Product development and X-Ray microtomography of a traditional white pan bread from plasma functionalized flour

Abstract

Cold plasma (CP) technology has emerged as a novel non-thermal technology with the potential to improve food quality or impart functionality to ingredients. Our previous studies on wheat flour demonstrated how the structure and functionality of wheat flour might be modified using CP to provide an alternative to chemical additives (Chaple et al., 2020). However, understanding of the further effects of plasma functionalized ingredients in existing or new product formulation is limited. This study investigated the effects of CP treatment of wheat flour on traditional white pan bread development. The bread was formulated using plasma functionalized flour (PFF), and critical product characteristic responses were analyzed. Plasma treatment of flour positively affected the bread's expansion ratio, crust color, and water activity. Farinograph analysis suggests improvement in water absorption capacity, dough development time, and dough stability. X-Ray Microtomography (XRMT) analysis was conducted to understand how plasma functionalising the flour impacted the microstructure of bread. The 3D scans suggested no macro-change in the bread matrix compared to control; however, the porosity decreased in line with the increasing plasma treatment duration of the flour. The texture profile analysis showed an improvement in the gluten network developed in the dough developed from PFF. Sensory analysis results showed overall acceptance for bread formulated with PFF compared with a commercial sample. Overall, CP treatment of the flour improved the functionality in relation to dough and bread preparation and can thus provide an alternative to chemical additives in bread making. The CP processes may be modulated to deliver tailored effects for bread product development.

Keywords: Cold plasma processing; Farinograph analysis; Pan bread; Wheat flour; X-ray microtomography.

Graphical abstract

Fig. 1

Schematic of the experimental set-up for generation of plasma using dielectric barrier discharge model.

Fig. 2

Flow diagram for bread-making procedure of traditional pan bread.

Fig. 3

Images of bread from cross sectional, top and rear view, where (a) control is bread formulated from untreated flour (b) PFFB-10 is bread formulated from flour treated for 10 min (c) PFFB-20 is bread formulated from flour treated for 20 min (d) PFFB-30 is bread formulated from flour treated for 30 min.

Fig. 4

Water activity of bread samples where (a) is crust water activity and (b) is crumb water activity for different samples. The control is untreated flour bread, PFFB-10, PFFB-20 and PFFB-30 are bread formulated from flour treated for 10, 20 and 30 min respectively. All the data are expressed as mean± standard deviations. Means with different superscript letters in a column differ significantly (p < 0.05).

Fig. 5

Grayscale images of bread samples where (a) control is bread formulated from untreated flour (b) PFFB-10 is bread formulated from flour treated for 10 min (c) PFFB-20 is bread formulated from flour treated for 20 min (d) PFFB-30 is bread formulated from flour treated for 30 min.

Fig. 6

XRMT images of a) central section extracted from each bread with air voids separated and labelled b) histogram of size distribution of air voids c) 3D reconstruction of air voids d) 3-D reconstruction of air voids where, air voids touching the bounding box were removed, voxel size 0.073 × 0.073 × 0.073 mm.

Fig. 7

Sensory analysis profile of PFFB-30, control and retail sample. The parameters considered were crust color, crumb color, texture, aroma (crumb), aroma (crust), appearance and overall acceptance. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)