Development of online quality control of fermentation process during leaving of dough using FT-NIR and E-Nose

Abstract

Dough Proofing has a important role in texture formation and overall acceptability of the bread. The evaluation of kinetics during leaving of bread is essential prior to achieve a targeted quality of final product. The main challenge is the modeling of simultaneous heat and mass transfer happening spontaneously during proofing. In turn, a combination of rapid technique such as FTNIR spectroscopy and electronic nose seems to be fruitful for the online checking of degree of proofing and maintaining a high degree of quality control during large scale industrial operation and control the production process effectively. The study aims to develop the kinetics of dough proofing using FT-NIR spectroscopy and electronic nose. Spectroscopy was conducted with an optical probe in the diffuse reflectance mode. Two different temperatures (25 and 35 °C) were used to monitor the dough leavening while the RH was kept constant at 80%. Spectra were collected directly on the samples at every 5 min interval during entire period of proofing (up to 2 h) where the wave numbers ranged from 12,000 to 4,000 cm-1 . Principal component analysis (PCA), discriminant factorial analysis (DFA) and soft Independent modeling by class analogy (SIMCA) classification techniques were applied to the leavening process and process kinetics was calculated further. Simultaneously, electronic nose was used to provide quantitative and qualitative estimation of odor compounds during fermentation. For leavening, as per as PCA loading, four absorption zones (8,950-8,850, 7,200-6,800, 5,250- 5,150 and 4,700-4,250 cm-1 ) were identified and involved in describing the proofing process with time. NIR spectra were corrected for scatter effect and transformed through second order differentiation. The FOX 4000 electronic nose was able to differentiate the sample on the basis of aroma generation at different time during fermentation. The study confirms that electronic nose and FT-NIR spectroscopy can be utilized for the on-line monitoring of dough proofing.