1 g/100 g flour for 'Ventura' didn't show significant effect on its overall acceptability. The present study indicated that addition of CP could be an effective way to produce a bread with higher antioxidant activity and lower starch digestibility.

The effect of Arabic gum on frozen dough properties and the sensory assessments of the bread produced

The use of hydrocolloids in frozen dough has become frequent as bread improvers due to their anti-staling effect. Nevertheless, the impact of both different frozen storage and Arabic gum level in non-prefermented flat dough with following thawing procedure have not been studied. This work intended to study the effect of three different ratio of Arabic gum on rheological properties of 1, 7, and 30 days of frozen storage and the quality of the bread made from. In order to gain the least detrimental effects on gluten network, we used rapid rate freezing and microwave heating in thawing stage. Rheological results showed that the unfrozen samples to which Arabic gum had been added rendered the highest resistance to extension. The resistance of gum fortified samples were less than fresh dough, however the decline was not significant in 3.0% Arabic gum dough kept in a month storage (p > .05). The similar findings were obtained for extensibility and adhesiveness; in which the maximum incorporation of Arabic gum lessen the destructive impact of long freezing storage. Addition of 3% gum could be able to retard staling through an increment in hydrophilic bonds between water molecules and amylose during thawing (p < .05). The overall rating of Arabic gum enriched samples was similar with bread made from non-frozen dough, even after 30 days of storage as indicated by the sensory evaluation of breads.

PRACTICAL APPLICATIONS

Producing a chapatti-like fermented bread without long fermentation period. Formulation a frozen dough without using chemical additives. Introducing a proper use of a new defrosting method with the aim of achieving a better texture. Improvement in retarding staling by the use of Gum Arabic after 7 days.