Image Analysis – Comparison of Recipe Composition Effect

Abstract

Abstract Bread and bread crumb characteristics as the results of laboratory baking test were used to assess bread profile. Its texture was quantified by image analysis technique, performed by using the Kaiser reproset (stand, lighting), the COHU CCD camera and the NIS Elements 2.0 AR software. In the case of common cereals fortification (wheat, rye, barley, oat and corn wholemeal flours), tested substitution level were chosen from 10% to 50% of commercial wheat flour standard “M’09”. Its analytical parameters correspond with satisfying bakery quality (protein content 14.1%, Zeleny's value 36 ml, Falling Number 396 s). Non-fortified bread from M’09 reached specific volume of 365 mL/100 g, and bread texture was described by 14 cell/cm2 and mean cell area (MCA) 2.538 mm2. The second fortification attempt included four non-traditional wheat (spelt, dicoccum, spring wheat ‘Trinaldina’, one with purple grain) and millet. These recipe components were tested on two commercial wheat samples, marked as “M’06” and “M’07”. Their baking values differed in protein content only (12.3% vs. 11.5%, respectively), while the Zeleny's sedimentation and the Falling Number test results were comparable (49 ml vs. 49 ml and 324 s vs. 363 s, respectively. Lower protein content as well as higher Falling Number contributed to lower bread volume from M’07 flour (252 mL/100 g vs. 343 mL/100 g), and also its texture was less open (20 cells/cm2 at mean cell area 1.160 mm2 against 15 cells/cm2 at 1.520 mm2). Statistical approach comprised correlation and variation analyses (Tukey's test) on significance level of 95% for both methods. Addition of common cereals wholemeal caused progressive changes of both specific bread volumes and crumb morphology, i.e. volume of bread with 10% and 50% of rye wholemeal fell from z 235 mL/100 g up to 155 mL/100 g. An extraordinary position was revealed out for wheat wholemeal, which did not affect dough volume rise at baking stage due to similar protein structure (specific values of 233 mL/100 g a 259 mL/100 g, respectively). Cell densities were 21 cells/cm2 and 25 cells/cm2 for recipes with 10% and 50% of rye, respectively. Corresponding MCA's were evaluated on levels of 1.617 mm2 and 1,365 mm2, respectively. Compared to standard M’09, a decrease about 25% was registered. Influence of wheat wholemeal was equivocal likewise the specific bread volume – numbers of cell in bread crumb with 10% and 50% of that component were 18 per cm2 for both cases, whereas the proper MCA's were 1.830 mm2 in the former and 2.128 mm2 in the latter case (72% and 83% of standard M’09). Texture of the selected samples is documented on Fig. 1. Bread prepared from “M’07” was affected differently due to lower baking quality – crumb texture changes oscillated up to 20%. Figure 2 shows major influence for bread with TSP (77% increase in mean cell area, 23% decrease in number of cells/cm2). The most levelled change in these two bread crumb parameters was observed for bread with WPG – mean cell area increased about 20%, while number of cells/cm2 decreased about 23%.